Effects on chick performance and nutrient digestibility of an endo‐xylanase added to a wheat‐ and rye‐based diet in relation to fat source

Abstract

1. A study with growing chicks investigated the effects of an inclusion of an endo‐xylanase preparation (LYXASAN®) to a wheat‐ and rye‐based diet on performance and nutrient digestibility in relation to the fat source. 2. The basal diet contained 500 g wheat and 100 g rye/kg of diet. The basal diet was supplemented with either 65 g soya oil/kg or 60 g blended animal fat and 5 g soya oil/kg. 3. Endo‐xylanase added to the soya oil diet did not affect weight gain, but there was a numerical improvement in food conversion efficiency which was not statistically significant. When the endo‐xylanase preparation was added to the blended animal fat diet, both weight gain and food utilisation were improved by 9.5% and 6.0%, respectively (P< 0.05). 4. Digestibilities of organic matter, crude fat, crude fibre and NFE were not significantly affected by adding endo‐xylanase to the soya oil diet. However, when endo‐xylanase was included in the blended animal fat diet, digestibility of organic matter, crude fat, crude fibre and NFE were improved (P<0–05). The improvement in fat digestibility was the most pronounced, amounting to 9–4%. Nitrogen retention and metabolisable energy content were improved significantly by the addition of an endo‐xylanase to the animal fat diet (P< 0.05), by 6.6% and 6.5% respectively. 5. From the results of this study, it can be concluded that the effects on chick performance and nutrient digestibility of a dietary endo‐xylanase in a wheat‐ and rye‐based diet are influenced to a considerable degree by the type of fat in the diet.