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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.

The objective of the first experiment was to determine the effects of corn particle size on the diet apparent total tract digestibility (ATTD) of protein (CP), digestible energy (DE), metabolizable energy (ME) and N-corrected ME (AMEn) in addition to estimating the ME of corn in gestating sows. A total of 27 sows, during the second phase of gestation, were fed a common diet manufactured with corn ground to one of 3 target particle sizes (dgw): 400, 800, or 1200 µm. Titanium dioxide (0.25%) was included in the diet as an indigestible marker for digestibility calculations. Sows were fed experimental diets for 7 days to allow for diet adaptation before a 2-day collection period of urine and fecal samples. Reducing dgw of corn from 1,200 to 400 µm increased (linear, P < 0.01) ATTD CP and GE, DE, ME, AMEn and calculated ME of corn. The objective of the second experiment was to determine the effects of corn particle size on the total concentration and molar proportions of volatile fatty acids (VFA) in the feces of gestating sows. A total of 27 sows were fed treatments similar to Exp. 1 from day 61 to 82 of gestation. On day-82 and 83 of gestation, 2 fecal grab samples were collected for VFA analyses. Sows fed diets with decreasing corn dgw had increased (quadratic, P = 0.021) fecal acetic acid proportions, and decreased propionic (quadratic, P = 0.019) and valeric acid (P = 0.005). In conclusion, for every 100 µm decrease in corn dgw from 1,200 to 400 µm, corn ME value increased by 28.6 kcal/kg. Additionally, decreasing corn particle size led to an increase in the proportion of acetic acid and a decrease in propionic and valeric acid in fecal samples of gestating sows.