Veterinary Science & Technology

Effect of Organic Versus Inorganic Trace Mineral Supplement on Carcass Characteristics, Blood Mineral and Meat Heavy Metals Concentration in Growing Lambs under Ambient Heat Stress

Abstract

Arash Abdian Samarin and Mohammad Ali Norouzian*

Trace minerals are critical for production and reproduction in livestock. It has been demonstrated that organic mineral can be transported intact from intestinal lumen into mucosal cells, resulting in increased tissue supply of minerals and subsequently improved animal productivity. This study compared an organic amino acid-mineral complex supplement versus a non-organic mineral supplement in term of effect on performance, carcass and meat quality of finishing Zandi lambs under ambient heat stress. Eighteen Zandi male lambs (28.5 ± 1.4 kg BW) were randomly assigned to one of the three dietary treatments. Control, 2 and 3 basal diet supplemented with inorganic and organic trace mineral supplements (Zn, Cu, Mn and Co). Blood samples were collected days 0, 25, 50, and 70 of experiment from jugular vein. At the end of feeding period (70 days), lambs were slaughtered and meat samples from the longissimus thoracis muscle were analyzed for proximate composition (moisture, protein, fat and ash), macro (Ca, K, P, Na, Mg, S), micro (Cu, Zn, Co, Mn, Fe, Mo, Se, Cr) and heavy minerals (As, Al, Pb, and Cd). There was no effect of trace mineral source on lamb growth rate or carcass traits, but the fat content of longissimus muscle was decreased by 22.6% in organic mineral supplement fed lambs (P<0.05). The Zn and Fe contents in muscle was significantly (P<0.05) higher in lambs fed diets containing mineral supplement. Lower contents of heavy metals including Pb and Ni, were observed in muscle samples from lambs fed inorganic minerals (P<0.05). The results of the study indicate that dietary minerals supplementation can decrease carcass fat content and the concentration of heavy metals in muscle tissue of finishing lambs.