Relationships of early performance traits to lifetime profitability in Holstein cows

Abstract

Relationships of first lactation traits to lifetime profitability were studied based on data of 1112 lifetime performance records of purebred Holstein cows from the National Cooperative Dairy Cattle Breeding Project, which was implemented by Agriculture Canada in 1972. Lifetime profit was defined based on milk production, body weight, reproductive performance, herdlife, and prices for feed energy, milk, calves, salvage value, and fixed costs. First lactation traits with significant relationships to lifetime profitability were identified using the backward elimination procedure for least squares. Relative weights of each prediction trait were expressed as standard partial regression coefficients. Milk revenue in first lactation was the most important trait, followed by 3 min yield, and udder height. First lactation survival was found to be significant. Increasing age at first calving, number of days from first breeding to conception in first lactation, and teat diameter had significant negative effects on profit. Health traits in first lactation were not significant. The significant traits explained 35% of total variation in lifetime profitability. Key words: Dairy cow, lifetime profitability, early indicator traits