Factors influencing lactose production in dairy cows.
Above: Project Lead Juan Gargiulo
Lead Author: Juan I. Gargiulo
Project P9a: Milk with less lactose
Lactose is the main carbohydrate in cows’ milk and determines milk volume by influencing its water content. The concentration of lactose, along with other milk solids, varies across species and cow breeds.
The study analysed almost 400,000 herd test records from more than 30,000 cows across 85 farms in New South Wales to assess the relationship between lactose output and milk yield, composition and quality, genetics, and environmental factors.
Pearson correlations and linear mixed modelling were used to examine the effects of number of calvings, lactation stage, breed, year, season, climate, heritability, as well as differences between the overall population and cows consistently producing higher milk solids yield, fat yield and protein yield per unit of lactose yield.
Findings highlight key factors influencing lactose production and identify cows that produce lower milk volumes while maintaining milk solids yield, a trait aligned with local milk payment systems. Identifying these cows and their genetic backgrounds offers opportunities for targeted breeding programs to enhance milk production efficiency and composition while reducing environmental impact.
About Dairy UP
Dairy UP is a collaborative research, development and extension program for the NSW dairy industry. It aims to unlock the potential of pastures, cows, water and milk to increase productivity and profitability, and de-risk the industry and develop new markets.