Addition of white clover to orchardgrass pasture improves the performance of grazing lambs, but not herbage production

Abstract

Papadopoulos, Y. A., Charmley, E., McRae, K. B., Farid, A. and Price, M. A. 2001. Addition of white clover to orchardgrass pasture improves the performance of grazing lambs, but not herbage production. Can. J. Anim. Sci. 81: 517-523. Two earlymaturing cultivars (Juno and Hallmark), three late-maturing orchardgrass cultivars (Sumas, Rideau, and Kay), and a mixture of orchardgrass (Kay) and white clover (Huia) were seeded in a trial with two replicates. Plots were rotationally grazed for 3 successive years after the establishment year by crossbred lambs. Two contrasts were studied: Kay was compared with Kay/Huia and the early-maturing cultivars were compared with the late-maturing cultivars. Dry matter yield was less for the Kay/Huia than Kay in the 3-yr study, crude protein concentration was similar, and nitrate N concentration was less. Concentrations of ADF and NDF were less for Kay/Huia and stocking density was only 78% of that for Kay over the 3 yr. Efficiency of DM utilization for gain averaged 9.6 for Kay/Huia and 11.4 for Kay, but the difference is not significant. Body weight gain for lambs grazing Kay/Huia was 40% greater than for lambs grazing Kay; gains per hectare were numerically higher, resulting in bigger lambs with more fat cover. There were no differences in DM yield or chemical composition for early-and late-maturing cultivars. Daily gain for lambs grazing early-maturing cultivars tended to be greater, with most of the effect attributed to a response in 1989. Dressed weight, backfat depth relative to dressed weight were all numerically higher for lambs grazing the early-maturing varieties. We conclude that orchardgrass should be seeded with white clover to increase individual animal performance and output of lamb per hectare. Late-maturing cultivars, when planted in monoculture, had no influence on sward productivity, but appeared to offer some advantage for lamb performance.