The effect of non-genetic factors on milk yield and composition of Red Dane cattle in Zimbabwe

Abstract

A study was carried out to establish non genetic factors affecting milk, butterfat and protein yields in Zimbabwean Red Dane cattle. A total of 1325 unedited 305-day lactation records were obtained from Zimbabwe Livestock Identification Trust herd, with cows calving in the period 2002–2006. The Henderson Type III sum of squares in Genstat edition 14 program was used.

Parity, days in milk, year of calving and age of calving had significant effects (P< 0.05) on milk, fat and protein yield; milk yield; protein and fat yield; and milk and protein yield respectively. An increase in parity resulted in an increase in milk yield and composition up to parity 4 and started declining in parity 5. An increase in days in milk also resulted in an increase in milk yield whereby the milk yield increased at a declining rate as from 350 days to 550 days. Milk yield and composition declined in 2005 and there was a decline in protein yield from 2006 to 2009. Lastly, milk and protein yield resulted in a gradual increase up to 58 months followed by a declining trend up to 103 months. Month of calving and days dry did not have significant effects (P> 0.05) on milk yield and composition of Red Dane cattle in Zimbabwe. The study showed that non-genetic factors have a significant effect on milk yield and composition of Red Dane cattle in Zimbabwe.