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The primary purpose of genetic improvement in lean pig breeds is to enhance production performance. Owing to their similar breeding directions, Duroc and Pietrain pigs are ideal models for investigating the phenotypic convergence underlying artificial selection. However, most important economic traits are controlled by a polygenic basis, so traditional strategies for detecting selection signatures may not fully reveal the genetic basis of complex traits. The pathway-based gene network analysis method utilizes each pathway as a unit, overcoming the limitations of traditional strategies for detecting selection signatures by revealing the selection of complex biological processes. Here, we utilized 13 122 398 high-quality SNPs from whole-genome sequencing data of 48 Pietrain pigs, 156 Duroc pigs and 36 European wild boars to detect selective signatures. After calculating FST and iHS scores, we integrated the pathway information and utilized the r/bioconductor graphite and signet packages to construct gene networks, identify subnets and uncover candidate genes underlying selection. Using the traditional strategy, a total of 47 genomic regions exhibiting parallel selection were identified. The enriched genes, including INO80, FZR1, LEPR and FAF1, may be associated with reproduction, fat deposition and skeletal development. Using the pathway-based selection signatures detection method, we identified two significant biological pathways and eight potential candidate genes underlying parallel selection, such as VTN, FN1 and ITGAV. This study presents a novel strategy for investigating the genetic basis of complex traits and elucidating the phenotypic convergence underlying artificial selection, by integrating traditional selection signature methods with pathway-based gene network analysis.

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Sire has an important role because they could have more offspring than dam does. The research aims to determine the production performance of Friesian Holstein, estimation of heritability values, estimation of breeding values, and ranking of dairy cattle sires. The objects of the study were the complete record of milk production, lactation length, lactation peak, and dry period length from first to fourth lactation from 2017-2021. This study used the descriptive method. The results of the research showed that productivity performance is great, 1st lactation milk production was 8,029.28±1,112 kg, the lactation length was 321.26±38.48 days, the condition of average peak production was obtained on day 85.35±29.25 with milk production of 32.55±4.16 kg, and dry period length was 51.37±9.33 days. 2nd Lactation milk production was 7,761.66±1,145, the lactation length was 323.66±43.06 days, the condition of average peak production was on day 58.43±21.11 with milk production of 40.79±5.30 kg and the dry period length was 65.10±22.69 days. 3rd lactation milk production 3 was 7,788.92±1,148 kg, the lactation length was 326.64±46.74 days, peak production was on day 61.88 ±22.72 with milk production of 43.62±5.11 kg; the dry period length was 65.00±20.49 days. 4th Lactation milk production was 7,484.18±1,133 kg, lactation length was 323.04±42.23 days, peak production was on day 66.39±24.26 with the milk production of 43.82±5.68, the dry period length was 65.78±21.60 days. The estimated heritability value for milk production, 0.03 ± 0.02, is included in the low category. The ranking of 10 sires that have the potential to increase the genetic based on their estimated breeding value is 595.91 kg (O.S.Elmer-XA), 264.16 kg (M.Z.Merlin.-XA), 252.38 kg (L.Muscadet-XA), 247 .12 kg (C.Toyjet), 239.01 kg (S. Gypsy B), 214.82 kg (WestCoastPldge), 188.14 kg (M.Z.Merlin-ET), 178.56 kg (Brasilia), 166.43 kg (L.JetBowser-XA), 162.06 kg (MRMUDD-XA).

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Spermatogonial stem cell transplantation (SSCT) is an experimental technique for transfer of germline between donor and recipient males that could be used as a tool for biomedical research, preservation of endangered species, and dissemination of desirable genetics in food animal populations. To fully realize these potentials, recipient males must be devoid of endogenous germline but possess normal testicular architecture and somatic cell function capable of supporting allogeneic donor stem cell engraftment and regeneration of spermatogenesis. Here we show that male mice, pigs, goats, and cattle harboring knockout alleles of the NANOS2 gene generated by CRISPR-Cas9 editing have testes that are germline ablated but otherwise structurally normal. In adult pigs and goats, SSCT with allogeneic donor stem cells led to sustained donor-derived spermatogenesis. With prepubertal mice, allogeneic SSCT resulted in attainment of natural fertility. Collectively, these advancements represent a major step toward realizing the enormous potential of surrogate sires as a tool for dissemination and regeneration of germplasm in all mammalian species.

