Annual ryegrass (Lolium multiflorum lam.)-ruminant relation.

Italian ryegrass is the annual cool season forage species more cultivated for grazing in southern Brazil. Its interesting forage charac-teristics, in addition to the reduced production of native pasture species during low temperatures period (Autumn-Winter) justify its large scale utilization. However, the lack of knowledge of annual ryegrass morphophysiologic characteris-tics, as well as the grazing behavior of animals, may result in animal and vegetal production gain below the real productive potential. Research data results, up to the present time, show that the adequate management of this grass species suggests defoliation periods between 300 and 500 GD and dry matter availability between 8 and 18% of animal live weight, which allow greater animal and plant production. Dry matter offer near 8% of live weight (PV) favor animal performance per area, whereas forage offer close to 18% of animal live weight favor the individual animal performance, independently of the grazing system utilized. Other factors of important impact on morpho-physiologic characteristics of the pasture and animal grazing behavior are discussed in this paper, to serve as guideline for the management of animals, in Italian ryegrass pastures and furnish subsides to future research.