LUTEINIZING HORMONE SECRETION IN NELLORE HEIFER’S AFTER WEANING TO FIRST OVULATION
DOI:
https://doi.org/10.5216/cab.v10i4.3788Keywords:
Animal reproductionAbstract
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.
Downloads
Download data is not yet available.
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: 25 nov. 2024.
Issue
Section
Veterinary Medicine
License
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g. in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
