Heat treatment of soybean meal (SBM) is necessary to reduce the concentration of trypsin inhibitors, but excessive heat treatment may reduce AA concentration and digestibility because AA can be destroyed by the Maillard reaction. The objective of this experiment was to determine the effects of heat treatment of SBM on apparent ileal digestibility and standardized ileal digestibility (SID) of AA by growing pigs. A source of conventional dehulled SBM (48.5% CP) was divided into 4 batches. One batch was not additionally heated, 1 batch was autoclaved at 125°C for 15 min, 1 batch was autoclaved at 125°C for 30 min, and 1 batch was oven-dried at 125°C for 30 min. Four SBM-cornstarch diets were formulated, and each of the 4 batches of SBM was used as the sole source of dietary AA in 1 diet. A N-free diet was used to estimate basal endogenous losses of AA. Ten growing barrows with an initial BW of 25.3 ± 2.0 kg were individually fitted with a T-cannula in the distal ileum. Pigs were allotted to treatments in a replicated 5 × 5 balanced Latin square design with 5 diets and 5 periods. Each period lasted 7 d, and ileal digesta were collected on d 6 and 7 of each period. Results of the experiment indicated that the apparent ileal digestibility and SID of CP and all AA decreased linearly (P < 0.01) as the time of autoclaving increased from 0 to 30 min. The concentration of furosine and the color of samples of SBM indicated that autoclaving resulted in a Maillard reaction in the SBM. However, oven drying at 125°C for 30 min did not change (P > 0.10) the SID of CP and AA in the SBM or the furosine concentration, and the color in the oven-dried sample indicated that this sample was not heat damaged. In conclusion, the digestibility of all AA in autoclaved SBM is linearly reduced as the autoclaving time increases from 0 to 30 min. The reason for these changes is most likely that autoclaving at 125°C results in Maillard reactions in SBM. Copyright © 2011. American Society of Animal Science .

An accurate assessment of moisture content in feed ingredients is important because moisture influences the nutritional evaluation of feedstuffs. The objective of this study was to evaluate various methods for moisture content determination. In Exp. 1, the weight loss on drying (LOD) of corn, soybean meal (SBM), distillers dried grains with solubles (DDGS), whey permeate, whey powder, spray-dried porcine plasma (SDPP), fish meal, and a mixed diet of these 7 ingredients were measured by oven drying at 135°C for 2 h. Additionally, the samples were dried at 105°C for 3, 6, 9, 12, or 15 h. The LOD contents of the DDGS, whey permeate, and whey powder measured by drying at 135°C for 2 h were greater than the values measured by drying at 105°C for 3 h (p<0.05). All samples except SDPP (p = 0.70) dried at 105°C for 6, 9, 12, or 15 h caused more LOD compared with the samples dried for at 105°C for 3 h (p<0.05). The LOD contents of the individual ingredients were additive when dried at 105°C regardless of drying time. In Exp. 2, moisture contents of corn, SBM, wheat, whey permeate, whey powder, lactose, and 2 sources of DDGS (DDGS1 and DDGS2) were measured by the Karl Fischer method, oven drying at 135°C for 2 h, and oven drying at 125°C, 115°C, 105°C, or 95°C for increasing drying time from 1 to 24 h. Drying samples at 135°C for 2 h resulted in higher moisture content in whey permeate (7.5% vs 3.0%), whey powder (7.7% vs 3.8%), DDGS1 (11.4% vs 7.5%), and DDGS2 (13.1% vs 8.8%) compared with the Karl Fischer method (p<0.05). Whey permeate and whey powder were considerably darkened as the drying time increased. In conclusion, drying samples at 135°C for 2 h is not appropriate for determining the moisture content in whey permeate, whey powder, or DDGS as well as the mixed diet containing these ingredients. The oven-drying method at 105°C for 5 to 6 h appears to be appropriate for whey permeate and whey powder, and at 105°C for 2 to 3 h for DDGS.

