Effect of concentration of arabinoxylans and a carbohydrase mixture on energy, amino acids and nutrients total tract and ileal digestibility in wheat and wheat by-product-based diet for pigs

Abstract

The objective of this study was to evaluate the effects of dietary supplementation with a multi-carbohydrase complex rich in xylanase and arabinofuranosidase on the digestibility of diets with different contents of arabinoxylan. The experiment was performed on six pigs (58 kg). Pigs were randomly distributed among six treatments with increasing content of arabinoxylan (70–120 g/kg) with and without enzyme (Rovabio Advance®) supplementation according to a Latin square design. The graduated content of arabinoxylan was obtained using wheat and wheat bran. Digestibilities of ileal and total energy, dry matter, organic matter, protein, starch, crude fat, and fiber were measured using titanium oxide as an indigestible marker. The increase in arabinoxylan content in the diet had a negative effect on most of the digestibility parameters (P < 0.001, R² = 0.76). Only an interaction between the enzyme and diet composition was observed for energy digestibility (P = 0.044). Digestible energy content was significantly increased by 86 kcal/kg with the enzyme for the diet with the highest arabinoxylan content. The addition of enzyme also resulted in a significant increase in the digestibility of all nutrients tested, with average improvements of 3.5 and 3.3 % for organic matter and protein ileal digestibility, respectively, and 1.2, 1.9, and 1.6 % for total tract organic matter, protein, and energy digestibility, respectively. Ileal amino acid digestibility followed a similar trend, with an increase of 5 % units for the high arabinoxylan diet. This study confirms that the presence of arabinoxylan reduces the digestibility of nutrients in pig diets and that the addition of the enzyme improves the overall digestibility of nutrients.