Effects of Different Zinc Sources on Performance, Bio Distribution of Minerals and Expression of Genes Related to Metabolism of Broiler Chickens

Abstract

Different sources of Zinc (Zn) were compared to assess their possible effects on performance, nutrients retention, mineral distribution and some serum parameters of broiler chickens. A total of 200 one-day old Ross 308 chicks were divided into in equal four dietary treatments groups with five replicates each of ten chicks. The experimental groups were given the basal diet (inorganic ZnO), basal diet supplemented with organic Zn (Zn methionine), nano-ZnO and Znmix (organic Zn and nano-ZnO) at a concentration of 50 mg/kg of diet. After 42 days of feeding trial, the group supplemented with nano-ZnO exhibited the best final body weight and feed conversion ratio (2380 g/bird and 1.69, respectively). Nano-ZnO and Zn-mix supplementation significantly increased crude fat retention (86.70 and 86.75%, respectively). All sources of supplemented Zn other than inorganic ZnO significantly increased (P<0.05) Zn retention especially in the group supplemented with nano-ZnO (41.8%). Organic Zn and/or nano-ZnO sources supplemented to broiler diets significantly increased (P<0.05) iron and copper contents in the hepatic tissue and Zn content in the tibia. The mean of serum total cholesterol, triglycerides and very low density lipoprotien were significantly reduced (P<0.05) by dietary supplementation of organic Zn and/or nano-ZnO. The activity of malondialdehyde was significantly decreased (P<0.05), while Cu/Zn superoxide dismutase activity was significantly increased (P<0.05) by addition nano-ZnO or Zn-mix. Dietary Zn-mix and nano-ZnO positively affected mRNA expression of insulin like growth factor-1 and growth hormone genes in broilers when compared to the inorganic ZnO source. The present findings prospected that replacing traditional inorganic ZnO source with nano-ZnO or combining nano-ZnO and Zn methionine at applied concentration, promoted the growth of broilers, enhanced Zn up take and antioxidant status without negative effect on selected minerals distribution in tissues.