Dataset of seminal plasma proteome of Nellore bulls with high and low percentage of abnormalities sperm.

OBJECTIVES: Bovine seminal plasma proteins perform several functions related to sperm function. Changes in the expression pattern or abundance of seminal proteins are related to changes in the fertilizing capacity of bulls. Considering the role of seminal plasma proteins in sperm function and animal reproduction, we investigated changes in the protein abundance profile in response to sperm morphological changes using a proteomic approach. DATADESCRIPTION: In our present investigation, we employed liquid chromatography coupled with mass spectrometry to elucidate the proteomic composition of seminal plasma obtained from Nellore bulls exhibiting varying percentages of sperm abnormalities. Following semen collection, seminal plasma was promptly isolated from sperm, and proteins were subsequently precipitated, enzymatically digested using porcine trypsin, and subjected to analysis utilizing the Acquity nano UHPLC System in conjunction with a mass spectrometer. This dataset encompasses a total of 297 proteins, marking the inaugural instance in which a comparative profile of seminal plasma proteins in young Nellore bulls, categorized by their sperm abnormality percentages, has been delineated using LC-MS/MS. The comprehensive nature of this dataset contributes pivotal proteomic insights, representing a noteworthy advancement in our understanding of the reproductive biology of the Nellore breed.

Uterine tone influences fertility of Merino ewes following laparoscopic artificial insemination.

Artificial insemination (AI) plays a critical role in facilitating rapid genetic and production gains within the sheep industry. However, variable rates of AI success remain a concern for the industry and a barrier to adoption. Furthermore, the degree to which female factors influence the success of intrauterine laparoscopic AI rather than natural mating remains unknown. As such, this study investigates the effect of several factors collected during the time of AI, on the success of intrauterine laparoscopic AI. Data was generously donated by artificial breeding companies and stud breeders during routine commercial AI operations. AI data was collected over 3 breeding seasons during commercial AI programs (N = 24 programs) using Merino ewes (N = 24,700). Sire ID (N = 253), time of AI following progesterone removal (approx. 43-59 h post removal), uterine tone and intra-abdominal fat (both scored 1-5) as well as age of the ewe were all recorded at the time of AI. Transcutaneous ultrasound subsequently determined pregnancy rate approximately 55 days post-AI. A multivariate regression analysis was performed and revealed pregnancy success to increase when semen was inseminated into a ewe with a uterine tone score of 4 or 5 (P < 0.001). The remaining factors fell short of significance within the multivariate model. An interclass coefficient variation matrix was also used to determine the proportion of variation contributed to AI success by random factors allocated in the model; site, sire, AI date and breeding season (45.99 %, 29.94 %, 15.15 % and 8.92 %, respectively). These results highlight the influence of uterine tone on ewe fertility following laparoscopic AI, but also that program location and the sire used can further modify this influence on pregnancy rate. These factors must now be considered in combination with semen factors per individual sire used during AI to ascertain the contribution of several factors to the success of laparoscopic AI in Australia.

Genomics and Dairy Bull Fertility.

Current evidence suggests that dairy bull fertility is influenced by genetic factors, and hence, it could be managed and improved by genetic means. There are major mutations that explain about 4% to 8% of the observed differences in conception rate between bulls segregating in most dairy breeds. Research has shown that genomic prediction of bull fertility is possible, and this could be used to make accurate genome-guided selection decisions, such as early culling of predicted subfertile bull calves. Inbreeding negatively influences bull fertility, and the increase in homozygosity seems an important risk factor for dairy bull subfertility.

Impact of Sire on Embryo Development and Pregnancy.

The use of in vitro embryo production (IVP) has increased globally, particularly in the United States. Although maternal factors influencing embryo development have been extensively studied, the influence of the sire is not well understood. Sperm plays a crucial role in embryo development providing DNA, triggering oocyte maturation, and aiding in mitosis. Current sire fertility measurements do not consistently align with embryo production outcomes. Low-fertility sires may perform well in IVP systems but produce fewer pregnancies. Testing sires in vitro could identify characteristics affecting embryo development and pregnancy loss risk in IVP and embryo transfer programs.

