Breeding Strategies For Sahiwal Cattle Genetic Resources In Kenya

This book is an account of the research, development and future prospects of the Sahiwal cattle in Kenya. The development of a stable local breed started in the early 1940's when Sahiwal bulls were imported from Pakistan and India for continual backcrossing with the indigenous Zebu cattle. Presently, the developed Sahiwal breed has stabilized and is widely utilised in the medium to low production systems. This work reviews critical concepts that are important in genetic improvement and utilization of Sahiwal cattle such as genetic basis for selection, quantitative traits, reproductive management and the breed standards in Kenya, Pakistan and India. The book categorically reviews past performance and genetic parameters of Sahiwal cattle in Kenya with more emphasize on the National Sahiwal Stud (NSS) where selection and culling decisions were made. It proposes the need to move from the currently closed nucleus breeding scheme at the NSS which offers little options for diverse selection to an open nucleus breeding scheme (ONBS). Transiting to an ONBS would allow for more rapid genetic improvement within the NSS and thus maintain inbreeding and genetic variability at desirable levels.

This book contains information on the findings of a research that was carried out to analyze genetic and environmental effects on growth of Sahiwal cattle in Kenya. A brief introduction of the subject, problem and objectives of the study are presented in chapter one. Chapter two gives a review of production of Sahiwal cattle and genetic evaluation and parameters in the tropics. Chapter three outlines the methodology used to analyze environmental factors, (co)variance components, genetic and phenotypic parameters and trends. Chapter four and five presents the results and discussions, respectively. In summary, how the environment and genetics (maternal and direct additive genes) affects growth of Sahiwal cattle in the tropics is discussed. High genetic correlations between growth traits permit selection on early growth traits to improve growth performance in later years. Declining genetic trends reflects suboptimal selection and management decisions. It is recommended that selection be at one year and supplementation be done during drought to improve growth and allow for expression of full genetic potential.

The study was conducted to draw together for comparative purposes, empirical measures of performance of Kenya Sahiwal crossbred cattle in different production systems. Two livestock productivity modeling approaches of PRY and Gross Margin analysis were applied. The PRY package was used to obtain herd productivity indices based on demographic parameters and produce related input parameters. Gross Margin analysis computed profitability of different enterprises based on the total monetary value of animal products and the total cost per unit animal per year. The increase in productivity of the Kenya Sahiwal crossbred herds demonstrated that genetic effects can be fully exploited in marginal areas of Kenya by systematic use of crossbreeding systems to achieve a cumulative and permanent genetic improvement in growth potential and milk production. It is important that a robust and efficient breeding programme is developed for sustainable increase of productivity of the crossbreds in the low-input productions systems in Kenya and other areas with similar production circumstances.