Effect of genotype and nutrition interaction on growth and Nutrient utilization by naked neck and normally Feathered White Leghorn Chicks. Tomar Simmi1,*, Verma S.V.S.2, Principal Scientist (Retd.), Bhanja S.K.2, Dhama K.3 1Avian Medicine, CARI, Izatnagar-243 122, India 2Division of Nutrition and Feed Technology, Central Avian Research Institute, Izatnagar-243 122, India 3Division of Avian Diseases, Indian Veterinary Research Institute, Izatnagar - 243122, India *Reprint request: Dr. Simmi Tomar, Tel.:+91–581-2300204/2303223 Ext. 3021; Fax: +91–581-2301321
Abstract A bioassay was conducted with White Leghorn (WL) and naked neck (Na) chicks from 0 to 8 week of age to examine the effect of genotype and nutrition interaction. Six test diets combining two ME levels (10.88 or 11.71 MJ/kg) with three protein levels (160, 180 or 200 g/kg) were formulated and the performance of chicks evaluated. The naked neck chicks consumed significantly (P<0.05) more feed than the normally feathered. Although the dietary protein levels had no significant (P>0.05) effect on feed intake of birds but the energy level exerted a highly significant effect. No significant difference in body weight gains of the two genotypes during 0–4 wk was evident but the naked neck birds gained significantly (P<0.01) more weight during 5–8 week period than the normally feathered counter parts. The efficiency of feed conversion was significantly (P<0.01) affected by the genotype as well as by dietary protein and energy level during 0–4 wk period only. Both the genotype and protein levels had no significant effect on the digestibility of dietary nutrients by chicks as examined during the 7th wk of feeding period. The normally feathered birds retained significantly (P<0.05) more nitrogen than the naked neck counter parts. Both the genotypes absorbed more dietary fat from high rather than low energy diets. Ca retention was not significantly affected by the genotype but tended to be more on high-energy diets. The dietary protein level (P<0.05) and not the genotype or energy level affected the utilization of dietary P by birds. Top Key words Naked neck chicks, Growth bioassay, Feed conversion efficiency, Nutrient retention. Top |