Impact of the Sire on Pregnancy Loss.

For over a century, scientists have attempted to develop techniques to accurately predict the fertility potential of a male's semen sample. In most livestock species, the sire is responsible for multiple pregnancies per year and up to hundreds of thousands of pregnancies if used for artificial insemination. Use of subfertile or infertile sires can have devastating impacts in regard to the reproductive efficiency of a cow herd. Despite the rapid expansion of fertility studies through advancements in molecular, genomic, and computer techniques, our understanding of male fertility is still far from complete. This article will provide an overview of the impact of the sire in pregnancy loss.

Genomic background of biotypes related to growth, carcass and meat quality traits in Duroc pigs based on principal component analysis.

As the swine industry continues to explore pork quality traits alongside growth, feed efficiency and carcass leanness traits, it becomes imperative to understand their underlying genetic relationships. Due to this increase in the number of desirable traits, animal breeders must also consider methods to efficiently perform direct genetic changes for each trait and evaluate alternative selection indexes with different sets of phenotypic measurements. Principal component analysis (PCA) and genome-wide association studies (GWAS) can be combined to understand the genetic architecture and biological mechanisms by defining biological types (biotypes) that relate these valuable traits. Therefore, the main objectives of this study were to: (1) estimate genomic-based genetic parameters; (2) define animal biotypes utilizing PCA; and (3) utilize GWAS to link the biotypes to candidate genes and quantitative trait loci (QTL). The phenotypic dataset included 2583 phenotypic records from female Duroc pigs from a terminal sire line. The pedigree file contained 193,764 animals and the genotype file included 21,309 animals with 35,651 single nucleotide polymorphisms (SNPs). Eight principal components (PCs), accounting for a total of 99.7% of the population variation, were defined for three growth, eight conventional carcass, 10 pork quality and 18 novel carcass traits. The eight biotypes defined from the PCs were found to be related to growth rate, maturity, meat quality and body structure, which were then related to candidate genes. Of the 175 candidate genes found, six of them [LDHA (SSC1), PIK3C3 (SSC6), PRKAG3 (SSC15), VRTN (SSC7), DLST (SSC7) and PAPPA (SSC1)] related to four PCs were found to be associated with previously defined QTL, linking the biotypes with biological processes involved with muscle growth, fat deposition, glycogen levels and skeletal development. Further functional analyses helped to make connections between biotypes, relating them through common KEGG pathways and gene ontology (GO) terms. These findings contribute to a better understanding of the genetic relationships between growth, carcass and meat quality traits in Duroc pigs, enabling breeders to better understand the biological mechanisms underlying the phenotypic expression of these traits.

Intra-specific correlations between ejaculate traits and competitive fertilization success: a meta-analysis across species and fertilization modes.

Understanding of how selection can act on traits that improve competitiveness and subsequent paternity has advanced, including the idea that internal and external fertilization presents different environments that may select differentially on ejaculate traits. However, no studies have quantitatively synthesized the intra-specific relationships between these traits and paternity. Therefore, we conducted a meta-analysis across 52 papers to determine which ejaculate traits positively correlate with paternity share and how these correlations vary with fertilization mode. Overall, most ejaculate traits were positively associated with paternity, with the notable exception of sperm length. Sub-analyses on sperm number, sperm length, and sperm velocity revealed no statistical differences between fertilization modes in the relationship between traits and paternity when all effect sizes across species were combined. However, in a sub-analysis on fish species only, we found evidence that sperm velocity may be more important in external fertilizers. We also observed differences in the importance of phylogenetic relatedness and some species-specific differences. Our results suggest that while most ejaculate traits should be under positive directional selection in both internal and external fertilizers, sperm length may be subject to more nuanced selection pressures. Overall, we highlight important patterns of intra-specific relationships between ejaculate traits and competitive fertilization success.

The association between calf birth weight and the postcalving performance of its dairy dam in the absence of dystocia.

