Effect of Different amounts of Zinc Oxide Nanoparticles on the Performance and Activity of Mucosal Enzymes in Japanese Quail from 1 to 21 Days of Age

This study aimed to investigate the effect of varying quantities of zinc oxide nanoparticles (ZnO NPs) on growth performance and mucosal enzyme activity in Japanese quails at an early age. Using a completely randomized experimental design, 160 one-day-old quail chicks were randomly assigned to 4 experimental treatments and each treatment contained 4 replicate pens of 10 birds. The experimental treatments included T1: control (a basal diet containing 35.2 mg Zn only ), T2, T3, and T4  containing basal diet plus 20, 40, and 60 mg ZnO NPs, respectively. Performance characteristics were recorded weekly. After 21 days, one quail was selected and slaughtered from each experimental cage with a body weight equal to the average body weight of quails in the same experimental cage. After slaughtering and opening the abdominal cavity, a 5 cm sample was taken from the jejunum of the small intestine. The jejunum sample was stored at -80°C until the measurement of alkaline phosphatase, amylase, and lipase enzymes. The results showed that live weight was higher in the T3 and T4 groups than in the control group (P<0.05). The feed conversion ratio was also lower in birds fed with basal diets supplemented with 40 and 60 mg ZnO NPs/kg  (T3 and T4, respectively), compared to control treatments (P>0.05). The results showed that amylase and lipase activity increased in the birds fed with 40 and 60 mg ZnO NPs/kg  of the basal diet, in comparison to the control treatment; however, they were not significant (P>0.05). The results of this study indicated that the addition of 40 or 60 mg ZnO NPs/kg to the basal diet could be used as a supplement to improve performance traits and enhance mucosal enzyme activity in Japanese quail in the starter stage.