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Concentrations of progestagens and oestrogens in the faeces of pregnant Lipizzan, trotter and thoroughbred mares.
Abstract: 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.
Publication Date: 1991-01-01 PubMed ID: 1795293 The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
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The research explores and compares levels of certain hormones in the droppings of different pregnant mare breeds. It is found that specific hormone concentrations differ based on the breed and duration of pregnancy.
Introduction and Methodology
- The research focused on studying the levels of two sets of hormones, progestagens and oestrogens, in the faeces of pregnant Lipizzan, Trotter, and Thoroughbred mares.
- Faecal samples were collected from Lipizzan mares between 7-16 weeks after mating, while samples from all three breeds were taken during the last three months of pregnancy.
- After giving birth, Thoroughbred mares’ samples were also collected for an additional six days.
- The obtained samples were compared and contrasted to samples from non-pregnant mares, which acted as control groups.
- The concentrations of the studied hormones were measured using an enzyme immunoassay.
Key Findings during Pregnancy
- By week 11 of pregnancy, Lipizzan mares exhibited a significant increase in progestagen concentration compared to non-pregnant mares. The concentration of oestrogens also rose significantly by the 13th week.
- In the last three months of pregnancy, the levels of oestrogens were substantially higher in Trotter mares when compared to the other two breeds.
- Alongside this, concentrations of the two types of progestagens studied, 20 alpha-OH-progestagens, and 20 beta-OH-progestagens, increased to peak values in the last month of gestation.
- While the research found no significant difference among the three breeds regarding 20 alpha-OH-progestagens’ concentration, the Lipizzan breed showed significantly lower levels of 20 beta-OH-progestagens than the Thoroughbred breed in the 10 weeks leading to parturition.
- Likewise, the Lipizzan breed had significantly lower concentrations of 20 beta-OH-progestagens than the Trotter breed in the last four weeks of gestation.
Changes in Hormone Levels after Birth
- The hormone levels in Thoroughbred mares reduced to their original baseline values within 4 days after giving birth — oestrogen levels declined by the third day, while progestagens diminished by the fourth day.
- This quick decrease indicates how rapidly the hormonal environment can change after birth and assists in understanding the hormonal shifts inside a mare’s body.
Conclusion
- The research concludes that high concentrations of progestagens (with 20 alpha- and 20 beta-hydroxyl groups) are present in the faeces of pregnant mares, particularly in the last month of gestation.
- In addition, notable breed-based hormonal disparities were noted during gestation, highlighting the need for breed-specific pregnancy monitoring.
Cite This Article
APA
Schwarzenberger F, Möstl E, Bamberg E, Pammer J, Schmehlik O.
(1991).
Concentrations of progestagens and oestrogens in the faeces of pregnant Lipizzan, trotter and thoroughbred mares.
J Reprod Fertil Suppl, 44, 489-499.
Publication
Researcher Affiliations
- Institut für Biochemie, Veterinary Medical University, Vienna, Austria.
MeSH Terms
- Animals
- Estrogens / analysis
- Feces / chemistry
- Female
- Gestational Age
- Horses / metabolism
- Immunoenzyme Techniques
- Labor, Obstetric
- Pregnancy
- Pregnancy, Animal / metabolism
- Pregnenes / analysis
- Progestins / analysis
Citations
This article has been cited 7 times.- Martínez L, de Andrés PJ, Caperos JM, Silván G, Fernández-Morán J, Casares M, Crespo B, Vélez D, Sanz L, Cáceres S, Illera JC. Predicting Sex in White Rhinoceroses: A Statistical Model for Conservation Management. Animals (Basel) 2023 Aug 10;13(16).
- Martínez L, Silván G, Cáceres S, Caperos JM, Fernández-Morán J, Casares M, Crespo B, de Andrés PJ, Illera JC. Preliminary Findings on How Different Management Systems and Social Interactions Influence Fecal Glucocorticoid Metabolites in White Rhinoceros (Ceratotherium simum). Animals (Basel) 2022 Mar 31;12(7).
- Lehman CP, Rota CT, Millspaugh JJ. Nutritional condition and physiological stress levels of elk in the Black Hills, South Dakota. PeerJ 2019;7:e7185.
- Stewart RA, Pelican KM, Brown JL, Wildt DE, Ottinger MA, Howard JG. Oral progestin induces rapid, reversible suppression of ovarian activity in the cat. Gen Comp Endocrinol 2010 Apr 1;166(2):409-16.
- Woolley LA, Millspaugh JJ, Woods RJ, van Rensburg SJ, Mackey RL, Page B, Slotow R. Population and individual elephant response to a catastrophic fire in Pilanesberg National Park. PLoS One 2008 Sep 17;3(9):e3233.
- Popp LG, Serafini PP, Reghelin AL, Spercoski KM, Roper JJ, Morais RN. Annual pattern of fecal corticoid excretion in captive Red-tailed parrots (Amazona brasiliensis). J Comp Physiol B 2008 May;178(4):487-93.
- Karaer MC, Kankılıç T, Tavşanoğlu Ç, Cotman M, Čebulj-Kadunc N, Dovč A, Snoj T. Effects of season and sex on the concentrations of fecal glucocorticoid metabolites in captive and free-ranging endangered mountain gazelles (Gazella gazella). Front Vet Sci 2024;11:1386009.
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