The objective of the study was to quantify the association between the birth weight of a calf and the subsequent performance of its dairy dam in the absence of any recorded calving assistance. A total of 11,592 lactation records from 4,549 spring-calving dairy cows were used. The association between a series of quantitative cow performance metrics (dependent variable) and calf birth weight (independent variable) was determined using linear mixed models; logistic regression was used where the dependent variable was binary. Nuisance factors in the models were calf sex, heterosis coefficient of both the cow and calf, dry period length immediately before the birth of the calf, cow age at calving relative to the median cow age per parity, breed proportion of the cow, cow live weight between 100 and 200 d of lactation relative to the mean cow weight per parity, and contemporary group. Calf birth weight was included in the model as either a continuous or a categorical variable. Primiparous and multiparous cows were analyzed separately. Mean (SD) calf birth weight was 36.2 (6.8) kg. In primiparous cows, calf birth weight was associated with milk yield in the first 60 d of lactation, calving to first service interval, calving body weight (BW), and both nadir BW and body condition score (BCS). In multiparous cows, calf birth weight was associated with total milk, fat, and protein yield in the first 60 and 305 d of lactation, peak milk yield, total milk solids, both calving and nadir BW, and BCS loss from calving to nadir. Relative to primiparous cows that gave birth to calves weighing 34 to 37 kg (i.e., population mean), their contemporaries who gave birth to calves that weighed 15 to 29 kg produced 9.82 kg more milk in the first 60 d of lactation, had a 2-d shorter interval to first service, and were 8.08 kg and 5.51 kg lighter at calving and nadir BW, respectively; the former was also 0.05 units lower in BCS (5-point scale, 1 = emaciated and 5 = obese) at nadir. Relative to multiparous cows that gave birth to calves that were 34 to 37 kg birth weight, multiparous cows that gave birth to calves that were 15 to 29 kg yielded 59.63 kg, 2.44 kg, and 1.76 kg less milk, fat, and protein, respectively, in the first 60 d of lactation; produced 17.69 kg less milk solids throughout the 305-d lactation; and were also 10.49 kg lighter at nadir and lost 0.01 units more BCS to nadir. In a separate series of analyses, sire breed was added to the model as a fixed effect with and without calf birth weight. When calf birth weight was not adjusted for, 60-d milk yield for multiparous cows who gave birth to calves sired by a traditional beef breed (i.e., Angus, Hereford) produced 59.63 kg more milk than multiparous cows who gave birth to calves sired by a Holstein-Friesian. Hence, calf birth weight is associated with some subsequent dam performance measures; however, where associations do exist, the effect is biologically small.

Effects of Metabolites, Sex, Sire, and Muscle Type on Chilled Lamb Meat Colour.

Meat is an important source of high-value protein providing sustainable nutrition for human health. The discolouration of meat results in significant waste, which threatens the sustainability of meat production in terms of availability, affordability, and utilisation. Advancing the knowledge of factors and underlying mechanisms for meat discolouration supports the sustainability transformation of meat production practices. Previous studies found that colour stability may be associated with signature changes in certain metabolites, including NADH, glutamate, methionine, and testosterone. This study aimed to confirm the effect of these metabolites and sex, sire, and muscle type on lamb meat colour. NADH and glutamate improved colour stability as evidenced by the increased metmyoglobin reductase activity, while methionine and testosterone had detrimental effects. Overall, lamb meat was discoloured with retail display for up to 10 days at 4 °C. The semitendinosus muscle had higher L*, b*, and hue angle and lower a* (p < 0.05) than other muscles, especially in ewes. Lamb meat from rams had a higher L* and hue angle and lower a* than the ewes (p < 0.05), especially in the colour-labile group, suggesting an interaction between sex and sire. The outcomes of this study will help make the production of meat more sustainable by assisting the meat industry in improving the selection of animals for meat production and processing practices to reduce meat waste due to discolouration.

The development of new biomarkers of spermatozoa quality in cattle.

