Luteal inadequacy during the early luteal phase of subfertile cows

in Reproduction

Summary. A study was made of early luteal function (up to Day 6) in cyclic and pregnant heifers and also in older, subfertile cows. There were no differences in vivo or in vitro between cyclic and pregnant heifers, indicating no luteotrophic effect of the embryo at this stage, but the increase in postovulatory peripheral progesterone concentrations was delayed (P < 0·01) and occurred more slowly (P < 0·001) in the subfertile cows than in the heifers. The corpora lutea of the subfertile cows were heavier (P < 0·001) than those of the heifers on Day 6. Basal progesterone production by dispersed luteal cells was similar between heifers and subfertile cows, but there was a difference (P < 0·001) in the pattern of response to exogenous LH and PGE-2. Cells from subfertile cows were less sensitive to the stimulatory effects of PGE-2 and although LH increased (P < 0·001) progesterone production by all cells, this stimulation by a low dose of LH was inhibited by PGE-2 in luteal cells from subfertile cows. This effect did not occur in the luteal cells from heifers. These results indicate the possibility that luteal inadequacy, due to a diminished response to circulating luteotrophic hormones, may contribute to embryo mortality in subfertile cows.

Keywords: luteal inadequacy; subfertility; cows

 

An official journal of

Society for Reproduction and Fertility

Index Card

Cited By

PubMed

Google Scholar

Related Articles

Altmetrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 39 39 8
PDF Downloads 98 98 37