Investigation of the Effect of Silver Nanoparticles Coated on Zeolite on Performance, Intestinal Morphology and Gastrointestinal Microbial Population in Broiler Chickens under Heat Stress Conditions

Nowadays silver nanoparticles are being considered as an alternative to antibiotics. Silver is one of the most important elements in nanotechnology due to extensive antibacterial activity. The aim of present experiment was to evaluate the effect of silver nanoparticles coated on zeolite and organic acids on performance, intestinal morphology, gastrointestinal microbial population and carcass characteristics in broiler chickens under heat stress conditions. A total of 375 day-old (Cobb 500) broiler chickens were randomly assigned to 5 treatment groups consisting of 5 replicates of 15 birds in each. Treatments included: (1) basal diet, (2) basal diet containing 1% zeolite, (3) basal diet containing 1% of zeolite-coated with 0.5% silver nanoparticles, (4) Basal diet containing 1 g/kg a mixture of organic acids and (5) Basal diet containing 1% of zeolite-coated with 0.5% of silver nanoparticles and 1g/kg a mixture of organic acids. Two chickens per each replicate were slaughtered on days 21 and 42 for measuring of the internal organs weight and microbial population enumerating, and on days 35 and 42 for morphology of the intestine. The experimental results showed that silver nanoparticles had higher feed conversion rate compared with other treatments. Also, villi length was significantly different between treatments and control group on d 35 of experiment (P<0.05). The silver nanoparticles treatment and the silver nanoparticles with organic acids treatment had the highest villi length on 42 d of experiment (P<0.05). The effect of experimental treatments had no significant effect on gastrointestinal microbial population on d 21 and 42 of experiment (P>0.05). In conclusion, the results of present study showed that silver nanoparticles coated on zeolite with organic acid could be used as a feed additive with no adverse effect under heat stress condition in broilers chicken treatments.