EFFECT OF ZINC OXIDE LEVELS SUPPLEMENTATION ON SEMEN CHARACTERISTICS AND FERTILITY RATE OF BUCKS RABBITS UNDER SUBTROPICAL CONDITIONS

The present study was conducted in the experimental farm of Animal Production Department, Faculty of Agriculture, South Valley University, Qena, Egypt, where there is a prevailing a subtropical climate. The experiment started in 15th of January 2012 to the end of May 2012. The work aimed to study the effect of zinc oxide (Zn O) levels supplementation on semen quality and fertility rate of buck New Zealand White (NZW) rabbits under subtropical conditions. A total number of thirty buck rabbits (16 weeks of age and average body weight 2368±14.21) were randomly divided into three equal treatments (10 bucks of each) without significant difference in average body weight between treatments. The 1st treatment (T1), rabbits saved as control (0 g Zn O supplement/ kg diet). The 2nd and 3rd treatments (T2 and T3), rabbits were fed with basal diet containing 75 and 150 ppm Zn O/ kg diet, respectively (0.096 and 0.192 g Zn O supplement/ kg diet, respectively). The results indicated that all the physical semen characteristics of NZW were significantly (P<0.05) improved by Zn O supplementation of buck NZW rabbits except ejaculate volume and sperm motility. Sperm concentration, total sperm count and live spermatozoa were significantly increased (P≤0.05) in the bucks of T2 and T3 as compared to the control ones. Moreover, fertility rate and litter size at birth were higher (P<0.05) in the bucks of T2 and T3 (Zn O supplementation) as compared to the bucks in T1 (control group). In conclusion, adding 75 or 150 ppm zinc O/ kg diet improved the physical characteristics of semen quality and fertility rate of buck NZW rabbits under subtropical conditions.