Timing of mating and ovarian response in llamas (Lama glama) treated with pFSH

Anim Reprod Sci. 1997 Aug;48(2-4):325-30. doi: 10.1016/s0378-4320(97)00047-x.

Abstract

The effect of the timing of mating on ovarian response in llamas was evaluated using 20 adult llamas weighing 90-120 kg which had been in oestrus for 5 days and were treated with 20 mg pFSH every 12 h for the following 5 days (total dose: 200 mg of FSH-NIH-P1). They were randomly allocated to Group A (N = 10) and mated immediately at the end of pFSH treatment or to Group B (n = 10) and mated 36 h after the end of pFSH treatment. Llamas of both groups were given hCG (750 iu, i.m.) immediately after mating. A second mating was allowed 12 h later. Ova and embryos were recovered by non-surgical uterine flushing 7 days after the first mating. Ovarian response was immediately evaluated afterwards via laparoscopy. The mean ovulation rate of 4.5 corpora lutea for Group A was significantly lower (P < 0.01) than the mean of 13.8 observed for Group B. The total ovarian response (number of corpora lutea + follicles > 10 mm) was also significantly higher (P < 0.01) in Group B than in Group A. Twenty-seven ova were recovered in each group, corresponding to 60% and 20% (P < 0.01) of the corpora lutea observed in Groups A and B, respectively; however, no significant difference (P > 0.05) in fertilisation rate was observed. The results show that pFSH induces superovulation in llamas treated during oestrus and that a 36-h interval between the end of FSH treatment and mating increases ovulation rate and the total ovarian response but does not affect the number of ova/embryos recovered.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Camelids, New World / physiology*
  • Cohort Studies
  • Estrus / drug effects
  • Estrus / physiology*
  • Female
  • Follicle Stimulating Hormone / administration & dosage
  • Follicle Stimulating Hormone / pharmacology*
  • Ovulation Induction / methods*
  • Random Allocation
  • Sexual Behavior, Animal
  • Superovulation / drug effects
  • Superovulation / physiology*

Substances

  • Follicle Stimulating Hormone