Banca de DEFESA: SARA ADRIANA SALINAS LAURA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE: SARA ADRIANA SALINAS LAURA
DATA: 14/04/2026
HORA: 14:00
LOCAL: Sala de defesa do DZO
TÍTULO:

Effect of injected vitamin A during pregnancy or in newborn calves on performance, beef quality, and muscle lipogenesis

PALAVRAS-CHAVES:

epigenético, programação fetal, vitamina A

PÁGINAS: 65
GRANDE ÁREA: Ciências Agrárias
ÁREA: Zootecnia
SUBÁREA: Nutrição e Alimentação Animal
RESUMO:

This study aimed to evaluate the effects of VA injection in pregnant cows or neonatal calves on offspring performance, carcass traits, beef quality and expression of genes in the muscle tissue of Angus × Nellore animals finished in the feedlot. Thirty-six male and female calves from multiparous and primiparous cows were randomly assigned in a 3 × 2 factorial design (3 vitamin A protocols and 2 sexes). Vitamin A protocols were done as follows: no VA injection (Control); VA injection in pregnant cows at 250 d of gestation (VAcow; 2.000.000 IU single dose); VA injection in calves just after birth and 60 d of age (VAcalf; 200.000 IU each dose). After weaning, animals were taken to the feedlot with an average body weight of 213+25.7 kg, distributed into 12 pens, with three animals per pen. The feedlot lasted 207 d of feeding and then, the animals were slaughtered in a commercial abattoir. Gene expressions were analyzed using RT-qPCR. Steers had greater (P=0.03) average daily gain (ADG), than heifers . Back fat thickness was greater in heifers (P <0.001) and VAcow animals also tended (P = 0.08) to increase backfat thickness. The ribeye area was greater (p = 0.04) in vacow steers, compared to other groups. Intramuscular fat content was greater (P = 0.04) in VAcow steers, being similar to the heifers animals, regardless vitamin A protocol. The expression of DKL1 and ZNF423 genes was downregulated (P < 0.05) in VAcow animals, while CPT2 expression was upregulated (P = 0.03) in this protocol. Meanwhile, the RXRA gene was less expressed (P = 0.05) in both VAcow and VAcalf animals. Regarding progeny sex, the expression of the PPARG, SREBF1, CPT2, ACOX, GHR, MYH1, MYH2 genes were higher (P < 0.05) and MYH7 tended to be higher (P = 0.08) in females. However, PAX7 expression was higher (P = 0.05) in males. In conclusion, VA injection during gestation can improve intramuscular fat in steers and alter the expression of several genes, demonstrating that this vitamin has a long-term effect on the progeny. In addition, vitamin A injection did not increase intramuscular fat in heifers.

MEMBROS DA BANCA:
Externo à Instituição - OTÁVIO RODRIGUES MACHADO NETO - UNESP (Suplente)
Presidente - MARCIO MACHADO LADEIRA (Membro)
Externo à Instituição - MARCIO DE SOUZA DUARTE - nd (Membro)
Externo à Instituição - KAROLINA BATISTA NASCIMENTO - UFSJ (Membro)
Interno - ERICK DARLISSON BATISTA (Membro)
Interno - DANIEL RUME CASAGRANDE (Membro)
Externo ao Programa - ADENILSON JOSE PAIVA - DZO/FZMV (Suplente)