Nutrient digestibility in broiler chickens fed diets containing high levels of soybean oil is affected by the source of fiber

Abstract This study evaluated the effects of including soluble and insoluble dietary fiber sources in soybean oil-containing diet for broiler chickens on coefficient of apparent ileal digestibility (AID) of amino acids, coefficient of apparent retention (AR) of nutrients, and nitrogen-corrected apparent metabolizable energy (AMEn). A total of 180 broilers were divided into 30 groups and fed 3 diets from day 14 to 21 of age. The diets were corn–soybean meal containing 6.8% soybean oil without or with soybean hulls (SBH) or sugar beet pulp (SBP) at 8.0% as sources of insoluble and soluble fiber, respectively. The SBH and SBP contained 6.0% and 14.7% of soluble dietary fiber and 60.5% and 37.0% of insoluble dietary fiber, respectively. The AID of indispensable amino acids was decreased (P < 0.05) due to dietary inclusion of SBH, but not of SBP. Dietary SBH and SBP reduced the AR of gross energy (by 14% and 8%, respectively) and AMEn (by 20% and 14%, respectively). Overall, inclusion of SBH or SBP at 8.0% in a corn–soybean meal-based diet for broilers that contains high level of soybean oil might not improve nutrient digestibility. However, SBP has less detrimental effects on nutrient digestibility than SBH.