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Genotype × environment interaction (G × E) is of increasing importance for dairy cattle breeders due to international multiple-environment selection of animals as well as the differentiation of production environments within countries. This theoretical simulation study tested the hypothesis that genomic selection (GS) breeding programs realize larger genetic benefits by cooperation in the presence of G × E than conventional pedigree-based selection (PS) breeding programs. We simulated two breeding programs each with their own cattle population and environment. Two populations had either equal or unequal population sizes. Selection of sires was done either across environments (cooperative) or within their own environment (independent). Four scenarios, (GS/PS) × (cooperative/independent), were performed. The genetic correlation (r g ) between the single breeding goal trait expressed in two environments was varied between 0.5 and 0.9. We compared scenarios for genetic gain, rate of inbreeding, proportion of selected external sires, and the split-point r g that is the lowest value of r g for long-term cooperation. Between two equal-sized populations, cooperative GS breeding programs achieved a maximum increase of 19.3% in genetic gain and a maximum reduction of 24.4% in rate of inbreeding compared to independent GS breeding programs. The increase in genetic gain and the reduction in rate of inbreeding realized by GS breeding programs with cooperation were respectively at maximum 9.7% and 24.7% higher than those realized by PS breeding programs with cooperation. Secondly, cooperative GS breeding programs allowed a slightly lower split-point r g than cooperative PS breeding programs (0.85∼0.875 vs ≥ 0.9). Between two unequal-sized populations, cooperative GS breeding programs realized higher increase in genetic gain and showed greater probability for long-term cooperation than cooperative PS breeding programs. Secondly, cooperation using GS were more beneficial to the small population while also beneficial but much less to the large population. In summary, by cooperation in the presence of G × E, GS breeding programs realize larger improvements in terms of the genetic gain and rate of inbreeding, and have greater possibility of long-term cooperation than conventional PS breeding programs. Therefore, we recommend cooperative GS breeding programs in situations with mild to moderate G × E, depending on the sizes of two populations.

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Studies of multiple paternity in mammals and other animal species generally report proportion of multiple paternity among litters, mean litter sizes, and mean number of sires per litter. It is shown how these variables can be used to produce an estimate of the probability of reproductive success for a male that has mated with a female. This estimate of male success is more informative about the mating system that alternative measures, like the proportion of litters with multiple paternity or the mean number of sires per litter. The probability of success for a mated male can be measured both theoretically and empirically, and gives an estimate of the intensity of sperm competition and of a male's "confidence of paternity" upon mating. The probability of success for mated males for ten "exemplar" species of mammals is estimated and they are compared for insights into the functioning of their mating systems.

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Interbull has been responsible for comparing dairy bulls across countries since the mid-1980s. The current methodology is called MACE (multiple across country evaluations) which has been in use since 1995. Now that genomic data are being utilized in many countries, this has led to two serious problems. The first is that of preselection of young bulls such that the young animals are no longer a random sample of progeny from a sire by dam mating pair. Secondly, some countries are becoming less willing to share genomic data with Interbull. Both issues raise concern over the future of Interbull and international comparisons. This paper suggests a competition model as a potential replacement for MACE. The competition model makes pairwise comparisons between all pairs of bulls within a country and combines these differences across countries through bulls that are used in more than one country. Pedigree information is ignored as are all genomic data because bulls are treated as fixed. The model produces one international ranking of bulls averaging out any genotype by environment interactions which may exist. The competition model is illustrated by a small example. The limitations and advantages of the competition model are discussed.

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In this work, we performed simulations to develop and test a strategy for exploiting surrogate sire technology in animal breeding programs. Surrogate sire technology allows the creation of males that lack their own germline cells, but have transplanted spermatogonial stem cells from donor males. With this technology, a single elite male donor could give rise to huge numbers of progeny, potentially as much as all the production animals in a particular time period. One hundred replicates of various scenarios were performed. Scenarios followed a common overall structure but differed in the strategy used to identify elite donors and how these donors were used in the product development part. The results of this study showed that using surrogate sire technology would significantly increase the genetic merit of commercial sires, by as much as 6.5 to 9.2 years' worth of genetic gain compared to a conventional breeding program. The simulations suggested that a strategy involving three stages (an initial genomic test followed by two subsequent progeny tests) was the most effective of all the strategies tested. The use of one or a handful of elite donors to generate the production animals would be very different to current practice. While the results demonstrate the great potential of surrogate sire technology there are considerable risks but also other opportunities. Practical implementation of surrogate sire technology would need to account for these.

