UTILIZATION OF FULL-FAT RAPESEED AND RAPESEED MEALS IN RATIONS FOR BROILER CHICKS

Abstract

Two experiments were conducted to assess the use of full-fat rapeseed (RS) or rapeseed meal (RSM) in rations for broiler chicks. The first experiment included comparisons between Span (a low erucic acid variety) and Bronowski (a low glucosinolate variety) RS and the effects of addition of two types of fat (crude Span rapeseed oil and stabilized tallow) in the rations used. Parameters studied included rate of gain, feed conversion, size of thyroids, livers and hearts and composition of carcasses, hearts and livers. The second experiment studied the effects of protein level and amino acid supplementation on nutrient retention in broiler chicks fed Span RS. Inclusion of 20% raw Span or Bronowski RS in broiler rations resulted in depressed weight gain and feed conversion, increased thyroid size and production of leaner carcasses as compared to those obtained when a control ration or rations containing autoclaved RS were fed. Raw Bronowski RS resulted in superior weight gain and feed conversion as compared to raw Span RS. Use of 12% Span RSM with either RSO or stabilized tallow or 12% Bronowski RSM with RSO gave performance similar to that of chicks fed the control ration. When stabilized tallow was used with Bronowski RSM, performance was improved over that obtained with the control ration. The use of full-fat RS, RSM or RSO did not cause fat accumulation in the hearts and livers of chicks. The percentage of dry matter, fat and energy retained by chicks fed the control ration was significantly higher than in chicks fed raw or autoclaved RS. Protein retention was not affected by inclusion of RS in the rations.