Dietary impact of NDF from different sources on the apparent ileal digestibility of amino acids

Abstract

Nowadays the use of fiber rich by-products is increasing in pig feeding. However, dietary fiber has significant impact on the nutritive value of the feed; therefore knowledge on the effect of inclusion of different fibrous components on digestibility of nutrients, particularly amino acids is crucial. The aim of the present trial was to study how the apparent ileal digestibility of selected amino acids (lysine, methionine, cystine, threonine, isoleucine, arginine, tryptophan, valine) is changed as a response of increasing dietary NDF from different source such as wheat bran and soyhulls. For that purpose a total of 40 cannulated growing pigs (35 kg BW) were used in two replicates. Ten experimental treatments were achieved by including 0, 25, 50, 75 and 100 g wheat bran (WB) or soyhulls (SH) per kg of a corn, soybean based diet. The 5 days adaptation period was followed by a 3×12 hours of ileal digesta collection. The effect of different WB and SH levels on the apparent ileal digestibility of amino acids were analyzed separately by ANOVA. Our results show that dietary NDF has negative impact on the apparent ileal digestibility of amino acids and, however, the magnitude of this reducing effect is depending on the NDF source. Due to the fact that 25 g/kg of wheat bran and soyhulls level depress the apparent ileal digestibility of the most amino acids but higher rate of inclusion has no further negative effect, the amino acid supplementation should not be increased if more than 25 g/kg of wheat bran or soyhulls are used in diet formulation.