Effect of Environmental Heat Stress on Oxidative Stress Genes in Liver and Intestine of Broilers Fed with Silver Nanoparticles Coated on Zeolite and Organic Acids

The effect of external heat stress on the oxidative stress genes in the liver and intestine of broiler chickens fed with silver nanoparticles coated on zeolite and organic acid was investigated.

450 one-day-old Cobb chicks were divided into 5 groups of 15, with 6 replicates of each group and kept for 42 days in the same rearing conditions. 1) Control (basal diet), 2) A base diet with 1% zeolite, 3) A basic diet supplemented with 0.5% nanosilver-coated clinoptilolite at 1%, 4) A base diet with 0.15% organic acid, and 5) A base diet with 1% zeolite covered in 0.5% nanosilver and 0.15% organic acid.  The heat stress (34±1˚C temperature for 6 hours per day) was provided from 35th to 42th days. To examine antioxidant enzymes gene expression on day 42, liver and intestinal samples were taken.

In treated groups, the relative expression of the liver SOD gene was not significantly different compared with control group (P>0.05), whereas in all treatment groups SOD and glutathione peroxidase (GPX) expression had shown decrease in the intestine compare to control group (P<0.05). In group treated with zeolite coated with nanosilver and an organic acid, the relative expression of the catalase (CAT) gene showed decrease while it increased in group treated with a basal diet.

It was observed that the intestine has higher levels of antioxidant enzymes activity compared to the liver. Also, to increase the growth efficiency, it is preferred to use the combination of silver nanoparticles with organic acids.