Preliminary findings of genotype variations in growth rate and feed intake of weaner deer

Abstract

Deer are seasonal animals with a feed intake that varies with day length, reaching a low in winter. Feed intake then rises rapidly in spring. Superimposed on the nutritional response to day length are the genetics of the deer. This paper documents preliminary findings of live weight gain in winter and spring and intake during September for red deer (Cervus elaphus) and elk (Cervus elaphus canadensis) x red deer hybrids. Two experiments examined the relative growth rates and feed intake of rising 1 year old red and elk x red hybrid male deer during winter and spring 2001 and 2002. Live weight gain was higher in the elk x red than the red deer in both winter (averaging 262 and 144 g/d respectively) and spring (averaging 390 and 272 g/d respectively). Dry matter intake in September 2001 was 1.64 and 2.13 kg DM/d for red and elk x red deer respectively (P=0.003). Dry matter intake in September 2002 averaged 2.04 and 2.35 kg DM/d (P<0.05) for the red and elk x red deer respectively. Feed intake, when expressed as a percentage of body weight or metabolic body weight terms did not differ between the red and elk x red deer, indicating that the main driver of intake was body size, rather than any true genotype differences. A major difference in weight gain between the genotypes was related to the different size of the animals rather than an inherent difference in their feed conversion efficiency. This r esearch indica tes that maximising the potential of weaners to reach spring slaughter weights is a result of having heavy weaners going into winter combined with a good feeding programme to maximise feed intake. Keywords: elk, genotype, food intake, live weight gain, red deer, seasonality