UTILIZATION OF WHOLE TOWER RAPESEED BY LAYING HENS AND BROILER CHICKENS

Abstract

Laying hens received diets containing 10% Tower rapeseed which was fed either as raw whole seed, autoclaved whole seed or autoclaved and ground seed. Performance was measured over ten 28-day periods. Broiler diets contained 10 or 20% Tower rapeseed either as raw whole seed, dry-heated whole seed or autoclaved whole seed. Laying hens consuming 10% dietary raw whole rapeseed produced significantly (P < 0.05) more eggs than did birds fed an isocaloric, isonitrogenous corn–soybean meal control diet. Egg production of birds fed either the control diet, autoclaved whole rapeseed or autoclaved ground rapeseed was not significantly (P < 0.05) different. Birds fed rapeseed produced smaller eggs (P < 0.01), while those birds offered autoclaved ground rapeseed produced eggs with significantly (P < 0.05) superior shell quality compared to eggs from the control birds. Broiler chickens consuming raw rapeseed had larger thyroids than did control birds, while autoclaving, and to a lesser extent dry-heating, corrected this anomaly. Body weight gain to 4 wk of age was not influenced by dietary treatment, although birds eating 20% dry-heated rapeseed showed a significantly (P < 0.05) inferior feed intake:body weight gain in comparison to that calculated for control birds. It is concluded that whole Tower rapeseed can be well utilized by both broiler chickens and laying hens at inclusion levels of 10–20% and 10%, respectively, and that no advantages accrue from grinding the seed. For broiler chickens, there is an indication that rapeseed should be heat-treated.