Three experiments were conducted to evaluate a novel source of high-protein distillers dried grains produced by Buhler Inc. (HP-DDG_Buhler) and fed to growing pigs. The standardized ileal digestibility (SID) of AA in HP-DDG_Buhler and in soybean meal (SBM) was determined in Exp. 1. Nine pigs (109.8 ± 2.78 kg of BW) were fitted with a T-cannula in the distal ileum and allotted to a triplicated 3 × 3 Latin square design with 3 diets and 3 periods per square. Diets containing HP-DDG_Buhler or SBM as the only source of AA and an N-free diet were formulated. The SID of indispensable AA was less (P < 0.01) in HP-DDG_Buhler than in SBM (Arg, 87.5 vs. 93.9%; His, 76.7 vs. 88.7%; Ile, 76.4 vs. 87.5%; Leu, 77.8 vs. 86.8%; Lys, 75.4 vs. 88.4%; Met, 82.8 vs. 88.4%; Phe, 77.9 vs. 87.3%; Thr, 72.5 vs. 83.5%; Trp, 85.1 vs. 91.0%; Val, 73.3 vs. 84.3%). The DE and ME in HP-DDG_Buhler and in corn were measured in Exp. 2 using 16 growing barrows (24.6 ± 1.66 kg of BW). A corn-based diet and a diet containing 50% corn and 48.2% HP-DDG_Buhler were formulated. The total collection method and the difference procedures were used. The concentrations of DE and ME in HP-DDG_Buhler were greater (P < 0.001) than in corn (5,043 vs. 4,002 kcal/kg of DM and 4,690 vs. 3,921 kcal/kg of DM, respectively). Experiment 3 was a 9-wk growth assay using 40 pigs (initial BW: 58.2 ± 2.28 kg) allotted to 5 dietary treatments, with 8 replicates of individually housed pigs per treatment. Treatments included a control diet based on corn and SBM and 4 diets in which HP-DDG_Buhler replaced 33, 66, 66, or 100% of the SBM in the control diet. All HP-DDG_Buhler diets contained supplemental Lys and Thr to provide similar concentrations of SID Lys and Thr in all diets; one of the diets in which HP-DDG_Buhler replaced 66% of the SBM and the diet in which HP-DDG_Buhler replaced 100% of the SBM also contained crystalline Trp. Dietary treatments had no effect on ADG (1.15, 1.13, 1.16, 1.12, and 1.14 kg), ADFI (3.33, 3.35, 3.39, 3.30, and 3.33 kg), or G:F (0.35, 0.34, 0.34, 0.34, and 0.34 kg/kg). Carcass traits of pigs fed the diet in which HP-DDG_Buhler replaced 100% of the SBM were not different from those of pigs fed the control diet. In conclusion, HP-DDG_Buhler contains more DE and ME than corn, but has decreased SID values for AA compared with SBM. Soybean meal can be replaced by HP-DDG_Buhler in diets fed to finishing pigs without any effect on growth performance or carcass characteristics, provided that diets are adequate in indispensable AA. Copyright © 2009. American Society of Animal Science .

An experiment was conducted to determine the efficacy of mycotoxin sequestering agents for binding or degrading aflatoxin B1 (AFB1) and deoxynivalenol (DON) by anin vitromethod. Ten toxin binder products including 5 bentonite clays (bentonite A, B, C, D, and E), 2 cellulose products (cellulose A and B), a yeast cell wall, an activated charcoal, and a mixture product containing minerals, microorganisms, and phytogenic substances were used in this experiment. Anin vitroprocedure was used to mimic the digestive process in pigs. The binding ability for AFB1 of the cellulose products was less compared with the values of other sequestering products (p < 0.05). The percent adsorption of AFB1 by bentonite clays, cellulose products, yeast cell wall product, activated charcoal product, and the mixture product were 92.5 (average of 5 bentonite products), −13.5 (average of 2 cellulose products), 92.7, 100.2, and 96.6, respectively. The respective values for DON were 3.24, 11.6, 22.9, 14.4, and 4.3. In conclusion, most toxin sequestering agents used in the present study had potential to bind AFB1 rather than DON based on thein vitrostudy which simulated the pH condition of the gastrointestinal tract of pigs.

