A Comparison of Raw and Cooked Dried Egg White as a Source of Protein for the Chick

Abstract

When raw dried egg white (RDEW) was the source of protein for chicks fed a 6 or 30 ppm zinc diet for 21 days, lack of feathering and poor weight gains occurred, despite a level of biotin 14 times the requirement, in contrast to chicks fed RDEW cooked at 80 C. Variations in source and type of chick, source of egg white, and the main source of energy were made in an attempt to correct these conditions. When zinc was limiting and sucrose was the source of energy, consistent differences in growth between RDEW and CDEW-chicks were not found for either Leghorn or broiler-type chicks. When zinc was high, CDEW-chicks were significantly improved in weight and feathering than RDEW-chicks, regardless of type or source of chick or source of egg white. When dextrin was fed, the feather scores of all RDEW-fed chicks were significantly improved. Those of low-zinc chicks did not differ significantly from CDEW-chicks fed sucrose. When zinc was not limiting, CDEW + sucrose chicks were significantly larger in weight and lower in feather scores than RDEW + dextrin chicks and did not differ from chicks on casein-based diets. These experiments do not pinpoint the reason for the poor performance of chicks fed RDEW plus 30 ppm Zn diets but suggest that when RDEW is used as a protein source for young chicks, another protein source should also be fed to check the growth potential of the chicks.