Abstract
Nutritive value of rape seed meal, which had not been used as feedstuff of poultry in this country, was studied feeding 4 samples of the meal to White Leghorn chicks or broiler-type (White Cornish male×White Plymouth Rock female) chicks.
Experimental: Two sources of rape seed, one was domestic and the other imported from Canada, were pre-treated at 2 different conditions before solvent extraction. One condition designated as Procedure 1 was to treat at 105°C. for 45 minutes and the other designated as Procedure 2 at 115°C. for one hour. Control starter and finisher diets were mainly composed of yellow corn, soybean meal, and fish meal, and experimental diets contained 10% of one of 4 samples of rape seed meal on the basis of iso-calorie and isonitrogen.
The following conclusions were obtained:
1. In the preliminary experiment, in which only 32 chicks were fed either the control or the Canadian rape seed meal diet, growth rate of the chicks on rape seed meal were retarded significantly. However, in the following 2 experiments with 450 chicks, no statistically significant difference was observed on the growth rate and feed efficiency (gain/feed) between the chicks on the control diet and on the diets with rape seed meal. No significant difference was also observed among the chicks on each of 4 samples of rape-seed meal.
2. The thyroid gland of chicks on the rape seed meal diets was enlarged significantly. Heavier thyroid was obtained on rape seed meal of Japanese origin than that of Canadian origin. Canadian meals treated by either Procedure 1 or 2 showed similar influence on thyroid gland of the chicks at 4 and 8 weeks of age. Japanese meal treated by Procedure 1 gave heavier thyroid at 4 weeks of age than that by Procedure 2 did, but both meals showed similar influence at 8 weeks of age.
3. Weight of thyroid gland per kg body weight of the chicks fed Canadian meals at 4 weeks of age was almost same to that of the chicks at 8 weeks of age. Therefore, apparent biological equilibrium between thyroid gland and body weight was observed already at 4 weeks of age on Canadian meals, but this was not true on Japanese males.
