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Journal Cover   Livestock Science
  [SJR: 0.715]   [H-I: 69]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1871-1413
   Published by Elsevier Homepage  [2800 journals]
  • Editorial Board
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179




      PubDate: 2015-08-28T21:44:23Z
       
  • Assessment of genomic selection for introgression of polledness into
           Holstein Friesian cattle by simulation
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): Giustino Gaspa, Roel F. Veerkamp, Mario P.L. Calus, Jack J. Windig
      Naturally hornless cattle are called polled. The possibility to introgress the allele responsible (P) for polledness in a cattle population that is more intensively selected for other traits is investigated in this paper. Gene introgression, generally carried out by several steps of backcrossing and selection, takes a long time and may lead to unacceptable genetic loss in other traits or inbreeding. The main objective of the current study was to evaluate the use of genomic selection to speed up the introgression of a target allele in a conventional dairy cattle breeding scheme with overlapping generations. A cattle population and a breeding program were simulated and run over a 12 year selection period. Assuming that the polled population was inferior for overall genetic merit , two selection strategies were evaluated: i) selection on conventional BLUP-EBV (CBLUP); ii) selection on genomic EBV (GEBV) obtained with the genomic relationship matrix used in BLUP (GBLUP). Both selection strategies were applied with (PSEL) and without (NOPSEL) selection for the single polled locus (P). The overall level of genetic merit, the P allele frequency and the inbreeding level (F) in the new born animals were monitored each year, as well as the average genetic gain per year of selection (ΔG). The overall genetic level of new born animals was higher for GBLUP compared to CBLUP, with an average ΔG/year of 8.34% (GBLUP) against 7.49% (CBLUP). The PSEL scenario reduced genetic gain, but P allele frequency increased from 0.130 to 0.415 (CBLUP) and from 0.128 to 0.440 (GBLUP) for PSEL, after 12 years of selection. No substantial changes in allele frequency were recorded for NOPSEL scenarios, both for CBLUP and GBLUP breeding schemes. The overall inbreeding rates for GBLUP were 0.28%/y (NOPSEL) and 0.30%/y (PSEL) and for CBLUP 0.52%/y (NOPSEL) and 0.44%/y (PSEL). In conclusion, application of GS to gene introgression helped to speed up the process of introgression of a gene while simultaneously increasing the genetic gain and reducing the inbreeding rate.


      PubDate: 2015-08-28T21:44:23Z
       
  • Polled Fleckvieh (Simmental) cattle – Current state of the breeding
           program
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): K.-U. Götz, B. Luntz, J. Robeis, C. Edel, R. Emmerling, J. Buitkamp, H. Anzenberger, J. Duda
      Systematic breeding of polled Fleckvieh (Simmental) cattle in Bavaria dates back until 1974 when the first polled cow was purchased for breeding purposes. Until 1985 three polled bulls and two more polled dams were purchased and from 1984 on the first homozygous bulls were produced via embryo transfer. Until 1990 the polled allele was only common in beef strains of the Fleckvieh breed. At the beginning of the 1990s the first polled alleles were introduced into the dairy herd of the State Research Farm in Grub. This research farm acted as the nucleus for the introgression of the polled allele in the dual-purpose lines of the Fleckvieh breed. Since 2003 polled calves in all herds under milk recording were systematically recorded and the polled phenotype was regularly examined by employees of the Bavarian State Research Institute for Agriculture. At the same time a systematic cooperation with Bavarian herdbook organizations and AI-stations was established. Between 2000 and 2011 in total 193 polled bulls were raised at the Bavarian State Research Institute for Agriculture (LfL), of which 37 entered AI-stations. Currently the dual-purpose population of Fleckvieh comprises 7055 polled cows and 175 polled AI-sires. In 2013 and 2014 approximately 22,000 and 32,000 polled calves were born per year. The analysis of relationships showed that the polled bulls are less related to the horned population and that until now the introgression has caused negligible amounts of additional inbreeding. It is expected that in 2021 the proportion of polled cows in the Fleckvieh dual-purpose population will be at 10.5% of all cows if the progression of polledness continues linearly. However, it can be expected that the progression will accelerate due to the new possibilities offered by genomic preselection of polled AI-bulls. First experiences with genomically preselected polled bulls show a very good acceptance among breeders.


      PubDate: 2015-08-28T21:44:23Z
       
  • Polled cattle in the Roman Netherlands
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): Roel C.G.M. Lauwerier
      Most cattle in the Netherlands have been deliberately dehorned, which some people consider to be a cruel practice. But the breeding of genetically hornless (or polled) cattle is also regarded as unnatural and cruel to animals. Nevertheless, this is a practice which, like elsewhere in Europe, was also common here in the past. Unlike elsewhere in Europe, in the Netherlands polledness, a dominant trait, occurred mainly in the Roman period and disappeared again in the Middle Ages. Polled cattle were particularly common in the coastal area beyond the borders of the Roman Empire, where up to 40% of animals were hornless. By contrast, to the south of the border, polled cattle were rare. No polled animals have so far been found in Nijmegen, at the time the country's most important military and civilian centre. The question is why this is the case, and why polled cattle subsequently disappeared from the Netherlands. There is little evidence to explain the presence of polled cattle on one side of the Roman border, their near absence on the other, and their total disappearance after the Roman period on the basis of natural selection. Nor do functional considerations – superiority as a source of food or supplier of tractive power – provide us with any conclusive answers. The most likely explanation is that it was mainly emotional and aesthetic considerations that led farmers and other users of cattle to decide what a ‘good’ cow was, and that was a cow with horns. The fact that polled cattle occurred in the coastal area during the Roman period may be associated with a different ideal, and possibly also with a lack of economic power that prevented farmers from being selective. After the Roman period, the desire for ‘good’ horned cattle will have caused the disappearance of the dominant polled cattle. A growing demand for horn as a raw material for the manufacture of objects might also have played a role. These factors should probably be viewed in the context of an influx of other breeds brought by new population groups that ‘drove out’ the old cattle populations. The current debate in the Netherlands as to the desirability of breeding polled cattle would appear to be nothing new, having already exercised the minds of farmers centuries ago.


      PubDate: 2015-08-28T21:44:23Z
       
  • The history of breeding for polled cattle
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): R. Schafberg, H.H. Swalve
      In this review, the history of breeding for polled cattle is compiled from literature as well as graphic representations of cattle in art and science. Domesticated taurine cattle originated around 8500 years BCE in the Near East and spread from there to Africa as well as to Europe. Earliest findings of polled domesticated cattle are from today’s Slovakia and Germany from 6000 years BCE. Textual findings and especially graphic displays can be found of polled cattle in Ancient Egypt. Although archaeological finds of skulls that can be evaluated for natural polledness are rare, archaeological texts and graphical displays indicate that genetically polled cattle in Ancient Egypt were present and quite numerous. Polled cattle apparently were also kept by Germanic tribes and can be followed through medieval times into the 17th and 18th century where textual accounts are more frequent. In Scandinavian countries and Great Britain polled cattle have survived in greater proportions up to today while in the middle of Europe polled cattle were not well regarded by farmers and almost became extinct. Among the British breeds, Angus and Galloway were established as beef cattle breeds in the 17th/18th century, and still flourish. However, the British polled dairy breed Suffolk became extinct. It was one of the ancestral breeds of the Red Polled beef breed and was used in attempts to promote polled dairy cattle in France in the 19th century. Reports of single individuals in polled cattle found in predominantly horned populations possibly indicate several origins of the polled mutations. Recently, at least two different types of mutations, located on BTA01, have been found to be responsible for the mutation commonly referred to as the polled allele. One is the so-called ‘Celtic’ type, found in Scandinavia and Britain while the’‘Friesian’ type is found in cattle of the Holstein family. Today, aspects of animal welfare more and more influence farmers’ attitudes towards naturally polled cattle and also governmental policies play an important role. For the important horned dairy breeds of central Europe, e.g. Holstein, Brown Swiss and Fleckvieh, as well as for the beef breed Charolais, breeding programs for the introgression of the polled allele are starting and will be aided by new tools such as genomic selection.


      PubDate: 2015-08-28T21:44:23Z
       
  • Effects of space allowance in the waiting area on agonistic interactions
           and heart rate of high and low ranking horned dairy cows
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): Nora Irrgang, Katharina A. Zipp, Sarah Brandt, Ute Knierim
      One possible alternative to avoid the disbudding of calves is to keep the cows horned. This, however, requires adapted housing conditions. An important aspect to reduce agonistic interactions that may lead to injuries is to provide appropriate space allowances in all parts of the stable. This study investigated the influence of three different space allowances in the waiting area of the milking parlour (4.0, 2.5, 1.7m²/cow) on the risk of injury and stress. In a research herd of 85–87 horned dairy cows, heart rate and number of physical agonistic interactions (“butting” and “being butted”) per cow and hour during waiting were recorded in nine lower and nine higher ranking focal cows. Furthermore, heart rate in the milking parlour and the number of flinches, steps and kicks per cow and minute (“FSK-reponses”) in eight to nine lower and 11 higher ranking focal cows were collected. Results showed that social rank had no influence on heart rate and FSK. being butted (p=0.029), FSK-responses (p=0.002) and heart rates in the waiting area and parlour (p=0.000) were significantly affected by space allowance. the lowest space allowance of 1.7m² per cow resulted in Higher values, although for heart rates there were significant interaction effects with time of day (morning or afternoon milking) (p=0.021 to p=0.000): Less clear Results and generally Higher values were found in the afternoon. in terms of animal welfare, a larger space allowance than 1.7m²/cow in the waiting area appears beneficial. under the conditions investigated, except for FSK-responses, no consistent benefit could be detected by providing 4.0m²/cow instead of 2.5m²/cow.


      PubDate: 2015-08-28T21:44:23Z
       
  • Introducing structural elements into the free resting area in
           loose-housing systems with horned dairy cows: Effects on lying behaviour
           and cleanliness
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): C. Menke, M. Peer, C. Schneider, A. Spengler, S. Waiblinger
      The transition of tie-stalls to loose housing systems is often accompanied by starting dehorning. Deep-litter and straw-flow systems can be more cost-effective and advantageous for various aspects of the welfare of dairy cows than cubicle loose housing. However, the number of social encounters and disturbances of lying animals can be higher in these systems especially for animals with horns. The use of structural elements may improve the situation and the aim of this project was to investigate the potential effects of structural elements in the free resting area on resting behaviour, animal cleanliness and straw usage in herds of horned dairy cows. On five commercial farms that keep horned dairy cows in a deep-litter system, data were collected in situations without and with a structural element present. Lying behaviour was recorded by scan sampling for each individual animal every 5min. The cleanliness of the cows was assessed at the beginning and end of the four-day recording period. The proportion of scans in which animals were lying in 24h, during day and at night as well as the change in cleanliness were analysed using linear mixed models. Straw usage was evaluated by counting the number of bales used on each of the four days on four farms. The proportion of lying was higher with the structural elements present than without for 24h (p<0.001) and at night (p<0.001), while no effect was found during the day (p=0.964). This was particularly true for high-ranking and middle-ranking animals (interaction rank*structure: p=0.007), for which lying time increased by about 1h on average, while for low-ranking animals it increased only about 10min. The strength of the effect, however, varied considerably between individual farms. Animals were also less dirty with the structural element present than without (p=0.008). For straw usage, no uniform trend was found on the farms. In conclusion, the results indicate a positive effect of the presence of a Y-shaped structural element in the free resting area of straw yard systems on lying time and cleanliness of horned dairy cows. The use of structural elements in straw yard or comparable systems thus has the potential to improve the welfare of horned dairy cows and furthers keeping of horned cows as an alternative to dehorning.


