Pandey, A. K., Gupta, S. K., Rao, M. Mutha, Kalsotra, Rajat, Dubey, Nitin, Sharma, Utsav, and Kaul, A. K.
Rambouillet sheep (n=15) were subjected to superovulation treatment using FSH (Folltropin-V, Bioniche Animal Health, Canada) during the period between August and November, 2013. The sheep were randomly divided into two groups. Group 1 (n=7) animals were administered 80 mg of NIH-FSH-P1 in six divided doses for 3 days at 12 hour interval in a tapering doses schedule (20 mg, 20 mg, 15 mg, 15 mg, 5 mg and 5 mg) where as ewes of Group 2 (n=8) were given 100 mg NIH-FSH-P1 in the tapering dose schedule (25 mg, 25 mg, 15 mg, 15 mg, 10 mg and 10 mg) as that of group 1. All the ewes received progesterone (P4) impregnated vaginal sponges for 12 days with FSH treatment initiated either on day 9 or 11 and 200 IU eCG along with first/fifth FSH injection. P4 sponges were withdrawn at the time of penultimate FSH injection. Oestrus detection was done using apronized rams from 24-48 hr after sponge withdrawal and those in oestrus were naturally served for 2-3 times at 12 hr interval. Embryos were collected by retrograde surgical technique between day 3 and 5 after oestrus. Animal with two or more corpora lutea (CL) were considered to have responded to superovulation (SOV) treatment. A 57.14 % (4/7) and 75% (6/8) ewes of group 1 and 2, respectively responded to SOV treatment. The ovarian response was highly variable and ranged between two and eight CL irrespective of groups. The mean ovarian response was 2.0±1.06 (14/7) and 2.37 ± 0.8 (19/8) in groups 1 and 2, respectively. The mean number of transferable embryos in groups 1 and 2, respectively was 1.0± 0.57 (4/4) and 1.83 ±0.75 (11/6). The mean ovarian response as well as embryo recovery did not differ significantly (P >0.05) between groups. From the results it may concluded that the reasons for poor ovulation rate (over all 2.2 ± 0.63; 33/15), high anovulation rate (over all 3.4 ± 0.93; 51/15), poor embryo recovery rate (45.45%; 15 embryos/33 CL) as well as less no. embryos recovered per animal (over all 1.50 ± 0.5) need to be investigated and warrant further studies. [ABSTRACT FROM AUTHOR]