EFFECTS OF COMPLEMENTARY GRAZING BY GOATS ON SWARD COMPOSITION AND ONSHEEP PERFORMANCE MANAGED DURING LACTATION IN PERENNIAL RYEGRASS AND WHITE CLOVER PASTURES

The liveweight (LW) response of Gallega and Lacha ewes with their sing le suckling lambs when grazing with a mob of goats on perennial ryegra ss (Lolium perenne L.)/white clover (Trifolium repens L.) pastures and its consequence on sward composition were analysed. From early March (turnout) to mid-June (lamb weaning), swards were grazed either simult aneously mixed in a 1:1 goat to sheep ratio or separately in a goat-fi rst and sheep-last sequential grazing at 6 or 8 cm sward heights or in a 4-paddock rotation where goats grazed swards from 9 to 7 cm followe d by sheep from 7 to 4 cm. Changes in botanical composition and in she ep liveweight performance were more significantly affected by the mana gement and species grazing than by the sward height treatment. Swards where goats were last in had higher herbage masses, higher live clover and lower dead and stem proportions than swards where sheep and goats were mixed or sheep were last in. As a consequence of a sward clover enhancement over all treatments, ewe and lamb performances were benefi ted especially in the Lacha genotype, with the rotational and sequenti al managements having, respectively, an output of 298 and 252 kg LW/ha greater than the mixed management. These results suggest that goats c ould be used as a pasture management tool when integrated with sheep u nder these different grazing systems to enhance ovine performance duri ng lactation. (C) 1998 Elsevier Science B.V. All rights reserved.