Repeat Breeding In Bos Taurus In Makueni, Kakamega And Nandi Counties, Kenya

Abstract

The optimum dairy cattle production aims at getting a calf per cow per year. This is, however, limited by bovine repeat breeding syndrome (RBS) caused by fertilization failure or early embryonic death among others. Although RBS in bovine has been studied widely in other countries, there is a scarcity of information on RBS in Kenya’s small scale dairy cattle. This study therefore aimed at estimation of the prevalence of RBS in selected counties in Kenya, with the following specific objectives: (1) To determine the prevalence of RBS in cattle. (2) To determine the risk factors associated with the occurrence of RBS in cattle and (3) To estimate the direct losses due to RBS. Non-experimental cross-section study was carried out in 205 small scale dairy farms in three counties of Kenya. A total of 553 cows/heifers were recruited and per rectal examination performed to determine their reproductive status. Cow-level and management-level risk factors, as well as the cost of semen, were acquired through a questionnaire. Chi-square statistic was used to determine the unconditional association between RBS and the risk factors at p<0.05. Univariate and multivariate mixed-effect logistic regression was carried out to model the effects of cow-level and management-level risk factors against the RBS. The results revealed that among the small scale farmers Friesians were the popular breed at 52.98% followed by Ayrshire, Crosses, Guernsey and Jersey at 36.89%, 6.51%, 2.17% and 1.45% respectively. The mean age of cattle in the farms was 5 years. Strict AI use was at 87%, 68% and 25% in Makueni, Kakamega and Nandi Counties respectively while natural service was 13%, 32% and 75% in the same counties respectively. The overall prevalence of RBS in cattle in the three counties was at 18.44%, while the average number of services per conception was 1.86 which is above the recommended 1.5. Makueni County had the highest prevalence of RBS in xvi cattle (31.96%) followed by Kakamega and Nandi County at 20.85% and 12.5% respectively. In addition, the majority of farms had poor adoption of early pregnancy diagnosis (PD) which would delay the realization and treatment of RBS in the affected herds. It was also revealed that crossbred cattle in all the counties had the highest percentage of RBS (38.9%) compared to purebred cattle. In addition, cattle kept in zero-grazing system (30.1%) had the highest level of RBS as compared to other grazing systems. The parity and age of the cattle were also relevant to RBS with 76% of cattle with RBS being multipara and 65% being over the age of 4 years. Significantly majority of farmers (71.22%) had no training on heat detection, with only 20% of farmers aware of mounting and standing to be mounted as the primary sign of heat in cattle. The direct estimated annual loss associated with RBS was over 1 billion Kenya shilling as a result of the cost of lost straws of semen associated with the syndrome. The factors that were found to be positively associated with RBS were: breed of the cattle (P = 0.0382) and Ovarian dynamics (P = 0.0016) whereas the effect of training on heat detection and by whom (P = 0.0202) and the grazing system under which the cattle were kept (P =0.0037) were negatively associated with RBS. It is concluded that RBS has a high prevalence in the Kenya small scale dairy farms with high economic losses associated with the syndrome. In particular, crossbreeding increases the rate of RBS in cattle. There was as well a hormonal-linked cause of RBS which was established on the basis of the ovarian dynamics. There is inadequate training of farmers on heat detection which affects the breeding in cattle and consequently the success rates of AI. Cattle in the zero-grazing system were more affected by RBS and therefore, farmers in these setups need to be more equipped in dealing with the syndrome. In monetary terms, RBS is causing an annual loss of over 1 billion Kenyan shillings within the small scale dairy industry. xvii Based on the study, it is recommended that the small scale dairy farmers be encouraged to keep more purebred cattle. Similarly per rectal examination of the reproductive system should be performed in cattle to address the management of RBS. The nutrition status of the cows should be improved and maintained at a good body condition as well as provide the required mineral supplementation to reduce the infertility cases. Early post service PD is strongly advocated for in identification, diagnosis and treatment of RBS. Finally, animal welfare should be improved and adhered to especially in the zero-grazing system; to ensure the cows are not under any stress hence improve the estrus sign of mounting and standing to be mounted which is crucial in calculation of service time.