Impact of Extended Heat Treatment on the Amino Acid Digestibility and TMEn Content of a Formaldehyde-Treated Diet

Eliminating the contamination of broiler carcasses by pathogens such as Salmonella that can cause human illness continues to be a tremendous challenge and concern for the poultry industry and government regulatory agencies. One source for the introduction of these pathogens in poultry production can be the feed. Extended heat conditioning of diets prior to pelleting combined with the addition of preservatives such as formaldehyde has proven effective in reducing the risk of Salmonella in poultry diets. However, there has been a concern that the addition of some forms of formaldehyde to diets subjected to extended heat treatment could decrease the metabolizable energy and amino acid availability of the diet. To partially address this question, the TMEn and digestible amino acid coefficients of a broiler starter diet treated with 0 (control) or 0.3% formaldehyde solution prior to heat treatment at 82 degrees C for 4.5 min were determined. Cecectomized and intact adult Single Comb White Leghorn roosters were used for determining amino acid digestibility and TMEn, respectively. The addition of the formaldehyde compound did not affect either the TMEn or the digestible amino acid content of the diet, except for a marginal (less than 1%) decrease in arginine digestibility. These results indicate that the supplementation of poultry diets with formaldehyde solution prior to extended heat treatment to eliminate Salmonella contamination did not impact the nutritional value of these diets for poultry.