Behaviour of growing lambs housed on straw or woodchip bedding materials and their preference for floor type

Abstract

Straw is widely used as a bedding material for housed sheep, but alternatives are needed in regions where straw is expensive or in short supply. The aim of this work was to compare time budgets, growth and food intake of growing, finishing lambs housed on either woodchip or straw bedding materials and also to evaluate the preferences shown by lambs when given a choice of bedding materials. One hundred and twenty-eight spring-born (approximately nine-month-old) Suffolk × Mule (Bluefaced Leicester × Welsh Speckled Face) and Charollais × Mule lambs (mean weight 35.3 ± 0.28 kg) were randomly allocated within breed, sex and weight range to pens of four lambs and housed on either woodchip or straw. They were fed hay and concentrates ad libitum over an eighteen-day period. Lying, standing and eating behaviours were observed at 15 min intervals over 24 h on days 7 and 14 after housing. On day 17 the lambs were moved to the alternative bedding material and were observed for a further 48 h to assess the effects on time budgets of a novel bedding material in a familiar housed environment. Over all days, the proportions of observations when lambs were either lying, standing, eating hay or eating concentrates were 0.69, 0.15, 0.07 and 0.06 respectively and there were no significant effects of bedding material ( P > 0.05). On the first day after a change to the novel bedding material, the proportion of observations when lambs were lying fell by 6% ( P < 0.001) with a parallel increase in standing behaviour, and a trend towards recovery to previous levels on the second day ( P < 0.05). Although there were significant effects of breed ( P < 0.001) and sex ( P < 0.05) on growth rate and food intake, bedding material did not affect animal performance ( P > 0.05). The 64 Suffolk × Mule lambs were then used in a preference test in which their use of bedding materials for various activities was observed every 15 min over four consecutive 12 h days. Lambs used woodchip as a bedding material when lying or standing almost twice as often as straw ( P < 0.001) but showed no preference between bedding types when eating hay or concentrates ( P > 0.05). There were no significant effects of either sex of lamb, day of observation or prior experience of the bedding materials on the preference for woodchip (all P > 0.05). It is concluded that woodchip is a suitable alternative bedding material to straw, that is preferred by lambs over straw and is unlikely to affect lamb performance through changes in the proportion of time spent lying, standing or eating.