Effect of Grass-White Clover Mixtures on Steer Performance and Sward Characteristics in Atlantic Canada

Pasture production in winter cold regions such as Atlantic Canada is limited by the availability of winter hardy and productive grass and legume species, Perennial ryegrass (Lolium perenne L.), meadow fescue (Festuca prarensis Huds.) and timothy (Phleum pratense L.) grown in binary mixtures with white clover (Trifolium repens L.), and naturalised pasture consisting of Poa spp., Agrostis spp. and white clover, were compared under grazing, Steers were used to graze the swards from 16-26 cm down to 8 or 11 cm post-grazing surface heights, Dry matter intake was higher for natural pasture than for sown pastures, Animal gains were greatest for perennial ryegrass­white clover and lowest for the natural pasture, On timothy-white clover pasture the animal gains declined in the second season which coincided with poor persistence of timothy. Animal gains per ha were similar for 8 and 11 cm surface heights. Tiller densities of meadow fescue and timothy were very low and that of perennial ryegrass reached only 8000/m2, The stolon length of white clover varied considerably among mixtures. Breeding of hardy pasture cultivars in winter cold regions is essential for improved pasture productivity.