Feeding maize to maintain milk yields during a short period of low pasture availability

Abstract

Twenty-four Friesian and Friesian cross cows in mid-lactation were used in a 2 X 2 factorial experiment to study the immediate and residual effects on milk yield of feeding concentrate during a 4 week period of low pasture availability. Cows grazing pastures of 1800 kg DM ha-1 averaged 6.5 and 9.3 kg milk cow-1 day-1 when fed 0 and 3 kg maize cow-1 day-1 respectively (P < 0.01). Cows on pastures of 3300 kg DM ha-1 averaged 13.0 kg milk cow-1 day-1 at both levels of maize feeding. After 4 weeks cows returned to a common pasture and residual effects of treatments on milk yields were nil after 3 weeks. Four to 8 weeks after treatments were removed, changes in liveweight and fatty acid composition of milk fat suggested cows previously on pastures of low availability had higher pasture intakes than cows from pastures of high availability.