Influence of age of broiler chicks and duration of feeding of their sensitivity to raw soyabean.
Two broiler starter diets (24% CP, 2.9 Meal ME/kg) and two broiler finisher diets (22% CP, 3.0 Meal ME/kg) containing either raw or heat-treated full fat soyabeans were fed to 120 Anak broiler Chicks at both starter (10-45 days of age) and finisher (46-66 day of age) phase in a completely randomized design experiment to determine the influence of age of chicks and duration of feeding raw soyabeans on their sensitivity to raw soyabean diets. The results of the experiment revealed that broiler chicks showed susceptibility (P< 0.01) to the growth-depressing effect of raw soyabean diets irrespective of the age at which they started consuming the diet (10 versus 46 days). However, older birds earlier conditioned to a normal diet took a shorter time (one week) to show growth depression from raw soyabean feeding than younger birds that were not fully conditioned to a normal diet, which exhibited growth depression after four weeks. The adverse effect of feeding raw soyabeans to starting broiler chicks on their growth rate was not permanent but was reversed by switching over to cooked soyabean diet during the finishing phase. Multiple regression analysis revealed that age of chicks was a more important factor influencing sensitivity of broiler chicks to raw soyabean diets. It had a greater (P<0.0r) influence on feed intake and body weight gain than duration of feeding raw soyabeans, although the latter had a greater (P<0.05) influence on feed conversion ratio than the former.
Journal of Applied Chemistry and Agricultural Research Vol. 6 1999: pp. 88-93