Is the behaviour of grazing cattle influenced by the presence of a hedge in the pasture?

Abstract

The interest in using shrubs and trees as forage for cattle is raising in temperate regions, along with the environmental measures promoting hedges along pasture. This study aimed at determining the influence of the presence of a woody hedge on grazing cattle behavior as well as the evolution of this behavior during the grazing season. Twelve heifers were set to graze a standard ryegrass and clover meadow during the grazing season of 2013. The animals were divided in 2 groups : one with a free access to a hedge composed by 10 temperate shrub and tree species, the other with no access to a hedge (control). Their behavior (grazing, browsing and other activities) was monitored during 14h d-1 replicated 3d week-1 during 3 periods (May, July and September). Results suggest that both season and presence of a hedge have an influence on the behavior of heifers. Grazing, resting and rumination varied between the two groups in each period (P<0.05). The time spent browsing was influenced by the season (P<0.001); the heifers with an access to the hedge could browse 19.3% of the total time in May against 5.9 and 5.4% in July and September. Both control and experimental heifers grazed more with the progressing season, but the animals without the hedge grazed always more than the heifers that could graze and browse (49.6 vs 43.0%). In conclusion, browsing woody species represents a significant part of the time spent for forage ingestion, and variation in this behavior over the whole grazing season requires to investigate the influence of both pasture and browse availability and composition