Equations for estimating ileal amino acid digestibility and digestible energy in bakery byproducts fed to nursery pigs

Objective: The present experiment aimed to determine standardized ileal digestibility (SID) of amino acids (AA) and digestible energy (DE) in 4 bakery byproducts fed to nursery pigs and to develop prediction equations for estimating SID of AA and DE in bakery byproducts.Methods: 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.A 55 Latin square design was used with 5 treatments, 5 pigs, and 5 periods.Four sources of bakery byproducts containing 9.1% to 38.4% neutral detergent fiber (NDF) were used.Three experimental diets contained each bakery byproduct at 96.6% as the sole source of nitrogen 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.Each period consisted of 6 d of adaptation, 1 d of fecal collection, and 3 d of ileal collection.Results: 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 indispensable AA except Lys and DE in bakery byproducts.Prediction equations were developed for estimating SID of AA and DE: SID of Met (%) = 86.7-0.54NDF(r 2 = 0.74 and p<0.001);SID of Thr (%) = 73.4-1.00NDF(r 2 = 0.57 and p<0.001); and DE (kcal/kg as-is) = 4,819-81.96NDF(r 2 = 0.93 and p<0.001),where NDF is expressed as % as-is.Conclusion: Amino acid digestibility and DE differed among various bakery byproducts fed to nursery pigs.Neutral detergent fiber can be used to estimate SID of AA and DE in bakery byproducts for nursery pigs.