Effects of increasing levels of pea and rapeseed meal in broiler diets

A feeding trial with a total of 1296 male Ross 308 broilers was carried out in two identical trials to determine the effect of the replacement of SBM by either RSM (Feeding Group 2 (FG 2) 10%, FG 3: 15%), peas (FG 4: 10%, FG 5: 20%) or a combination of both (FG 6: 10% RSM/10% peas, FG 7: 10%/20%, FG 8: 15%/10%, FG 9: 15%/20%). A RSM and pea free diet served as the control (FG 1). Each trial involved 3 phases (phase 1: 0.-10. day; phase 2: 10.-24. days; phase 3: 24.-35. days). The SBM-substitutes in the feed mixtures of phase 1 were halved. Feed mixtures were compiled according to references of AVIAGEN (2007) based on the level of ileal digestible amino acids (EVONIK, 2010). There were no coccidiostats used in the mixtures. The total feed intake as well as the feed intake throughout all phases differed significantly between the feeding groups. FG4 and FG7 showed only numerically the highest feed intake, whereas the control showed a significantly higher feed intake than groups 2 and 3. This effect was reflected by the weights at the end of fattening. FG 4 and FG 7 achieved the highest and FG 2 and 3 the lowest weights. The control again differed only to FG 2 and 3. The same applied to the carcass weights. There were no distinctions in feed conversion between the feeding groups. Slaughtering results did not show any significant effects according to the percentages of commercial cuts. Feeding groups fed a combination of RSM and peas showed collectively a better performance than the RSM groups. The observed differences might be the results of overestimated SID values for RSM and an underestimation of SID in peas. In conclusion, a combination of 15% RSM and 20% peas in feed mixtures for fast growing Ross 308 broilers is possible without any detrimental effects on performance if the diet is supplemented appropriately with free amino acids (lysine, methionine, threonine).