Superovulation in llamas (Lama glama) with pFSH and equine chorionic gonadotrophin used individually or in combination.
The purpose of this experiment was to evaluate the efficacy of pFSH and/or equine chorionic gonadotrophin (eCG) for inducing superovulation in llamas. Sixteen adult llamas weighing on average 130 kg (range 110-140) and which had been showing signs of oestrus for 5 days were randomly allocated to three treatment groups and one control group (n = 4). Llamas in Group A received eCG (500 IU, i.m.) once daily for 3 days, those in Group B received pFSH i.m., in decreasing doses every 12 h for 5 days for a total of 220 mg, while those in Group C received eCG (500 IU, i.m.) once, and pFSH (total of 156 mg, i.m.) in decreasing doses for the next 4 days. Llamas in Group D (control) received saline (5 ml, i.m.) every 12 h for 5 days. All llamas were allowed to be mated on the evening of Day 5 and were given hCG (750 IU, i.m.) at that time; a second mating was carried out 12 h later. A non-surgical ova/embryo collection technique was performed 7 days after the first mating and then the ovarian response was evaluated by way of laparoscopy. All 16 llamas were mated successfully. The mean (SEM) number of ovulations (7.3 +/- 3.1) in Group B was significantly higher (P < 0.05) than in the other groups (1.5 +/- 0.5, 2.0 +/- 0.7, and 0.3 +/- 0.3 for groups A, C and D, respectively). The number of follicles > 10 mm at the time of ova/embryo collection was significantly higher (P < 0.05) in the groups treated with eCG. A total of 21 ova/embryos was recovered from the all flushed llamas, corresponding to 47.7% of corpora lutea observed. Of the 21 ova, 15 were fertilised; 13 of those were classified as excellent blastocysts and the remaining 2 were classified as dead or degenerating. Results demonstrate that llamas can be successfully ovarian superstimulated while expressing behavioural oestrus and suggest that pFSH is more effective than eCG to induce superovulation.
Correa
J E
JE
Faculty of Veterinary Sciences, Universidad Austral de Chile, Valdivia, Chile.
Ratto
M H
MH
Gatica
R
R
D000704:Analysis of Variance; D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000502:physiology; D002161:Camelids, New World / Q000502:physiology*; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000494:pharmacology*; D003338:Corpus Luteum / Q000187:drug effects / Q000502:physiology; D004338:Drug Combinations; D004971:Estrus / Q000187:drug effects / Q000502:physiology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006736:Horses; D010535:Laparoscopy / Q000662:veterinary; D008297:Male; D010053:Ovary / Q000187:drug effects / Q000502:physiology; D011247:Pregnancy; D011897:Random Allocation; D013480:Superovulation / Q000187:drug effects* / Q000502:physiology; D013552:Swine
D006063:Chorionic Gonadotropin; D004338:Drug Combinations; D005640:Follicle Stimulating Hormone