Factors affecting conception rates in cattle following embryo transfer
Embryo Transfer Technology (ETT) plays an important role in improving productivity of dairy cattle (Bos indicus). Embryo Transfer Technology allows top quality female livestock to improve a herd or flock in much the same way that artificial insemination has allowed greater use of superior sires. The technology hastens genetic enhancement by virtue of its capacity to reduce generation interval and is also useful in progeny testing programmes. A retrospective study analysed conception rates data collected over a period of six years, from 2007 to 2012. A total of 115 embryos had been transferred during that period. The factors affecting conception rates (CR) included embryo developmental stage, deposit site and stage of recipient in days after estrus. The deposit site had a significant effect on CR (χ2 =0.27395; p<0.05). The quality and stage of the embryo development influenced the CR. Generally, CR reduced as the growth of the embryo. Days after estrus also significantly affected the CR, whereby transfer on day 8 resulted in more conceptions in recipient animals. Even though ETT has several benefits and requires consistent promotion, challenges such as lack of trained personnel and equipment for ovulation and packaging of embryos at the farm site need to be addressed.
Key words: Artificial insemination, Bos indicus, conception rate