Early weaning of Nelore cows and its effect on fetal programming and the productive and reproductive performance of the next progeny

• Grant number: 22/03571-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2022
• End date: April 30, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Arlindo Saran Netto
• Grantee: Germán Darío Ramírez Zamudio
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 17/18937-0 - Earlier weaning of calves from Nellore cows and its effects on the fetal programming and on the produtive and reprodutive performance of the next progeny, AP.TEM
• Associated scholarship(s): 23/07354-4 - Effect of early weaning in Nellore cows on the gastrointestinal and seminal microbiome and morphology of ruminal and intestinal epithelium of the next progeny, BE.EP.PD

Abstract

The objective of this proposal is to evaluate the effects of fetal programming through the early weaning (150 days vs. 240 days) of beef cows on the performance of the dams, the weaned offspring and the next progeny. In total, 200 pairs of pregnant cow and calf (100 primiparous and 100 pluriparous cows) will be divided into two groups, with (1) early weaning, in which male and female calves will be weaned at 150 days of age, and (2) conventional weaning at 240 days of age. In Exp. 1 calves that will be weaned early and conventionally will be reared and finished to evaluate the effects of this early weaning on productive performance, and female calves will be evaluated for their reproductive capacity. In Exp. 2 and 3, the next progeny of these dams will be evaluated from birth to slaughter (Exp. 2, males) or reproduction (Exp. 3, females). Exp. 4, several reproductive traits will be measured to assess the effect of early weaning on the reproductive performance of these dams in the subsequent breeding season. It is intended to analyze the effects of the two different maternal conditions during the gestational period on the productive and reproductive characteristics during the cow-calf, rearing and finishing periods and on the carcass characteristics of steers. In addition, we intend to compare the effect of these two maternal conditions on primiparous and pluriparous cows. Thus, the effects of this management will be evaluated both on the offspring of the next generation and on the calves that will be submitted to weaning, as well as in the dams. (AU)