Estimates of genetic and crossbreeding parameters for milk components and potential yield of dairy products from New Zealand dairy cattle

Abstract

ABSTRACT Milk composition can vary significantly among individual cows and breeds, and the dairy products that can be made from that milk are limited by available milk components. The objective of this research was to estimate genetic and crossbreeding parameters for lactation yields of milk, fat, protein and lactose, and use these to determine potential yields of dairy products from New Zealand dairy cattle. A mass‐balance milk‐processing model was used to estimate yields of milk products for 4310 first lactation heifers that produced milk in the 2010–2011 dairy season. Estimates of heritability for yields of whole and skim milk powders were moderate (0.31). Heterosis effects for product yield per lactation was significant only for cheese and butter production ( P < 0.05). The use of genetic parameters and correlations for dairy product yield could increase the rate of gain for specific product yields, but have to be evaluated in conjunction with other traits of interest in breeding worth.