Amino acid digestibility and energy use by weaned piglets fed yellow corn, sorghum and an exogenous enzymes combination

Abstract

In weaned piglet diets, about 20% of the total protein and amino acids (AA) comes from the inclusion of sorghum or yellow corn. Therefore, the fraction of digestible amino acids of these ingredients is important for diet formulations. The ileal-cannulated pig model is not used in younger pigs due to difficulties related to implanting T-cannula in the distal ileum and possible subsequent problems. Thus, the present study evaluated the apparent digestibility of yellow corn and sorghum in piglets by total collection and digestibility of amino acids by the slaughter method. Fifty weaned piglets, at 21-d-old, were divided into two assays to determine effects of multi-carbohydrase (MC) preparation (700 U α-galactosidase, 2,200 U galactomannanase, 3,000 U xylanase, and 22,000 U β-glucanase per kg of diet) and phytase (Phy, 500 FTU per kg of diet) supplementation on the apparent total tract digestibility (ATTD) of dry matter (DM), crude protein (CP), ash, digestible (DE) and metabolizable (ME) energy and standardized ileal digestibility (SID) of AA in yellow corn (YC) and sorghum. Piglets were individually caged and ileal digesta were collected at slaughter (38 d old). A completely randomized experimental design with a 2 × 2 (0 and 200 MC; 0 and 50 Phy) factorial treatment arrangement. A basal diet (BD) was used for an additional group of 5 piglets. Corn BD was used for ATTD determination, and corn-starch BD2 containing 50 g/kg casein was used to estimate AA losses. YC and sorghum replaced 30% of BD. There was no interaction effect (P > 0.05) of the enzyme combination on the apparent digestibility of nutrients, energy, AID and SID of AA of YC and sorghum. The apparent effect from the combination of the enzymes, in fact, was due to the presence of MC, as shown by its isolated inclusion. The supplementation of MC improved ATTD of sorghum DM (P = 0.041) regardless of Phy-supplementation. Piglets weaned at 21 days of age showed lower capacity to use energy and nutrients in the subsequent three weeks, compared to NRC and the Brazilian tables. Isolated or combined, the enzymes did not increase the digestibility coefficients of YC, however, MC increased DM digestibility of sorghum.