The effect of substitution of soybean with canola meal in laying hen diets formulated on the basis of total or digestible amino acids on performance and blood parameters

An experiment was conducted to study the effect of substitution of soybean meal (sbm) with canola meal (cm) in diets formulated on the basis of total or digestible amino acid (aa) on productive performance, egg quality, and selected organ weight and blood parameters in laying hens from 73rd to 83rd weeks of age. a total of 128 laying hens were allotted randomly to a completely randomized design arranged as a 2×2 factorial experiment with two protein sources (soybean meal and 30% soybean replaced by canola meal), and two diets formulated for total or digestible amino acids. four experimental diets were formulated with four replicates of eight birds each. increased egg weight, egg mass and improved feed conversion ratio (fcr) were recorded for diets containing sbm compared with cm (p<0.05). egg weight was increased (p<0.05) by sbm formulated on di-gestible amino acid compared to other dietary treatments. increased shell thickness (p<0.05) was recorded for cm when the diet was formulated on total amino acid basis. yolk color and relative weight (rw) of the liver were increased (p<0.05) by canola meal diet formulated on digestible amino acid. blood parameters were not affected (p>0.05) by treatments. the results of this study showed that soybean meal caused better performance than canola meal, and feed formulation based on digestible aa in sbm diet resulted in better performance in laying hens