Efficacy of Crestar (Progesterone analogue) and Prosolvin (Prostaglandin analogue) in heat synchronization of indigenous smallholder dairy and commercial beef cows

Abstract

Efficient breeding program for livestock improvement cannot be designed in the absence of prior knowledge of heat synchronization coupled with artificial insemination. Comparison of a prostaglandin (Prosolvin) and a progesterone analogue (Crestar) in heat synchronization in smallholder dairy and commercial beef cows was done in Mutoko, Beatrice and Marondera. The research aimed at establishing the estrus response and conception rates of animals synchronized. A total of 106 cows of Mashona, Brahman and Tuli breeds in second and third parity were used in the study. All the cows were of body condition score three. Equal numbers of animals were treated with Prosolvin and Crestar in three districts, ear tagged and confined in the paddock. The stockmen were responsible for estrus detection. Insemination was done based on the AM-PM rule. Conception rates were determined after three months by rectal palpation. The data was subjected to Chi-Square Tests for association using Gen Stat Statistical Package (7.2 version). The Prosolvin treated cows had a higher estrus response of 85% while the Crestar treated animals had a lower mean estrus response of 67%. The parity, cow breed and enterprise had no significant effect on estrus response (P>0.05). Silent estrus was associated with Crestar treated cows significantly more (7%) than with Prosolvin treated cows (2%). The treatments for heat synchronization had no significant effect on conception rate (P>0.05). The parity, cow breed and breed of semen used for insemination had a significant effect on conception rate (P<0.05) with third parity, Tuli breed and Red Dane semen breed having the highest conception rate (54%, 54% and 58% respectively). The procedures of thawing frozen semen and the techniques of semen deposition through the cervix have to be properly followed to achieve high conception rates. Animals can also be inseminated twice to increase chances of conception. Keywords: Artificial Insemination, Brahman, conception rate, estrus, Mashona, Tul