Ileal and total tract nutrient digestibility in wheat wet distillers solubles and wheat dried distillers grains with solubles when fed to growing pigs

The digestibility of dietary components, amino acids and energy in growing pigs fed with wheat wet distillers solubles (WWDS) and wheat dried distillers grains with solubles (WDDGS) was studied in growing pigs fitted with a post valve T-caecum (PVTC) cannula. Eight PVTC cannulated pigs were used in a cross-over arrangement, with four animals per treatment. The coefficients of apparent ileal (CAID) and apparent total tract digestibility (CATTD) of dry matter, organic matter and energy decreased linearly (P < 0.05) in diets with increasing dietary inclusion of WWDS and WDDGS. The CAID of crude protein (CP) and fat were unaffected by the dietary inclusion level of WWDS and WDDGS. The CAID of all amino acids were unaffected by increasing dietary inclusion of WWDS and WDDGS. The coefficients of ileal standardized digestibility (CSID) of CP, lysine and histidine were higher (P < 0.05) in the WWDS product than in the WDDGS product, while the opposite was found for the CSID of methionine, cysteine, isoleucine, leucine and valine. The CSID of CP and phenylalanine in WWDS and WDDGS, and of lysine in WWDS were at the same level as those reported for wheat bran. However, the CSID of CP and essential amino acids were lower in WWDS and WDDGS than in wheat, wheat flour and wheat middlings. The digestibility values presented make it possible to formulate diets for pigs with inclusion of WWDS and WDDGS with better precision, in particular with respect to the supply of essential amino acids.