Brief Communication: Effect of Post-Mating Pro Gestagen Administration on Pregnancy Rate in Crossbred Goats Following an Induced Estrus

Abstract

Estrus induced with progesterone or progestagens have low fertility compared to natural estrus. However, post-mating progesterone administration has been reported by increases embryo development and pregnancy rate; therefore the aim of this study was to evaluate the effect of post-mating progestagen administration on pregnancy rate after medroxyprogesterone acetate (MAP) induced estrus in crossbred goats. Estrus induction was started at 31.3 Ó 1.7 days post-partum with intra- vaginal sponges impregnated with 60 mg of MAP during 14 days and at time of sponge removal were applied 500 IU of eCG intramuscular. Estrus was detected every 6 hours from 24 hours onwards after sponge withdrawal. Goats were naturally mated with two entry bucks. Five days post-mating, mated goats were randomly assorted into two groups, control group (n=18), without any treatment, and MAP group (n=18), receiving a sponge with 60 mg of MAP for fourteen days. Ultrasonographyc diagnosis of pregnancy was performed at day 50 post-mating. MAP treatment, did not affect the pregnancy rate, with 44.4% (8/18) in MAP group, while in control group was 55.5% (10/18), P>0.05. In conclusion, MAP treatment with a sponge impregnated with 60 mg of MAP between days 5 and 19 post-mating did not affect the pregnancy rate after progestagen induced estrus during the early post-partum period in crossbred tropical goats