Does Cu supplementation affect the mechanical and structural properties and mineral content of red deer antler bone tissue?

Abstract

The main factors affecting the mechanical (and other) properties of bone, including antler, are the proportions of ash (especially Ca and P) and collagen content. However, some trace minerals may also play more important roles than would be expected, given their low levels in bone and antler. One such trace mineral is Cu. Here, we studied the effects of Cu supplementation on the mechanical and structural characteristics, and mineral content of antlers from yearling and adult (4 years of age) red deer fed a balanced diet. Deer (n=35) of different ages (21 yearlings and 14 adults) were studied. A total of 18 stags (11 yearlings and 7 adults) were injected with Cu (0.83 mg Cu/kg BW) every 42 days, whereas the remaining 17 (10 yearlings and 7 adults) were injected with physiological saline solution (control group). The Cu content of serum was analysed at the beginning of the trial and 84 days after the first injection to assess whether the injected Cu was mobilized in blood. Also, the mechanical and structural properties of antlers and the mineral content in their cortical walls were examined at three (yearlings) or four (adults) points along the antler beam. The effect of Cu supplementation was different in yearlings and adults. In yearlings, supplementation increased the Cu content of serum by 28%, but did not affect antler properties. However, in adults, Cu supplementation increased the Cu content of serum by 38% and tended to increase the cortical thickness of antlers (P=0.06). Therefore, we conclude that, even in animals receiving balanced diets, supplementation with Cu could increase antler cortical thickness in adult deer, although not in yearlings. This may improve the trophy value of antlers, as well as having potential implications for bones in elderly humans, should Cu supplementation have similar effects on bones as those observed in antlers.

Parenteral Cu Supplementation of Late-Gestating and Lactating Iberian Red Deer Hinds Fed a Balanced Diet Reduces Somatic Cell Count and Modifies Mineral Profile of Milk

“…Experimental hinds were subcutaneous injected every 42 days with 0.83 mg of Cu per kg body weight (BW; 1 cm 3 per 30 kg live BW) from day 202 of gestation to day 126 (week 18) of lactation (standard lactation period in natural conditions of hinds) using Glypondin (König S.A., Buenos Aires, Argentina) as previously used by Gambín et al [2] for deer. The control group was injected with a physiological saline solution with the same volume and at the same frequency as the experimental group.…”

“…However, despite that the increase in the Cu injected group was five times that of saline control, the difference did not reach statistical significance (p = 0.101). 2 The experimental unit was the animal (n = 9 for Cu supplemented group and n = 8 for control group). In addition, fat, protein, lactose, and dry matter concentrations were computed as the mean of the two aliquot replicates from each milking.…”

“…Data are means ± standard error of mean 2 . 2 The experimental unit was the animal (n = 9 for Cu supplemented group and n = 8 for control group per lactation week). In addition, fat, protein, lactose, and dry matter concentrations were computed as the mean of the two aliquot replicates from each milking.…”

“…However, Cu supplementation presents benefits even when deer are fed balanced diets. Thus, Gambín et al [2] found that supplementation with Cu increased antler cortical thickness in adult deer. This may improve the trophy value of antlers.…”

“…Parenteral mineral supplementation is a common practice in deer [2,9,10]. Although this technique requires a more laborious handling than minerals added to feed, it ensures that the same quantity of the mineral is supplied for all animals, and also that minerals supplemented bypass the gastrointestinal tract, thus avoiding interactions with other minerals leading to secondary deficiencies.…”