LUTEINIZING HORMONE SECRETION IN NELLORE HEIFER’S AFTER WEANING TO FIRST OVULATION

Authors

  • Daniel Cardoso Agência Paulista de Tecnologia do Agronegócio-Pólo Regional Extremo Oeste-Unidade de Pesquisa de Araçatuba
  • Guerra Fábio Ferreira Funepe
  • Guilherme Paula Nogueira UNESP

DOI:

https://doi.org/10.5216/cab.v10i4.3788

Keywords:

Animal reproduction

Abstract

The aim was to evaluate the LH secretion in B. indicus heifers, on the presence or absence of gonadal steroid, generating information about the mechanisms evolved on sexual maturation in Nellore heifers. LH and progesterone concentration were quantified by RIA. First ovulation was determined by plasma progesterone concentration (>1 ng/ml). Greater mean LH concentrations was observed in ovariectomized (OVX; P?0.05) compared to intact heifers (INT). Mean LH concentration increased (P?0.05) during the sexual maturation, in both intact and ovariectomized heifers. The number of peaks was higher (P?0.05) in ovariectomized heifer. The results suggest decrease in estradiol hypothalamus negative feedback during Nellore heifer’s sexual maturation. It was possible to conclude that in pre-pubertal Nellore heifers the increase on positive gonadal steroids feedback was necessary to increase LH secretion before first ovulation.
KEY WORDS: Cattle, endocrinology, hypothalamus, puberty, steroids.

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Author Biographies

Daniel Cardoso, Agência Paulista de Tecnologia do Agronegócio-Pólo Regional Extremo Oeste-Unidade de Pesquisa de Araçatuba

Pesquisador Científico - APTA - Pólo Regional Extremo Oeste

Área de Produção Animal

Guerra Fábio Ferreira, Funepe

FUNEPE - Penápolis -SP

Guilherme Paula Nogueira, UNESP

DAPSA - UNESP - Araçatuba

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Published

2009-12-20

How to Cite

CARDOSO, D.; FERREIRA, G. F.; NOGUEIRA, G. P. LUTEINIZING HORMONE SECRETION IN NELLORE HEIFER’S AFTER WEANING TO FIRST OVULATION. Brazilian Animal Science/ Ciência Animal Brasileira, Goiânia, v. 10, n. 4, p. 1277–1284, 2009. DOI: 10.5216/cab.v10i4.3788. Disponível em: https://revistas.ufg.br/vet/article/view/3788. Acesso em: 17 jul. 2024.

Issue

Vol. 10 No. 4 (2009)

Section

Veterinary Medicine

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