Two experiments were conducted to evaluate the efficacy of dietary DL-methionine hydroxy analog-free acid (MHA-FA, 88%) compared with DL-methionine (DLM, 99%) as Met sources in pigs. In Exp. 1, a total of 245 crossbred pigs (initial BW of 6.4 kg [SD = 0.5]) were allotted to 7 treatments in 7 replicates for an experimental period of 28 d. The basal diet (BD) was formulated to contain 17.5% CP and 0.21% Met. Dietary treatments included 1) BD, 2) BD + 0.030% DLM, 3) BD + 0.060% DLM, 4) BD + 0.090% DLM, 5) BD + 0.034% MHA-FA, 6) BD + 0.068% MHA-FA, and 7) BD + 0.103% MHA-FA; the MHA-FA was supplemented on an equimolar basis to the DLM. Because of a nonlinear response, exponential regression analysis was used to evaluate the responses, and a comparison of the equations was then made to determine the relative effectiveness of the 2 Met sources. With increases in dietary Met, weight gain increased (P < 0.05). Compared with DLM on a product-to-product (wt/wt) basis, the relative effectiveness of MHA-FA was calculated to be 73% for increasing weight gain and 54% for decreasing the feed:gain. In Exp. 2, a total of 30 weanling barrows [initial BW of 16.8 kg (SD = 2.8)] were used in a metabolism study to evaluate the relative value of MHA-FA to DLM. The BD was formulated to contain 16.9% CP and 0.21% Met. Dietary treatments included 1) BD, 2) BD + 0.030% DLM, 3) BD + 0.060% DLM, 4) BD + 0.046% MHA-FA, and 5) BD + 0.092% MHA-FA; the MHA-FA levels were chosen based on a pre-experiment estimate of bioequivalence in an attempt to provide approximately equal pig responses. There was no difference in fecal N output among the treatments; however, urine N linearly decreased with increasing concentrations of both sources (P = 0.034 for DLM, and P = 0.007 for MHA-FA), which resulted in a linear increase in retained N for both DLM (P = 0.012) and MHA-FA (P = 0.005). In addition, N retention (% of intake) linearly increased with increasing level of DLM (P = 0.014) and MHA-FA (P = 0.007). Using a slope-ratio procedure for comparison of the responses from the 2 sources, the relative biological equivalence value of MHA-FA to DLM in this experiment was 64.2% based on percent N retention and 66.3% based on the grams of N retained per day. Based on the results from both experiments, these data indicated that the mean relative bioequivalence of MHA-FA to DLM was 64% on a product-to-product (wt/wt) basis or 73% on an equimolar basis.

In most animal growth experiments, groups of animals are housed within a pen. Occasionally, an individual animal shows a very different growth rate than its pen mates or dies during the experiment. When this happens, if pen feed intake (PFI) cannot be reestimated for the calculation of ADFI and feed efficiency, an observation will be lost from the data set. Therefore, we propose a model to estimate individual feed intake (IFI) of pigs in group feeding, with subsequent validation of the model using group feeding simulation studies. In the proposed model, the feed intake (FI) of each affected pen is partitioned into FI for maintenance (FI_m) and FI for growth (FI_g) for each animal within that pen. First, individual pig FI_m for the period is calculated using the 1998 National Research Council estimation of ME for maintenance. Then, FI_m for all pigs in the pen is summed. The difference between the summed FI_m and the total PFI is that which supported growth in the pen. Next, FI_g is calculated by apportioning the remaining feed equally to each unit of gain within the pen. Finally, the estimated IFI for the pig being removed from the pen is the sum of FI_m and FI_g for that pig; this FI estimate is subtracted from the original PFI to leave the new PFI for the remaining pigs. The validity of the estimated IFI is dependent on the accuracy of the maintenance energy equation and the energy analysis of the feedstuffs. In simulation studies, we compared the accuracy of the proposed method with 2 other methods. In simulation study 1, the proposed model showed better accuracy than at least one of the other methods during all tested periods (P < 0.001). In simulation study 2, the greater accuracy of the proposed method compared with 2 other methods was demonstrated again. Because calculation of IFI is relatively cumbersome, we developed a feed intake correction spreadsheet (FICS), an Excel spreadsheet containing macros for FI correction. All of the calculation procedures in the proposed model are included within the feed intake correction spreadsheet. The Excel file and instructions are being made available via a Web site. Copyright © 2007. . Copyright 2007 Journal of Animal Science