Santana Mário L, Bignardi Annaiza B, Pereira Rodrigo J, Oliveira Junior Gerson A, Freitas Anielly P, Carvalheiro Roberto, Eler Joanir P, Ferraz José B S, Cyrillo Joslaine N S G, Mercadante Maria E Z
Grupo de Melhoramento Animal de Mato Grosso (GMAT), Instituto de Ciências Agrárias e Tecnológicas, Universidade Federal de Rondonópolis (UFR), Rondonópolis 78735-901, Brazil.
Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
Animals (Basel). 2023 Jul 15;13(14):2321. doi: 10.3390/ani13142321.
The prenatal environment is recognized as crucial for the postnatal performance in cattle. In tropical regions, pregnant beef cows commonly experience nutritional restriction during the second half of the gestation period. Thus, the present study was designed to analyze the genotype by prenatal environment interaction (G × Epn) and to identify genomic regions associated with the level and response in growth and reproduction-related traits of beef cattle to changes in the prenatal environment. A reaction norm model was applied to data from two Nelore herds using the solutions of contemporary groups for birth weight as a descriptor variable of the gestational environment quality. A better gestational environment favored weights until weaning, scrotal circumference at yearling, and days to first calving of the offspring. The G × Epn was strong enough to result in heterogeneity of variance components and genetic parameters in addition to reranking of estimated breeding values and SNPs effects. Several genomic regions associated with the level of performance and specific responses of the animals to variations in the gestational environment were revealed, which harbor QTLs and can be exploited for selection purposes. Therefore, genetic evaluation models considering G × Epn and special management and nutrition care for pregnant cows are recommended.
产前环境被认为对牛的产后性能至关重要。在热带地区，怀孕的肉牛母牛在妊娠期后半段通常会经历营养限制。因此，本研究旨在分析基因型与产前环境互作（G×Epn），并确定与肉牛生长和繁殖相关性状水平及对产前环境变化反应相关的基因组区域。使用当代组出生体重的解作为妊娠环境质量的描述变量，将反应规范模型应用于来自两个内洛尔牛群的数据。更好的妊娠环境有利于犊牛断奶前的体重、一岁时的阴囊周长以及首次产犊的天数。G×Epn足够强大，除了导致估计育种值和单核苷酸多态性（SNP）效应重新排序外，还会导致方差成分和遗传参数的异质性。揭示了几个与动物性能水平和对妊娠环境变化的特定反应相关的基因组区域，这些区域含有数量性状基因座（QTL），可用于选择目的。因此，建议采用考虑G×Epn的遗传评估模型以及对怀孕母牛进行特殊管理和营养护理。
