Digestibility, nitrogen and phosphorus balance of the pig diets with different levels of wheat middling in substitution to the corn with or without addition of enzymes

An experiment was carried out to evaluate the effect of the substitution until 30% of the diet corn for wheat middling with or without addition of enzymes on the digestive utilization of the energy and nitrogen and phosphorus balances. Twenty-four barrows were used, half brothers, with 51.62 kg initial BW, housed in metabolic cages maintained in semi-acclimatized atmosphere. A 3 x 2 factorial design was used (3 wheat middling levels - 0, 15 and 30%, with or without addition of enzymes), with four replications each, being the animal the experimental unit. The increased levels of wheat middling until 30% and the addition of enzymes did not influence (P > 0.05) the digestibility of the dry matter, crude energy, digestible energy and metabolized energy and energy metabolizibility, N retention, fecal and urinary N losses. However, the addition of 30% of wheat middling reduced (P < 0.05) the fecal excretion of P and increased (P < 0.05) the P absorption. The regression analysis showed that for each wheat middling gram added to the diet, fecal P reduces in 0.05g and absorption increases 0.11g. The substitution until 30% of the diet corn for wheat middling did not affect the energy and N balances, but it improved P balance. The addition of exogenous enzymes did not affect the digestive and metabolic parameters.

pigs; digestibility; wheat middling; enzymes; nitrogen; phosphorus