Grass intake and grazing behaviour of dry and suckling ewes according to sward height

摘要

Intake of grass depends both on animal status (physiological state, body reserves) and on sward characteristics. Grass availability and more especially its height has a major effect on intake (Hodgson, 1985, Proc Nutr Soc, 44, 339-346). The aim of thepresent study was to measure the interactions between ewes' status (lactating vs dry) and sward height on the intake of grass and its behavioural components. A group of 12 Limousine x Romanov 3-6 year old ewes, six of them dry and the other six sucklingtwins for 6 weeks, were strip-grazed on short (4-6 days old) leafy cocksfoot re-growths. Another similar group at the same time grazed longer (3 weeks old) and mainly leafy regrowths. The short sward was grazed from 10 down to 6 cm high measured with asward stick, and the tall one from 20-25 down to 12-15 cm. Grass intake (IG) was estimated individually by the alkanes' technique (Mayes et al, 1986, J Agric Sci, 107, 161-170).