ABSTRACT
The objective of this experiment was to study and compare the effects of dietary supplementation of organic and inorganic zinc (Zn) on growth performance, nutrient utilisation and gene expression pattern of glucose transporter protein in peripheral blood mononuclear cells (PBMC) in Malabari kids. Fifteen, 3-4-month-old goat kids were divided into three groups uniformly by using completely randomised design (CRD). Group G1 was fed on basal diet as per NRC requirement, and G2 and G3 were fed on basal diet + 40 ppm Zn as inorganic zinc sulphate (ZnSO4) and 40 ppm Zn as organic Zn methionine, respectively, for a period of 91 days. Supplementation of inorganic and organic Zn had no significant effect on dry matter (DM) intake. The digestibility of crude protein (CP), ether extract (EE), neutral detergent fibre (NDF), hemicellulose and cellulose was significantly more in the organic Zn-supplemented group. The average daily gain and feed:gain ratio were significantly (p < 0.05) better in group G3 in comparison to G1 and G2, while the nitrogen retention was found to be (p < 0.01) higher in group G3 than in group G1. Zinc balance was found to be significantly (p < 0.01) increased in both supplemented groups with respect to unsupplemented group G1. The blood glucose level was (p < 0.01) lower in group G3 compared to group G1 suggesting the insulin-like activity of Zn. Serum Zn concentration was significantly (p < 0.01) increased in both Zn-supplemented groups. There was a significant (p < 0.05) rise in glucose transporter GLUT1 expression in groups G2 and G3 when compared to control group G1. Moreover, GLUT1 expression was found to be higher (p < 0.05) in group G3 as against the animals of group G2. Lowered blood glucose level might have stimulated more glucose transporter GLUT1 expression in PBMC. Organic Zn supplemented at 40 ppm level resulted in better growth performance, nutrient digestibility and nitrogen as well as Zn retention in goat kids. There was better absorption, and hence, less amount of Zn got excreted in the organic Zn-supplemented group.
