Influence of endophyte-infected tall fescue on serum prolactin and progesterone in gravid mares.
Abstract: Thirty mares in late gestation were used in a 3-yr study to assess effects of the tall fescue endophyte Acremonium coenophialum on serum prolactin (PRL) and progesterone. Two paddocks of each treatment, 0 or 100% infected 'Kentucky 31' tall fescue, were grazed by the mares for 21 d. Blood was collected three times per week until parturition. At 7-d intervals, mares were challenged with thyrotropin-releasing hormone (TRH) while grazing and blood was collected postinjection. Mares grazing 100% infected tall fescue (E+) had decreased serum PRL compared with mares grazing the 0% infected tall fescue (E-) in 2 of 3 yr. Within 8 d postgrazing, serum PRL for E+ mares equaled or surpassed values of the E- mares. Serum PRL was not different during the 3rd yr. In response to TRH, serum PRL rate of increase was similar between treatments but remained elevated (P less than .01) in the E+ mares at the 180-, 240-, and 300-min sample times. Serum progesterone was lowered (P less than .05) by E+ but increased to control values within 10 d postgrazing. It is concluded that serum PRL and progesterone in the gravid mare were decreased by the presence of A. coenophialum in 'Kentucky 31' tall fescue grass but normal levels were reestablished within 2 to 3 wk.
Publication Date: 1992-01-11 PubMed ID: 1582909DOI: 10.2527/1992.701217xGoogle Scholar: Lookup
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- Journal Article
Summary
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This study investigates the effects of a fungal endophyte, Acremonium coenophialum, in tall fescue grass on the levels of serum prolactin and progesterone hormones in pregnant horses.
Introduction
- The research was targeted at the effects of a fungal grass parasite, Acremonium coenophialum, that infects ‘Kentucky 31’ tall fescue grass, on the hormone levels in pregnant (gravid) mares.
- The hormones examined were serum prolactin (PRL), which plays a critical role in milk production, and progesterone, which is important for maintaining pregnancy.
Methodology
- The study used thirty mares in late pregnancy over the course of three years.
- The horses were allowed to graze either on 0% or 100% infected tall fescue grass for 21 days.
- Blood samples were taken three times a week until delivery. Additionally, every seven days, the mares were injected with thyrotropin-releasing hormone (TRH), which regulates the production of PRL, and blood samples were taken post-injection.
Findings
- The study found that mares grazing on entirely infected grass had lower levels of serum PRL compared to those grazing on grass with no infection for two out of the three years studied.
- However, these levels returned to normal or exceeded those of mares grazing on non-infected grass within eight days of stopping grazing on the infected grass.
- In response to TRH injections, initially, the rate of PRL increase was similar for both groups, but it stayed high in mares grazing on the infected grass at later periods—180, 240, and 300 minutes following the injection.
- The level of progesterone was lowered by grazing on the infected grass, but this effect was temporary, with levels returning to normal within ten days after grazing on the infected grass stopped.
Conclusion
- The presence of A. coenophialum in fescue grass decreased the levels of the serum PRL and progesterone hormones in pregnant mares.
- However, the effect was temporary, and hormone levels returned to normal within 2 – 3 weeks after stopping grazing on the infected grass.
Cite This Article
APA
McCann JS, Caudle AB, Thompson FN, Stuedemann JA, Heusner GL, Thompson DL.
(1992).
Influence of endophyte-infected tall fescue on serum prolactin and progesterone in gravid mares.
J Anim Sci, 70(1), 217-223.
https://doi.org/10.2527/1992.701217x Publication
Researcher Affiliations
- Department of Animal and Dairy Science, University of Georgia, Athens 30602.
MeSH Terms
- Acremonium / growth & development
- Animal Feed
- Animals
- Female
- Food Microbiology
- Horses / blood
- Poaceae / microbiology
- Pregnancy
- Pregnancy, Animal / blood
- Progesterone / blood
- Prolactin / blood
- Random Allocation
- Thyrotropin-Releasing Hormone / pharmacology
Citations
This article has been cited 4 times.- Ferguson TD, Vanzant ES, McLeod KR. Endophyte Infected Tall Fescue: Plant Symbiosis to Animal Toxicosis. Front Vet Sci 2021;8:774287.
- Britt JL, Greene MA, Wilbanks SA, Bertrand JK, Klotz JL, Bridges W Jr, Aiken G, Andrae JG, Duckett SK. Feeding Tall Fescue Seed Reduces Ewe Milk Production, Lamb Birth Weight and Pre-Weaning Growth Rate. Animals (Basel) 2020 Dec 3;10(12).
- Britt JL, Greene MA, Bridges WC, Klotz JL, Aiken GE, Andrae JG, Pratt SL, Long NM, Schrick FN, Strickland JR, Wilbanks SA, Miller MF, Koch BM, Duckett SK. Ergot alkaloid exposure during gestation alters. I. Maternal characteristics and placental development of pregnant ewes1. J Anim Sci 2019 Apr 3;97(4):1874-1890.
- Duckett SK, Andrae JG, Pratt SL. Exposure to ergot alkaloids during gestation reduces fetal growth in sheep. Front Chem 2014;2:68.
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