Comparative evaluation of organic zinc supplementation as proteinate with inorganic zinc in buffalo heifers on health and immunity

Graded Murrah buffalo heifers (18) were randomly allotted to 3 dietary groups varying in source and level of Zn supplementation in concentrate mixture to study the effect of organic (O) Zn (Zn proteinate; Zn-prot) supplementation (80 or 140 ppm) compared to inorganic Zn (I) (ZnSO4) (140 ppm) on serum biochemical parameters, antioxidant status and ovarian folliculogenesis. Mineral and biochemical constituents in serum and antioxidant enzyme activities in haemolysate were measured on 90th d of experiment. Antibody titres (log2) against Brucella abortus S19 and chicken RBC antigens was measured in serum at 7, 14, 21 and 28th d post sensitization (humoral immunity) and cell mediated immunity was assessed (120 d) by in-vivo delayed type hypersensitivity (DTH) against phytohemagglutinin-P (PHA-P). After 60 days of feeding, ovarian folliculogenesis study was made daily with ultrasound scanner in all the animals for next 60 days. Highest Zn concentration in serum without affecting the retention of other minerals (Cu, Mn and Fe) was observed with 140 ppm Zn supplementation as Zn-prot and mineral concentrations was comparable between 80 ppm Zn as Zn-prot and 140 ppm Zn as ZnSO4. Alkaline phosphatase, total protein, globulin, and glucose concentrations in serum increased with organic Zn supplementation. Organic Zn lowered lipid peroxidation (140O<80O<140I) and improved RBC catalase, glutathione peroxidase and superoxide dismutase (140O>80O>140I) activities. Antibody titres against B. abortus and chicken RBC and in vivo DTH response improved with organic Zn supplementation. Similarly, irrespective of the dose, organic Zn supplementation significantly increased the number of large follicle with greater follicular size in ovary. The study indicated that 140 ppm Zn supplementation as Zn-prot resulted in better antioxidant status, immune response and folliculogenesis in ovaries than inorganic source and the Zn supplementation could be reduced from 140 to 80 ppm as Zn-prot without any adverse effect in buffalo heifers.