The effects of grazing chicory (Cichorium intybus) and birdsfoot trefoil (Lotus corniculatus) on venison and velvet production by young red and hybrid deer

Abstract

The effects of grazing chicory, Lotus corniculatus, and perennial ryegrass/white clover pasture on growth, voluntary feed intake (VFI), and venison and velvet production was studied in red and hybrid deer from weaning to slaughter at one year of age. Twenty five percent of red and 75% of hybrid stags attained the target slaughter weight (50 kg carcass or greater) when grazing pasture and spiker velvet antler weight was low (approximately 0.2 kg/stag). Mean carcass weight of deer grazing chicory was higher than for deer grazing pasture (P < 0.05), due to increased liveweight gain (LWG) in both autumn and spring, and to higher dressing‐out percentage at slaughter. Carcass weights for red and hybrid stags were 56.0 and 59.3 kg, respectively, when grazed on chicory and 48.6 and 53.3 kg, respectively, when grazed on pasture (P < 0.01). Hybrid hinds grazing chicory had a significantly higher carcass weight (P < 0.05) and dressing‐out percentage (P < 0.01) than those grazing pasture. Chicory had a higher organic matter digestibility (OMD) than pasture, and VFI was higher than on pasture during autumn but was similar in spring. Relative to pasture, chicory grazing increased total spiker velvet antler production (323 v 225 g/stag) by advancing the dates of pedicle initiation, antler initiation, and of first velvet cutting and increasing the rate of velvet antler length growth. Initiation of velvet growth was correlated with liveweight (LW), with each 10 kg increase in LW advancing the dates of pedicle initiation, commencement of velvet growth, and first velvet cutting by 10, 18, and 13 days, respectively. Earlier velvet growth in deer fed chicory could thus largely be explained by the higher liveweight of deer grazing this forage. Observations from deer grazing lotus were limited due to problems with lotus establishment. Grazing lotus increased LWG of stags during autumn compared with perennial ryegrass/white clover pasture (248 v 176 g/day) and increased the efficiency of growth in spring, with LWG being similar to deer grazing pasture, but VFI being lower (1.53 v 2.00 kg OM/day). OMD of lotus was higher than pasture during autumn, but not in spring. Stags grazing lotus produced similar velvet antler weight to stags grazing pasture. Total condensed tannin (CT) concentration in hand plucked and oesophageal fistulae (OF) extrusa samples, respectively, were 48 v 13 g/kg OM for lotus, 3.1 v 5.8 g/kg OM for chicory, and 0.3 v 1.5 g/kg OM for pasture. It was concluded that chicory was of high feeding value for increasing venison and velvet production from young deer. Results suggest that the CT content of lotus may improve the efficiency of growth in young deer.