Predicted dairy product yields and deficits of lactose for manufacturing under differing selection and manufacturing scenarios in New Zealand

Abstract

The New Zealand dairy industry is pasture-based and more than 90% of milk products are exported. The breeding goal of the breeding programme of New Zealand dairy cattle is to improve the capability of the cow to convert feed into farmer profit. The breeding objective rewards yields of protein and fat but penalises milk volume and ignores lactose, despite it being an important component of milk powders. With the industry currently in deficit for lactose, this study investigated the expected response to selection over the next 10 years and its impact on the annual industry production of milk, its components and yields of dairy products based on expected cow performance, number of cows and a fixed area for dairying. After 10 years of selection (with no increase in herbage production), there was a 5% increase in milk production per hectare. Total milk exports increased by 5.9% and the lactose deficit increased by 14% when 60% of milk was processed into whole milk powder.