Abstract

Feeding behaviour and efficiency of feed utilisation, measured as residual feed intake (RFI; defined as actual feed intake minus predicted feed required), were measured in dairy calves aged six to seven months-old, and associations between the two variables were determined. The intake, feeding behaviour, and live weight of 219 female Holstein-Friesian calves were recorded for 46 days. Animals were housed in an outdoor facility comprising 28 pens, each with a single-access feeder containing dried, cubed lucerne. Efficient animals were associated with lower intakes (r² = 0.29), fewer meals/day (r² = 0.05), less time spent eating/day (r² = 0.03), and slower eating rates (r² = 0.03). The 30 most efficient animals consumed less (mean ± standard error of difference; 6.15 vs 7.46 ± 0.20 kg cubes/day), had fewer meals (4.03 vs 4.85 ± 0.29 meals/day), and spent less time feeding (2.68 vs 2.93 ± 0.11 hours/day) compared to the 30 least efficient animals (all P <0.05). Rate of liveweight gain, eating rate, amount eaten per meal, and meal duration did not differ between the 30 most efficient and 30 least efficient animals (P >0.05). In conclusion, differences in feeding behaviour were found between dairy calves selected for divergence in efficiency which may have implications for their management.

TC, Green, GC Waghorn, NJ Beausoleil, and KA MacDonald

Proceedings of the New Zealand Society of Animal Production, Volume 71, Invercargill, 281-285, 2011