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This study was conducted to evaluate the effects of dietary supplementation of different sources of zinc on the quantitative and qualitative characteristics of semen and blood testosterone in Mahabadi mature bucks. Twenty-four mature male goats (40 ± 0.86 kg), approximately 1-1.5 years old, were divided into three groups (n = 8) and assigned to experimental treatments for 56 days in a completely randomized design. The treatments included: 1. control (a basal diet containing 22.14 mg/kg zinc without zinc supplement), 2. basal diet + 35 mg/kg Zn as ZnSO4 (an inorganic source of Zn), and 3. basal diet + 35 mg/kg Zn as ZnMet (an organic source of Zn). Qualitative (ejaculate volume, sperm concentration) and quantitative (viability, membrane integrity, morphology, and CASA detected parameters) properties of semen and plasma testosterone and Zn, Cu, and Fe concentrations were evaluated. Results showed that ZnMet vs. ZnSO4 increased sperm membrane integrity and plasma Zn concentration and reduced morphologically abnormal spermatozoa (P=0.05), but there were no significant differences in other parameters. Viability, membrane integrity, morphology, some of the CASA detected parameters (total motility, straight-line velocity, average path velocity, beat cross frequency of sperm), and the plasma concentration of testosterone in zinc-supplemented groups was significantly higher than the control group. In conclusion, the positive effects of an organic source of Zn were seen in reducing abnormal spermatozoa and improving membrane integrity, plasma Zn concentration, and plasma testosterone concentration. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of dietary zinc (Zn) source and level of supplementation on performance, egg quality, blood parameters, and egg yolk Zn content in laying hens from 28 to 36 weeks of age. Two hundred laying hens (Hy-Line W-36) were weighed individually and placed randomly in cages with five treatments, five replicates of 8 birds in each using a 2×2+1 factorial arrangement. Treatments consisted of a control diet (cornsoybean meal as a basal diet without Zn supplementation) and the diet supplemented with 80 and 120 mg of Zn/kg, added as either Zinc-sulfate (ZnSulf) or Zn-methionine (ZnMet), respectively. Treatments did not impact on the laying hen performance. Eggshell thickness was improved (P<0.001) by ZnMet in comparison to ZnSulf. Eggshell thickness improved by increasing Zn from 80 to 120 mg/kg of the diet (P<0.05). Plasma HDL (P<0.001), alkaline phosphatase activity (P<0.05), total protein, and albumin concentrations (P<0.001) increased by ZnMet in comparison to ZnSulf supplementation. Plasma Fe, Cu, Zn, and P, and Zn contents of the egg yolk were not affected by Zn sources or levels. Plasma Ca was higher in hens receiving 120 mg/kg ZnMet/kg than other treatments (P<0.01). In conclusion, more positive effects on eggshell quality and some blood parameters were found by dietary ZnMet supplementation at 80 or 120 mg/kg diet than ZnSulf in laying hens under the conditions of this study. [ABSTRACT FROM AUTHOR]