Behavioral, follicular and gonadotropin changes during the estrous cycle in donkeys.
Abstract: Sexual behavior, follicular development and ovulation, and concentrations of circulating gonadotropins during the estrous cycle were studied during the summer in 7 jennies. Mean behavioral estrous length was 6.4 +/- 0.6 days (mean +/- SEM, n=19; 5.6 +/- 0.5 days preovulatory and 0.8 +/- 0.2 days post-ovulatory). Mean diestrous length was 19.3 +/- 0.6 days (n=14). Females in estrus typically showed posturing, mouth clapping, clitoral winking, urinating and tail raising. Mouth clapping began approximately one day sooner and lasted approximately one day longer than winking and tail raising, so that the total duration of clapping was significantly greater than for the other two signs. Follicular changes and concentrations of gonadotropins were determined for 14 estrous cycles (2 per jenny). The follicular end points [diameter of the largest follicle and number of large (>25 mm), medium (20-24 mm), and small follicles (<20 mm)] showed a significant day effect. The diameter of the largest follicle and the number of large follicles began to increase significantly 7 days prior to ovulation with a maximum value the day before ovulation. Medium follicles reached a maximum number 4 days prior to ovulation, and small follicles decreased significantly prior to ovulation. After ovulation, all follicular end points, except the number of small follicles, remained low for the next 12 days. Mean values of FSH were low during estrus and high during diestrus with 2 significant peaks, one 3 days and one 9 days after ovulation. In contrast, mean levels of LH were low during diestrus and high during estrus with a maximum value the day after ovulation. The LH profile showed a more prolonged gradual increase prior to ovulation, than that which has been reported for ponies and horses.
Publication Date: 1981-08-01 PubMed ID: 16725637DOI: 10.1016/0093-691x(81)90106-0Google Scholar: Lookup
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Summary
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This research article explores the sexual behavior, follicular development and ovulation, and gonadotropin concentrations changes during the estrous cycle of jennies (female donkeys) during the summer. The research teams extensively analyses the length of behavioral estrous, the specific behaviors females exhibit in estrus, the changes in follicular size and count, and the varying levels of gonadotropins across the estrous cycle leading up to and following ovulation.
Behavioural Changes
- The study observed a set of behavioral patterns related to sexual readiness in the female donkeys during their estrous cycle. These behaviors comprised of posturing, mouth clapping, clitoral winking, urinating and tail raising.
- The mean behavioral estrous (period of sexual receptivity and fertility) length was found to be around 6.4 days, out of which approximately 5.6 days were preovulatory and around 0.8 days were post-ovulatory. Diestrous (period of sexual inactivity) length averaged to about 19.3 days.
- The research indicated that mouth clapping behavior began approximately one day sooner and lasted roughly one day longer than the other behaviors, indicating it as a dominant sign in the cycle.
Follicular Changes
- The changes in the ovaries were seen in terms of follicular growth, with follicular end points like the diameter of the largest follicle and the count of large, medium and small sized follicles being tracked.
- About 14 estrous cycles were studied, and it was seen that the diameter of the largest follicle and the count of the larger follicles significantly increased 7 days prior to ovulation, reaching a maximum the day before ovulation.
- Medium sized follicles gathered their maximum number 4 days before ovulation; however, small follicles decreased significantly before ovulation. Post-ovulation, all follicular end points except small follicles remained low for a 12-day period.
Gonadotropin Changes
- The study also observed the variations in concentrations of two key hormones – Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) – during estrus and diestrus.
- FSH levels were typically low during estrus, and high during diestrus with two significant peaks observed 3 and 9 days after ovulation.
- Conversely, LH levels remained low during diestrus, peaking during estrus, with the greatest value appearing the day after ovulation. The increase in LH was more gradual and prolonged before ovulation as compared to what is reported for horses and ponies.
Cite This Article
APA
Vandeplassche GM, Wesson JA, Ginther OJ.
(1981).
Behavioral, follicular and gonadotropin changes during the estrous cycle in donkeys.
Theriogenology, 16(2), 239-249.
https://doi.org/10.1016/0093-691x(81)90106-0 Publication
Researcher Affiliations
- Department of Veterinary Science, University of Wisconsin, Madison, Wisconsin 53706 USA.
Citations
This article has been cited 6 times.- Aoki T, Shibata M, Violin G, Higaki S, Yoshioka K. Detection of foaling using a tail-attached device with a thermistor and tri-axial accelerometer in pregnant mares.. PLoS One 2023;18(6):e0286807.
- Segabinazzi LGTM, Gilbert RO, Ambrosia RL, Bergfelt DR, Samper JC, Peterson EW, French HM. Structural and Functional Dynamics of the Ovary and Uterus during the Estrous Cycle in Donkeys in the Eastern Caribbean.. Animals (Basel) 2022 Dec 24;13(1).
- Dorado J, Bottrel M, Ortiz I, Díaz-Jiménez M, Pereira B, Consuegra C, Carrasco JJ, Gómez-Arrones V, Domingo A, Hidalgo M. Factors Affecting Embryo Recovery Rate, Quality, and Diameter in Andalusian Donkey Jennies.. Animals (Basel) 2020 Oct 26;10(11).
- Derar RI, Hussein HA. Ovarian Follicular Dynamics during the Estrous Cycle in Jennies in Upper Egypt.. Vet Med Int 2011;2011:860518.
- Lemma A, Schwartz HJ, Bekana M. Application of ultrasonography in the study of the reproductive system of tropical jennies (Equus asinus).. Trop Anim Health Prod 2006 May;38(4):267-74.
- Fielding D. Reproductive characteristics of the jenny donkey--Equus asinus: a review.. Trop Anim Health Prod 1988 Aug;20(3):161-6.
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