Effect of previous grazing experience on the grazing behaviour of lambs

Abstract

An experiment was conducted to evaluate the effects of controlled grazing experience, acquired at two different ages, before or during weaning, on initial acceptance of pasture and on forage preferences of weaned lambs. Forty lambs with their dams were exposed to either white clover (WC) or ryegrass (RG) pastures for 7 days, 1 h day −1, at either 14 weeks (before weaning) or 19 weeks of age (during weaning). This constituted the sole grazing experience of the lambs. Ten lambs not exposed to pasture comprised the control group. During the fourth week after weaning, each animal was tested for 5 days, 30 min day −1, on a pasture containing both WC and RG in alternating strips. The lambs were tested in pairs and each pair was treated as an experimental unit. Whether the lamb was grazing or not and what forage was being grazed were recorded every 20 s. Overall results showed that pasture-experienced lambs had longer grazing bouts ( P < 0.01) and grazed for almost twice as long (192%) as did control lambs ( P < 0.01). WC-experienced lambs spent a higher ( P < 0.05) proportion of their grazing time on WC strips than did RG-experienced lambs (69% vs. 45% of the total grazing). Lambs exposed to pasture at different ages did not differ ( P > 0.05) in pasture acceptance or forage preferences. We conclude that giving unweaned lambs a short grazing experience, in the presence of their dams, can increase both the initial acceptance of pasture and the preference for a certain type of forage after weaning.