Effect of Dietary Supplementation of Either Zinc Oxide or Nano-Zinc Oxide on Growth Performance, some Serum Biochemical Parameters, Androgen Receptor Gene Expression and Microscopical Structure of the Testis in Growing V-Line Male Rabbits

Abstract

This study is directed to assess the impacts of either zinc oxide (ZnO) or nano-zinc oxide (n-ZnO) dietary supplementation on the growth trials, some serum biochemical parameters, and testicular functions in growing V-line male rabbits. A total of 45 V-line were randomly separated into 3 equal groups; the first group (acted as control) was fed on a plain ration, and the two other groups (second and third groups) were nourished for 3 months on a plain diet supplemented with 60 mg ZnO/ kg and 60 mg n-ZnO/ kg, respectively. Growth performances; body weight (BW), body weight gain (BWG), food consumption (FC), and food conversion ratio (FCR), as well as serum levels of superoxide dismutase (SOD), catalase (CAT), triiodothyronine (T 3 ) and thyroxine (T 4 ), and testosterone were recorded monthly. The study also extended to examine androgen receptor (AR) gene expression and microscopical structure of testicular tissue at the end of the 5 th -month-old. Results revealed that the n-ZnO group exhibited significant (P ≤ 0.05) improvement over that of the ZnO group on all growth performances and serum biochemical parameters compared with the control group except for FC, T 3, and T 4 , which were insignificantly changed. Moreover, AR gene expression and microscopical findings of the testis exhibited a significant improvement in the 2 nd and 3 rd groups compared to the control group. It could be concluded that either ZnO or n-ZnO dietary supplementation acts as an ameliorative tool for production and reproduction in growing V-line male rabbits however, the n-ZnO is more effective.