LAMB PRODUCTION AND FEED-INTAKE IN RELATION TO DEGRADABILITY CHARACTERISTICS AND METABOLIZABLE PROTEIN-CONTENT OF DRIED SUBTERRANEAN CLOVERDIETS

A study was undertaken of three cultivars of subterranean clover (cvv. Larisa, Trikkala and Goulburn), harvested at 50% flower and again aft er 30 days, for liveweight gain and wool growth of lambs. Live weight gain (LWG) and wool growth (WG) of lambs were significantly higher (P < 0.001) at 50% flower than from the later harvest. The LWG and WG of lambs fed three cultivars of subterranean clover ranged from 137 to 16 2 and 8.9 to 12.7 g day(-1), respectively at 50% flower while at the l ater harvest, they ranged from 97 to 106 and 7.1 to 7.8 g day(-1) resp ectively. No significant differences in the live weight gain were obse rved between cultivars. The higher wool growth of lambs fed cv. Trikka la at 50% flower compared with lambs fed cv. Goulburn or cv. Larisa wa s associated with significantly higher intake of metabolisable protein , but no difference in wool growth and metabolisable protein were obse rved between lambs fed cv. Goulburn and cv. Larisa diets. The relation s of feed intake with degradability characteristics of dry matter and cell wall organic matter (CWOM) were investigated. The inclusion of ra te of degradation of CWOM with CWOM content pet se significantly impro ved the predictive relationship for organic matter intake (R-2 = 0.55) and digestible organic matter intake (R-2 = 0.65). This study has qua ntified strong predictive relations of live weight gain and wool growt h with the intake of metabolisable protein (R-2 = 0.66) for subterrane an clover. (C) 1998 Elsevier Science B.V.