Effects of toasting, inclusion levels and different enzyme supplementations of faba beans on growth performance of broiler chickens

Faba beans (Vicia faba) are an alternative protein source that likely can be used to a higher extent in broiler diets. White-flowered faba beans contain antinutritional substances (ANS) such as non-starch polysaccharides (NSP), trypsin inhibitors, and lectins, which might limit its inclusion level. Lectins and trypsin inhibitors are heat labile and previous studies have shown that steam-pelleting and enzyme treatment improves the nutritional value of faba beans. However, alternative to pelleting would facilitate for farmers to add faba beans on-farm. Currently, there are machines available for toasting faba beans on-farm, which might be used for broiler mash diets. The objective of this study was to investigate the effect of inclusion level (0, 10, 20 and 30%), toasting (140 degrees C 5.5 min) and different enzymes (xylanase + phytase vs. xylanase, phytase, amylase, protease) of faba bean diets on growth performance and organ parameters in broilers. To test this, 2 experiments 34 and 35 days, using a total of 480 chickenswere performed. Feed intake, body weight (BW) and feed conversion ratio were registered weekly, in addition, organ and carcass weights were registered at slaughter. The results showed that inclusion of 20% faba beans is possible in a pelleted diet with maintained broiler growth performance. When 20% was included in a mash diet, feed intake and BW decreased compared to chickens fed pelleted diets, irrespectively of pre-toasting of the beans. It can be concluded that toasting cannot replace pelleting. Supplementation of protease and amylase in addition to xylanase and phytase did not improve the nutritional value of faba beans.