title: Production characters of the Sahiwal and Ayrshire breeds and their crosses in Kenya.
abstract: Data were analysed for lactation character of Ayrshire, Ayrshire x Sahiwal, Sahiwal x Ayrshire and Sahiwal females and on survival and growth characters of progeny of Ayrshire, Sahiwal, Simmental and Mixed breed sires mated to these females in the temperate highlands ecological zone of Kenya. The Ayrshire females had significantly higher total lactation yield than the other breeding groups; however, the Ayrshire females received preferential treatment. Despite this the Sahiwal-Ayrshire crosses were superior (3.8%) to the Ayrshire females in productivity index per cow per year because of a shorter calving internal and a higher level of calf survival. Sahiwal females had significantly lower total lactation yield than Ayrshire and Sahiwal x Ayrshire cross females. At 2 years of age female progeny of Sahiwal and Simmental sires were significantly heavier than the female progeny of Ayrshire sires but not of Mixed breed sires, viz. Sahiwal x Ayrshire and calves with sires not known. The Ayrshire breed was shown to be superior to the Sahiwal breed in transmitted effects for milk production and the Sahiwal breed was superior to the Ayrshire breed in transmitted effects for growth rate. It is concluded that the Sahiwal breed has potential to contribute to both milk and beef production programmes when combined in crosses with Bos taurus breeds of cattle in ecological zones similar to the lower to mid-potential areas of the temperate highlands of Kenya.
mesh_terms: D000818:Animals; D001724:Birth Weight; D001947:Breeding; D002417:Cattle / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D003433:Crosses, Genetic; D005260:Female; D007630:Kenya; D007774:Lactation; D008297:Male; D008892:Milk / Q000378:metabolism*; D009026:Mortality; D011247:Pregnancy; D012098:Reproduction; D013045:Species Specificity; D014886:Weaning