225 Raising the bar: Feed intake and competitive behavior of dairy goats when offered different feed bunk heights.

Abstract

Commercially-housed dairy goats are typically fed from ground level, but their natural feeding behaviour includes foraging from variable heights. The objective of this study was to evaluate the feed intake and behaviour of dairy goats when offered different feeding heights in a competitive feeding environment. Thirteen group-housed, non-lactating goats were exposed to 3 feeder heights: floor-level (head lowered), head-level, and elevated-level (head angled upwards). One feeder height was provided daily for 12 d, resulting in 4 presentations of each height. Each feeder contained ad libitum alfalfa haylage and a corn-based supplement (230 g), refreshed twice daily. Feeding space was restricted to 13.5 cm/goat. Goats ate more from the elevated- compared to the floor- and head-level feeders (0.77 ± 0.06 vs 0.92 ± 0.06 kg vs 0.99 ± 0.06 kg DM/d, for floor-, head- and elevated-level feeders, respectively; P=0.03). Feeding time was generally highest at head-level, but lowest at floor-level during morning feeding and lowest at elevated-level during afternoon feeding feeding (morning: 15.9 ± 1.8 vs 25.3 ± 1.9 vs 20.0 ± 1.9 min/d; P<0.01; afternoon: 26.8 ± 2.0 vs 29.0 ± 2.1 vs 21.1 ± 2.1 min/d; P<0.1). This corresponded to increased waiting time for feeder access during afternoon feeding for floor-level compared to head- and elevated-level feeders [4.2(3.2–5.4) vs 2.8(2.1–3.6) vs 2.1(1.6–2.8) min/d; P<0.1). Aggression while feeding [3.4(2.5–4.6) vs 8.5(6.2–11.7) vs 9.8(5.2–11.1) bouts/d; P<0.001] and pushing to gain feeder access (7.5 ± 0.8 vs 9.9 ± 0.8 vs 10.6 ± 0.8 bouts/d; P<0.1) was highest for the head- and elevated-level compared to floor-level feeders during morning feeding, but was not different during afternoon feeding. Agonistic physical contact (butting, chasing, head-clashing) was greatest at floor-level compared to elevated-level during afternoon feeding (19.7 ± 2.1 vs 14.6 ± 2.1 vs 12.2 ± 2.1 bouts/d; P=0.03). These results show that elevated feeding surfaces may promote increased feed intake but also greater competition; this may be due to a preference to feed from raised heights or due to aspects of the feeding trough.