      PubDate: 2015-08-28T21:44:23Z
       
  • Breeding for polledness in Holstein cattle
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): Jack J. Windig, Rita A. Hoving-Bolink, Roel F. Veerkamp
      Currently almost all dairy cattle are dehorned as calf to avoid injuries later in life. A welfare friendly alternative to dehorning is to breed polled cattle. This paper explores the potential to breed for polledness in the Holstein breed, and investigates the genetic merit and relatedness of both polled and horned bulls. In 2009 there were 33 polled bulls available for artificial insemination (AI), two of them being homozygous for polledness. In 2014 more than 150 bulls were available, 31 of them being homozygous. Breeding values for the total merit index (NVI-Dutch Flemish Index) have increased considerably for polled bulls. In 2009 the difference in average Estimated Breeding Value (EBV) for NVI between polled bulls (available for AI) and the top 100 horned AI bulls was 180 points, equivalent to about 18 years of selection at that time. In 2014 the difference was reduced to 149 points, equivalent to about 5 years of (genomic) selection. Genomic selection has made an important contribution to this reduced difference between polled and horned bulls. Polled bulls in 2009 were more inbred (F=0.045) than horned bulls (F=0.037) but less related to cows born at Dutch farms in that year (r=0.070 vs. 0.089). Using optimal contributions and a combination of polled and horned bulls, a next generation of animals can be bred that combines a high genetic merit with a relatively low relatedness and higher frequency of polledness. However, homozygous polled bulls born in 2012–2014 had a relatively high average inbreeding level (F=0.079) and almost all originated from the same two polled founder bulls. This may form a potential risk for lethal alleles showing up with inbreeding. Overall, breeding high genetic merit polled Holstein cows has become a realistic perspective, but care must be taken to avoid high relatedness and inbreeding levels.


      PubDate: 2015-08-28T21:44:23Z
       
  • Attitudes of farmers towards cattle dehorning
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): F. Kling-Eveillard, U. Knierim, N. Irrgang, F. Gottardo, R. Ricci, A.C. Dockès
      To better understand how farmers decide to manage animals with or without horns and how they choose the method they use to dehorn, 9 group interviews were carried out in Italy, Germany and France in different regions, different production systems and among different cattle breeds, in the framework of the EU-Project ALCASDE (alternatives to castration and dehorning). The groups gathered 94 cattle farmers. Ultimately, managing animals with or without horns is not a mere detail but is rooted in different views on the farming profession, on the human–animal relationship, and on the practical and daily work with the animals. Farmer safety and animal safety is often pointed out in connection to loose housing. In favour of keeping horns, different aspects are combined: ethical considerations towards the animals (integrity of the animal, avoidance of pain and stress), a strong farmer–animal relationship, and in rustic breeds, aesthetic and tourism considerations. Practical and material aspects play a role, such as, for example, the type of housing system and equipment, the amount of available time, and the organisation and equipment for carrying out dehorning if needed. Many farmers are convinced that disbudding or dehorning are painful but their sensitivities differ largely. Among the farmers who dehorn their animals, some expressed a real unease on this subject during the interviews. On the one hand, they express a concern for the animals and their welfare, and on the other hand, they voluntarily implement a practise that they know is accompanied by pain, although it is intended to improve animal welfare during the animals’ life span. For most of the farmers we met, adult dehorning is to be avoided, as it is too stressful and painful for the animals, and disbudding at a young age is preferable. Using polled (genetically hornless) cattle is still rare, and opinions are divided. Most farmers do not think that it is feasible at short notice to have polled cattle with a high quality of production and reproduction.


      PubDate: 2015-08-28T21:44:23Z
       
  • Introduction to the special issue on alternatives for cattle dehorning
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): Jack J. Windig, G. Cozzi, I. Vessier



      PubDate: 2015-08-28T21:44:23Z
       
  • Dehorning of cattle in the EU Member States: A quantitative survey of the
           current practices
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): G. Cozzi, F. Gottardo, M. Brscic, B. Contiero, N. Irrgang, U. Knierim, O. Pentelescu, J.J. Windig, L. Mirabito, F. Kling Eveillard, A.C. Dockes, I. Veissier, A. Velarde, C. Fuentes, A. Dalmau, C. Winckler
      A survey was carried out to describe the extent and current practice of cattle disbudding/dehorning in the EU Member States. Disbudding was defined as removal of horns in calves of up to 2 months of age, whereas dehorning was defined as removal of horns in older animals. Specific questionnaires were created regarding dairy, beef, and suckler production systems and they were submitted to local experts of each country belonging to relevant institutions like universities, national farmers' associations, cattle breeders associations, farm veterinarians and practitioners. Figures on disbudding/dehorning practices were produced for each production system for both the whole European Union and the North, Centre, East and South EU macro-regions. A total of 652 questionnaires were collected and 64%, 24% and 12% of them related to dairy cattle, beef cattle and suckler cows, respectively. Data from the survey showed that in Europe, 81% of the dairy, 47% of the beef and 68% of the suckler currently keep disbudded/dehorned animals, while the prevalence of polled cattle is rather low, especially in the dairy cattle sector (5% of all cattle farms; <1% of dairy farms). Regardless of production system, prevalence of dehorned animals is the highest in the North macro-region. Polled cattle farms are almost exclusively located in the North where polled beef breeds are raised for fattening. Dehorning is performed primarily on loose housed cattle to reduce the risk of injuries for herdmates and the stockman. Dehorning is less frequently performed in organic farms. As method of horns removal, disbudding is generally preferred over surgical removal of the horns in older cattle. Hot-iron is the most used disbudding method especially in the North and Centre. Use of caustic paste is reported more frequently in the South and the East. In the large majority of EU farms, the stockman is the person in charge for disbudding and some kind of medication for pain relief is administered to the animals only in a small percentage of farms (<30%). Surgical dehorning of more aged cattle is mainly performed with the wire/saw method. Compared to disbudding, it is more often carried out by a veterinarian and pre- and post operative medications (44% farms) is also more common.


      PubDate: 2015-08-28T21:44:23Z
       
  • To be or not to be horned—Consequences in cattle
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): Ute Knierim, Nora Irrgang, Beatrice A. Roth
      In cattle, both males and females of horned breeds have permanent horns which are directly connected with the frontal sinuses of the skull and are growing during their entire life. To date a large proportion of cattle is disbudded or dehorned, or increasingly bred for polledness. This review explores the possible consequences of cattle having horns or not, both for the cattle themselves and for the farmers. During natural selection horns may have provided advantages concerning predator defence or in competition for mates and resources. Additionally, there are indications that horns serve as honest signals in mate selection, as they reflect individual health. Presence or absence of horns will likely affect quality and quantity of social interactions as well as social relationships in a herd. It clearly affects the way of cattle fighting. Only few studies deal with social behaviour in horned herds in comparison to hornless herds, and they rely on single herd observations or need to be interpreted with caution because of confounding factors. However, it appears that horned cattle attempt to keep greater inter-individual distances and resort less to physical interactions than hornless cattle, leading to more stable social relationships under suitable environmental conditions and management. Cattle may, furthermore, use horns for self-grooming of body regions which are otherwise out of reach. Even less is known on possible physiological functions of horns. While there is good evidence regarding a thermoregulatory function, other claimed functions, e.g. concerning digestion, have not been scientifically investigated yet. Although farmers in favour of keeping horned cattle, for instance for ethical reasons, are able to reduce the increased risk of animal injuries and human accidents by providing improved housing and management conditions and maintaining a good human–animal relationship, it may be economically advantageous to keep hornless cattle. If disbudding/dehorning is carried out, the consequences in terms of stress and pain can be alleviated by a combination of local anaesthesia and anti-inflammatory treatment, as well as sedation of animals insufficiently used to handling. However, possible negative side effects of sedation should be addressed in future studies. Furthermore, the possibility of longer lasting pain after disbudding/dehorning is not sufficiently investigated yet. Finally, it is an open question whether the removal of horns alters the social behaviour of the animals, or is a mere symptomatic measure to adjust them to husbandry conditions that are insufficiently adapted to the species-specific needs of cattle.


      PubDate: 2015-08-28T21:44:23Z
       
  • Hot-iron disbudding: stress responses and behavior of 1- and 4-week-old
           calves receiving anti-inflammatory analgesia without or with sedation
           using xylazine
    • Abstract: Publication date: September 2015
      Source:Livestock Science, Volume 179
      Author(s): D. Caray, A. de Boyer des Roches, S. Frouja, S. Andanson, I. Veissier
      Cattle are often disbudded in a procedure that is painful to them. In an effort to find practical ways to reduce poor welfare due to hot-iron disbudding, we tested a combination of sedation and nonsteroidal anti-inflammatory analgesia (NSAID) that farmers themselves can apply to calves at two different postnatal ages. We compared Prim’Holstein and Charolais calves, male or female, aged 1 or 4 weeks, subjected to hot-iron disbudding without (vigil calves), or with sedation (xylazine calves, 0.2mg/kg xylazine 2%), and to sham-disbudded calves without sedation or analgesia (control calves). Both groups of disbudded calves received NSAID (3mg/kg Ketoprofen 10 %®). Calf behavior was observed during disbudding and the following 15min, and then between 2h and 7h post-disbudding. Salivary cortisol and heart rate were measured from 20min before to 240min after disbudding. Compared to control and xylazine calves, vigil calves reacted strongly to disbudding by vocalizing (mean vocalizations during the 15min post-disbudding: vigil calves, 1.95; control calves, 0.2; and xylazine calves, 1.30, a value that was not significantly different from the other two), and higher salivary cortisol concentrations 30min post-disbudding (vigil calves, 4.08ng/mL; control calves, 1.59ng/mL; and xylazine calves, 1.18ng/mL). An increase in heart rate of 17bpm above baseline was observed in vigil calves during the 10min post-disbudding, whereas the heart rate of control calves did not vary and that of xylazine calves decreased by 39bpm. Significant differences in salivary cortisol concentration and heart rate were observed at 45min and 30min post-disbudding, respectively. Vocalizations were observed between 2 and 7h after disbudding in both vigil and xylazine calves. Responses to disbudding were the same whatever the age, sex, or breed of the calves. The results suggest that sedation with xylazine can reduce the stress calves experience right after disbudding but not after 2h, and that the pain produced by disbudding is the same at 1 or 4 weeks of age.


      PubDate: 2015-08-28T21:44:23Z
       
  • Exercise increases brain-derived neurotrophic factor level in serum of
           horses
    • Abstract: Publication date: Available online 24 August 2015
      Source:Livestock Science
      Author(s): Sasithorn Kongoun, Metha Chanda, Pawinee Piyachaturawat, Witchuda Saengsawang
      Serum-BDNF levels are known to reflect functions of the nervous system. It has been shown in humans that exercise increases serum-BDNF levels. However, how exercise training affects serum-BDNF in horses is unknown. Knowing how BDNF is altered in response to exercise training in horses will provide insight into the nervous system’s response to exercise and may provide a novel indicator to improve the training program for sport horses. Here we investigated the effect of exercise on the level of serum-BDNF in horses by comparing BDNF levels in serum from sedentary horses to those from active horses that are trained and participated in polo matches. The level of total serum-BDNF was significantly higher in active horses compared with that of sedentary horses. Individual forms of BDNF (pro, truncated and mature BDNF) were also significantly higher in active horses, especially the truncated-BDNF. The findings suggest that exercise increases basal levels of horse serum-BDNF, indicating the positive response of the horse nervous system to physical activities.


