Meat quality of farmed red deer fed a balanced diet: effects of supplementation with copper bolus on different muscles

Abstract

Supplementation with copper (Cu) improves deer antler characteristics, but it could modify meat quality and increase its Cu content to levels potentially harmful for humans. Here, we studied the effects of Cu bolus supplementation by means on quality and composition of sternocephalicus (ST) and rectus abdominis (RA) muscles (n=13 for each one) from yearling male red deer fed with a balanced diet. Each intraruminal bolus, containing 3.4 g of Cu, was administered orally in the treatment group to compare with the control group. Meat traits studied were pH at 24 h postmortem (pH24), colour, chemical composition, cholesterol content, fatty acid (FA) composition, amino acid (AA) profile and mineral content. In addition, the effect of Cu supplementation on mineral composition of liver and serum (at 0 and 90 days of treatment) was analysed. No interactions between Cu supplementation and muscle were observed for any trait. Supplementation with Cu increased the protein content of meat (P<0.01). However, Cu content of meat, liver and serum was not modified by supplementation. In fact, Cu content of meat (1.20 and 1.34 mg/kg for Cu supplemented and control deer, respectively) was much lower in both groups than 5 mg/kg of fresh weight allowed legally for food of animal origin. However, bolus of Cu tended to increase the meat content of zinc and significantly increased (P<0.05) the hepatic contents of sodium and lead. Muscles studied had different composition and characteristics. The RA muscle had significantly higher protein content (P<0.001), monounsaturated FA content (P<0.05) and essential/non-essential AA ratio (P<0.01) but lower pH24 (P<0.01) and polyunsaturated FA content (P=0.001) than the ST muscle. In addition, RA muscle had 14.4% less cholesterol (P=0.001) than ST muscle. Also, mineral profile differed between muscles with higher content of iron, significantly higher (P<0.001) content of zinc and lower content of calcium, magnesium and phosphorus (P<0.05) for ST muscle compared with RA. Therefore, supplementation with Cu modified deer meat characteristics, but it did not increase its concentration to toxic levels, making it a safe practice from this perspective. Despite the lower content of polyunsaturated FA, quality was better for RA than for ST muscle based on its higher content of protein with more essential/non-essential AA ratio and lower pH24 and cholesterol content.

Carcass and meat quality characteristics from Iberian wild red deer (Cervus elaphus) hunted at different ages

“…Current results are similar to those observed by Hutchison et al . for the longissimus dorsi muscle from fallow deer does fed on pasture or grain and by Serrano et al . for sternocephalicus and rectus abdominis muscles from red deer fed on balanced diets.…”

“…who claimed that protein content in deer meat may vary between 20% to as high as 25%, thus confirming that deer meat is a relatively rich source of proteins. Finally, ash content (1.23% as average in the current study) is very similar (approximately 1% to 2%) in all deer species and in all muscles and comparable across most studies . Values for chemical composition obtained in the current study were thus similar to those reported in the literature for meat from farmed fallow deer and from farmed red deer feeding on pastures …”

“…A lack of normal acidification in the muscle during the development of rigor mortis is therefore a common phenomenon in game and deer meat, as these species often have low muscle glycogen reserves prior to slaughter and because the available reserves may be depleted if the animals are harvested under stressful conditions . This fact can give rise to an abnormally high ultimate pH values (above 6) and result in DFD meats that are very common even for farmed deer with incidences up to 50–60% . The incidence is so high that it is possible that consumers do not associate the characteristics of this type of meat as a defect but as part of the intrinsic quality of venison meat .…”

“…5 This fact can give rise to an abnormally high ultimate pH values (above 6) and result in DFD meats that are very common even for farmed deer with incidences up to 50-60%. 5,40 The incidence is so high that it is possible that consumers do not associate the characteristics of this type of meat as a defect but as part of the intrinsic quality of venison meat. 40 In any case, in the current study, the incidence of DFD meats was not affected by the slaughter age and the percentage of carcasses with an ultimate pH below 6.0 was lower than values commonly observed for deer meat (12%, 2% and 8% for L, M and H for 9th rib at 48 h post mortem and 0%, 0% and 4% for L, M and H for LTL muscle at 72 h post mortem).…”

Chemical and physico‐chemical changes during the dry‐cured processing of deer loin

“…Taking into account that genetic factors influence enzymatic activities and that the meat composition influence the biochemical changes produced during the different stages of dry‐cured meat process (Bermúdez et al ., ), the results obtained in this research will provide us with information about the possibility of using deer meat for the preparation of dry‐cured loin. In this context, venison meat is characterised by low fat and cholesterol contents and high levels of protein, essential amino acids, essential and long‐chain polyunsaturated fatty acids and iron (Lorenzo et al ., ; Maggiolino et al ., ; Serrano et al ., ).…”