Response of cross breed and local Cows to estrus synchronisation using a prostaglandin or a combination of prostalglandin and progestrone
Two studies were conducted in Mazabuka (Southern province) to investigate the response of crossbreed and local cows to estrus synchronization using prostaglandin and progesterone.The study involved 55 crossbreed cows and 35 local cowsof body condition score of atleast 2.0. Study 1 involved 35 crossbreed cows and 35 local cows. A l l the cows were injected with 2ml of alfaglandin (prostaglandin) and repeated 11 days later. The cows were then observed for estrus signs. In study 2, a total of 55 crossbreed cows were used. Of these , 35 cows were injected with 2ml alfaglandin while 20 cows were inserted with vaginal implants(CIDRs) followed by an injection of 2ml of ciderol; on day 8, the 20 cows were injected with 2ml of alfaglandin. Estrus signs were observed in all the cows. The cows that were observed to be on estrus were artificially inseminated 12 hours after they were first seen on heat. In study 1, the results obtained showed that the response rate for the crossbreed cows and the local cows that were given alfaglandin were relatively low (34% andl4% respectively). The crossbreed cows had a higher response rate as compared to the local cows. There were no significant differences in the response time to estrus synchronization between the two breeds. BCS had an effect on the response rate and cows with a BCS of 3 had the highest response rate. In study 2, the results obtained showed that the response rate for the crossbreed cows that were inserted with a vaginal implant and given an alfaglandin injection had a higher response as compared to the crossbreed cows that were given alfaglandin only (55% and34% respectively). There were no significant differences in the response time to estrus synchronization between the two protocols. BCS had an effect on the response rate and cows with a BCS of 3 had the highest response rate. The most important finding of the first study is that the rate of response to estrus did differ between the two breed. These results support the concept that there are disparities in several reproductive characteristics in Bos indicus and Bos Taurus cattle. Another important outcome of the study was that the response to synchronization occurred over a range of hours such that it was not possible to achieve timed Artificial insemination (TAI). It was concluded that the protocol was not economically viable for use by farmers. In the second experiment, it was concluded that the prostaglandin + progesterone protocol was more effective in synchronizing estrus as compared to the prostaglandin protocol. The response rate was within the expected range and it was possible to do TAI. It was then concluded that the prostaglandin+ progesterone protocol was economically viable for use by farmers.
- Agriculture