      PubDate: 2015-08-25T21:25:28Z
       
  • Limited creep-feeding supplementation effects on performance of beef cows
           and calves grazing limpograss pastures
    • Abstract: Publication date: Available online 25 August 2015
      Source:Livestock Science
      Author(s): Andre D. Aguiar, Joao M.B. Vendramini, John D. Arthington, Lynn E. Sollenberger, Gregory Caputti, Joao M.D. Sanchez, Odislei F.R. Cunha, Wilton L. da Silva
      Limpograss (Hemarthria altissima) is a warm-season grass used by cow-calf producers in South Florida; however, limpograss protein concentration may limit animal performance. The objective of this study was to test the effects of creep-fed protein supplement on performance of cow-calf pairs grazing limpograss pastures. The experiments were conducted in Ona, FL from June to September 2011 (Experiment 1) and from June to August 2012 (Experiment 2). Twenty-four cows and calves [Angus-sired calves on crossbred cows (approximately 63% Bos taurus and 37% Bos indicus)] were randomly distributed in eight limpograss pastures (1.0ha/pasture). In Experiment 1, calves received 200g/d of soybean meal (SBM, 48% CP) daily by creep-feeding or no supplement (control). Treatments were distributed in a randomized complete block design with four replicates. In Experiment 2, calves received 200 or 400g/d of SBM daily by creep-feeding or no supplement (control) distributed in a randomized incomplete block design with three replicates for 200g/d and control and two replicates for 400g/d. In Experiment 1, there was no difference in HM (P=0.54; mean=4,500±800kg/ha), in vitro digestible organic matter (IVDOM; P=0.92; mean=62±1.4%) and crude protein concentration (CP; P=0.14; mean=14.3±0.9%) between treatments. In addition, there was no difference in cow and calf ADG (P=0.51; mean=0.25±0.1kg/d and P=0.24; 0.55±0.1kg/d for cows and calves ADG, respectively). In Experiment 2, there was no effect of creep-feeding on HM (P=0.28; mean=6,800±700kg/ha), IVDOM (P=0.31; mean=52±3.5%), and CP (P=0.63; mean=11.1±0.5%) concentrations; however, there was a linear (P=0.03) increase in ADG from 0.33 to 0.62kg/d for calves receiving from 0 to 400g/d SBM. Cow ADG was similar among treatments (P=0.44; mean=0.23±0.12kg/d). Calves receiving 400g/d SBM had 0.75kg BW/kg feed added gain efficiency {[(BW gain of creep-fed calves (kg) – BW gain of control calves (kg)]/amount of feed consumed during the experimental period (kg)]}, and a tendency for 70% linear increase in economic return (P=0.06), when compared with the control calves. Limited creep-feeding of SBM supplement may be an effective management practice to improve weaning weights of beef calves on limpograss pastures.


      PubDate: 2015-08-25T21:25:28Z
       
  • Effects of excessive energy intake and supplementation with chromium
           propionate on insulin resistance parameters, milk production, and
           reproductive outcomes of lactating dairy cows
    • Abstract: Publication date: Available online 24 August 2015
      Source:Livestock Science
      Author(s): T. Leiva, R.F. Cooke, A.P. Brandão, A.C. Aboin, J. Ranches, J.L.M. Vasconcelos
      This experiment compared insulin resistance parameters, milk production, and reproductive outcomes in: 1) lactating dairy cows consuming adequate or excessive energy, and 2) lactating dairy cows consuming excessive energy and receiving or not Cr-propionate supplementation. Seventeen primiparous and multiparous, non-pregnant, lactating Holstein cows (initial days in milk=76±2) were assigned on d 0 to: 1) concentrate intake to meet their requirements of net energy for lactation (NE L ) without Cr supplementation (MAN; n=5), 2) concentrate intake to exceed their NEL requirements without Cr supplementation (HIGH; n=6), and 3) HIGH with 2.5g/d of Cr propionate (HIGHCR; n=6). Throughout the experiment (d 0 to 210), cows were offered corn silage for ad libitum consumption, and individually received a corn-based concentrate twice daily. Concentrate intake was formulated to allow diets to provide 100% of daily NEL requirements of MAN, and 160% of daily NEL requirements of HIGH and HIGHCR cows. Cow BW, BCS, and milk production were recorded weekly. Blood samples were collected weekly, prior to and at 2 and 4h after the morning concentrate feeding. Six glucose tolerance tests (GTT) were performed, every 42d, by infusing cows with 0.5g of glucose/kg of BW. Follicle aspiration for in vitro embryo production was performed via transvaginal ovum pick-up 2d after each GTT. Increase in BCS from d 0 to 210 was greater (P≤0.04) in HIGH and HIGHCR vs. MAN. Milk production was similar (P=0.92) between treatments. Within weekly samples, serum non-esterified fatty acids concentration were greater (P≤0.05) for MAN vs. HIGH and HIGHCR. Serum insulin concentrations and insulin:glucose ratio were often greater (P≤0.05) for HIGH, intermediate for HIGHCR, and lesser for MAN (treatment×day interaction, P<0.01). During the GTT, serum insulin concentrations and insulin:glucose ratio were greater (P≤0.05) for HIGH compared with HIGHCR and MAN from 10 to 60min relative to the time of glucose infusion. Proportion of embryo produced per oocyte collected was greater (P≤0.02) for MAN vs. HIGH and HIGHCR, and similar (P=0.59) between HIGH and HIGHCR. In conclusion, lactating cows consuming excessive concentrate and NEL experienced increased insulin resistance and reduced proportion of embryo produced per oocyte collected compared with cows consuming adequate amounts of energy, whereas Cr-propionate supplementation was effective in alleviating insulin resistance caused by excessive NEL intake.


      PubDate: 2015-08-25T21:25:28Z
       
  • Corrigendum to “The importance of the DMRT3 ‘Gait
           keeper’ mutation on riding traits and gaits in Standardbred and
           Icelandic horses” [Livestock Science 176 (2015) 33–39]
    • Abstract: Publication date: Available online 20 August 2015
      Source:Livestock Science
      Author(s): Kim Jäderkvist, Niina Holm, Freyja Imsland, Thorvaldur Árnason, Leif Andersson, Lisa S. Andersson, Gabriella Lindgren



      PubDate: 2015-08-20T21:03:00Z
       
  • Ingestive behavior and short-term intake rate of cattle grazing on tall
           grasses
    • Abstract: Publication date: Available online 14 August 2015
      Source:Livestock Science
      Author(s): Masato Yayota, Aki Kato, Megumi Ishida, Shigeru Ohtani
      Tall grasses (> 1m tall) are an important forage resource for grazing ruminants. Understanding the ingestive behavior and short-term intake rate of cattle grazing on tall grasses will help facilitate grazing management of tall grass pastures. The aim of this study was to determine the allocation of jaw movements in grazing cattle in relation to tall grasses and to assess whether such allocations of jaw movements are effective for maintaining a short-term intake rate. Four plants were used as test plants: bahiagrass (Paspalum notatum Flügge; a short grass), Sudangrass (Sorghum × drummondii; a typical tall grass) and two growth forms of a dwarf bamboo (Sasa senanensis; a semi-woody form of tall grass): a naturally growing form (NGDB, approximately 2m tall) and a form that is under grazing (DBUG,<0.8m). Four Japanese Black cows were allowed to graze each plant in random order. The grazing jaw movements and intake rate were measured using an integrated method with a microsward technique and acoustic monitoring. The cows performed the highest number of total bites (simple bites+chew-bites) for bahiagrass, an intermediate number of total bites for Sudangrass and DBUG and the lowest number of total bites for NGDB (P<0.05). The total number of chews (simple chews+chew-bites) was similar among NGDB, DBUG, and Sudangrass, whereas the total number of chews for bahiagrass was less than that for dwarf bamboos. The number of observed chew-bites exhibited an order similar to that observed for the number of total bites. As a result of each jaw movement, cows ingesting the DBUG moved their jaws more frequently among the plants, and cows ingesting the bahiagrass performed the fewest grazing jaw movements. Bite mass was considerably greater in the cows ingesting NGDB than in the cows ingesting other plants. Conversely, the chew mass for bahiagrass was clearly greater than that for the two taller plants. Cows ingesting Sudangrass processed the least amount of forage with each chew (P<0.05). The intake rate did not significantly differ among the plants (P>0.05), except for Sudangrass. Cows ingested Sudangrass at a lower intake rate than observed for the other plants (P<0.05). The results suggest that cattle were able to control their ingestive jaw movements depending on plant characteristics such as height, the spatial arrangement of the leaves and leaf morphology. However, the lower short-term intake rate for tall grasses implies that there is a limit to the adaptability of grazing jaw movements.


      PubDate: 2015-08-16T20:59:30Z
       
  • Effect of floor type on Hoof lesions, dirtiness, immune response and
           production of beef bulls
    • Abstract: Publication date: Available online 8 August 2015
      Source:Livestock Science
      Author(s): M. Keane, M. McGee, E.G. O’Riordan, A.K. Kelly, B. Earley
      The objective of the study was to investigate the effect of old and new concrete slats (CS) with or without rubber mats (RM) on animal performance, hoof health, dirt scores and health status of finishing bulls. Continental crossbred beef bulls (n=72; mean initial live weight=441 (s.d. 45.1) kg) were blocked by breed and live weight and randomly assigned by block to one of four treatments; 1) Old CS 2) New CS, 3) Old CS covered with RM, 4) New CS covered with RM. Each treatment had 3 pens of 6 bulls at a space allowance of 2.9m2 per animal. Bulls were fed a total mixed ration (TMR) of silage and rolled barley on a 54:46 dry matter (DM) basis for 148 days. Feed was weighed into each pen daily and refusals were weighed twice weekly. Bulls were weighed every three weeks to coincide with dirt scoring. Total leukocyte, neutrophil, lymphocyte, eosinophil and monocyte percentage, red blood cell number and haemoglobin concentrations were measured on day 0 and day 148. Bull's hooves were inspected for the presence of lesions at the start of the study and again at slaughter. After slaughter, carcass weight, carcass gain, conformation and fat score, kidney and channel fat and hide weight were recorded. Bulls on RM had a greater average daily gain (ADG) (0.16kg/day) (P<0.01), kidney and channel fat weight (KCF) (P<0.05), hide weight (P<0.01) and a better feed conversion ratio (FCR) (P<0.05) than those on CS. Floor type had no effect on dry matter intake (DMI), slaughter weight, carcass weight, kill out percentage, conformation score or fat score. Bulls on RM had 44% more hoof lesions (P<0.01) than those on CS. There were slat×time (P<0.05) and mat×time (P<0.001) interactions for dirt scores. Bulls on slats were dirtier than those on mats on days 63, 84 and 126 (P<0.05) while bulls on new slats were dirtier than those on old slats on days 21 and 42 (P<0.001). Floor type had no effect (P>0.05) on any of the haematology variables measured which suggests that the immunological status of the bulls was not affected by treatment. While there was no evidence of lameness in bulls on RM, the increased number of hoof lesions suggests that hoof health may be compromised in bulls housed on RM.


      PubDate: 2015-08-11T20:43:46Z
       
  • Impact of inbreeding on fitness-related traits in the highly threatened
           Sorraia horse breed
    • Abstract: Publication date: Available online 5 August 2015
      Source:Livestock Science
      Author(s): H.J. Kjöllerström, L.T. Gama, M.M. Oom
      The Sorraia horse population can be regarded as a universal equine genetic resource, most likely the representative of the ancestor of Iberian saddle horses and probably the ancestor of several New World horse breeds. The breed was recovered in 1937 and managed without further additions to the initial founder group of 12 horses, originating an extant population with extremely high inbreeding levels (mean F=0.38). There are only about 300 animals representing the Sorraia horse population worldwide, which places it in a critical risk status and strongly supports the need to establish a conservation-breeding plan aiming at a long-term self-sustaining population. Data on all registered horses in the Sorraia Studbook were used to study the impact of inbreeding on offspring's viability at birth and at 6 months of age, and a sub-sample was used to determine the influence of inbreeding on stallion and mare fertility rates, foaling intervals and age at first parturition. The effect of inbreeding on the analysed traits was only significant for the relationship of mare fertility with mare inbreeding coefficient (P=0.003). The influence of age of the mare was quadratic, with a reduction in foal mortality (both at birth and at six months of age) and an increase in foaling interval as age of mare increased. Stud farms had a statistically significant influence on age at first parturition. Decisive management-breeding plans must be taken to control inbreeding levels in Sorraia horses, and contribute to the conservation of this breed.


