Abstract
The experiment was conducted to compare the growth response of chicks to varying levels of supplemented urea, diammonium citrate (DAC) and L-glutamic acid. The chicks were fed the amino acid diets which contained all essential amino acids at their requirements and were supplemented with urea, DAC and glutamic acid as a non-essential nitrogen source at the levels of 3.17, 6.35, 9.52, 12.69 and 15.87 g N/kg diet, respectively. As dietary level of urea increased, body weight gain and nitrogen retention increased until the level of 6.35 g N/kg diet and beyond this level no further improvement in the performance was not observed. Above the level of 6.35 g N/kg diet body weight gain and nitrogen retention were significantly higher than those of the basal diet except for body weight gain at the level of 9.52 g N/kg diet, whereas they were significantly inferior to those of glutamic acid at all dietary levels. With the increase of dietary DAC, body weight gain and nitrogen retention increased until the level of 6.35 g N/kg diet and thereafter decreased by the inhibitory effect which presumably responsible for dietary citrate level on chick growth. At the levels of 3.17, 6.35 and 9.52 g N/kg diet the performance of chicks was significantly improved as compared to that of the basal diet, and growth promoting effect of DAC under the level of 6.35 g N/kg diet was comparable to that of glutamic acid. From the regression curves the dietary level (g N/kg diet) of urea above which and the levels of DAC and glutamic acid at which, chicks could retain nitrogen most, were 6.13, 6.27 and 11.3, respectively.
