medigraphic.com
Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán

2004, Number 1

<< Back Next >>

Rev Biomed 2004; 15 (1)

Reproductive behavior of thoroughbred mares in a farm with deliveries at the beginning of the year

Vázquez-Dueñas S, Escobar-Medina FJ, Colina-Flores F, Hayden-Valles S

Language: Spanish
References: 23
Page: 27-31
PDF size: 32.22 Kb.


ABSTRACT

Introduction. The reproductive behavior of Thoroughbred mares bred in a farm located at 19° 30’N and 119° 27’ W, where deliveries are programmed to occur at the beginning of the year was studied.
Materials and methods. The mares were kept in grazing pasture and given supplemental feed on a daily basis. The breeding season runs from February 15 to June 30. From December 1 to January 31, the mares that failed to conceive were exposed to artificial light to extend natural photoperiod.
Results. The 35.7%, 17.8%, 19.4% and 12.4% of parturitions occurred in January, February, March, April, and May, respectively. The intervals from parturition and first estrus, first mating, and conception were 14, 25 and 117 days, respectively. 51.0% of ovulations occurred in the left ovary, 43.9% in the right ovary, and 5.1% showed corpora lutea in both ovaries. 48.3% of pregnancies developed in the right uterine horn, 47.5% in the left, and 4.2% in both. 42.9% of foals were females and 57.1% were males.
Discussion. As a result of restricting the mating season to the months of February to June and of exposing the females that failed to conceive in that period to an extended photoperiod during December and January, the incidence of parturitions was higher at the beginning of the year.


REFERENCES

  1. Ginther OJ. Occurrence of anestrus, estrus, diestrus and ovulation over a 12-month period in mares. Am J Vet Res 1974; 35: 1173-9.

  2. Neely DP. Reproductive endocrinology and fertility in the mare. En: Neely DP, Liu IKM, Hillman RB, editores. Equine Reproduction. Nutley, New Jersey: Hoffman-La Roche; 1983. p. 11-22

  3. González MAF, Valencia MJ. Estudio del comportamiento reproductivo de la yegua en México. Veterinaria México 1977; 8: 19-22.

  4. Orozco JL, Escobar MFJ, de la Colina FF. Actividad reproductiva de la yegua y la burra durante los días con menor cantidad de horas luz. Veterinaria México 1992; 23: 47-50.

  5. Hintz HF, Hintz RL, Lein DH, Van Vleck LD. Length of gestation periods in Thoroughbred mares. Equine Med Surg 1979; 3: 289-92.

  6. Escobar MFJ. Comportamiento reproductivo de la yegua y la burra. Veterinaria Zacatecas 1997; 1: 22-6.

  7. Bronson FH, Heideman PD. Seasonal regulation of reproduction in mammals. En: Knobil E, Neill JD, editores. The Physiology of Reproduction. 2nd ed. New York: Raven Press; 1994. p. 541-84.

  8. Kooistra LH, Ginther OJ. Effect of photoperiod on reproductive activity and hair in mares. Am J Vet Res 1975; 36: 1413-9.

  9. Oxender WD, Noden PA, Hafs HD. Estrus, ovulation, and serum progesterone, estradiol and LH concentrations in mares after an increased photoperiod during winter. Am J Vet Res 1977; 38: 203-7.

  10. Scraba ST, Ginther OJ. Effect of lighting programs on onset of ovulatory season in mares. Theriogenology 1985; 24: 667-79.

  11. Knuth DE. Seminumerical algorithms. The art of computer programming. Reading (Mass): Addison Wesley, 1981.

  12. Cochran WG. Técnicas de muestreo. Bogotá, Colombia: C.E.C.S.A.; 1978.

  13. Matthews RG, Ropiha RT, Butterfield RM. The phenomenon of foal heat in mares. Aust vet J 1967; 43: 579-82.

  14. Saltiel A, Gutiérrez A, de Buen-Llado N, Sosa C. Cervico-endometrial cytology and physiology aspects of the post-partum mare. J Reprod Fertil 1987; 35 (suppl): 305-9.

  15. Saltiel A, Calderon A, Garcia N, Hurley DP. Ovarian activity in the mare between latitude 15° and 22°N. J Reprod Fertil 1982; 32 (suppl): 261-67.

  16. Palmer E, Driancourt MA, Ortavan R. Photoperiodic stimulation of the mare during winter anoestrus. J Reprod Fertil 1982; 32 (suppl): 275-82.

  17. Fitzgerald BP, McManus C. Photoperiodic versus metabolic signals as determinants of seasonal anestrus in the mare. Biol Reprod 2000; 63: 335-40.

  18. Kersten S. Mechanisms of nutritional and hormonal regulation of lipogenesis. EMBO Rep 2001; 2: 282-6.

  19. Barash IA, Cheung CC, Weigle DS, Ren H, Kabigting EB, Kuijper JL, Clifton DK, Steiner RA. Leptin is a metabolic signal to the reproductive system. Endocrinology 1996; 137: 3144-7.

  20. Merkt H, Gunzel AR. A survey of early pregnancy losses in West German Thoroughbred mares. Equine vet J 1979; 11: 256-66.

  21. Bell RJ, Bristol F. Fertility and pregnancy loss after delay of foal oestrus with progesterone and oestradiol-17b. J Reprod Fertil 1987; 35 (suppl): 667-8.

  22. Koskinen E, Katila T. Uterine involution, ovarian activity, and fertility in the post-partum mare. J Reprod Fertil 1987; 35 (suppl): 733-4.

  23. Woods GL, Baker CB, Baldwin JL, Ball BA, Bilinski J, Cooper WL, Ley WB, Mank EC, Erb HN. Early pregnancy loss in brood mares. J Reprod Fertil 1987; 35 (suppl): 455-9.




2020     |     www.medigraphic.com