      PubDate: 2015-08-07T20:08:19Z
       
  • Forage Yield and Cattle Carrying Capacity Differ by Understory Type in
           Conifer Forest Gaps
    • Abstract: Publication date: Available online 5 August 2015
      Source:Livestock Science
      Author(s): Kesang Wangchuk, Georg Gratzer, Andras Darabant, Maria Wurzinger, Werner Zollitsch
      A study was conducted in the Himalayan mixed conifer forests to generate estimates of cattle carrying capacity of logged sites, using consumable forage dry matter and nutrient content. Field samples were collected from four major understory vegetation types dominated by Yushania microphylla (ground cover proportions of 100% and 50%), Rubus nepalensis, Synotis alata and Sambucus adnata. The amount of dry matter, total digestible nutrient and digestible crude protein removed by cattle grazing was highest for the vegetation with 100% Y. microphylla. Vegetation with S. adnata, S. alata and R. nepalensis provided low consumable dry matter yield and nutrient content per hectare area. For vegetation with 100% Y. microphylla, based on consumable dry matter, total digestible nutrients and digestible crude protein, the cattle carrying capacities were estimated at 4.17, 2.27 and 1.27 Livestock Units per Year (LUY) per hectare, respectively. Vegetation with 50% Y. microphylla provided about one LUY per hectare both in terms of consumable DM and nutrient content. Vegetation with S. alata also provided nutritional carrying capacity of about one LUY per hectare but the carrying capacity in terms of consumable dry matter was lower than one LUY per hectare. Cattle carrying capacity, both in terms of dry matter and nutrient content was lower than one LUY per hectare for vegetation with S. adnata and R. nepalensis. We concluded that, depending on the type of understory vegetation, carrying capacity differs within hemlock-dominated mixed conifer forest in the Eastern Himalaya. Forage utilization was higher for S. alata, S. adnata and R. nepalensis vegetation, suggesting the need for vigilance to avoid overgrazing in these vegetation types. The study indicates the opportunity to select appropriate carrying capacities allowing optimum cattle density and providing the required level of nutrition, while avoiding over-grazing. We recommend our estimates to be used as guide to better understand the carrying capacity of logged sites in the Himalayan conifer forest.


      PubDate: 2015-08-07T20:08:19Z
       
  • Effects of calving difficulty on the subsequent reproductive performance
           and milk production of Holstein, brown swiss and their crosses
    • Abstract: Publication date: Available online 7 August 2015
      Source:Livestock Science
      Author(s): Mahmoud S. El-Tarabany
      Calving ease affects the welfare of cow and has economic implications for the farm. The degree of calving difficulty varies from no assistance needed to surgery being required. The aim of this study was to estimate the incidence of calving difficulty and evaluate the effects of calving ease on the subsequent reproductive and production performance of pure Holstein (HO), Brown Swiss (BS) and their F1 crosses (BF) under Egyptian conditions. The pure BS and BF heifers had significantly (P< 0.05) higher incidence of calving ease (87.9 and 83.8%, respectively) when compared with pure HO heifers (78.6%). Furthermore, the incidence of calvings of the most severe level was lowest in pure BS heifers. The reproductive function of pure BS and BF cows was not affected by difficult levels of calving, although their subsequent reproductive indices were reduced to some extent at the very difficult calving conditions (category C). In contrast, pure HO cows at very difficult level (category C) had significantly (P< 0.05) longer calving interval and days open (474 and 198 d, respectively), compared with those calved without difficulty (396 and 149 d, respectively). Pure HO cows experienced very difficult calvings had decreased Total-MY, 305-MY and Peak-MY at a rate of 34.6, 35.2 and 40.9%, respectively when compared with those calved without difficulty. However, production indicators of pure BS and BF cows were more tolerant with conditions of calving difficulty. In conclusion, pure BS and BF cows can cope with the difficult levels of calving under Egyptian conditions, while pure HO had lower fertility and milk yield parameters under the same conditions.


      PubDate: 2015-08-07T20:08:19Z
       
  • Genetic association between leg conformation in young pigs and sow
           reproduction
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): Hong Thu Le, Katja Nilsson, Elise Norberg, Nils Lundeheim
      Lameness is an issue of concern in pig production due both to animal welfare and to economical aspects. Lame sows are believed to suffer from pain and stress which is reported to have a negative influence on reproduction. Leg conformation and locomotion traits in young animals are associated with the risk of lameness at higher age. The purpose of this study was to estimate the genetic parameters of leg conformation traits recorded at performance testing (around 5 months of age) and their genetic correlations with reproduction traits. Information on leg conformation traits from 123,307 pigs scored and on reproduction traits from 22,204 litters in the first and second parity from Swedish Yorkshire nucleus herds were available for genetic analysis. Eight conformation and locomotion traits, coming from the old or the new scoring system in Sweden, included old movement, old overall leg score, new movement, new toes quality, new front leg quality, new rear leg quality, standing-under-position syndrome and new overall score. Four reproduction traits were analyzed by parity: the number of total born piglets, the number of liveborn piglets, the number of stillborn piglets and weaning to service interval. Estimates of heritabilities and genetic correlations between traits were obtained using a multi-trait linear animal mixed model. The heritability estimates were low to moderate, ranging from 0.02 to 0.20 for conformation traits and from 0.06 to 0.10 for reproduction traits. Significant genetic correlations were found between new toes quality and new overall score and the number of liveborn piglets in the 1st parity (−0.35 and −0.31, respectively), indicating that sows with even toes and better overall leg score tend to have higher number of liveborn piglets. Old movement score showed significant correlations with number of total born and number of liveborn piglets in both parities (0.20 to 0.36) and with weaning to service interval in the 2nd parity (−0.35±0.11). Similarly, standing-under-position syndrome was highly associated with number of total born and number of liveborn piglets in both parities (−0.54 to −0.35), indicating that sows with better movement and not suffering from standing-under-position syndrome are likely to have larger litter size and shorter interval to return heat after weaning. Heritabilities and significantly favorable genetic correlation estimates suggest the possibility of simultaneous improvement of both leg quality and reproduction performance by selecting on sound leg conformation and locomotion of young pigs.


      PubDate: 2015-07-19T01:59:43Z
       
  • Effect of cysteamine hydrochloride supplementation on the milk performance
           of dairy cow
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): C. Wang, C.J. Dong, Z.Q. Wang, F. Yang, H.L. Mao, Z. Wu, Q. Zhou, H.F. Wang
      Cysteamine (CS) can increase serum growth hormone concentrations and the growth performance of broiler, sheep, and pigs. However, information of CS supplementation on the milk performance of dairy cows is limited. An experiment was conducted to investigate the effect of dietary cysteamine hydrochloride (CSH) supplementation on lactation performance of dairy cows. Forty-eight multiparous mid-lactation Holsteins were fed a control diet or supplemented with 15, 30, or 45g/d CSH preparation (cysteamine HCl 20%) for 63d, including 7d for adaptation. The base diet was formulated to meet the nutrient requirements of lactating dairy cows according to the Chinese feeding standard (China Standard NY/T 34,Feeding standard of dairy cattle 2004 Issued by Ministry of Agriculture of People's Republic of ChinaBeijing) and the DMI, milk yield, milk composition, and plasma parameters were measured. Milk yield was 7.1% and 6.3% higher for the two higher supplementation amounts (SEM=0.50, P<0.05), and milk protein content was 7.7%, 8.7%, and 8.1% higher for the three supplemented groups (SEM=0.077, P<0.05), respectively, than the control. Plasma urea N were lower for the 30 and 45g/d CSH groups than for the control. Level of plasma somatostation was reduced and plasma growth hormone was enhanced in CSH groups compared with that of control (P<0.01). Supplementation of CSH preparation at 30g/d increased milk production of dairy cows while 15g/d has no positive effect on milk yield or milk efficiency.


      PubDate: 2015-07-19T01:59:43Z
       
  • Intake, digestibility, and nitrogen efficiency in Holstein heifers fed
           treated jatropha (Jatropha curcas L.) kernel cake
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): L.D. da Silva, O.G. Pereira, S.C. Valadares Filho, K.G. Ribeiro, R.F.D. Valadares, T.C. Silva, S.A. Santos
      The effects of dietary substitution of soybean meal (SBM) with ethanol-treated jatropha kernel cake with seed shells (TJC) on nutrient intake and digestibility, nitrogen balance, pH, rumen ammonia nitrogen (NH3–N), serum levels of alanine aminotransferase (ALT, EC 2.6.1.2) and aspartate aminotransferase (AST, EC 2.6.1.1), and ruminal degradation kinetics of SBM and TJC crude protein (CP) in Holstein heifers were evaluated. Four rumen-cannulated heifers were distributed in a 4×4 Latin square design, [body weight (BW)=379±2.13kg]. Each experimental period lasted 15 days, with eight days for diet adaptation and seven days for data collection. The heifers were fed four complete isonitrogenous diets containing 65% corn silage and 35% concentrate on a dry matter (DM) basis. The treatments consisted of four levels of SBM substitution for TJC+urea/ammonium sulfate: 0, 33, 67, and 100%, on a DM basis. Ethanol treatment of the jatropha kernel cake removed >99% of the phorbol esters. The effective degradability of the CP for TJC was 425.6g/kg. Intakes of DM, organic matter (OM), CP, ether extract (EE), neutral detergent fiber (NDF) and total digestible nutrients (TDN) decreased linearly with the substitution of SBM with TJC. The DM intakes were 18.0, 16.2, 16.8 and 11.3g/kg BW for 0, 33, 67 and 100% substitution, respectively. There was no effect of the TJC inclusion level on nutrient digestibility. The rumen pH increased linearly with increasing substitution levels. The rumen NH3–N was not affected by the inclusion of jatropha (7.79mg/dL overall mean). The amounts of ingested and absorbed nitrogen (N) and the N-balance decreased linearly with increasing TJC levels. The serum levels of ALT and AST were not affected by the inclusion of TJC in the diets. Despite the decrease in phorbol esters, ethanol treatment of jatropha kernel cake was not enough to promote adequate nutrient intake by the heifers.


      PubDate: 2015-07-19T01:59:43Z
       
  • Growth performance and carcass characteristics of three chicken strains in
           response to incremental levels of dietary Moringa oleifera leaf meal
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): N.A. Sebola, V. Mlambo, H.K. Mokoboki, V. Muchenje
      A 90-day feeding trial was conducted to determine the effect of Moringa oleifera leaf meal supplementation on growth performance and carcass characteristics of three chicken strains (male and female) that are normally reared under extensive production systems in South Africa. Moringa leaves were harvested by hand, air-dried and milled into M. oleifera leaf meal (MOLM). The MOLM was chemically analysed and used to dilute a commercial broiler finisher diet at 0 (MOLM0), 25 (MOLM25), 50 (MOLM50), and 100 (MOLM100) g/kg DM, producing four dietary treatments. Two hundred and sixteen (216) Potchefstroom Koekoek (PK), Ovambo (OV) and Black Australorp (BA) chickens were raised on a commercial starter mash for 4 weeks. On the fourth week, experimental diets were offered and growth performance data were collected over a period of 13 weeks. Carcass characteristics were measured upon slaughter at the end of the 13-week feeding period. Diet×strain interaction was significant (P<0.001) for feed intake but not (P>0.05) for growth rate and FCE. Feed intake responded to incremental levels of MOLM in an asymptotic fashion. Maximum feed intake was achieved at dietary MOLM inclusion levels between 50 and 70g/kg DM. Black Australorp chickens had the highest feed conversion efficiency (FCE) of 2.35, while OV and PK chickens had lower FCE values of 2.09 and 2.05, respectively. Diet, strain and gender, all had significant effects on dressing percent (P<0.001), leg and thigh weight (P<0.05), and wing weight (P<0.05). Male chickens attained higher (P<0.05) carcass weight, leg and thigh weight, dressing percent, and breast mass than female chickens (P<0.001). In female chickens, diets containing MOLM resulted in chickens with better carcass weight, leg and thigh weight, dressing percent, and breast mass compared to the control. In conclusion, Black Australorp chickens were better at utilizing diets with higher levels of MOLM compared to OV and PK strains. Inclusion of MOLM in chicken diets positively affected growth performance and carcass characteristics of the birds.


