EFFECTS OF GRAZING RED-CLOVER (TRIFOLIUM-PRATENSE) OR PERENNIAL RYEGRASS (LOLIUM-PERENNE) WHITE CLOVER (TRIFOLIUM-REPENS) PASTURES UPON GROWTH AND VENISON PRODUCTION FROM WEANER RED DEER (CERVUS-ELAPHUS)

Forty-four weaner red deer (Cervus elaphus) fawns (26 stags; 18 hinds) were used to investigate the effects of grazing pure red clover (Trif olium pratense) or perennial ryegrass (Lolium perenne)/white clover (T rifolium repens) pastures upon growth and venison production, with the objective of the stags attaining a minimum target slaughter liveweigh t (92 kg liveweight; 50 kg carcass) by 12 months of age. The experimen t commenced on 13 March and concluded on 26 November 1991. The deer we re rotationally grazed on either red clover or perennial ryegrass/whit e clover pasture during autumn and spring (feed allowances 6, 7 kg dry matter (DM)/h per day, respectively). During winter, all animals were combined and grazed together on perennial ryegrass/white clover pastu re, at a pasture residual DM of 1100 kg DM/ha. Pre-grazing herbage mas s for red clover and perennial ryegrass/white clover were respectively 3568 and 3706 kg DM/ha in autumn, and 2726 and 2150 kg DM/ha in sprin g, and 1736 kg DM/ha for perennial ryegrass/white clover in winter. Po st-grazing herbage mass for red clover and perennial ryegrass/white cl over averaged respectively 1822 and 1882 in autumn and 1705 and 1334 i n spring, and 1170 kg DM/ha for perennial ryegrass/white clover in win ter. Total nitrogen (N) concentration and organic matter digestibility of both feed on offer and diet selected were higher in red clover tha n perennial ryegrass/white clover. Liveweight gain of red clover stags (237 versus 207 g/day) and hinds (197 versus 159 g/day) was significa ntly higher than that of perennial ryegrass/white clover animals in au tumn (P < 0.01) and in spring (346 versus 281; 260 versus 188 g/day; P < 0.001). Weaner stags and hinds grazing red clover forage had signif icantly higher voluntary feed intake than the comparable animals grazi ng perennial ryegrass/white clover pasture in both autumn (P < 0.05) o r spring (P < 0.001). By 12 months of age, stags grazing red clover we re 6 kg heavier and hinds 7 kg heavier than animals grazing perennial ryegrass/white clover forage. All (100%) red clover stags attained the minimum target slaughter liveweight (92 kg liveweight; 50 kg carcass) by 12 months of age at the end of November, compared to 90% of perenn ial ryegrass/white clover stags. Carcass weights (kg) and dressing per centage (%) of red clover stags were significantly higher than those o f perennial ryegrass/white clover stags (58.9 versus 53.3 kg, P < 0.01 ; 56.2 versus 52.4%, P < 0.001), but the carcass GR was not different (P > 0.05) either before or after being adjusted to equal carcass weig ht. It was concluded that early venison production from grazed perenni al ryegrass/white clover pastures is possible, and that this can be fu rther improved by inputs of red clover. Red clover offers very good po tential as a special-purpose forage for venison production.