PS10-18. Ileal Amino Acid Digestibility and Digestible Energy in Bakery Byproducts Fed to Nursery Pigs.

Abstract Ileal amino acid (AA) digestibility and energy values in the ingredients are important for pig diet formulations. Bakery byproducts are often used in swine diets due to the high starch and sugar concentrations. The AA digestibility and energy values of bakery byproducts potentially vary depending on the raw materials and manufacturing processes. The objective of the present experiment was to determine standardized ileal digestibility (SID) of AA and digestible energy (DE) in bakery byproducts fed to nursery pigs. Additionally, prediction models for estimating SID of AA and DE in bakery byproducts were developed. Five barrows with an initial body weight of 16.6 kg (standard deviation = 1.7) were fitted with a T-cannula at the distal ileum and individually housed in pens. Four sources of bakery byproducts containing 9.1% to 38.4% neutral detergent fiber (NDF) were obtained. Three experimental diets were prepared to contain each bakery byproduct at 96.6% as the sole source of AA and energy. The fourth experimental diet consisted of a source of bakery byproduct (38.4% NDF) at 70.0% as the sole source of nitrogen. A nitrogen-free diet was prepared to determine the basal endogenous AA losses. The experimental diets were assigned to the animals in a 5 × 5 Latin square design with 5 pigs, 5 animals, and 5 periods. Each period consisted of 6 days of adaptation, 1 day of fecal collection, and 3 days of ileal collection. The SID of most AA and DE differed (P < 0.05) among 4 bakery byproducts. The NDF concentration was negatively correlated (P < 0.05) with the SID of all indispensable AA except Lys and DE in bakery byproducts. Prediction models for estimating SID of AA and DE were developed: SID of Met (%) = 86.7 – 0.54 × NDF (r2 = 0.74 and P < 0.001); SID of Thr (%) = 73.4 – 1.00 × NDF (r2 = 0.57 and P < 0.001); DE (kcal/kg as-is) = 4,819 – 81.96 × NDF (r2 = 0.93 and P < 0.001), where NDF is expressed as % as-is. In conclusion, AA digestibility and DE differed among bakery byproducts fed to nursery pigs. The SID of most indispensable AA and DE in bakery byproducts for nursery pigs can be estimated based on NDF.