Abstract

GIRALDO, Carlos A; OLIVERA, Martha  and  RUIZ CORTES, Zulma T. Effect of variation of body weight and body condition and leptin and luteinizing hormone receptor expression, on postpartum anovulation of zebu (Bos indicus) cows. Rev Colom Cienc Pecua [online]. 2008, vol.21, n.2, pp.228-238. ISSN 0120-0690.

This study seek for the relationship between body weight (BW) and body condition, the time of appearance of first dominant follicles (DF) and the presence of leptin and LH receptors in the ovaries. Ovarian ultrasonography was performed during the postpartum period on eleven Zebu cows to monitor their follicular dynamics. When the third DF was detected, the cows were treated with LH (n=4) or saline solution (n=4) and 48h later they were ovariectomized to determine leptin and LH receptors by indirect immunofluorescence (IFI) and immunohistochemistry (IHQ). Cows that did not display DF were also ovariectomized (control, n=3). No significant effect of variation of BW and BC on the days to third DF was found. There was also a negative correlation between BW loss and daily BW loss with the time to the first and third DF. In FDLH group, 75% (3/4) of cows, ovulation was induced. In FDSS group, cows did not ovulate. The IFI studies for leptin and LH receptors detection were technically impossible due to the presence of autofluorescence. In the IHQ studies for both receptors, pattern of expression similar during the follicular development was found suggesting a comudulation at the ovarian level, being greater in hemorrhagic bodies and dominant follicles, and minor in growing follicles, at granulosa, theca and luteinized cells levels.

Keywords : leptin receptor; LH receptor; postpartum anestrus.

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