author(s)
Renu Kumari, Ashoka Kumar, BC Mondal, Sanjay Singh, SK Rastogi, Jyoti Palod, Anshu Rahal, Mrigakshi Yadav and Himani Sharma

abstract
This study was conducted to investigate the effects of dietary supplementation of nano-chromium and phytase enzyme on the performance and carcass characteristics of broiler chickens. A total of 240 day-old broiler chickens (Vencobb-430) were assigned to eight treatment groups according to a completely randomized design. Each treatment consisted of three equal replicates, each contained ten chicks. Chicks were fed on basal diets supplemented with different concentrations of nano chromium without and with phytase at the level of 0, 400ppb Nano-cr, 800 ppb Nano-cr, 1600ppb Nano-cr and with phytase at the level of 250FTU Phytase, 400ppb Nano-Cr+250 FTU Phytase, 800ppb Nano-Cr+250 FTU Phytase and 1600 Nano-Cr+ 250 FTU Phytase, respectively, for period of 42days. Dietary nanochromium (800ppb) supplementation with phytase (250ftu) increased final body weight (BW) at the end of the experimental period (6 weeks). Average weight gain was significantly (P<0.05) higher in chickens fed on nano chromium and phytase supplemented diet. Feed intake was also significantly (P<0.05) improved by incorporation of nanochromium with phytase in basal diet. However, the efficiency of feed conversion was better in treatment group T₂ which fed with 400ppb nano chromium. Carcass traits such as dressing and eviscerated percentage was significantly (P<0.05) greater in T₄ (Nano chromium supplemented @ 1600ppb) treatment group. Defeathered weight was increased in treatment group which was supplemented with nano chromium (1600ppb) with phytase. Cholesterol level and ether extract in meat was also significantly (P<0.05) decreased in nano chromium supplemented groups in comparison to control group and phytase supplemented group. The present results suggest that dietary chromium supplementation with phytase improved growth performance and increasing level of nano chromium in diet may produce lean meat with decreasing muscle cholesterol and fat percentage.