Determining the apparent ileal digestibility of amino acids for soybean meal from select soybean varieties with varying levels of crude protein

Abstract

SUMMARY: A total of 240 Ross 308 one-day old male broilers were placed in batteries for a 15-d study to evaluate apparent ileal digestibility (AID) of amino acids (AA) for soybean meal (SBM) from specialty variety soybeans grown in South Carolina. The AID of AA using the indirect method with titanium dioxide as a marker. There were 10 replicates per treatment with 6 broilers per cage. On d 9, cages were allotted to 1 of 4 dietary treatments. Two treatment sources consisted of soybeans from a similar region (Midwest) and solvent extracted either commercially or experimentally. Thus, dietary treatments contained either commercially processed SBM with 44% CP (crude protein; CON; CPi, 46.5% Solvent Extracted Soybean Meal, Cooperative Producers, INC., Hastings, NE) or experimentally processed SBM with 50% CP (PCON), 52% CP (52SBM), or 56% CP (56SBM). Broilers fed CON and 56SBM had increased (P < 0.01) AID Arg, His, Lys, Thr, and Trp compared to those fed PCON and 52SBM. The AID of Met increased (P = 0.007) in broilers fed CON and 56SBM compared to 52SBM. Broilers fed CON and 56SBM had increased (P < 0.01) AID of Val compared to PCON and 52SBM. The 56SBM had increased (P < 0.01) concentrations of digestible AA content compared to other sources. In addition, PCON had increased (P < 0.01) concentrations of digestible methionine, threonine, aspartic acid, proline, and serine compared to 52SBM. Therefore, accounting for digestible AA content of SBM varieties can lead to a greater opportunity to reduce diet cost.

Keywords

• amino acid digestibility
• broilers
• soybean meal
• soybean variety