title: The effects of different thermal treatments and organic acid levels on nutrient digestibility in broilers.
abstract: Poultry feed is a potential vector for pathogens. Heat processing and organic acid treatments may decontaminate feed and can affect bird performance as well as feed digestibility. The present study was performed to investigate the effect of different thermal treatments including pelleting (P), long-term conditioning at 85°C for 3 min (L), or expanding at 110°C (E110) and 130°C for 3 to 5 s (E130) without or with 0.75 and 1.5% organic acid supplementation (63.75% formic acid, 25.00% propionic acid, and 11.25% water) on performance, nutrient digestibility, and organ weights of broilers. In total, 960 one-day-old broiler chicks were randomly assigned to 8 replicates using a 3 × 4 factorial arrangement. Performance variables were determined, and the relative organ weights and ileal and total amino acid (AA) digestibilities were measured at d 35. The organic acid inclusion linearly improved feed efficiency in the first week (P ≤ 0.05). The acid inclusion levels and thermal treatments had no significant effect on the performance variables at later intervals of the growing period of the birds. The L group showed the lowest ileal AA and CP digestibility. The inclusion of organic acids had a quadratic effect on total and ileal digestibility of isoleucine (P ≤ 0.05), whereas it had no significant effect on the ileal digestibility of other AA and nutrients. The relative weights of the jejunum and small intestine were significantly higher in the E130 group compared with P and L (P ≤ 0.05). In conclusion, our study demonstrated that long-term heat conditioning can decrease ileal nutrient digestibility, whereas pelleting and expansion, independently of organic acid addition, seemed to have no negative impact on broiler performance and nutrient digestibilities. Moreover, adding a blend of organic acids to broiler diets had neither positive nor negative effects on nutrient digestibility and final broiler performance. This indicates the feasibility of short-term thermal treatment and acid supplementation for hygienization of broiler feed without negatively influencing performance.
authors.affiliation: Institute of Animal Nutrition, Department of Veterinary Medicine, Freie Universität Berlin, Königin-Luise-Str. 49, 14195 Berlin, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Goodarzi Boroojeni
authors.forename: A
authors.initials: A
authors.lastname: Mader
authors.forename: F
authors.initials: F
authors.lastname: Knorr
authors.forename: I
authors.initials: I
authors.lastname: Ruhnke
authors.forename: I
authors.initials: I
authors.lastname: Röhe
authors.forename: A
authors.initials: A
authors.lastname: Hafeez
authors.forename: K
authors.initials: K
authors.lastname: Männer
authors.forename: J
authors.initials: J
authors.lastname: Zentek
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D002645:Chickens / Q000254:growth & development / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D004063:Digestion; D006358:Hot Temperature; D007421:Intestine, Small / Q000378:metabolism; D008297:Male; D011897:Random Allocation; D015430:Weight Gain
chemical_list: D000596:Amino Acids
keywords: expanding; feed decontamination; long-term conditioning; organic acid; pelleting