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Effects of physicochemical characteristics of feed ingredients on DE and ME and apparent total tract digestibility (ATTD) of GE, DM, and nutrients were determined in growing pigs using ingredients with different ratios between insoluble dietary fiber (IDF) and soluble dietary fiber (SDF). Eighty growing barrows (BW: 48.41 ± 1.50 kg) were allotted to a randomized complete block design with 10 diets and eight replicate pigs per diet. Dietary treatments included a corn-based diet, a wheat-based diet, a corn–soybean meal (SBM) diet, and seven diets based on a mixture of the corn–SBM diet and canola meal, distillers dried grains with solubles (DDGS), corn germ meal (CGM), copra expellers, sugar beet pulp (SBP), synthetic cellulose, or pectin. Values for the ATTD of DM and nutrients were also compared with the in vitro digestibility of GE, DM, and nutrients. Results indicated that the ATTD of GE was greater (P < 0.05) in wheat than in canola meal, DDGS, CGM, copra expellers, SBP, and synthetic cellulose, but not different from corn, SBM, or pectin. SBM had greater (P < 0.05) DE and ME (DM basis) compared with all other ingredients. The concentration of ME (DM basis) was greater (P < 0.05) in wheat than in canola meal, DDGS, CGM, copra expellers, SBP, synthetic cellulose, and pectin, but not different from corn. Stronger correlations between total dietary fiber (TDF) and DE and ME than between ADF or NDF and DE and ME were observed, indicating that TDF can be used to more accurately predict DE and ME than values for NDF or ADF. The DE, ME, and the ATTD of DM in ingredients were positively correlated (P < 0.05) with in vitro ATTD of DM, indicating that the in vitro procedure may be used to estimate DE and ME in feed ingredients. Swelling and water-binding capacity were positively correlated (P < 0.05) with the ATTD of IDF, TDF, nonstarch polysaccharides (NSP), and insoluble NSP, and viscosity was positively correlated (P < 0.05) with the ATTD of NDF, IDF, and insoluble NSP, indicating that some physical characteristics may influence digestibility of fiber. However, physical characteristics of feed ingredients were not correlated with the concentration of DE and ME, which indicates that these parameters do not influence in vivo energy digestibility in feed ingredients. It is concluded that the DE and ME in feed ingredients may be predicted from some chemical constituents and from in vitro digestibility of DM, but not from physical characteristics. [ABSTRACT FROM AUTHOR]

Effects of inclusion rate of fiber-rich ingredients on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of GE and on the concentration of DE and ME in mixed diets fed to growing pigs were determined. The hypothesis was that increasing the inclusion rate of fiber decreases digestibility of GE, and thus, the contribution of DE and ME from hindgut fermentation because greater concentrations may reduce the ability of microbes to ferment fiber. Twenty ileal-cannulated pigs (BW: 30.64 ± 2.09 kg) were allotted to a replicated 10 × 4 incomplete Latin Square design with 10 diets and four 26-d periods. There were 2 pigs per diet in each period for a total of 8 replications per diet. A basal diet based on corn and soybean meal (SBM) and a corn-SBM diet with 30% corn starch were formulated. Six additional diets were formulated by replacing 15% or 30% corn starch by 15% or 30% corn germ meal, sugar beet pulp, or wheat middlings, and 2 diets were formulated by including 15% or 30% canola meal in a diet containing corn, SBM, and 30% corn starch. Effects of adding 15% or 30% of each fiber source to experimental diets were analyzed using orthogonal contrasts and t-tests were used to compare inclusion rates within each ingredient. The AID and ATTD of GE and concentration of DE and ME in diets decreased (P < 0.05) with the addition of 15% or 30% canola meal, corn germ meal, sugar beet pulp, or wheat middlings compared with the corn starch diet. However, inclusion rate did not affect the calculated DE and ME or AID and ATTD of GE in any of the ingredients indicating that concentration of DE and ME in ingredients was independent of inclusion rate and utilization of energy from test ingredients was equally efficient between diets with 15% and 30% inclusion. Increased inclusion of fiber in the diet did not influence transit time in the small intestine, but reduced the time of first appearance of digesta in the feces indicating that transit time was reduced in the hindgut of pigs fed high-fiber diets. However, this had no impact on DE and ME or ATTD of GE in test ingredients. In conclusion, fiber reduced the DE and ME in the diet. However, inclusion rate of fiber-rich ingredients in diets did not affect calculated values for DE and ME in feed ingredients indicating that microbial capacity for fermentation of fiber in pigs is not overwhelmed by inclusion of 30% high-fiber ingredients in the diets. [ABSTRACT FROM AUTHOR]

