Função ovariana de novilhas Nelore alimentadas com dieta suplementada com gordura protegida ruminal
Carregando...
Data
2010-04-01
Autores
Guardieiro, Monique Mendes
Bastos, Michele Ricieri [UNESP]
Mourão, Gerson Barreto
Carrijo, Luiz Henrique Dantas
Melo, Eduardo de Oliveira
Rumpf, Rodolfo
Sartori, Roberto
Título da Revista
ISSN da Revista
Título de Volume
Editor
Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Resumo
O objetivo deste trabalho foi avaliar o efeito da suplementação alimentar com gordura protegida ruminal sobre as estruturas ovarianas e sobre a concentração sérica de progesterona, em novilhas Nelore mantidas em pasto. Quarenta novilhas foram divididas em dois grupos: um suplementado com gordura protegida Megalac-E (G); e outro sem suplementação de gordura (C). O grupos foram avaliados em delineamento crossover. Utilizaram-se dietas isoenergéticas e isoproteicas. Após 15 dias de suplementação, os animais foram submetidos a um protocolo hormonal, para avaliação da influência da suplementação com gordura no metabolismo da progesterona. Para isto, em um dia aleatório do ciclo (D0), inseriu-se um implante intravaginal de liberação de progesterona (CIDR), e aplicou-se prostaglandina F2α (PGF2α, i.m.). No D7, o implante foi retirado, e outra aplicaηão de PGF2α foi realizada. No D18, foi feita uma nova aplicaηão de PGF2α e, então, foram observados diariamente os exames ultrassonográficos ovarianos e a ocorrência de estro. Para o ensaio com progesterona, colheu-se sangue 4 dias após a inserção do implante e, novamente, 7 e 14 dias após a ovulação. A concentração de progesterona sérica no D4 foi maior no grupo G. Não houve diferença nas concentrações séricas de progesterona 7 e 14 dias após a ovulação, nem no diâmetro do folículo ovulatório, nem no volume luteal. A suplementação com Megalac-E altera o metabolismo de progesterona, mas não altera a função ovariana em novilhas zebuínas em pasto.
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 F2α (PGF2α, im). on D7, CIDR was removed and another injection of PGF2α was performed. on D18, a new treatment with PGF2α 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.
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 F2α (PGF2α, im). on D7, CIDR was removed and another injection of PGF2α was performed. on D18, a new treatment with PGF2α 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.
Descrição
Palavras-chave
Bos indicus, ácidos graxos, corpo lúteo, folículo, progesterona, Bos indicus, fatty acids, corpus luteum, follicle, progesterone
Como citar
Pesquisa Agropecuária Brasileira. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Informação TecnológicaPesquisa Agropecuária Brasileira, v. 45, n. 4, p. 408-414, 2010.