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This study aimed to describe the diagnosis of health problems and to evaluate the cost of their treatment for cattle raised in feedlots to be slaughtered or to be sold as sires for cow-calf systems. Bovine respiratory disease and digestive disorders were the main problems diagnosed in the feedlot for slaughter; the cost for treatment was high, accounting for 9.7 to 20.9 kg of live weight (LW) or the equivalent of 7 to 15% of total LW gained over the days on feed. Due to the high intake of starch-rich concentrate, rumen and fecal pH was lower, whilst rumen osmolarity and blood lactate were higher in cattle fed for slaughter. Cattle affected by digestive disorders spent on average four additional days in the feedlot. Diseases and cost of treatments were associated with lower average daily gain and considerable economic losses. Health problems commonly observed in the feedlots for slaughter were not observed in the feedlots for males to be sold as sires. The most likely reason for this observation was the more careful nutrition and prophylactic health management in sire production systems, which produce animals of much higher selling price. Results from this study suggest that health problems found in feedlots for slaughter may not only reduce animal productivity and profitability, but also the welfare of the animals. The systemic understaffing of livestock cattle workers and veterinarians in large feedlots in Brazil results in under reporting of diseases and lack to understand epidemiological context and disease prevention.(AU)

No presente estudo coletou-se e se interpretou dados sobre os principais problemas sanitários, bem como a respeito dos custos com os tratamentos de bovinos de corte confinados em dois sistemas diferentes: o tradicional, isto é, aquele que objetiva produzir animais prontos para o abate e o sistema de produção de touros destinados à venda destes como reprodutores. A porcentagem de bovinos confinados para o abate e que adquiriram problemas sanitários foi consideravelmente maior do que nos sistemas que os confinam para a venda como futuros reprodutores. As pneumonias e os transtornos digestórios foram os principais problemas diagnosticados no confinamento para o abate e os custos com os tratamentos foram elevados e, em média, representaram entre 9,7 e 20,9 kg de peso vivo ou o equivalente de 7 a 15% das arrobas ganhas durante o período confinado. O crescimento exagerado e a aglutinação (paraqueratose) das papilas ruminais foram os principais achados macroscópicos nos rúmens dos bovinos confinados para o abate. Devido à maior ingestão de grãos, o pH ruminal e fecal foi sempre menor, enquanto que a osmolaridade ruminal e o lactato sanguíneo foi sempre maior nos animais confinados para o abate. O tempo de permanência no confinamento foi maior, em média 4 dias, para os animais que adquiriram qualquer problema digestório. Isso, aliado ao fato de também terem os menores ganhos de peso diários, pode resultar em um considerável prejuízo. Os ganhos de peso diários foram similares para os animais confinados (que ingeriram mais de 85% de concentrados) para o abate e para os que foram confinados para a venda como reprodutores, que consumiram cerca de 50% de concentrados em sua dieta.(AU)

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O objetivo deste estudo foi avaliar o efeito da somatotropina recombinante bovina (rbST) sobre os marcadores do metabolismoenergético, proteico, mineral e hepático de touros mantidos em semiconfinamento. Foram utilizados 20 touros de raçasAberdeen Angus e Brangus, sendo divididos aleatoriamente em dois grupos (Placebo e rbST), para que no Placebo fosseadministrado via subcutânea duas doses de NaCl, 0,9% e no rbST fosse administrado o rbST (Lactotropin®). Foram realizadascinco coletas de sangue, com intervalo de 14 dias, para avaliação da concentração de triacilgliceróis e colesterol comomarcadores energéticos, ureia, como indicador proteico, fosfatase alcalina e fósforo como marcadores minerais e asenzimas aspartato aminotransferase (AST) e a gama glutamiltransferase (GGT) como indicadoras da função hepática. Aaplicação de rbST não influenciou os marcadores energéticos, minerais, e proteico, exceto a enzima hepática GGT (P 0,05).Estes resultados indicam que a utilização do rbST em touros não alterou o metabolismo, pois os parâmetros avaliadosmantiveram-se dentro dos padrões considerados fisiológicos para a espécie.

The aim of this study was to evaluate the effect of recombinant bovine somatotropin (rbST) on metabolic markers for energy, protein, mineral and hepatic metabolism of sires kept grazing and receiving concentrate. Twenty sires Aberdeen Angus and Brangus used for this experiment were divided in two groups (Placebo and rbST). The group Placebo received subcutaneous administration of NaCl, 0.9% and rbST receive rbST twice. Five blood collections with 14 days of interval were made for evaluation of triglyceride and cholesterol as energetic metabolism markers, urea, as proteic marker, alkaline phosphatase and phosphorus as minerals markers and aspartate aminotransferase (AST) and gamma glutamyltransferase (GGT) as indicators of the hepatic function. The rbST did not influence the energetic, mineral and proteic markers, except the hepatic enzyme GGT (P<0,05). These results indicated that the use of rbST in sires did not affect metabolism, therefore evaluated parameters remaining in the physiological range for the specie.

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