      PubDate: 2015-07-19T01:59:43Z
       
  • Effects of a supplement containing multiple types of gluconeogenic
           precursors on production and metabolism in Holstein bull calves during
           heat stress
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): M. Hossein Yazdi, H. Amanlou, H.R. Mirzaei-Alamouti, M.T. Harkinezhad, A. Nabipour, E. Mahjoubi, N. Aghaziarati, G.R. Noori, L.H. Baumgard
      Glucose appears to be a preferred systemic fuel during heat stress (HS) in a variety of species. Increasing the dietary grain content can enhance the post-absorptive carbohydrate status, but providing excessive fermentable starch can cause rumen disorders and this is especially true during HS. Current study objectives were to evaluate the effects of a glycerol based supplemental product on growth and metabolic variables in Holstein bull calves during controlled HS. Before the start of the experiment, bull calves (n=14; 163.6±30.1kg body weight) were subjected to thermal neutral conditions [26.5±3.4°C and a temperature–humidity index (THI) of 70.4±2.8] for 7d (period 1; P1). During this period, productive parameters as well as blood metabolites were measured and used as covariates for the subsequent HS period. Following P1, a cyclical HS pattern was implemented for 21d (P2) where daily ambient temperatures ranged from 29.1 to 39.7°C and the THI was >74 for 24h/d and >83 for at least 14h/d. During P2, half of the HS calves (n=7) received a control diet (CON) and the other half received the control diet supplemented with a product (300g/d) containing gluconeogenic precursors (GLU). Throughout each period respiration rate, rectal temperature and skin temperature at the shoulder and rump were recorded at 0600, 1100 and 1500h daily. Blood samples were obtained prior to and 4h post the a.m. feeding during both periods. Although HS markedly reduced DMI (18%) and growth as expected, supplemental GLU did not affect body weight gain. Supplemental GLU decreased the shoulder temperature at 0600 and 1500h (P<0.01), and decreased respiratory rate at 1500h (P<0.02). Feeding GLU did not affect blood urea nitrogen (BUN), glucose or nonesterified fatty acids (NEFA) concentrations, but increased circulating insulin prior to the a.m. feeding (P<0.03) and this demonstrates that GLU was effective at enhancing the post-absorptive carbohydrate status. Our results suggest that feeding supplemental GLU improves some body temperature indices but did not enhance growth performance in Holstein bull calves during HS.


      PubDate: 2015-07-19T01:59:43Z
       
  • Evaluating complementary effects of ethanol extract of propolis with the
           probiotic on growth performance, immune response and serum metabolites in
           male broiler chickens
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): A. Daneshmand, GH. Sadeghi, A. Karimi, A. Vaziry, S.A. Ibrahim
      The aim of this study was to evaluate the effects of propolis (a natural resinous substance that bees collect from different sources of plants) extract alone or in combination with probiotics on the growth performance and immune response of male broiler chickens. A total of 256 broiler chickens were randomly assigned to 4 treatments: maize-soybean meal basal diet with no supplement as control, the basal diet containing propolis (0.20g/kg), probiotic (0.45g/kg), or a combination of propolis (0.20g/kg) and probiotic (0.45g/kg). Each treatment consisted of 4 replicated pens with 16 broiler chickens per pen. Broiler chickens had ad libitum access to feed and water and the light program was 23h light/1h dark. The inclusion of propolis extract decreased (P<0.05) body weight and feed intake. Propolis extract alone or in combination with probiotic increased (P<0.05) the relative spleen weight in broiler chickens at 42d of age compared to the control and probiotic. The relative weight of bursa of Fabricius was greater (P<0.05) in broiler chickens receiving probiotics, propolis extract, or their combination compared to those fed the control diet. Supplementation of diet with probiotic, propolis extract, or a combination of both caused an increase (P<0.05) in the concentration of antibody titer to Newcastle Disease virus. In conclusion, supplementation of the diet with propolis extract decreased the body weight of broiler chickens, however, inclusion of propolis, probiotic, and their combination in the diet caused an immunomodulatory effect in broiler chickens.


      PubDate: 2015-07-19T01:59:43Z
       
  • Effects of maize crop maturity at harvest and dietary inclusion rate of
           maize silage on feed intake and performance in lambs fed high-concentrate
           diets
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): Carl Helander, Peder Nørgaard, Konstantinos Zaralis, Kjell Martinsson, Michael Murphy, Elisabet Nadeau
      This study investigated the effects of maize maturity at harvest and dietary inclusion rate of maize silage on feed intake, average daily gain (ADG) and carcass traits of growing ram lambs fed high-concentrate diets. Precision-chopped maize was harvested at two stages of maturity (Early: dough stage and Late: dent stage) and ensiled as round bales. Early or late cut maize silage was fed as the sole forage or together with grass silage, to 40 ram lambs in each of two consecutive years. The four treatments in each year were: (1) early cut maize silage as 50% of the forage dry matter (DM) proportion (E50), (2) early cut maize silage as 100% of the forage DM proportion (E100), (3) late cut maize silage as 50% of the forage DM proportion (L50) and (4) late cut maize silage as 100% of the forage DM proportion (L100). The proportion of forage in each of the diets was on average 42% on a dry matter (DM) basis and the concentrate consisted of dried distillers’ grains plus solubles, rolled barley and cold-pressed rapeseed cake in year 1 (Y1) or heat-treated rapeseed expeller in year 2 (Y2). Daily DM intake (DMI) was 1.24 and 1.40kg, averaged over treatments, in Y1 and Y2, respectively. Increasing the dietary inclusion rate of maize silage from 50 to 100% of the forage DM proportion resulted in increased DMI in Y1 (P<0.05) and increased carcass fatness in Y2 (P<0.01), whereas increased maturity stage at harvest tended to result in increased DMI in Y2 (P<0.10). Feed conversion ratio (FCR; kg DMI per kg ADG), was lower for the treatments E100 and L50 than for E50 and L100, respectively (P<0.01) in Y2. The body weight of the lambs increased linearly over time, in both years. In conclusion, maize silage can replace grass silage in the diets of high-producing lambs. Increased metabolizable protein (MP) to metabolizable energy (ME) ratio of the diet increased ADG of the lambs. Also, increased ADG decreased mega joule ME intake per kg ADG, in finishing lambs.


      PubDate: 2015-07-19T01:59:43Z
       
  • Genetic parameters of type traits in two strains of dual purpose
           autochthonous Valdostana cattle
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): Serena Mazza, Cristina Sartori, Roberto Mantovani
      The main objectives of this study were (i) to investigate the best fitting model for the genetic analysis of type traits and (ii) to estimate the genetic parameters of 4 composite (body size, muscularity, body shape, and udder) and 22 individual type traits between and within the two strains of the Valdostana dual purpose breed: the Aosta Red Pied (ARP; n=25,183 records) and the Aosta Black Pied and Chestnut (ABP-CHES; n=14,701 records). All type traits were scored from 2000 to 2012 on primiparous cows using a 1 to 5-point scale system. A model comparison was undertaken by considering the Akaike Information Criterion values obtained from the analysis, producing a final model that took into account the effects of herd-year-classifier, days in milk, age at calving as fixed and the animal additive genetic effect as random. Heritability estimates obtained through single trait animal model analysis varied from 0.03 for thinness (in both strains) to 0.32 (ARP) and 0.29 (ABP-CHES) for stature. Medium-low heritability estimates were obtained for individual muscularity traits (0.22 for ARP and 0.13 for ABP-CHES), and for individual udder type traits (0.12 on average in both Valdostana strains). The highest genetic correlations between composite traits were for muscularity with body shape in both Valdostana strains (0.55 for ARP and 0.52 for ABP-CHES). Different and opposite values of genetic correlations were found for the composite body shape and the composite udder traits (0.13 for ARP and –0.25 for ABP-CHES; P<0.01), probably due to the different breeding purposes set up for the two Valdostana strains. Regarding the individual type traits, for the ARP strain the highest genetic correlation was 0.97 (between thigh, buttocks side and rear view), whereas for the ABP-CHES strain it was 0.98 (between stature and body length), meaning that improving one trait of each pair led to a positive variation in the other. Most of the genetic correlations between the individual muscularity traits and the individual udder traits were negative, especially those involving udder volume (from –0.19 to –0.42 in ARP, and from –0.17 to –0.41 in ABP-CHES; P<0.01), indicating a substantial antagonistic situation of type traits related to dairy and beef traits. In conclusion, the selection for the dual purpose in local breeds such as in Valdostana cattle implies a thorough consideration of opposite morphological traits.


      PubDate: 2015-07-19T01:59:43Z
       
  • Nordic dairy cow model Karoline in predicting methane emissions: 2. Model
           evaluation
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): Mohammad Ramin, Pekka Huhtanen
      Models are widely used to predict methane (CH4) emissions, and can be used to develop mitigation options and policies. The objective of the current study was to evaluate the performance of the Nordic dairy cow model Karoline in predicting CH4 emissions. Karoline is a dynamic, deterministic and mechanistic simulation model that describes the digestion and metabolism of nutrients, and production in a dairy cow. The model was evaluated against observed data from studies reporting CH4 emissions from respiration chamber studies. The dataset included a total of 184 treatment means from 31 published papers. The dietary and animal characteristics used for the model evaluation represent the typical range of diets fed to dairy cattle. When analyzed with a fixed model regression, there was a good relationship between predicted and observed CH4 emissions measured from respiration chamber studies with a small root mean square error of prediction (R 2=0.93, RMSPE=10.1% of the observed mean). The mean bias was small (1.9%) but statistically significant, and there was no slope bias. Most of the error was due to random variation (96.4%), whereas the contributions of mean and slope bias were small. By considering study as the random effect in the model (mixed model regression analysis), the fit improved to R 2= 0.98 and RMSPE decreased to 6.1% of the observed mean. The influence of some input variables such as total dry matter intake, proportion of concentrate, dietary concentrations of crude protein, neutral detergent fiber and ether extract, and organic digestibility (OMD) on the residuals (observed–predicted) of CH4 emissions were not significant. The residuals of both CH4 emissions and OMD were significantly related to each other, indicating the Karoline model requires accurate estimates of digestion kinetic parameters as input variables. When the laboratory was used as a class variable in the model, the residuals of CH4 emissions were significantly different both between the laboratories and also between experiments within individual laboratories. It is concluded that the Nordic dairy cow model Karoline is a useful tool in predicting CH4 emissions and understanding the system behavior. The model can also be used in developing mitigation strategies for the national inventories of CH4 emissions.


      PubDate: 2015-07-19T01:59:43Z
       
  • Nordic dairy cow model Karoline in predicting methane emissions: 1. Model
           description and sensitivity analysis
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): Pekka Huhtanen, Mohammad Ramin, Peter Udén
      Decreasing methane (CH4) emissions is necessary both environmentally, as CH4 has a strong greenhouse gas effect and nutritionally as CH4 represents a loss of feed energy. Karoline is a whole dairy cow mechanistic, dynamic model predicting nutrient supply and milk production. The objectives of this study were to revise the digestion and CH4 emissions modules of the Karoline model. In addition, a sensitivity analysis was conducted to evaluate the importance of the accuracy of input data required in predicting CH4 emissions. Modifications were made in the equations predicting digesta passage kinetics, microbial cell synthesis, digestion in the hind-gut, and utilization of hydrogen. The Karoline model predicted similar decreases in both organic digestibility (OMD) and neutral detergent fibre digestibility (NDFD) and improvements in the efficiency of microbial nitrogen synthesis with increasing dry matter intake (DMI) as reported in the literature. The proportion of ruminal digestion of total NDFD (0.95) and fecal metabolic and endogenous output (98g/kg DMI) also agree with the literature data. Predicted total CH4 emissions increased with a diminishing rate by increased DMI. Predicted CH4 emissions as a proportion of GE intake decreased linearly with increased DMI. The relationships between feeding level and CH4 emissions (a decrease of 7.8kJ/MJ gross energy per multiple of maintenance) were in good agreement with experimental data. The sensitivity analysis suggested that feed variables related to digestion kinetics of NDF [indigestible NDF (iNDF) and digestion rate of potentially digestible NDF] have a strong influence on predicted CH4 emissions; for example, predicted CH4 emissions decreased with increasing iNDF concentration. Digestion rates of starch and insoluble protein had smaller effects on predicted CH4 emissions than NDF digestion rates. Fat had a strong negative influence on predicted CH4 emissions (0.27kJ/MJ gross energy per 1g fat/kg DM). The sensitivity analysis suggested that accurate values of digestion kinetic variables are required for satisfactory predictions of CH4 emissions with mechanistic models. Based on reliable predictions of digestibility, microbial protein synthesis and CH4 emissions, it can be concluded that the revised Karoline model is a promising tool for predicting CH4 emissions and understanding the underlying mechanisms.


