Concentrations of progestagens and oestrogens in the faeces of pregnant Lipizzan, trotter and thoroughbred mares.
Faecal samples were collected at weekly intervals from pregnant Lipizzan mares during Weeks 7-16 following mating and from Lipizzan, Trotter and Thoroughbred mares during the last 3 months of gestation. After parturition, samples were taken daily from the Thoroughbred mares for another 6 days. Non-pregnant mares served as controls. The concentrations of unconjugated oestrogens (Eg), 20 alpha-OH-progestagens (20 alpha-G) and 20 beta-OH-progestagens (20 beta-G) were measured by enzyme immunoassay. In the faeces of Lipizzan mares, immunoreactive progestagens were significantly (P less than 0.01) elevated above the levels in non-pregnant mares by Week 11, and Eg by Week 13 of pregnancy onwards. During the last 3 months of gestation, concentrations of Eg were significantly higher in Trotter mares than in Lipizzan and Thoroughbred mares. Concentrations of 20 alpha-G and 20 beta-G increased to maximal values in the last month of gestation. There was no significant difference among the 3 breeds with respect to 20 alpha-G but, during the 10 weeks before parturition, concentrations of 20 beta-G in the Lipizzan mares were significantly lower (P less than 0.05) than those in the Thoroughbred mares. They were also significantly lower than those of the Trotter mares during the last 4 weeks of gestation. After parturition, the concentrations of Eg and progestagens had declined to baseline values by Days 3 and 4 respectively. From these results we conclude that high concentrations of progestagens with 20 alpha- and 20 beta-hydroxyl groups are present in the faeces of pregnant mares, especially during the last month of gestation.
Schwarzenberger
F
F
Institut für Biochemie, Veterinary Medical University, Vienna, Austria.
Möstl
E
E
Bamberg
E
E
Pammer
J
J
Schmehlik
O
O
D000818:Animals; D004967:Estrogens / Q000032:analysis*; D005243:Feces / Q000737:chemistry*; D005260:Female; D005865:Gestational Age; D006736:Horses / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D007743:Labor, Obstetric; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011283:Pregnenes / Q000032:analysis; D011372:Progestins / Q000032:analysis*
D004967:Estrogens; D011283:Pregnenes; D011372:Progestins