mohammadreza bakhtiarizade

The effect of zinc Nano-particles (Zn- nano- complex) on bull sperm quality after freeze-thawing process studied. Ejaculates collected from four Holstein bulls twice a week. On the day of semen collection, four ejaculates were pooled and diluted with Bioxcell extender containing 0, 0.000001, 0.00001, 0.0001, 0.001, 0.01 molar of zinc Nano-complex and frozen. After thawing, sperm motility and motion parameters, plasma membrane integrity, abnormal morphology, plasma membrane functionality and mitochondrial activity were determined. The proportion of the total and progressive motile sperm, the plasma membrane integrity and proportion of the spermatozoa with abnormal morphology was not different among groups. Zinc Nano-complex groups represented a higher plasma membrane functionality than that of control group. Moreover, our flowcytometric data suggested that spermatozoa in the groups of zinc Nano-complex possessed higher mitochondrial activity as compared with the control group. Mitochondrial activity in 0.01 was higher than the 0.000001 group. In conclusion, supplementation of zn Nano-complex, can improve the plasma membrane functionality and mitochondrial activity of bull spermatozoa in a dose dependent manner without any deleterious effect on motility parameters.

The relationship between live body weight, body length, girth circumference, animal hight, upper, middle as well as lower width of fat-tail, fat-tail length, fat-tail gap length, fat-tail depth and fat-tail circumference along with fat-tail weight were determined using records of 731 Loribakhtiari sheep. Principal Component and Least Square Analyses were applied to solve the collinearity instability. Collinearity problems as portrayed by variance inflation factors above 5 or 10 were evident in some of independent variables. Results showed that the problem of collinearity in relation with fat-tail weight of 11 independent variables could be solved by using Principal Component Analysis method. Fat-tail gap length, fat-tail depth, and fat-tail circumference vs. girth circumference, and fat-tail length respectively represented the highest and the lowest coefficients regarding the estimation of fat-tail weight.