Genetic evaluation of Kenyan Boran herds and Kenya Boran embryo export in Kenya

Abstract

The Kenyan Boran cattle has remained a breed of interest for beef production by many countries because of its superiority in terms of growth, reproduction, carcass traits, maternal traits and cow productivity indices in the tropics over other Bos indicus and Bos taurus breeds. Due to this potential, Kenya BorancattJe are being used in the genetic improvement programmes of other indigenous and exotic cattle for beef and milk production in many countries, this has enhanced the export of Kenya Boran germplasm from Kenya to other parts of the world. Literature review, stakeholder interviews and records of growth(weaning weight and bulling weight) and reproductive performance (age at first calving and calving intervals) were used to analyse the legal and institutional frameworks in the access and export of Kenya Boran embryos from Kenya and to determine the performance of embryo donor cows relative to the rest of the population. Analysis for growth and reproductive performance were carried out by algorithm and sparse restricted maximum likelihood (ASREML) fitting an animal model and ignoring or including maternal genetic or permanent environmental effects. Different institutions were found to have facilitated and authorized the collection and export of the embryos, there was disharrnony in the way these regulatory functions were conducted. The poor interrelationship between the stakeholder institutions was a major constraint to monitoring and documentation of export of genetic materials, making it difficult to follow the movement of genetic materials beyond the borders of Kenya. Lack of proper documentation and clear provisions on how benefits derived from the utilization of exported animal genetic resources are to be distributed complicate any prospects of benefit sharing should such opportunities arise. Mean estimated breeding values (EBVs) for WW and AFC were regressed against year of birth while that of CI was regressed against year of calving to determine genetic trends for each trait. Direct heritability estimates for Mogwooni ranch were 0.36, 0.14 and 0.26 for WW, AFC and CI, respectively while that for Kapiti ranch were 0.21, 0.30, 0.03 and 0.11 for WW, BuW, AFC and CI respectively. The estimates of heritability obtained in the current study for growth and fertility traits indicate that genetic progress is possible for WW, AFC and CI through selection and good management. The Kenya Boran animals used as embryo donors were not "genetically superior" compared to the other animals born within the same years except that more of the embryo donors showed 'good performance for CI compared to the other traits analysed, which could be due to the long years they stayed in the herd before culling. The results of this study indicate that selection for recruitment into the embryo transfer program was not based on EBYs and the performance of animals used as embryo donors were not significantly different from the other animals for all the traits analysed.