Resumo

MONTANO, Erika L  e  RUIZ CORTES, Zulma T. Why first dominant follicles of postpartum zebu cattle do not ovulate in colombian tropic?. Rev Colom Cienc Pecua [online]. 2005, vol.18, n.2, pp.127-135. ISSN 0120-0690.

The efficiency of meat bovine production is strongly related to the reproductive capacity. The pospartum ovarian ciclicity is mainly influenced by suckling, energy balance (body condition) and cow-calf interaction. Restoring the energy homeostasis and reducing the suckling stimulus, could result in ovulation for some animals. However, cows that do not respond to these practices, are probably showing the individuality of follicular dynamics.Circulating growth factors and other hormones acting both at central and local level, can be determining this individuality. The adipose hormone, leptin, is an important link between body condition, energy balance and reproductive status of the animal. Similary, IGF factors are well known to excerce important effects on reproductive system at the hypothalamus-hypophisis-gonadal axis. The interaction between those two systems, leptin and IGF-I, is the focus of this review in order to contribute to the understanding of the nutrition-reproduction interface as main cause of the anovulation postpartum in zebu cattle.

Palavras-chave : anovulation; insulin growth factor; leptin.

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