There is a current need for new biomarkers of spermatozoa quality, that consistently and correctly identify spermatozoa that will successfully contribute to subsequent embryo development. This could improve the standardization of semen analysis, decrease early embryo mortality, and use these biomarkers as a selection tool before servicing females. This study utilized imaging techniques to identify potential biomarkers of sperm quality, using sires previously classified as high (n = 4) or low (n = 4) performing at producing blastocysts in vitro. Spermatozoa were assessed before and following a gradient purification protocol, to understand how populations of cells are impacted by such protocols and may differ between in vivo and in vitro use. Pre-gradient samples from low-performing sires had an increased incidence of DNA damage, although post-gradient samples from high-performing sires were found to have an increased incidence of DNA damage. When evaluating morphology via fluorescent microscopy, the most prevalent defects in pre-gradient samples from high-performing sires were tail defects, which are successfully removed during purification processing. The most prevalent defects in pre-gradient samples from low-performing sires were aggresome defects located in the head, which would be brought into an oocyte upon fertilization and may impair embryo development. Image-based flow cytometry (IBFC) was employed to quantify defect prevalence to evaluate a greater sample size decreasing the variability that exists in manual assessments. Using IBFC, aggresome defects were again identified in the heads of spermatozoa from low-performing sires. Post-gradient samples from low-performing sires had a significantly greater (p < 0.05) incidence of aggresome defects than post-gradient samples from high-performing sires. Additionally, IBFC was used to evaluate spermatozoa viability following gradient purification. Distinct populations of sperm cells were identified. High-performing sires had more spermatozoa in the population deemed most viable than low-performing sires. This study demonstrated that spermatozoa defects vary in populations before and following gradient purification, indicating that it may be beneficial to separately evaluate semen for in vivo and in vitro use. Furthermore, a prevalent defect in low-performing sires that could explain a discrepancy between successful fertilization and embryo development was identified. Therefore, elucidating a malfunction regulated by sire, that could potentially affect early embryo development.

Paternal effects on fetal programming.

Paternal programming is the concept that the environmental signals from the sire's experiences leading up to mating can alter semen and ultimately affect the phenotype of resulting offspring. Potential mechanisms carrying the paternal effects to offspring can be associated with epigenetic signatures (DNA methylation, histone modification and non-coding RNAs), oxidative stress, cytokines, and the seminal microbiome. Several opportunities exist for sperm/semen to be influenced during development; these opportunities are within the testicle, the epididymis, or accessory sex glands. Epigenetic signatures of sperm can be impacted during the pre-natal and pre-pubertal periods, during sexual maturity and with advancing sire age. Sperm are susceptible to alterations as dictated by their developmental stage at the time of the perturbation, and sperm and seminal plasma likely have both dependent and independent effects on offspring. Research using rodent models has revealed that many factors including over/under nutrition, dietary fat, protein, and ingredient composition (e.g., macro- or micronutrients), stress, exercise, and exposure to drugs, alcohol, and endocrine disruptors all elicit paternal programming responses that are evident in offspring phenotype. Research using livestock species has also revealed that sire age, fertility level, plane of nutrition, and heat stress can induce alterations in the epigenetic, oxidative stress, cytokine, and microbiome profiles of sperm and/or seminal plasma. In addition, recent findings in pigs, sheep, and cattle have indicated programming effects in blastocysts post-fertilization with some continuing into post-natal life of the offspring. Our research group is focused on understanding the effects of common management scenarios of plane of nutrition and growth rates in bulls and rams on mechanisms resulting in paternal programming and subsequent offspring outcomes. Understanding the implication of paternal programming is imperative as short-term feeding and management decisions have the potential to impact productivity and profitability of our herds for generations to come.

Identification of runs of homozygosity associated with male fertility in Italian Brown Swiss cattle.

