Influence of water extract viscosity and exogenous enzymes on nutritive value of rye hybrids in broiler diets

Broiler chickens were fed diets based on four hybrids of rye varying in vis cosity of grain water extract (WEV). These diets were prepared with or with out arabinoxylan degrading enzymes to study the effect of grain viscosity a nd xylanase and arabinosidase supplementation on growth rate and feed effic iency, metabolisable energy (AME(n)), apparent retention of protein (APR) a nd digestibility of arabinoxylans in young broiler chickens. A wheat-based diet was used as:a control. Elimination of the detrimental effect of solubl e arabinoxylans (SAX) by the addition of both enzymes significantly improve d the feed intake, weight gain and feed to gain ratio, on average by 30, 57 , and 21%, respectively, as compared with the results of birds fed the corr esponding unsupplemented diets. These improvements were achieved as a resul t of improvement in AME(n), APR, and digestibility of soluble and total ara binoxylans by 5, 8, 45 and 34%, respectively. In general, the poorer the nu tritive value of the tested rye, the greater the benefit following enzyme s upplementation. The results of this study showed that it is possible to imp rove the nutritive value of rye for broiler chickens by selection and breed ing of rye varieties with a lower WEV and SAX content together with the app ropriate choice of feed enzymes that can hydrolyse and thus lower the visco sity of gut digesta and increase retention of nutrients.