Evaluation of reproductive traits and the effect of nutrigenetics on bulls submitted to fetal programming

摘要

Nutritional stimuli during the gestational period in dams have long-term effects on the offspring in terms of health and production rates. This study assessed the effect of fetal programming in 126 pregnant Nellore cows on reproductive and nutrigenetic traits of the progeny during the rearing phase. For that purpose, three nutritional treatments were used in these cows during pregnancy: PP ? protein-energy supplementation in the final third, FP ? protein-energy supplementation during the entire pregnancy, and NP ? (control) only mineral supplementation. The male progeny (64 bulls) was evaluated for scrotal circumference and seminal traits at 12, 15, and 18 months of age. In addition, we performed a genomic association (35 K SNPs) for scrotal circumference at 12 and 18 months of age. Only the total sperm defects showed significant difference between groups (P < 0.05), regardless of age, while major and minor sperm defects and vigor showed tendencies (P < 0.10). In the time analysis, only the minor sperm defects did not differ between ages, regardless of treatment (P = 0.92). We found genes that are associated with genetic variance at different ages and treatments (BTBD9, WNT2, ASZ1, WWOX and SLC26A8). Thus, prenatal protein-energy supplementation showed effects on the total of abnormal sperm cells between treatments, genotype-environment interaction, and some SNPs that explain more than 1% of the genetic variance on bulls during the rearing phase. These are evidences that different strategies of prenatal supplementation may have acted on epigenetic factors and may have caused changes in gene expression of animals. This contributes to the knowledge about mechanisms that involve fetal programming in beef cattle.