Ovarian steroid secretion changes after hCG stimulation in early pregnant pigs.
Administration of human chorionic gonadotropin (hCG) to promote ovarian steroid secretion near the time of recognition of pregnancy was evaluated. Neither 500 or 1000 IU of hCG caused a significant increase in luteal function as determined by progesterone (P(4)) concentrations in peripheral blood following treatment on Day 12. Estradiol concentrations were elevated (P<0.01) for the 500 IU hCG group on Days 13, 14, 15 and 16 versus the control group. The 1000 IU of hCG group had three-to five-fold greater (P<0.01) estradiol concentrations than controls on Days 14, 15 and 16 post mating. Treatment with hCG also reduced (P<0.05) the number of resorbed embryos. The results suggest that hCG treatment on Day 12 of pregnancy reduced embryo loss and influenced peripheral estradiol secretion patterns.
Tilton
J E
JE
Department of Animal and Range Sciences, North Dakota State University, Fargo, ND 58105 USA.
Schmidt
A E
AE
Weigl
R M
RM
Ziecik
A J
AJ