Abstract

Studies in New Zealand have shown that bulk milk collected from groups of ·-lactoglobulin AA phenotype cows has a different composition to bulk milk collected from groups of þ-lactoglobulin BB phenotype cows (Hill, 1993). Although all cows used in this study were different to those used by Hill (1993), differences in composition were similar with the ·-lactoglobulin AA phenotype cow group producing milk which contained less casein, fat and total solids than ·-lactoglobulin BB phenotype cow group. No significant differences was observed in the total protein, lactose or ash content in the milk of the two phenotype groups. In comparison with the þ-lactoglobulin AA and BB phenotype bulk milks, large variations in composition were observed in the milk from individual cows. As all cows were fed on identical pasture and subjected to identical farm management practices these results indicate that in addition to þ-lactoglobulin phenotype other genetic factors can have a significant influence on the composition of milk.

JP, Hill, and GR Paterson

Proceedings of the New Zealand Society of Animal Production, Volume 54, , 293-296, 1994