Search

Made available in DSpace on 2022-05-01T16:02:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 The beef fatty acid (FA) profile has the potential to impact human health, and displays polygenic and complex features. This study aimed to identify the transcriptomic FA profile in the longissimus thoracis muscle in Nellore beef cattle finished in feedlot. Forty-four young bulls were sampled to assess the beef FA profile by considering 14 phenotypes and including differentially expressed genes (DEG), co-expressed (COE), and differentially co-expressed genes (DCO) analyses. All samples (n = 44) were used for COE analysis, whereas 30 samples with extreme phenotypes for the beef FA profile were used for DEG and DCO. A total of 912 DEG were identified, and the polyunsaturated (n = 563) and unsaturated ω-3 (n = 346) FA sums groups were the most frequently observed. The COE analyses identified three modules, of which the blue module (n = 1776) was correlated with eight of 14 FA phenotypes. Also, 759 DCO genes were listed, and the oleic acid (n = 358) and monounsaturated fatty acids sum (n = 120) were the most frequent. Furthermore, 243 and 13, 319 and seven, and 173 and 12 gene ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways were enriched respectively for the DEG, COE, and DCO analyses. Combining the results, we highlight the unexplored GIPC2, ASB5, and PPP5C genes in cattle. Besides LIPE and INSIG2 genes in COE modules, the ACSL3, ECI1, DECR2, FITM1, and SDHB genes were signaled in at least two analyses. These findings contribute to understand the genetic mechanisms underlying the beef FA profile in Nellore beef cattle finished in feedlot. School of Agricultural and Veterinary Sciences (FCAV) São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science (FMVZ) University of São Paulo (USP) Commonwealth Scientific and Industrial Research Organization (CSIRO) Agriculture & Food School of Veterinary Medicine and Animal Science (FMVZ) São Paulo State University (UNESP) School of Agricultural and Veterinary Sciences (FCAV) São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science (FMVZ) São Paulo State University (UNESP)

Made available in DSpace on 2021-06-25T10:34:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-01 The reduction of age at puberty in young bulls is an important issue to reduce the growing phase and promote substantial savings in production cost as well as to reduce the generation interval. This study aims to estimate genetic parameters for age at puberty in males (APM), growth, carcass, and reproductive-related traits in young Nelore bulls. Additionally, the direct and correlated response for growth, reproductive, and carcass traits were also estimated when a selection was applied for APM in such young bulls. APM was determined through evaluations carried out after weaning, using information from andrological clinical examination, ultrasound records, and scrotal circumference measurements. Records from 181,345 Nelore animals born between 2010 to 2017 were used. These animals were calves from 5,257 sires and 50,742 dams, and belonged to 18 farms located in the Midwest, Southeast, Northeast, and North regions of Brazil. The relationship matrix was built using information from 265,813 animals. The covariance components and the genetic parameters for APM, adjusted scrotal circumference at 365 (SC365) and 450 (SC450) days of age, adjusted weight at 210 (W210) and 450 (W450) days of age, age at first calving (AFC), ribeye area (REA), subcutaneous fat thickness (SFT), and rump fat thickness (RFT) were estimated using a linear animal model. A threshold animal model was used for Stayability (STAY) and early heifer pregnancy (PP30) traits. The heritabilities obtained were: 0.30 (APM), 0.33 (SC365), 0.37 (SC450), 0.14 (W210), 0.26 (W450), 0.08 (AFC), 0.29 (PP30), 0.19 (STAY), 0.32 (REA), 0.19 (SFT), and 0.28 (RFT). The genetic correlations estimates between APM and growth, reproductive, and carcass related traits were: -0.39 (SC365), -0.58 (SC450), -0.01 (W210), 0.08 (W450), 0.30 (AFC), -0.24 (PP30), 0.35 (STAY), 0.08 (REA), -0.05 (SFT), and -0.30 (RFT). The APM is a new approach to evaluate early sexual precocity in young bulls, and it would allow better identification of young candidates when compared to those selected based on scrotal circumference measures. Genetic progress is expected for APM in young bulls since it would favor the heifer's sexual precocity together with the dam's longevity without impacting growth and carcass traits. The results of this study encourage the use of male sexual precocity trait assisted by genomic selection to improve the genetic evaluation reliability of young bulls. Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias (FCAV) Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP) Laboratório de Reprodução Animal Faculdade de Medicina Veterinária e Zootecnia (FAMEZ) Universidade Federal de Mato Grosso do Sul (UFMS) Faculdade de Zootecnia e Engenharia de Alimentos Universidade de São Paulo Departamento de Medicina Veterinária PROCRIAR Assistência Veterinária Departamento de Produção Animal Universidade Federal de Goiás Associação Nacional dos Criadores e Pesquisadores (ANCP) Faculdade de Medicina Veterinária e Zootecnia Universidade de São Paulo Departamento de Nutrição e Produção Animal Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias (FCAV) Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP)