Abstract
A feeding trial with laying hens was conducted to study the effect of rising levels of dietary wheat bran (WB) and two vegetable oils on digestibility and retention. In addition, two different adaption times were evaluated. The following treatments were applied: no WB/29 g/kg rapeseed oil, no WB/29 g/kg sunflower oil, 75 g/kg WB/45 g/kg rapeseed oil, 75 g/kg WB/45 g/kg sunflower oil, 150 g/kg WB/62 g/kg rapeseed oil, and 150 g/kg WB/62 g/kg sunflower oil. Samples of excrements were examined for dry matter, crude protein, ether extracts, starch, neutral detergent fiber, short-chain fatty acids, and elemental analyses. The effect of the adaption time showed a significantly negative effect on the digestibility of NDF and the retention of phosphorus when a longer prefeeding period was applied. Furthermore, the results demonstrate that regardless of high dietary fiber content, laying hens are capable of tolerating higher dietary fiber levels compared to the fiber level of corn soybean meal diets. Precondition is a balanced nutrient content between diets. Therefore, wheat bran supplementation can be regarded as an interesting option for a sustainable utilization of by-products to produce food of animal origin.