      PubDate: 2015-07-19T01:59:43Z
       
  • Effects of extracellular polysaccharides of Ganoderma lucidum
           supplementation on the growth performance, blood profile, and meat quality
           in finisher pigs
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): X.L. Li, L.P. He, Y. Yang, F.J. Liu, Y. Cao, J.J. Zuo
      The objective of the present study was to evaluate the effect of the addition of extracellular polysaccharides of Ganoderma lucidum (EPG) on growth performance, blood profile, and meat quality of longissimus muscle (LM) in finisher pigs. A total of 60 castrated finisher barrows [(Duroc×Yorkshire)×Landrace] with an average initial body weight (BW) of 54.6±0.6kg were randomly allotted to 1 of 2 treatments (3 pens/treatment and 10 pigs/pen): control (basal diet) and EPG (basal diet+800mg/kg of EPG). The duration of the experiment was 70d. Results showed that dietary EPG addition increased serum concentrations of immunoglobulin G (IgG) (P=0.017), interleukin-2 (IL-2; P=0.008), and globulin (P=0.024) and reduced albumin (P=0.032) and the ratio of albumin to total protein (P=0.035). Serum concentrations of triglyceride (P=0.043), total cholesterol (P=0.023), low-density lipoprotein (LDL) cholesterol (P=0.014), and creatine kinase (P=0.006) decreased in the EPG treatment group. Dietary supplementation of EPG affected fat traits by increasing marbling score (P=0.015), the content of total fat (P=0.045), and the proportion of oleic acid (P=0.023) in LM. Moreover, inclusion of EPG reduced stearic acid expressed as percentage of total fatty acids (P=0.018) in LM. Furthermore, the addition of EPG in diets increased the pH of LM of pigs at 45min (P=0.042) and 24h (P=0.036) post-mortem, and the redness (P=0.031) of LM. Increased content of inosine monophosphate acid (IMP) (P=0.044) and decreased drip loss (P=0.020) in LM of pigs were also observed in the EPG treatment group. In addition, dietary EPG addition has no adverse effect on the growth performance of finisher pigs. In conclusion, EPG is a potential feed additive for promoting animal health and improving quality of pork.


      PubDate: 2015-07-19T01:59:43Z
       
  • Close relationship between pre- and post-calving reticuloruminal pH levels
           in dairy cows
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): A. Steinwidder, M. Horn, R. Pfister, H. Rohrer, J. Gasteiner
      The aim of the present study was to investigate the effects of prepartum reticuloruminal pH values on postpartum pH values of lactating cows at two concentrate supplementation levels. An indwelling pH measurement system with a wireless data transmitting unit was given to 9 heifers and 11 cows orally 2 weeks before expected calving. The pH was measured from week 2 prepartum to week 6 postpartum. Prepartum, all animals were fed hay and grass silage only. After parturition the animals were assigned to one of two concentrate supplementation levels (Con and Low). During the first 6 weeks postpartum, 5.6kg and 2.9kg dry matter per day of concentrates were fed to cows in groups Con and Low, respectively. Before parturition, no effect of the week on the mean pH was found, but pH values varied considerably between individual animals. During the last week prior parturition, the median, lower and upper quartile values of the mean pH values were 6.47, 6.41 and 6.59 for heifers and 6.29, 6.19 and 6.39 for cows, respectively. Standard deviations of the mean pH values for heifers and cows were 0.15 and 0.12, respectively. After parturition, no diet effect on the mean pH and maximum pH values was found. The minimum pH differed between Con and Low, but the absolute levels were almost equal (6.02 and 6.04, resp.). A strong correlation (r>0.8; P<0.01) between the mean pH value before parturition (pHweek−1) and pH values after parturition was found. Animals having lower pH levels before parturition continued to have lower mean pH and minimum pH values during weeks 1 to 6 postpartum. Furthermore, these animals had stronger short term fluctuations of H3O+ concentrations and a longer time span with pH values below 6.2. The results support the theory of the existence of cow-specific baselines concerning rumen pH, pointing to individual differences in the rumen environment, fermentation and metabolism and emphasising the importance of further research on this topic.


      PubDate: 2015-07-19T01:59:43Z
       
  • Maintenance energy requirements of young Holstein cattle from calorimetric
           measurements at 6, 12, 18, and 22 months of age
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): H.P. Jiao, T. Yan, D.A. Wills, D.A. McDowell
      Twenty five-month old Holstein cattle (10 steers and 10 heifers) were used in a four-period (28d/period) study with measurements made at the age of 6, 12, 18, and 22 months, to evaluate effects of gender on energy utilization efficiency and maintenance energy requirement. Cattle were offered perennial ryegrass silage mixed with concentrates. In each period, the cattle were housed together in a cubicle accommodation for the first 20d, individually in metabolism units for the next 3d, and then in indirect open-circuit respiration calorimeter chambers for the final 5d with feed intake, feces and urine outputs, and gaseous exchange measured during the final 4d. There was no difference (P>0.05) in any period between gender groups in terms of growth performance, energy intake, energy output, or energetic efficiency, with the exception of period three when the steers had a greater (P<0.05) feed and energy intake than heifers. Data from the two groups were therefore pooled to develop relationships between metabolizable energy (ME) intake and retained energy (RE) for each measurement period and for the whole experimental period. Retained energy was strongly related to ME intake (P<0.001), with R 2 values ranging from 0.85 to 0.93. Net energy (NE) and ME requirements for maintenance (NEm and MEm) derived from these relationships were greater for cattle at the age of 6 months than those at 12, 18, and 22 months (NEm=0.57, 0.48, 0.47, and 0.41MJ/kg0.75; and MEm=0.78, 0.62, 0.59, and 0.63MJ/kg0.75, respectively). These maintenance energy requirements were greater than those recommended in energy feeding systems currently used in Europe, North America, and Australia. The results indicate that current feeding systems may underestimate maintenance requirements for young dairy cattle, resulting in a reduced estimate of the efficiency of production.


      PubDate: 2015-07-19T01:59:43Z
       
  • Animal performance, carcass characteristics and beef fatty acid profile of
           grazing steers supplemented with corn grain and increasing amounts of
           flaxseed at two animal weights during finishing
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): L. Pouzo, N. Fanego, F.J Santini, A. Descalzo, E. Pavan
      The objective of this study was to determine (1) the effects of increasing flaxseed addition to the corn grain supplemented at finishing to grazing steers on animal performance, carcass characteristics and longissimus muscle (LM) fatty acid profile, and (2) whether dietary treatments effects are affected by animal body weight (BW) at supplementation. Forty eight steers were assigned to eight treatment combinations defined by four dietary treatments (CNTRL, no supplement; FLAX-0, 0.7% BW of cracked corn grain; FLAX-1 and FLAX-2, FLAX-0 plus 0.125% and 0.250% BW of unprocessed flaxseed, respectively) and by two animal BW treatments generated by supplementing steer in early spring (EARLY) or late spring (LATE). Steers assigned to EARLY received their dietary treatment when reaching 366±27.3kg BW (August, 3rd) and those assigned to LATE when reaching 458±42.8kg (October, 10th). After 70d on trial, carcass data and LM samples (12th rib region) were collected for fatty acid (FA) analysis. Total DMI was greater in supplemented treatments (FLAX-0, FLAX-1 and FLAX-2) than in CNTRL, with no flaxseed level effect. Dietary treatment effects on performance and carcass characteristics were not affected by BW treatments. Increasing flaxseed supplementation linearly increased subcutaneous fat thickness; whereas increasing BW at initiation of supplementation decreased average daily again, but increase final BW, hot carcass weight, and LM total fatty acid content. Animal BW at initiation of supplementation affected dietary treatments effects on LM n-6/n-3 ratio; ratio was highest in FLAX-0 and lowest in CNTRL and FLAX-2 in both BW treatments; did not differ between BW treatments in CNTRL and in FLAX-2, but was greater in EARLY than in LATE in FLAX-0 and FLAX-1. Trans-vaccenic acid proportion was greater in CNTRL than in supplemented treatments, but was not affected by flaxseed level; similar trend was observed for CLA cis-9, trans-11 proportion. Linolenic acid proportion did not differ between CNTRL and supplemented treatments, but was linearly increased with flaxseed level. Fatty acids changes with increasing animal BW at supplementation were associated with the increased in total muscle fatty acid content; total and individual polyunsaturated fatty acids were lower in LATE than in EARLY, whereas trans-vaccenic acid and CLA cis-9, trans-11 were greater. Adding flaxseed to the corn grain supplemented increase subcutaneous fat thickness of grazing steers without negatively affecting fatty acid profile, except for a reduction in trans-vaccenic acid proportion. Therefore, adding flaxseed to the corn supplemented to grazing steers increases carcass fatness while reducing the negative effect of corn supplementation on LM n-6/n-3 ratio but not on trans-vaccenic acid. Increasing BW at supplementation reduces supplementation effects on LM n-6/n-3 ratio.


      PubDate: 2015-07-19T01:59:43Z
       
  • Ammonia and amino acids modulates enzymes associated with ammonia
           assimilation pathway by ruminal microbiota in vitro
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): Pengpeng Wang, Zhiliang Tan, Leluo Guan, Shaoxun Tang, Chuanshe Zhou, Xuefeng Han, Jinhe Kang, Zhixiong He
      The objective of this study was to evaluate the effects of ammonia and amino acids (AA) supplementation on activities of ruminal enzymes involved in ammonia assimilation. In addition, the temporal changes of ruminal bacterial populations and enzyme activities during in vitro incubation were investigated. Rumen fluid from four ruminally fistulated goats was used in a 3×3 factorial arrangement of treatments with ammonia equivalent to 1, 4, and 15mM ammonium chloride (NH4Cl), and with an added AA mixture (containing 992g casein acid hydrolysate plus 1.4g l-cysteine plus 8.68g l-tryptophan) at 0, 1, and 15.5g/L in the in vitro culture solution. Both ammonia and AA supplementation increased (P<0.01) ammonia–nitrogen and volatile fatty acids concentrations. There was an interaction (P=0.04) between NH4Cl and AA concentrations on the yield of microbial crude protein. The population of total bacteria was dose-dependent with ammonia concentration (P=0.01), but was increased following AA increment (P<0.01). Supplement of AA activated (P<0.01) enzymes of glutamine synthetase (GS), glutamate synthetase (GOGAT), and glutamate dehydrogenase (GDH), but inhibited (P<0.01) enzyme of alanine dehydrogenase (ADH), all of which were important in ammonia assimilation for ruminal microbiota. And all these four enzymes were more active at the later period of process. The GDH activity was significantly associated with the population of Prevotella ruminicola (r=0.66; P<0.01), while the correlations between ADH activity and Fibrobacter succinogenes (r=0.41, P=0.04) or Butyrivibrio fibrisolvens (r=0.45, P=0.02) were not strong. Enzymes of GS, GOGAT and GDH had strong correlations (P<0.01) with yield of MCP. These results suggest that AA supplementation alters fermentation pattern, and stimulates the GS–GOGAT and GDH pathways of ammonia assimilation.


      PubDate: 2015-07-19T01:59:43Z
       
  • Production attributes of Merino sheep genetically divergent for wool
           growth are reflected in differing rumen microbiotas
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): I. De Barbieri, L. Gulino, R.S. Hegarty, V.H. Oddy, A. Maguire, L. Li, A.V. Klieve, D. Ouwerkerk
      Divergent genetic selection for wool growth as a single trait has led to major changes in sheep physiology and metabolism, including variations in rumen microbial protein production and uptake of α-amino nitrogen in portal blood. This study was conducted to determine if sheep with different genetic merit for wool growth exhibit distinct rumen bacterial diversity. Eighteen Merino wethers were separated into groups of contrasting genetic merit for clean fleece weight (CFW; low: WG− and high: WG+) and fed a blend of oaten and lucerne chaff diet at two levels of intake (LOI; 1 or 1.5 times maintenance energy requirements) for two seven-week periods in a crossover design. Bacterial diversity in rumen fluid collected by esophageal intubation was characterized using 454 amplicon pyrosequencing of the V3/V4 regions of the 16S rRNA gene. Bacterial diversity estimated by Phylogenetic distance, Chao1 and observed species did not differ significantly with CFW or LOI; however, the Shannon diversity index differed (P=0.04) between WG+ (7.67) and WG− sheep (8.02). WG+ animals had a higher (P=0.03) proportion of Bacteroidetes (71.9% vs 66.5%) and a lower (P=0.04) proportion of Firmicutes (26.6% vs 31.6%) than WG− animals. Twenty-four specific operational taxonomic units (OTUs), belonging to the Firmicutes and Bacteroidetes phyla, were shared among all the samples, whereas specific OTUs varied significantly in presence/abundance (P<0.05) between wool genotypes and 50 varied (P<0.05) with LOI. It appears that genetic selection for fleece weight is associated with differences in rumen bacterial diversity that persist across different feeding levels. Moderate correlations between seven continuous traits, such as methane production or microbial protein production, and the presence and abundance of 17 OTUs were found, indicating scope for targeted modification of the microbiome to improve the energetic efficiency of rumen microbial synthesis and reduce the greenhouse gas footprint of ruminants.


