Abstract

Grazing systems are described for producing venison carcasses weighing 50-65 kg (92-120 kg liveweight) in the spring by one ear of age (30 November), using red and hybrid (0.25 elk: 0.75 red) deer stags. Grazing perennial ryegrass/white clover pasture at 10cm surface height during autumn, winter and spring resulted in 73% of young stags attaining the desired slaughter target, but variation between years was large (range 25-100%), with a contributing cause being variation between years in winter growth rate. When red clover and chicory were grazed during autumn and spring, with pasture grazing during winter, the proportion of young stags attaining the desired slaughter target was consistently increased to 90-100% and mean carcass weights were increased by 11 & 17% respectively. Largest responses in deer growth to red clover (26%) and chicory (47%) over perennial ryegrass - based pastures were seen during autumn. Both voluntary feed intake (VFI) and digestibility of the diet selected were higher for deer grazing chicory and red clover than perennial ryegrass-based pasture, with the largest effects seen during summer and autumn, when perennial ryegrass was of lowest nutritive value. In indoor studies, both the rates of ruminal degradation and outflow of chicory were greater than for perennial ryegrass, with similar results found for red clover. It was concluded that the faster breakdown and clearance of red clover and chicory from the rumen than perennial ryegrass explained their higher digestibility and VFI by grazing deer. Management of red clover and chicory to increase persistence on commercial deer farms and grazing systems to support year round supply of venison in a branded market strategy are also discussed. For successful venison production by 12 months of age, target growth rates during winter of 100g/day for red deer and 150g/day for hybrids are suggested.

TN, Barry, PR Wilson, and PD Kemp

Proceedings of the New Zealand Society of Animal Production, Volume 59, , 140-144, 1999