SUPEROVULATION OF ACYCLIC CROSSBRED HEIFERS

The study was conducted on 4 crossbred heifers, each of which were ind uced to superovulate twice at suitable period of interval alternately with 1 of the 2 treatments. Treatment group - A (n = 4) comprised cont rolled internal drug release (implant contains 1.9 g (progesterone) va ginal implant for 9 days plus 75 units NIH standard FSH administered i n 6 equally divided doses at 12 hr intervals on days 7, 8 and 9 of the implant (implantation day = day 0). The implant was withdrawn at the time of fifth injection of FSH. Treatment group - B (n = 4) was same a s A except that 1000 IU PMSG was also administered on day sixth in add ition to vaginal implant and FSH. Rectogenital palpation revealed that 3/4 animals responded in both the treatment groups. One animal did no t respond and developed polycystic ovaries after group - A treatment. All the 3 animals of group - A and 2/3 animals of group - B yielded 20 and 23 embryos/ova, respectively. The 20 embryos/ova of group - A inc luded 4 retarded, 6 morulae and 10 compact morulae, of which 2, 4, 5, 5 and 4 were graded as excellent. good, fair, poor and retarded, respe ctively. The 23 embryos/ova of group - B included 4 unfertilized, 8 mo rulae, 2 compact morulae and 9 blastocysts, of which 17, 2 and 4 were graded as good, fair and retarded/unfertilized, respectively. Superovu lation response and total embryo recovery did not decline after repeat ed treatment but the average quality of embryos produced after repeate d superovulation was inferior. Unfertilized, fragmented and retarded e mbryos/ova were recovered after repeated treatments only. Many of the embryos produced out of repeated treatment were sticky. These findings gave an indication that inferior quality of embryos after repeated su perovulation might be clue to subclinical endometritis.