Intensive selection for improved productivity has been accompanied by an increase in inbreeding rates and a reduction in genetic diversity. The increase in inbreeding tends to impact performance, especially fitness-related traits such as male fertility. Inbreeding can be monitored using runs of homozygosity (ROH), defined as contiguous lengths of homozygous genotypes observed in an individual's chromosome. The goal of this study was to evaluate the presence of ROH in Italian Brown Swiss cattle and assess its association with bull fertility. First, we evaluated the association between ROH and male fertility using 1,102 Italian Brown Swiss bulls with sire conception rate records and 572 K SNPs spanning the entire genome. Second, we split the entire population into 100 high-fertility and 100 low-fertility bulls to investigate the potential enrichment of ROH segments in the low-fertility group. Finally, we mapped the significant ROH regions to the bovine genome to identify candidate genes associated with sperm biology and male fertility. Notably, there was a negative association between bull fertility and the amount of homozygosity. Four different ROH regions located in chromosomes 6, 10, 11, and 24 were significantly overrepresented in low-fertility bulls (Fisher's exact test, p-value <0.01). Remarkably, these four genomic regions harbor many genes such as WDR19, RPL9, LIAS, UBE2K, DPF3, 5S-rRNA, 7SK, U6, and WDR7 that are related to sperm biology and male fertility. Overall, our findings suggest that inbreeding and increased homozygosity have a negative impact on male fertility in Italian Brown Swiss cattle. The quantification of ROH can contribute to minimizing the inbreeding rate and avoid its negative effect on fitness-related traits, such as male fertility.

Survey of the use of beef semen in dairy herds in Pennsylvania and nearby states.

Because dairies across the United States have rapidly adopted breeding to beef breed sires, the use of beef semen has increased dramatically in recent years. The objective of this survey was to gather information about the use of beef semen by dairy producers in the Northeast United States to generate beef × dairy cattle for beef markets. The survey was conducted using the services of the Center for Survey Research at the Pennsylvania State University-Harrisburg campus. Respondents had two options for returning their responses: 1) mail the paper survey to CSR in the postage-paid business-reply envelope included in the mailing, or 2) complete the survey online via an open-access web survey link. A total of 669 surveys were received and a final number of 617 surveys were included in the responses based on completeness and validity of the responses. Because of the broad electronic distribution, a true response rate cannot be calculated. Of these, 463 (75.0%) were completed via returned paper survey, and 154 (25.0%) were completed via web, between November 9, 2021 and February 16, 2022. Of the 617 respondents, 539 were from Pennsylvania. Due to the large variations in returned survey copies by state, results are reported without state separation. Across all respondents, 69.7% reported milking 100 or fewer cows and over 90% of collected responses reported Holsteins as the predominant dairy breed in the Northeast. Only 18.8% of the respondents did not currently, nor plan to, breed with beef semen. Deciding which beef bulls to use on Northeast dairy farms was primarily based on the recommendation of the semen sales representative (54.5%) and the price of the semen purchased (42.3%). In addition, 89.7% of respondents cited using Angus genetics in their beef bull selections. However, there was no difference in reported profitability of crossbreeding between respondents who indicated using other beef breeds vs. those who indicated just using Angus (P ≥ 0.19). In conclusion, using beef sires on dairy females, regardless of the breed of beef sire, adds value to the resulting progeny from dairy farms in the Northeast.

Live and carcass production traits for progeny of purebred sires in comparison with the clone of a USDA prime yield grade one carcass.

Cloning is a technology by which an animal's tissue can be salvaged and replicated. Carcasses that grade USDA prime-yield grade 1 (P1) represent a rare and antagonistic outcome and are a goal for terminal sire selection in the United States. A terminal sire progeny test generated offspring for a crossbred bull (14% Zebu, 86% Angus; ALPHA), born in 2012 via somatic cell nuclear transfer (SCNT) from a carcass that graded P1. ALPHA progeny (steers and heifers) were compared against progeny of three purebred (Angus; Charolais; Simmental) reference sires. Live production traits included weaning weight, morbidity, mortality, and days on feed; carcass traits included abscessed liver frequency and lung lesion frequency, individual quality and yield grade (YG) parameters, and carcass value. Observed carcass traits for progeny from the Angus, Charolais, and Simmental sires were reflective of the carcass outcomes expected for each sire's respective breed. Calves sired by the Angus were the earliest maturing indicated by the youngest chronological age at harvest (P ≤ 0.02) concomitant with the most backfat (P < 0.01), and the greatest marbling scores (P < 0.01). Calves sired by the Charolais had the heaviest carcass weight (P = 0.04), greatest cutability as assessed by USDA calculated YG (P < 0.01) and were the heaviest muscled based on "longissimus" muscle area (P < 0.01). ALPHA-sired calves were the most similar in carcass outcomes to calves sired by the Simmental, combining advantageous quality and yield parameters to produce an intermediate for carcass quality and yield. The economic value of moderate carcass outcomes is reflected in the carcass value per century weight, in which ALPHA-sired steers tended (P = 0.07) to be of the greatest value compared to other sire groups. ALPHA progeny performed comparably to high-performing reference sires for terminal sire production traits and the P1 genetics in which ALPHA was cloned have economical and biological value in modern U.S. beef production.

