Evaluation of Some Reproductive Traits in Local Kenana heifer and Crossbred Cows in Relation to Nutritional and Hormonal Treatment

Abstract

The effect of nutrition and hormonal treatment on ovarian stimulation was investigated in the first experiment. In this experiment 6 kenana heifers were used, they were fed steaming up ration for 3 months after that all heifers were inserted with 2 sponges impregnated with progesterone. They were left for 7 days, on days 6 all the heifers were injected with prostaglandin PGF2a(500mg). The sponges were removed on day 7, and at the same day they were injected with GnRH(0.2mg ). A bull was introduced 72 hours after GnRH treatment for natural insemination. The results showed that the response to nutritional and hormonal treatment were 33.3%, and these responded heifer showed estrus 24 hours at the end of hormonal treatment, 33.3% of heifers showed mating behaviours without a clear estrus signs, while 33.3% of heifers did not responded. In experiment two 12 crossbreed cows were used and divided randomly to two groups. In group (A) 5 cows were treated with single injection of prostaglandin PGf2a(500mg)after 72 hours they were artificially inseminated (A.I). In group (B) 7 cows were treated with 2 injection of PGf2a (500mg), 11 days apart and artificially inseminated 72 hours, after the second injection. The results of this experiment showed that three cows (60%) of ix cows in group A showed estrus sings 24 hours after treatment, while two cows (40%) did not show estrus behaviour. Pregnancy test after 60 days performed by rectal palpation, showed that 60% for cows gave positive results while 40% gave negative result in group (A). In group B five of seven cows (71.4%) showed estrus behaviour 24 hours after the first injection of PGF2a, all cows (100%) in group B were observed in estrus after the second injection of PGF2a. Results of rectal palpation showed that all cows (100%) were pregnant 60 days after insemination.