Embryo recovery from exercised mares.
Abstract: The effect of exercise on mare reproductive efficiency was evaluated by comparing rates of embryo recovery from mares assigned to either an exercise regimen or a non-exercise (control) regimen. Exercised mares were worked daily for 30 min under average ambient conditions of >30 degrees C and >50% humidity. Mares were inseminated during estrus and subjected to uterine flush for embryo recovery on d 7 after ovulation for two consecutive cycles. After this, mares were allocated to the opposite group and allowed an estrous cycle without reproductive manipulation; then insemination and uterine flushing were conducted on two more consecutive cycles. Prostaglandin F(2alpha) was administered on the day of uterine flush. Mare rectal temperature increased during exercise from a mean of 38 degrees C to a mean of 39.9 degrees C. Mares had ovulations from smaller follicles when exercised than they did under control conditions (39.8+/-0.5 compared with 41.5+/-0.5mm diameter; P<0.05), and had an increased time from PGF(2alpha) administration to subsequent ovulation (8.47+/-0.337 compared with 9.27+/-0.294 d; P<0.05). Embryo recovery from control mares was 22 of 35 (63%). Fewer embryos were recovered from exercised mares (11 of 32, 34%; P<0.05). The proportion of embryos classified as Grade 1 tended to be less in exercised than in non-exercised mares (4 of 11, 36% compared with 16 of 22, 73%; P=0.051). These data indicate that exercising mares in a hot and humid environment are associated with changes in ovarian follicle development and ovulation, and a reduction in embryo recovery.
Publication Date: 2008-01-20 PubMed ID: 18295989DOI: 10.1016/j.anireprosci.2008.01.015Google Scholar: Lookup
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- Journal Article
Summary
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This research investigates the impact of physical exercise on the reproductive efficiency of mares, finding that regular exercise in warm, humid conditions may alter ovarian follicle development, ovulation, and decrease embryo recovery rates.
Study Design and Execution
- The study set out to evaluate the effect of exercise on mare reproduction by comparing embryo recovery rates from mares subject to exercise routines with those of mares in a non-exercise control group.
- The mares in the exercise group were made to work for 30 minutes daily under average ambient conditions of over 30 degrees Celsius and over 50% humidity.
- Both control and exercised mares were inseminated during their estrus period and then underwent uterine flushing for embryo recovery on the seventh day after ovulation for two consecutive cycles.
- To compare the effects, the mares were then swapped between the exercise and control groups for another two consecutive cycles.
- A hormone, Prostaglandin F(2alpha), was administered on the day of uterine flushing.
Observations and Findings
- Mares subjected to exercise showed increased rectal temperatures, rising from an average 38 degrees Celsius to about 39.9 degrees Celsius.
- Exercised mares ovulated from smaller follicles compared to those under control conditions, and they required more time from Prostaglandin F(2alpha) administration to subsequent ovulation.
- A significant decrease was observed in embryo recovery from exercised mares (34%) in comparison to the control group (63%).
- The number of embryos classified as Grade 1 (high quality) also tended to be lower in exercised mares compared to the non-exercised ones.
Conclusions
- From the observations and findings, the research concludes that regular exercise in a hot and humid environment can lead to changes in ovarian follicle development and ovulation in mares.
- Notably, exercising mares in such conditions has an adverse effect on embryo recovery rates and may also affect the quality of the embryos.
Cite This Article
APA
Mortensen CJ, Choi YH, Hinrichs K, Ing NH, Kraemer DC, Vogelsang SG, Vogelsang MM.
(2008).
Embryo recovery from exercised mares.
Anim Reprod Sci, 110(3-4), 237-244.
https://doi.org/10.1016/j.anireprosci.2008.01.015 Publication
Researcher Affiliations
- Department of Animal Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843-2471, USA. cmorten@clemson.edu
MeSH Terms
- Animals
- Body Temperature / physiology
- Embryo Transfer / veterinary
- Female
- Horses / physiology
- Insemination, Artificial / veterinary
- Male
- Ovulation Induction / veterinary
- Physical Conditioning, Animal / adverse effects
- Physical Conditioning, Animal / physiology
- Pregnancy
- Random Allocation
Citations
This article has been cited 4 times.- Kang H, Zsoldos RR, Sole-Guitart A, Narayan E, Cawdell-Smith AJ, Gaughan JB. Heat stress in horses: a literature review. Int J Biometeorol 2023 Jun;67(6):957-973.
- Benammar A, Derisoud E, Vialard F, Palmer E, Ayoubi JM, Poulain M, Chavatte-Palmer P. The Mare: A Pertinent Model for Human Assisted Reproductive Technologies?. Animals (Basel) 2021 Aug 4;11(8).
- Campbell ML. Embryo transfer in competition horses: Managing mares and expectations. Equine Vet Educ 2014 Jun;26(6):322-327.
- Alkhadrawy JMH, Aboelmaaty AM, Abou-Ahmed MM, Ghallab AM. Effect of breeding season and age on follicular dynamics and hemodynamics in embryo donor mares subjected to luteolysis after embryo flushing. Open Vet J 2024 Mar;14(3):852-865.
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