Effect of early vs. late maturing sire lines and creep feeding on the cortisol response, intestinal permeability, and growth performance of nursery and finishing pigs.

A total of 21 litters (11 early and 10 late maturing Duroc × DNA 241) resulting in 241 pigs were used in 170 d trial to determine the effect of sire lines selected for either early or late maturing growth rates and creep feeding on the cortisol concentration, intestinal permeability, and growth performance of nursery and finishing pigs. Treatments were arranged in a 2 × 2 factorial with main effect of Duroc sire line (early or late maturing) and creep feeding (with or without). Creep feed was provided for 14 d prior to weaning. After weaning (approximately 21 d of age; initially 6.4 kg), no interactions were observed for blood cortisol. However, blood cortisol levels were increased (P = 0.011) in late maturing pigs compared to early maturing pigs. A lower percentage (P < 0.001) of early maturing pigs lost weight 3 d post-weaning compared to late maturing pigs. Likewise, early maturing pigs had improved (P < 0.001) average daily gain (ADG) and average daily feed intake (ADFI) during the first 3 d in the nursery and also had increased ADFI (P < 0.001) from days 2 to 14 in the nursery. Creep feeding had no effect on initial nursery performance. On day 7, after a 2-h fast, a subsample of pigs was administered an oral gavage of lactulose and mannitol dissolved in distilled water. No differences by sire line, creep feeding, or their interactions were observed in lactulose:mannitol ratio. For overall nursery growth performance, an interaction was observed for ADG (P = 0.007) and ADFI (P < 0.001), with creep feed providing a benefit in late maturing pigs, but not in early maturing pigs. Early maturing pigs had poorer gain-to-feed ratio (G:F) (P < 0.001) than late maturing pigs. For overall finishing performance, an interaction was observed for ADG (P = 0.037) and ADFI (P = 0.007), with creep feed providing a benefit in late maturing pigs, but not in early maturing pigs. This resulted in an interaction for final body weight (P = 0.005), with late maturing pigs that did not receive creep feed having decreased market weights (P ≤ 0.003) compared to the other treatments. In summary, early maturing pigs had decreased cortisol concentration at weaning and improved ADG and ADFI until approximately 100 kg, at which point late maturing pigs began to exhibit greater ADG. Late maturing pigs had improved G:F from 46 d of age until market. Interestingly, creep feeding late maturing pigs resulted in increased day 170 weight compared with providing no creep feed, whereas creep feed did not impact early maturing pigs (sire line × creep feed interaction, P < 0.005).

Finishing pig growth potential varies across different genotypes; however, limited research is available on performance of nursery pigs sired from boars selected for different finishing growth patterns. With selection of terminal sires focused on improved lean gain in late finishing, anecdotal or field observations suggest that starting weanling pigs on feed has become more challenging. Hence, our hypothesis that improving post-weaning feed intake by creep feeding may be of greater importance today than in the past due to sire line selection criteria. Therefore, our objective was to determine the possible interaction of Duroc sires selected for early vs. late maturing growth rates and creep feeding on the growth performance of pigs from birth to market. Early maturing pigs had increased feed intake from days 2 to 14 post-weaning compared to late maturing pigs. Likewise, a lower percentage of early maturing pigs lost weight from weaning to 3 d post-weaning. Early maturing pigs had improved average daily gain (ADG) and average daily feed intake until approximately 100 kg, at which point late maturing pigs began to exhibit greater ADG. Overall, offering creep feed to late maturing pigs resulted in improved growth performance compared to no creep feed, whereas creep feed did not impact early maturing pigs.

Phenotypic evaluation of pre-weaning growth traits of Akaushi- (Wagyu), Angus- and Brahman-sired calves in tropical conditions.

