Copper supplementation, velvet antler production and growth of rising 2-year-old red deer stags

Abstract

AIMS: To investigate whether copper supplementation to rising 2-year-old red deer stags (Cervus elaphus) in winter and/or spring improved velvet antler weight, grade and financial value, and liveweight gain. METHODS: Rising 2-year-old red deer stags (n=142) on a commercial deer farm in Hawke's Bay were allocated to two groups on May 14, 1996. One group received 20 g boluses of copper-oxide wire particles. On August 15 each group was reallocated in a crossover design, each sub-group receiving either the same copper-oxide treatment or no treatment, to produce control, winter-only, winter-plus-spring, and spring-only copper treatment groups. Blood samples were collected for serum ferroxidase measurements from seven deer per group and all deer were weighed at 4–6-week intervals. Dates of antler casting and velvet removal, and velvet antler weight and grade were recorded, and the financial value of velvet calculated. Livers from a sample of deer slaughtered at the end of the trial mid-December were analysed to determine copper content. RESULTS: Supplementation with copper did not significantly alter velvet antler weight, daily velvet antler growth rate, days from casting to removal, grade or value, or stag liveweight gain. Serum ferroxidase concentrations averaged 10.0–23.7 IU/1 in control deer. Copper supplementation increased mean serum ferroxidase concentrations by approximately 10 IU/1. Mean liver copper concentration in control deer was 99 µmol/kg and ranged from 194 to 386 µmol/kg in the three treated groups. CONCLUSION: Group mean serum ferroxidase concentrations of 10 IU/1 and above are adequate for optimum velvet production and liveweight gain in rising 2-year-old stags.