Effects of Replacing Canola Meal with Soybean Meal in Broiler Chicken Diet on Growth Performance, Carcass Traits, and Liver Enzymes during Different Rearing Periods.

Soybean meal is more beneficial than canola meal (CM) due to the better balance of amino acids in the nutrition of broilers. Three experiments were conducted to assess the impact of replacing soybean meal with CM at different levels during the rearing stages of Ross 308 male broilers on performance, carcass traits, and liver enzyme concentrations. In the first experiment, 420 one-day-old chicks received starter diets with six graded levels of CM from 0 to 15% for 10 days. In the second experiment, 360 eleven-day-old chicks were fed six experimental grower diets varying in CM from 0 to 25% over 14 days. In the third experiment, three hundred 25-day-old chicks were subjected to six finisher diets ranging in CM from 0 to 40% over 18 days. The findings revealed that the inclusion of the CM at the examined levels had no adverse effects on broilers' performance, carcass traits, and liver enzymes in the first and second experiments (P>0.05). Dietary CM inclusion of more than 32% in the third experiment had significant adverse effects on the performance, European broiler index, and liver enzymes of broilers (P<0.05). In conclusion, the CM can be included in broiler diets at levels up to 15% during the starter and 20% during the grower periods without adversely affecting growth performance and carcass traits. Nonetheless, an inclusion level of CM exceeding 32% of the diet during the finisher period resulted in decreased weight gain and harmful effects on liver function. [ABSTRACT FROM AUTHOR]