Effect of breed and non-genetic factors on percentage milk composition of dual-purpose cattle in Ashanti region, Ghana
This study was done to determine the effect of breed and non-genetic factors on percentage milk composition of smallholders’ dual-purpose cattle on-farm in the Ashanti Region. Fresh milk samples from various breeds of cows were assessed for percentage components of protein, fat, lactose, cholesterol, solidnon- fat and total solids using 72 cows from September 2012 to February 2014. The overall percentage milk composition across breed for protein, fat, lactose, cholesterol, solid-non-fat, total solid were 7.7 ± 0.07, 3.0 ± 0.02, 6.4 ± 0.04, 0.65 ± 0.01, 5.7 ± 0.02, 14.3 ± 0.03 respectively. The percentage milk components of dual purpose cows were significantly (p<0.01) influenced by breed and season. Parity and stage of lactation had little (p>0.05) effects on percentage compositon of fresh milk, however, the latter influenced (p<0.01) cholesterol levels. Gudali, and Sanga-Gudali crossbred had similar (p>0.05) percentage protein and fat whereas other breeds differed (p<0.01). Protein and solids-non-fat components were low (p<0.01) in major rains whilst lactose and total solids increased (p<0.01) with increasing intensity of rains. There were important interaction effects among breed, stage of lactation and season in percentage protein, fat, lactose and solid-non-fat components. It was concluded that breed influenced milk compositional yield and producers could select genotypes on production traits within environment comparable to where cows are intended to perform.
Keywords: breed, cows, milk composition, parity, season.