Factors influencing the response of broiler chickens to calcium supplementation of canola meal.

The present study was undertaken to investigate whether broiler chicks fed canola meal, as compared with diets of soybean meal, would respond to a higher level of supplemental calcium. Supplementing canola basal diets and soybean-meal basal diets with additional sulfur from sodium sulfate resulted in little or no change in broiler performance. However, supplementing diets with organic sulfur (cystine) caused a marked decrease in weight gain and feed intake, more severe with a canola diet than with a soybean-meal diet and which could be partially alleviated by increasing the calcium supplementation. A significant cystine-by-calcium interaction showed that feed intake dropped markedly, especially at the higher levels of calcium, as the levels of cystine supplementation increased. Part of the reduced performance, sometimes noted when diets supplemented with canola meal are used, may be due to a reduction in feed intake resulting from an interaction between dietary calcium and sulfur.