The objective was to assess the effect of sire breed on birth weight, average daily gain from birth to weaning, and actual weaning weight of calves. The calves were produced by AI using semen of five Akaushi (Wagyu), six Angus, and six Brahman bulls. Dams of calves were Beefmaster (n = 60) and Brown Swiss x Zebu (n = 21). The three sire breeds were used on both dam genetic types to produce the calves (45 males and 36 females). Each dam genetic type was raised in two ranches; therefore, all calves were born in four ranches, in the same calendar year. Average age at weaning weight m easurement was 186 days. The traits were analyzed with the MIXED procedure of SAS. The statistical model included the fixed effects of sire breed, dam genetic type, calf sex, ranch, and birth season within sire breed-ranch; sire within breed of sire was included as a random effect (except for weaning weight; P > 0.05). In addition, the model for weaning weight included calf age at weaning as a covariate. Birth weights and average daily gains of Akaushi-, Angus- and Brahman-sired calves were similar (P > 0.05). In contrast, Angus-sired calves were heavier (P < 0.05) at weaning than Akaushi- and Brahman-sired calves. Calves out of Brown Swiss x Zebu dams had higher (P < 0.05) pre-weaning average daily gains than calves out of Beefmaster dams. Angus-sired calves performed better at weaning.

Old breeds, new solutions? Effects of two different traditional sire breeds on skin lesions, tail lesions, tail losses, performance and behaviour of rearing pigs.

Some studies indicated a relationship between modern, fast-growing, lean-meat-producing hybrid pigs and the occurrence of tail-biting, one of the major issues of conventional pig husbandry. Therefore, this study investigated the effects of different local, traditional sire breeds on the behaviour and performance of rearing pigs. Between December 2019 and November 2020, a total of 1 561 piglets were weaned from hybrid sows (Bundes Hybrid Zucht Programm (BHZP) Landrace × BHZP Large White) that were paired with either Swabian-Hall (SH), Bentheim Black Pied (BB) or BHZP-Piétrain (Pi) boars. Tails of the piglets were left intact (43.5%) or docked (56.5%), and male piglets were castrated. Piglets were conventionally reared on fully slatted plastic flooring in mixed-sex groups. Starting one day after weaning, skin lesions were scored once per pig, and tail lesions and losses were scored weekly until the end of rearing. The average daily gain was documented for the suckling and rearing period. The activity behaviour of eight focal pens was analysed using video recordings. Differences between modern and traditional breeds were found in this study for so-called aggressive and non-aggressive biting pronounced by skin and tail lesions and tail losses. Significantly fewer BB pigs had severe skin lesions on the front body than SH or Pi pigs (P < 0.05). Additionally, piglets that were classified as light (<5.6 kg) at weaning showed skin lesion scores of 0 more often than piglets that were classified with a medium (≥5.6-≤8.3 kg) or heavy (>8.3 kg) weaning weight (P < 0.05). In the first half of the rearing period, significantly more BB pigs were assessed as having no tail lesions and tail losses than SH and Pi pigs (P < 0.01). However, these differences disappeared in the second half of rearing. Either docked or undocked Pi pigs had significantly higher average daily gains than SH and BB pigs (P < 0.05). The activity of the focal pens was not influenced by the sire breed or tail lesion class, which might be due to the limited sample size of eight pens. To conclude, the use of the traditional sire breed BB has the potential to reduce injurious behaviour in the offspring. However, adjustments to the housing and feeding should be taken to further reduce the incidence of tail lesions and losses and to enhance performance.

Genomic prediction of service sire effect on female reproductive performance in Holstein cattle: A comparison between different methods, validation population and marker densities.