      PubDate: 2015-07-19T01:59:43Z
       
  • The camel faecal metagenome under different systems of management:
           Phylogenetic and gene-centric approach
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): Suchitra S. Dande, Vaibhav D. Bhatt, Niteen V. Patil, Chaitanya G. Joshi
      The study investigated the composition of microorganisms in the camel (Camelus dromedarius) faecal samples, maintained under two groups of intensive (group 1) and extensive (group 2) systems of management at Jaisalmer district of Rajasthan, India by using culture-independent approach. The study included the comparison of camel faecal microbiota to other currently available gut/faecal metagenomes, in order to reveal potential differences in these gut environments. After shotgun sequencing of the camel fecal microbiome, we used the Metagenomics-Rapid Annotation Server Tool (MG-RAST) to identify the microbial diversity and metabolic potential of the camel gut. Of the sequenced data that passed quality control, 1.3% and 2.2% sequences contained ribosomal RNA genes in groups 1 and 2, respectively. The annotated protein features which were assigned to functional categories were 63.6% and 69.5%, in groups 1 and 2, respectively. The domain level breakdown of our samples revealed bacteria was the major domain in both systems of management. At the phylum level, Firmicutes (61.40% and 29.17%), Proteobacteria (11.10% and 47.85%), Bacteroidetes (8.04% and 3.83%) and Verrucomicrobia (7.48% and 10.35%) were predominant in the fecal microbial community of groups 1 and 2, respectively. The fecal metagenomes revealed Euryarchaeota phylum with Methanobrevibacter smithii as the major archaeal species in both these groups. Functional analysis using subsystems of MG-RAST revealed that sequences for protein metabolism were abundant in group 1 and those for metabolism of carbohydrates predominated in group 2. Glycoside hydrolases of carbohydrates functional category were seen in group 2. High taxonomic similarity of group 1 with cow rumen metagenomes, cattle faecal pool, canine gastro-intestine as well as group 2 camels with the termite gut was observed. Functional similarities of camel faecal metagenomes of groups 1 and 2 with cattle faecal pool and camel foregut were noticed. Altogether, these data suggest that agricultural and animal husbandry practices can impose significant selective pressures on the gut microbiota. The present study provided a baseline for understanding the complexity of camel gut microbial ecology while also highlighting striking similarities and differences when compared to other animal gastrointestinal environments and in future could help in developing strategies for improving the existing management conditions.


      PubDate: 2015-07-19T01:59:43Z
       
  • Breeding programs for dairy goats generate profits in Brazil
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): Leonardo Hunaldo dos Santos, Ana Maria Bezerra Oliveira Lôbo, Olivardo Facó, Heraldo Cesar Gonçalves, Raimundo Nonato Braga Lôbo
      This work aims to evaluate the economic feasibility of a breeding program for dairy goats in developing countries. A traditional scheme was compared with a scheme using a progeny test. In the traditional scheme, farm records are used and the selection of bucks is based on reproduction and milk yield of their dams, while the selection of does is based on their own performance and on their dam's performance. Analyses were performed using the ZPLAN software, which uses a deterministic approach to estimate genetic and economic gains in breeding programs. The traditional selection scheme showed no economic viability and did not cover the costs for maintenance of the breeding program. The scheme using progeny tests of young bucks was viable, with considerable genetic profits for the objectives of selection and individual traits. The economic returns of this program exceeded its costs, with a return on investment of approximately 3%. In this scheme, somatic cell count was the trait with the largest economic impact, followed by milk yield. The intensity of use of young bucks in progeny testing should not exceed 10%. Above this value, no substantial monetary gains were obtained for the objective of selection, besides the reduction of the net present value of the breeding program.


      PubDate: 2015-07-19T01:59:43Z
       
  • Polymorphisms of the membrane-associated ring finger 4, ubiquitin protein
           ligase gene (MARCH4) and its relationship with porcine production traits
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): K. Ropka-Molik, A. Dusik, K. Piórkowska, M. Tyra, M. Oczkowicz, T. Szmatoła
      Membrane-Associated Ring Finger (C3HC4) 4, E3 Ubiquitin Protein, encoded by MARCH4 gene, plays an important role in protein ubiquitination. MARCH4 gene may be one of the candidate genes related with some phenotypic traits due to its function and chromosome localization in QTLs associated with pork quality (meat color, pH, water holding capacity and texture parameters). In the present study, all exons and their flanking regions were screened for the presence of SNPs with the use of High Resolution Melt (HRM) method. The frequencies of two of eight identified polymorphisms were estimated on a large number of pigs represented by five breeds. The association study showed that SNPs ENSSSCG00000016176:g.576T>G (localized in the promoter region) and ENSSSCT00000017613.2:c.675+5C>A (in the second intron) affected growth traits and characteristics of carcasses as well as meat quality in pigs. Both SNPs were related with lean meat percentage, the weights of the most valuable cuts for example as ham and loin, loin eye area and backfat thickness (p≤0.01). Furthermore, analyzed polymorphisms affected the length of fattening period, feed:gain ratio and test daily gain. The presented influence of MARCH4 polymorphisms on meat quality parameters was not conclusive. The ENSSSCG00000016176:g.576T>G polymorphism was associated with meat pH, while ENSSSCT00000017613.2:c.675+5C>A SNP was related with meat color. The present research showed that porcine MARCH4 gene is an interesting candidate gene associated with important pig production traits.


      PubDate: 2015-07-19T01:59:43Z
       
  • Editorial Board
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178




      PubDate: 2015-07-19T01:59:43Z
       
  • Polymorphisms in the promoter of interleukin-12β2 and interleukin-23
           receptor genes influence milk production traits in Chinese Holstein cows
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): Yongjiang Mao, Xiaorui Zhu, Shiyu Xin, Meirong Zhang, Xiaolong Wang, Dan Cheng, Huiming Zhang, Sven König, Zhangping Yang, Liguo Yang
      Interleukin-12 (IL-12) and interleukin-23 (IL-23) are proinflammatory cytokines produced by macrophages and dendritic cells in response to infection with intracellular pathogens. Given the importance of IL-12 and IL-23 for modulating inflammation and the host immune response, the IL-12 and IL-23 receptor genes may be suitable candidate genes for studying disease resistance in dairy cattle. Twenty Chinese Holstein cows were selected randomly for PCR amplification and sequencing, and used for SNP discovery in the bovine IL-12Rβ2 and IL-23R promoter region. One SNP(c.-246G>T) in IL-12Rβ2 gene and 2 SNPs(c.-856A>G and c.-207T>C) in IL-23R gene were identified. Chinese Holstein cows (n=866) were then genotyped using Sequenom MassARRAY (Sequenom Inc., San Diego, CA) based on the 3 identified SNPs, and the associations between SNPs or haplotype of the genes and milk production traits, SCS were analyzed by the least squares method in the GLM procedure of SAS. The IL-23Rc.-856A>G and IL-23Rc.-207T>C showed close linkage disequilibrium (r 2=0.89). No association was found with SCS, but associations were found between 3 of these SNP with milk protein content and lactose content. The software MatInspector revealed that these SNPs were located within several potential transcription factor binding sites, and may alter gene expression, but further investigation will be required to elucidate the biological and practical relevance of these SNP.


      PubDate: 2015-07-19T01:59:43Z
       
  • Effect of supplementation with molecular or nano-clay adsorbent on growth
           performance and haematological indices of starter and grower turkeys fed
           diets contaminated with varying dosages of aflatoxin B1
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): A.O. Lala, A.O. Oso, A.M Ajao, O.M. Idowu, O.O. Oni
      A 12-wk feeding experiment was conducted to investigate the effect of supplementation with molecular or nano-clay adsorbent on growth performance and haematological indices of starter (0–56d) and grower (56–84d) turkeys fed diets contaminated with varying doses (0, 60, and 110ppb) of aflatoxin B1. Two hundred and sixteen 1-d-old male turkeys were assigned to 9 diets supplemented with no adsorbent, molecular clay adsorbent, and nano-clay adsorbent and contaminated with 0, 60, and 110ppb aflatoxin B1 in a 3×3 factorial arrangement of treatments with 3 replicate pens and 8 turkeys per pen. The turkeys were housed in an open-sided, deep litter system, which was partitioned into 27 pens (2×1.5m2) using wire mesh. As aflatoxin contamination increased from 0 to 110ppb, feed intake and weight gain decreased and feed conversion ratio (FCR) increased in starter turkeys, but the adverse effects of aflatoxin were progressively less from those fed the diets with no adsorbent to molecular clay adsorbent and then to nano-clay adsorbent (adsorbent× aflatoxin. P<0.044). Grower turkeys fed the diets with adsorbents consumed more feed and had better FCR than those fed the diets without adsorbent, and those fed the diets with nano-clay adsorbent had better FCR than grower turkeys fed the diets with molecular clay adsorbent (P<0.001). The highest mortality was observed in starter and grower turkeys fed the diet with no adsorbent and contaminated with 110ppb aflatoxin (adsorbent×aflatoxin, P=0.002). As aflatoxin increased in starter and grower turkeys fed the diets with no adsorbent, white blood cell (WBC) and lymphocyte counts increased and packed cell volume (PCV) decreased, whereas aflatoxin had no noticeable effect on those response criteria in turkeys fed the diets with molecular clay and nano-clay adsorbent (adsorbent×aflatoxin, P<0.05). Starter turkeys fed the diets with adsorbents had a greater Hb and monocyte concentration (P<0.001), whereas grower turkeys fed the diets with adsorbents had less heterophil and eosinophil counts (P<0.043) than those fed the diets with no adsorbent. In conclusion, supplementation of aflatoxin-contaminated diets with clay adsorbents seemed to improve weight gain and reduce mortality, and reduce adverse effects of aflatoxin on PCV and Hb in turkeys. Grower turkeys fed the diet supplemented with nano-clay adsorbent had better growth performance than those fed the diet supplemented with molecular clay adsorbent.


      PubDate: 2015-07-19T01:59:43Z
       
  • Impact of fermentation and addition of non-starch polysaccharide-degrading
           enzymes on microbial population and on digestibility of dried distillers
           grains with solubles in pigs
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): G.V. Jakobsen, B.B. Jensen, K.E. Bach Knudsen, N. Canibe
      Fluctuating prices on feedstock has led to a growing interest in alternative feed ingredients. Co-products from the biofuel industry are hence interesting to include in pig feeds, primarily due to the high protein content. Low nutritional value due to a high content of dietary fibre, however, limits the use of these ingredients. The current study aimed to increase the digestibility of dried distillers grains with solubles (DDGS), based on 80% wheat and 20% barley, by fermentation and enzyme addition. Four experimental diets were prepared based on 60% DDGS (fermented or not, without or with the addition of carbohydrases) and 40% of a basal diet composed mainly of maize starch: (1) a nonfermented liquid feed treatment (n-FLF); (2) a fermented liquid feed treatment (FLF); (3) the FLF supplemented with a mixture of xylanase and β-glucanase (XylGlu); and (4) the FLF supplemented with a mixture of cellulase and xylanase (CelXyl). Microbial population during fermentation of the treatments was determined and apparent ileal and total tract digestibility were measured on eight barrows surgically fitted with a simple T-shaped cannula at the distal ileum and fed the four treatments according to a double-Latin square design. Microbial activity of the three fermented DDGS treatments was relatively low with lactic acid bacteria counts between 8.8 and 8.9logcfu/g and lactic acid concentrations between 60.2 and 70.5mmol/kg. The addition of CelXyl to DDGS resulted in a significant decrease in the amount of non-starch polysaccharides (NSP) compared to the fermented DDGS (from 341.8g/kg DM to 312.9g/kg DM, P<0.001). Furthermore, addition of CelXyl to DDGS showed a reduction in the level of putrescine (46.5mg/kg DM in the DDGS versus 3.7mg/kg DM in the DDGS added CelXyl). Fermenting DDGS prior to feeding led to significantly increased apparent ileal digestibility (AID) of NSP (P=0.02), and apparent total tract digestibility (ATTD) of DM (P=0.01), CP (P=0.003), and P (P=0.04), along with tendency to increased ATTD of NSP (P=0.1). Addition of XylGlu and CelXyl resulted in further increases of both AID and ATTD of NSP compared to n-FLF (P≤0.03); with the greatest effect on the CelXyl treatment. In conclusion, the digestibility of DDGS in pigs was increased by fermentation. Addition of carbohydrases during fermentation can be a way of further increasing the NSP digestibility of DDGS.


