Effect of high energy intake on carcass composition and hypothalamic gene expression in Bos indicus heifers

Autor(es)

Diniz-Magalhaes, Juliane ^[1] ; Mesquita, Ligia Garcia ^[1] ; de Carvalho, Marina Vieira ^[1] ; Escarpellin Machado, Anna Beatriz ^[1] ; Valim Pimentel, Jose Rodrigo ^[2] ; Prada e Silva, Luis Felipe ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Med Vet & Zootecnia, Dept Nutr & Prod Anim, Pirassununga, SP - Brazil

^[2] Univ Sao Paulo, Fac Med Vet & Zootecnia, Dept Reprod Anim, Pirassununga, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: REVISTA BRASILEIRA DE ZOOTECNIA-BRAZILIAN JOURNAL OF ANIMAL SCIENCE; v. 46, n. 8, p. 664-669, AUG 2017.
• Citações Web of Science: 0

Resumo

The objective of this study was to evaluate the effect of high or low energy intake on carcass composition and expression of hypothalamic genes related to the onset of puberty. Twenty-four prepubertal Nellore heifers, 18-20-months-old, with 275.3 +/- 18.0 kg body weight (BW), and 4.9 +/- 0.2 (1-9 scale) body condition score (BCS) were randomly assigned to two treatments: high-energy diet (HE) and low-energy diet (LE). Heifers were housed in two collective pens and fed diets formulated to promote average daily gain of 0.4 (LE) or 1.2 kg (HE) BW/day. Eight heifers from each treatment were slaughtered after the first corpus luteum detection - considered as age of puberty. The 9-10-11th rib section was taken and prepared for carcass composition analyses. Samples from hypothalamus were collected, frozen in liquid nitrogen, and stored at -80 degrees C. Specific primers for targets (NPY, NPY1R, NPY4R, SOCS3, OXT, ARRB1, and IGFPB2) and control (RPL19 and RN18S1) genes were designed for real-time PCR and then the relative quantification of target gene expression was performed. High-energy diets increased body condition score, cold carcass weight, and Longissimus lumborum muscle area and decreased age at slaughter. High-energy diets decreased the expression of NPY1R and ARRB1 at 4.4-fold and 1.5-fold, respectively. In conclusion, the hastening of puberty with high energy intake is related with greater body fatness and lesser hypothalamic expression of NPY1 receptor and of beta-arrestin1, suggesting a less sensitive hypothalamus to the negative effects of NPY signaling. (AU)

• Processo FAPESP: 08/01072-7 - Efeito da leptina e da nutrição sobre o perfil de expressão de genes hipotalâmicos em novilhas zebuínas (Bos taurus indicus)
• Beneficiário: Luis Felipe Prada e Silva
• Linha de fomento: Auxílio à Pesquisa - Regular