Effect of trace mineral source on biochemical and hematological parameters, digestibility, and performance in growing lambs.

To study the efficacy of organic trace mineral supplementation on blood parameters, digestibility, and growth as compared to inorganic sources, 18 Zandi male lambs (with initial body weight, 28.5 ±1.4 kg and 110±5 days old) were divided into three groups of six animals in each in a completely randomized design. Lambs in the control group were fed basal diet containing 63 kg/100 kg of concentrate mixture, 22 kg/100 kg of alfalfa hay, and 15 kg/100 kg wheat straw. Animals in the experimental groups were additionally supplemented with trace minerals supplied by sulfates or a diet in which 25.7 ppm Zn, 14.3 ppm Mn, 8.9 ppm Cu from mineral-amino acid complex, and 0.86 ppm Co from Co glucoheptonate replaced with similar amounts of Zn, Mn, Cu, and Co from sulfates. All lambs were kept in individual pens with cemented floor and provision of individual feeding and watering. Lambs fed with either organic or inorganic trace mineral supplement showed higher dry matter intake and growth rate and better feed conversion efficiency (P<0.05) as compared to the control group. Blood glucose, urea nitrogen, cholesterol, and hepatic enzymes were similar among the treatments. Triglycerides (P<0.01) concentration was lower for mineral-supplemented groups. Blood vitamin B12 concentration increased with mineral supplementation and was higher for the lambs fed with organic source of trace elements as compared with those fed with inorganic mineral and the control diet (P=0.04). The results of this study showed that feeding organic trace elements improves growth performance of finishing lambs but did not affect nutrient digestibility and blood parameters.