Performance of Vanaraja chicken on diets containing different concentrations of metabolizable energy at constant ratio with other essential nutrients during juvenile phase

A study was conducted to evaluate the effect of varying dietary energy concentrations on performance of Vanaraja chicken during juvenile phase of life. Three hundred and fifteen straight run day-old chicks were divided at random into 7 groups of nine replicates each. Chicks in each of the 7 groups were fed one of the diet containing ME ranging from 2200 to 2800 kcal/kg diet from day one to 42 days of age. The concentrations of other essential nutrients (crude protein, methionine, lysine, calcium and non-phytate phosphorus) were adjusted to maintain constant ration with ME at all energy levels tested. At 42 days of age, the body weight reduced significantly (P<0.05) in groups fed diet containing ME below 2400 kcal/kg diet. The feed conversion ratio during 1 to 42 days of age varied (P<0.05) significantly with the energy levels and was comparable among the dietary groups containing 2600 to 2800 kcal ME/kg diet. Reducing the ME content of diet below 2600 kcal/kg diet adversely affected the feed conversion ratio. The DM digestibility was significantly (P<0.05) higher in chicks of the dietary groups received 2600 to 2800 kcal ME/kg diet as compared to all other dietary groups. No definite trend could be noticed on the RTC yields. The amount of fat deposition in abdominal area was significantly (P<0.05) reduced by reducing the dietary energy content. Reducing the dietary energy content below 2600 kcal progressively (P<0.05) increased the relative weights of the intestine and gizzard. The weight of bursa and spleen were comparable among all the dietary groups. The cost of feed required to produce kg weight gain in groups fed 2400 kcal ME/kg diet was significantly (P<0.05) less compared to those fed high ME diet (>2600 kcal/kg diet). Considering the weight gain and cost of production, it can be concluded that Vanaraja chicks need 2400 ME kcal/kg diet for optimum performance during 1 - 42 d of age.