Reproductive traits of dairy cattle are bound to the actual efficiency of farm operation, which therefore show great economic importance. Among them, some traits were deemed to be simultaneously affected by service sire and mating cow. Service sires are proved to play an important role in reproduction process of cows. However, limited study explored the genetic effect of service sire (GESS), let alone the genomic prediction of this effect. In the present study, 2244 genotyped bulls together with phenotypic records were used to predict the GESS on conception rate, 56-day non-return rate, calving ease, stillbirth and gestation length. The feasibilities of multi-step genomic best linear unbiased predictor (msGBLUP) and single-step genomic best linear unbiased predictor (ssGBLUP) were investigated under different scenarios, that is, different marker densities and validation population. The predictive accuracies and unbiasedness for GESS ranged from 0.159 to 0.647 and from 0.202 to 2.018, respectively, when validated on young bulls, while the accuracies and unbiasedness ranged from 0.409 to 0.802 and 0.333 to 1.146 when validated on random split data sets. It is feasible to predict GESS on reproductive traits by using a linear mixed model and genomic data, and high-density marker panel had limited contribution to the prediction. This research investigated the potential factors that influence the genomic prediction of GESS on reproductive traits and indicated the possibility of genomic selection on GESS, both in ideal and practical circumstances.

Risk factors for, and genetic association with, intestinal atresia in dairy calves.

Intestinal atresia is an under-diagnosed congenital defect in cattle. It results in complete occlusion of the intestinal lumen and, unless surgically corrected, results in death or euthanasia of the affected calf. There is limited information on the incidence of this condition or on risk factors, including predisposing alleles, associated with the defect. In this study, active surveillance of 39 dairy farms over 8 years identified 197 cases of intestinal atresia among 56 454 calves born, an incidence of 0.35%. The majority of cases (83%) had occlusion of the jejunum, although cases with blockage of the colon (14%) or anus (4%) were also identified. The defect was twice as common in male as in female calves (p < 0.0001), and was more common in progeny of older cows than in progeny of first or second lactation cows (p < 0.001). Year and farm of birth were also significantly associated with incidence (p < 0.05). The incidence of intestinal atresia was highest among the progeny of three related Jersey sires, suggesting that a gene for intestinal atresia was segregating within this family. Linkage analysis utilising 28 affected progeny of two half-sib putative carrier sires identified two putative quantitative trait loci associated with the defect, on chromosomes 14 and 26, although no clear candidate genes were identified. There was no evidence of a sire-effect among the progeny of Holstein-Friesian sires. However, a case-control genome-wide association study involving 91 cases and 375 healthy controls, identified 31 SNP in 18 loci as associated with the defect in this breed. These data suggest that intestinal atresia in dairy calves is not a simple Mendelian trait as previously reported but a complex multigenic disorder.

Assessment of animal health and production constraints: The case of three districts.

BACKGROUND: Animal production is an important tool for improving the living standard of humans and is the backbone of Ethiopia's agricultural development. The country is known for its high livestock potential, but it is not well exploited due to various hindering factors. OBJECTIVES: The objective of the study is to assess the key issues related to animal health and production. METHODS: The evaluation was carried out in three purposively selected districts of East Wollega zone, namely Gidda Ayana, Sibu Sire and Jimma Arjo by using well-designed and structured questionnaire surveys. RESULT: During the study period, 200, 145 and 165 respondents were sampled from the animal owners in the districts of Gidda Ayana, Sibu Sire and Jimma Arjo, respectively. Of these, about 97.89%, 95.68% and 94.9% practice extensive management in Gidda Ayana, Jimma Arjo and Sibu Sire, respectively. The majority of respondents in Gidda Ayana (98.1%), Jimma Arjo (97.21%) and Sibu Sire (98.9%) use natural pastures. For cattle breeding, uncontrolled natural mating is used in Gidda Ayana (90.79%), Jimma Arjo (86.3%) and Sibu Sire (95.69%). The major constraints of animal health and production were also assessed. Accordingly, a lack of access to adequate animal production and health expert in Gidda Ayana (27.33%), Jimma Arjo (29.36%) and Sibu Sire (31.59%) was recorded, whereas the lack of sustainable and structured modern livestock market was observed in Gidda Ayana (25.94%), Jimma Arjo (21.31%) and Sibu Sire (19.80%). CONCLUSION AND RECOMMENDATIONS: Livestock need improved animal health, management systems and breeding methods. The study revealed key issues related to animal health and production, such as poor management systems and breeding methods, limited coverage of veterinary services and a modern livestock market. Thus, it is indispensable to increase the coverage of veterinary services, animal extension services and alternative sources of animal feed.