Evaluation of maize gluten meal as a protein source in canine foods

Ten mature female dogs (19.0 ± 0.4 kg) were used in a replicated 5 × 5 Latin Square experiment to determine the feeding value of maize gluten meal (MGM) in a complete food fed to dogs. All foods contained 100 g poultry meal/kg and graded levels of MGM (4-320 g/kg dry matter) resulting in foods that were 100, 150, 200, 250 and 300 g/kg crude protein (CP). Daily dry matter (DM) intake averaged 307 ± 7 g/d. An increase in MGM resulted in an increase in faecal moisture from 516 to 575 g/kg (linear; P < 0.001) and faecal DM output increased from 24.2 to 32.9 g/d (linear; P < 0.001). The coefficient for apparent ileal digestibility (CIAD) of DM decreased from 0.89 to 0.83 (linear; P < 0.001) and the coefficient for apparent total tract digestibility (CTTAD) of DM decreased from 0.92 to 0.89 (linear; P < 0.001) as MGM increased. The coefficient for apparent large intestinal digestibility (CLIAD; 0.29) was not affected by treatment. Faecal excretion of CP increased from 5.6 to 8.1 g/d (linear; P < 0.001) as MGM increased. Crude protein CIAD increased from 0.73 to 0.82 (linear; P < 0.002) with increasing MGM whereas, CP CLIAD was not affected by treatment (0.40). Crude protein CTTAD increased from 0.84 to 0.91 (linear; P < 0.001) as MGM increased. Methionine had the highest overall CIAD ranging from 0.92 to 0.93 and threonine had the lowest CIAD ranging from 0.65 to 0.75. These data indicate that MGM is a highly digestible protein source for canine foods with inclusions of 84 to 322 g/kg.