STOCKING RATE EFFECTS ON SHEEP AND FORAGE PRODUCTIVITY UNDER RUBBER IN MALAYSIA

The productivity of grazing sheep was assessed under 7-year-old rubber at the Rubber Research Institute of the Malaysia Experimental Station at Sungai Buloh near Kuala Lumpur between October 1988 and May 1990. The sheep were Dorset x Marlin crossbred lambs and they grazed planted leguminous cover crops and naturally occurring species at a range of stocking rates. In the immature rubber trial, presentation yields of f orage declined with time regardless of stocking rate. In the mature ru bber trial, presentation yields of forage were low (<1000 kg/ha) due t o low light transmission. High stocking rates (>6 sheep/ha) resulted i n a decrease in the proportion of palatable species, namely Pueraria p haseoloides, Paspalum conjugatum, Asystasia gangetica and Mikania micr antha and an increase in the proportion of the less palatable species such as Calopogonium caeruleum and Cyrtococcum oxyphyllum. Daily livew eight gains ranged from 100 g/lamb per day at 4 sheep/ha to 70 g/lamb per day at 14 sheep/ha in the immature rubber trial. Only the lowest s tocking rate of 2 sheep/ha was continuously sustainable in the mature rubber trial. The estimated maximum liveweight gain that could be achi eved under immature rubber was 266 kg/ha per year at a stocking rate o f 13.2 sheep/ha.