Comparative nutrient digestibility in different ingredients fed to Duroc × Landrace × Yorkshire and Duroc × Berkshire × Jiaxing growing barrows

The objective of this study was to evaluate the differences in nutrient digestibility between Duroc × Landrace × Yorkshire (DLY) and Duroc × Berkshire × Jiaxing (DBJ) growing pigs when fed conventional ingredients. A number of 14 DLY and 14 DBJ growing barrows, surgically fitted with T-cannula in the distal ileum, were allotted to a 14 × 3 Youden Square Design with 7 experimental diets and 3 periods, respectively. Each diet was fed to 2 pigs in each breed, and each period lasted for 15 days, including 10 days for diet adaptation, 3 days for fecal collection and 2 days for digesta collection. The apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of indispensable amino acids (IAAs) and the apparent total tract digestibility (ATTD) of chemical constituents in corn and barley were calculated using the direct method, while those in wheat middlings, rice bran and alfalfa meal were calculated using the difference method. Hindgut disappearance was calculated as the difference between the AID value and ATTD value. Results showed that the AID of ether extract (EE) and neutral detergent fiber (NDF) in corn and barley were greater (P < 0.05) in DLY pigs than those in DBJ pigs. The ATTD of dry matter (DM), organic matter (OM) and EE and the hindgut disappearance of gross energy (GE), DM and OM in barley were greater (P < 0.05) in DBJ pigs than those in DLY pigs. DBJ pigs had greater (P < 0.05) AID of histidine, lysine and phenylalanine, and greater (P < 0.05) SID of arginine, histidine, lysine, phenylalanine and valine in corn and barley compared to DLY pigs. DBJ pigs also had greater (P < 0.05) SID of arginine, phenylalanine and valine compared to DLY pigs when fed wheat middlings. In conclusion, the differences in IAA and nutrient digestibility between DBJ and DLY pigs were affected by feed ingredient type. DBJ growing pigs showed significant greater ileal digestibility for most IAAs compared to DLY pigs when fed corn and barley diets.