Ovarian function of Nelore heifers fed a diet supplemented with rumen-protected fat

Authors

  • Monique Mendes Guardieiro FMVZ-UNESP, Botucatu
  • Michele Ricieri Bastos FMVZ-UNESP, Botucatu
  • Gerson Barreto Mourão ESALQ - USP
  • Luiz Henrique Dantas Carrijo Integral Nutrição Animal
  • Eduardo de Oliveira Melo Embrapa Recursos Genéticos e Biotecnologia
  • Rodolfo Rumpf Embrapa Recursos Genéticos e Biotecnologia,
  • Roberto Sartori Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz

DOI:

https://doi.org/10.1590/S1678-3921.pab2010.v45.2535

Keywords:

Bos indicus, fatty acids, corpus luteum, follicle, progesterone

Abstract

The objective of this work was to evaluate the effect of rumen-protected fat supplementation on ovarian structures and on serum progesterone concentration in Nelore heifers kept in pasture. Forty heifers were divided into two groups: one supplemented with rumen-protected fat Megalac-E (F); and another without fat supplement (C). The groups were evaluated in a crossover design. The diets were isocaloric and isoproteic. After 15 days of supplementation, the animals were submitted to a hormonal protocol to evaluate the influence of fat supplementation on progesterone metabolism. For this, on a random day of the cycle (D0), the heifers received an intravaginal progesterone-releasing device (CIDR) and an injection of prostaglandin F2á (PGF2á, im). On D7, CIDR was removed and another injection of PGF2á was performed. On D18, a new treatment with PGF2á was done and, then, daily observations of estrus and ovarian ultrasound exams were carried out. For progesterone assay, blood samples were collected 4 days after CIDR insertion, and 7 and 14 days following ovulation. Serum progesterone concentration on D4 was higher for Group F. There was no difference between groups for serum progesterone concentration at 7 or 14 days following ovulation, neither in the ovulatory follicle, nor in the corpus luteum volume. Supplementation with Megalac-E alters progesterone metabolism, but does not affect ovarian function in zebu heifers kept in pasture.

Author Biographies

Monique Mendes Guardieiro, FMVZ-UNESP, Botucatu

Departamento de Reprodução Animal e Radiologia Veterinária Área de Reprodução Animal

Michele Ricieri Bastos, FMVZ-UNESP, Botucatu

Departamento de Reprodução Animal e Radiologia Veterinária Área de Reprodução Animal

Gerson Barreto Mourão, ESALQ - USP

Departamento de Zootecnia Área de Melhoramento Animal

Luiz Henrique Dantas Carrijo, Integral Nutrição Animal

Área de Nutrição Animal

Eduardo de Oliveira Melo, Embrapa Recursos Genéticos e Biotecnologia

Departamento de Zootecnia Área de Reprodução Animal

Published

2011-01-18

How to Cite

Guardieiro, M. M., Bastos, M. R., Mourão, G. B., Carrijo, L. H. D., Melo, E. de O., Rumpf, R., & Sartori, R. (2011). Ovarian function of Nelore heifers fed a diet supplemented with rumen-protected fat. Pesquisa Agropecuaria Brasileira, 45(4), 408–414. https://doi.org/10.1590/S1678-3921.pab2010.v45.2535

Issue

Section

ANIMAL SCIENCE