Tropicultura (Jan 2000)
Effet dose-réponse de la gonadotropine (PMSG) sur la reproduction de la brebis Djalonké variété 'Mossi'
Abstract
Dose Effects of Pregnant Mare Serum Gonadotropin on Reproductive Performances of Djalonke var. 'Mossi' Ewes. The dose/response effects of PMSG (Pregnant Mare Serum Gonadotropin) were appreciated in 3 lots of Djalonke var. 'Mossi' ewes synchronised using an intravaginal device of progestagen associated with 0 ; 200 or 400 IU of PMSG. The use of ram jumping combined with plasma progesterone measurements showed that in the ewes treated with PMSG, estrus occured earlier after sponge removal : 54.7 ± 18 h in lot 0 ; 37.2 ± 12.5 h in lot 1 and 34.4 ±12 h in lot 2. However, the duration of estrus increased : 38.4 ± 36.3 h (lot 0), 43.2 ± 10.7 h (lot 1) and 57.6 ± 27.3 h (lot 2). The ovum of ewes treated with PMSG were not all good for fertilization and pregnancy because of the repeat heat frequency and fetus deaths found in the PMSG treated group. There is a dose dependant relation with PMSG, and the 200 IU of lot 1 seem to be better than the 400 IU of lot 2. Moreover during parturition, mortinatality was found in lot 2. The reproductive performances were weak for the lot without PMSG and may be related to the use of a progestagen standard dose not adapted to the small format of Djalonke var. 'Mossi' ewe.