      PubDate: 2015-07-19T01:59:43Z
       
  • Effect of dietary supplementation of butyric acid glycerides on
           performance, immunological responses, ileal microflora, and nutrient
           digestibility in laying hens fed different basal diets
    • Abstract: Publication date: August 2015
      Source:Livestock Science, Volume 178
      Author(s): R. Jahanian, M. Golshadi
      A total of 150 laying hens (55-wk-old) were used to investigate the effect of different levels of butyric acid glycerides (BAG) on performance, egg quality, ileal microbial populations, and nutrient digestibility in hens fed different basal diets. Dietary treatments consisted of 2 different basal diets (corn- or wheat-based diets) and 3 supplemental BAG levels (0, 2.5, and 5.0g/kg) in a 2×3 factorial arrangement with 5 replicate cages and 5 hens per cage. The study lasted for 77d, including 7d for adaptation and 70d as the main experimental period. In addition to performance variables, antibody responses to different antigens were assessed after the inoculation. Furthermore, ileal digesta was collected from 3 euthanized hens per replicate at the end of the study to determine microbial count and ileal nutrient digestibility. Results showed that dietary BAG supplementation (2.5 and 5.0g/kg) increased egg production and egg mass, but it had more impact in hens fed wheat-based diets (basal diet×BAG, P<0.05). Dietary supplementation of BAG increased both egg production and egg mass, but those response criteria were greater with 5.0g/kg compared with 2.5g/kg. The heavier egg weights were observed for the hens fed corn-based diets (P=0.001), however, feed intake was not influenced by dietary treatments. Supplemental BAG (2.5 and 5.0g/kg) improved feed conversion ratio and it was lower in hens fed 5.0g/kg than those fed 2.5g/kg of BAG, especially in those hens fed the wheat-based diets (basal diet×BAG, P=0.022). Yolk color index was greater (P<0.001) in eggs produced by hens fed on corn-based diets. In contrast to Newcastle antibody titer, dietary inclusion of BAG (2.5 and 5.0g/kg) increased (P=0.011) antibody response against sheep red blood cell during primary response. Serum concentrations of triglycerides and cholesterol were lower (P<0.01) in hens fed wheat-based diets, and they increased (P<0.01) as supplemental BAG level was increased. Total bacterial count and Escherichia coli (E. coli) population were greater (P<0.05) when hens were fed wheat-based diets, and dietary BAG supplementation (2.5 and 5.0g/kg) reduced (P<0.05) total bacteria and ileal E. coli enumerations. Supplemental BAG (2.5 and 5.0g/kg) increased digestibility coefficients of ether extract (P=0.009) and also total ash, even though there was the interaction on total ash (P=0.045). The present findings indicate that BAG supplementation of diets could increase production performance of laying hens, probably because of the decreased intestinal E. coli count, and this effect was more obvious in wheat-based diets.


      PubDate: 2015-07-19T01:59:43Z
       
  • Milk yield, feed efficiency and metabolic profiles in Jersey and Holstein
           cows assigned to different fat supplementation strategies
    • Abstract: Publication date: Available online 2 July 2015
      Source:Livestock Science
      Author(s): L. Alstrup , M.O. Nielsen , P. Lund , J. Sehested , M.K. Larsen , M.R. Weisbjerg
      The study aimed to analyze the combined effect of lactation stage and fat supplementation. Either protected or unprotected fat was fed to dairy cows to quantify effects on dry matter intake (DMI), mammary nutrient uptake, energy corrected milk (ECM) yield, milk composition, and energy, N and feed efficiency. Additionally, we studied the effect of adding Hydroxy-methionine-analog-isobutyrate (HMBi) to the ration supplemented with protected fat. A total of 107 Holstein cows and 54 Jersey cows were assigned to one of four different mixed dietary treatments: Control (CON), control supplemented with whole cracked rapeseed (WCR), control supplemented with rumen protected vegetable fat (Lipmix 40/60, Lipitec, NLM Vantinge Aps, Ringe, Denmark) (RPF), and RPF supplemented with HMBi (MetaSmart, Adisseo, France) (RPFA). Rations contained 2.63, 5.63, 5.55, and 5.59% crude fat on dry matter (DM) basis and 1.77, 4.29, 4.59, and 4.63% FA of DM for CON, WCR, RPF and RPFA, respectively. All cows were offered the same concentrate in the automatic milking system in addition to the mixed rations. After calving, cows were fed CON until they had gained 11kg (Jersey) or 15kg (Holstein) body weight, compared to their lowest recorded weight after calving. Subsequently, the cows were randomly assigned to one of the four treatments until the end of lactation. There was no effect of feeding strategy on DM intake during week 9 to 40 of lactation. Fat supplemented rations (WCR; RPF) increased yield of milk, ECM and lactose, but decreased milk protein and urea concentrations compared to CON. No effects of HMBi on milk yield and composition were detected. Lactation persistency was improved for all fat supplemented treatments for multiparous cows, particularly with WCR. Fat supplemented rations decreased energy efficiency in Jersey cows but increased energy efficiency in Holstein cows. Because fat supplementation reduced dietary protein concentration and increased milk production, protein intake was lower and N efficiency was higher on WCR and RPF than on CON. Metabolite concentrations in jugular vein blood plasma and concentration differences between jugular and milk veins, which reflect nutrient uptake by the mammary gland, were not affected by the ration fed, breed, or time from calving until ration change. In conclusion, fat supplementation during weeks 9-40 of lactation increased ECM yield and N efficiency irrespective of source of fat, whereas additional supplementation of HMBi showed no effect. The effect of fat persisted throughout lactation.


      PubDate: 2015-07-05T17:46:41Z
       
  • Crude glycerin changes ruminal parameters, in vitro greenhouse gas
           profile, and bacterial fractions of beef cattle
    • Abstract: Publication date: Available online 26 June 2015
      Source:Livestock Science
      Author(s): E.H.C.B. van Cleef , M.T.C. Almeida , H.L. Perez , F.O.S. van Cleef , D.A.V. Silva , J.M.B. Ezequiel
      As the biodiesel industry produces a large surplus of crude glycerin, this by-product is increasingly being considered as an attractive source of energy to replace corn in livestock diets. The objective of this study was to evaluate how the inclusion of up to 30% crude glycerin in Nellore cattle diets affects ruminal parameters such as pH, ammonia, and volatile fatty acids as well as greenhouse gas production, and concentration of the protozoal and bacterial fractions. Five ruminally cannulated Nellore steers were randomly assigned in a 5 × 5 Latin square design and fed diets containing 30% corn silage and 70% concentrate composed of sunflower meal, corn grain, soybean hulls, minerals, and 0, 7.5, 15, 22.5, or 30% crude glycerin (860g glycerol/kg). After 14 d of adaptation, animals were submitted to rumen content sampling for 7 d. With the supplementation of glycerin in the diets, total VFA and acetate concentrations decreased (linear, P= 0.03, P< 0.0001, respectively), and propionate concentrations increased (linear, P= 0.007; quadratic, P= 0.008), leading to an acetate to propionate ratio decrease (linear, P< 0.0001). The rumen ammonia was not affected while pH was quadratically affected and was lesser for glycerin treatments (quadratic, P= 0.04). Methane production was reduced (linear, P< 0.0001) when glycerin was added, as well as the CO2 (linear, P< 0.0001; quadratic, P= 0.0001; cubic, P< 0.0001). The concentration of liquid phase microorganisms was not affected, while the concentration of particle-associated bacteria fraction was decreased by the addition of crude glycerin in the diets. The inclusion of up to 30% of crude glycerin in diets for beef cattle decreased ruminal concentration of total VFA and acetate, increased propionate, reduced concentration of particle-associated bacteria, and decreased production of methane.


      PubDate: 2015-06-27T13:07:03Z
       
  • High pasture allowance does not improve animal performance in Supplemented
           dairy cows grazing alfalfa during autumn-winter
    • Abstract: Publication date: Available online 24 June 2015
      Source:Livestock Science
      Author(s): J.L. Danelon , M. Gaggiotti , R. Gallino , R.A. Palladino
      The aim of this study was to assess the effect of three alfalfa pasture herbage allowances on milk yield and composition during autumn-winter grazing season on early autumn calving dairy cows. Eighteen multiparous Holstein dairy cows were assigned to one of three treatments in a 3 × 3 Latin square design: low herbage allowance (14kgDM/cow; LHA), medium herbage allowance (27kgDM/cow; MHA) and high herbage allowance (41kgDM/cow; HHA). Dry matter disappearance was lower at LHA although remained similar between MHA and HHA (P<0.05). However, as herbage allowance (HA) increased, lower grazing efficiencies (as the proportion of material removed) were registered (P<0.05). Total dry matter intake (DMI; kg/d) was also lowest for LHA and similar between the other two treatments (P<0.05). Milk yield, 4%FCM, milk fat (g/kg) and casein (g/kg) tended to increase from LHA to HHA (P<0.10). Cows at LHA tended to loss weight whilst cows at MHA and HHA had a tendency to increase BW according the season progressed (P<0.10). In summary, managing cows at HHA will allow cows to a slightly increase in individual milk production and BW gain but in detriment of herbage utilization and potentially, milk production per hectare.


      PubDate: 2015-06-25T13:02:53Z
       
  • Genetic parameters and predictions for direct and maternal growth traits
           in a multibreed Angus-Brahman cattle population using genomic-polygenic
           and polygenic models
    • Abstract: Publication date: Available online 24 June 2015
      Source:Livestock Science
      Author(s): M.A. Elzo , M.G. Thomas , D.D. Johnson , C.A. Martinez , G.C. Lamb , D.O. Rae , J.G. Wasdin , J.D. Driver
      The objectives of this research were to compare variance components, genetic parameters, and EBV rankings for birth weight (BW) direct and maternal, weaning weight (WW) direct and maternal, and postweaning gain from 205 d to 365d (PWG) direct using three genomic-polygenic and one polygenic model representing four plausible beef cattle genetic evaluation scenarios for growth traits under subtropical conditions in the US southern region. In addition, EBV trends as percentage Brahman increased from 0% to 100% were evaluated for each trait and model. The dataset included 5,264 animals from a multibreed Angus-Brahman population born from 1987 to 2013. Genomic-polygenic models 1 (GP1; pedigree relationships for all animals; genomic relationships for genotyped animals), 2 (GP2; pedigree relationships for non-genotyped animals; genomic relationships for genotyped animals), and 3 (GP3; no pedigree relationships; genomic relationships for genotyped animals) used actual and imputed genotypes from 46,768 SNP markers. Variance components and genetic parameters were estimated using REML procedures. Variance component and genetic parameter estimates from GP1 were the most similar to those from the polygenic model, followed by those from GP2, and the least similar (especially for maternal traits) were those from GP3. Similarly, the highest rank correlations were those between animal EBV from the polygenic model and GP1, followed by those between animal EBV from GP1 and GP2 and between the polygenic model and GP2. Model GP3 performed poorly for maternal traits due to ignoring calf-dam relationships. These results indicated that the polygenic model and genomic-polygenic model 1 should be preferred. However, high genotyping costs still make the polygenic model preferable for commercial beef cattle operations. Brahman animals tended to have higher EBV for BW direct and WW direct, and lower EBV for PWG direct, BW maternal, and WW maternal. However, low regression coefficients for EBV on Brahman fraction ensured that high, medium, and low EBV animals from all breed compositions existed in this multibreed population.


      PubDate: 2015-06-25T13:02:53Z
       
 
 
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