An experiment was conducted to determine the apparent ileal digestibility (AID) and the standardized ileal digestibility (SID) of CP and AA in 4 sources of processed soybean products, in conventional dehulled soybean meal (SBM-CV), in conventional 00-rapeseed expellers (RSE), and in a fermented coproduct mixture (FCM) that contained rapeseed meal, wheat, soy molasses, and potato peel fed to weanling pigs. The 4 processed soybean products included 2 sources of enzyme-treated soybean meal (ESBM-1 and ESBM-2), extruded soybean meal, and soy protein concentrate (SPC). Twenty-seven weanling barrows (9.29 ± 0.58 kg initial BW) were surgically equipped with a T-cannula in the distal ileum. Pigs were randomly allotted to three 9 × 5 Youden squares with 9 pigs and five 7-d periods in each square. Seven cornstarch-based diets were prepared using each of the protein sources as the sole source of CP and AA. A N-free diet was prepared to calculate basal endogenous losses of CP and AA, and this diet was fed to 2 groups of pigs, which resulted in a total of 9 dietary treatments. Results indicate that the SID of CP was greater (P < 0.05) in ESBM-1 than in SPC, RSE, or FCM. The SID of Arg, His, Ile, Leu, Met, and Phe were greater (P < 0.05) in ESBM-1 than in SPC, and the SID of Lys was greater (P < 0.05) in SBM-CV than in ESBM-2. The SID of Thr, Trp, Val, and total indispensable AA were not different among the soybean products, but the SID of total dispensable AA in ESBM-1 was greater (P < 0.05) than in SPC. Therefore, the SID of total AA was greater (P < 0.05) in ESBM-1 than in SPC, but no other differences were observed among soybean meal (SBM) products. The SID of most AA in RSE and the SID of all AA in FCM were less (P < 0.05) than in all the SBM products, but the SID of all AA in RSE were greater (P < 0.05) than in FCM. Results of this research indicate that although processing of SBM results in increased concentration of CP, processing may also reduce the digestibility of AA, which is likely due to heat damage during processing. There are, however, differences among processed soy products, with some products having greater SID of AA than others. Results also indicate that fermentation of a mixture of rapeseed meal, wheat, and relatively low quality coproducts does not result in SID values that are similar to those of unfermented 00-rapeseed expellers or soybean products. [ABSTRACT FROM AUTHOR]

Objective: The hypothesis was that apparent ileal digestibility (AID), basal endogenous losses, and standardized ileal digestibility (SID) of amino acids (AA) are not affected by adding acid to collection containers or bags used to collect ileal digesta from pigs. Methods: Twenty-four growing barrows (initial body weight: 77.8±4.5 kg) that were fitted with a T-cannula in the distal ileum were fed diets for three 7-d periods. An N-free diet and 3 diets containing corn, soybean meal, or wheat middlings as the sole source of AA were used. Within each period, each of the 4 diets were fed to 6 pigs. Among the 6 pigs, digesta from 3 pigs were collected in bags containing no HCl, whereas 40 mL of 3 N HCl was included in the bags used to collect digesta from the remaining 3 pigs. Every other bag collected from each pig was emptied into a container without adding HCl, whereas the remaining bags were added to a container along with 40 mL of 3 N HCl for each bag. All digesta were stored at -20°C immediately after collection. Data were analyzed using a model that included feed ingredient, HCl in bags, HCl in containers, and all 2-way and 3-way interactions as fixed effects. No 3-way interactions were significant, and data were, therefore, reanalyzed independently for each diet as a 2×2 factorial. Results: There were no interactions between adding HCl to collection bags and to containers, and no effects of adding HCl to collection bags or containers for AID, basal endogenous losses, or SID of most AA were observed. Conclusion: It is not necessary to add acid to digesta collection bags or collection containers if ileal digesta are stored at -20°C immediately after collection. [ABSTRACT FROM AUTHOR]

An experiment was conducted to test the hypothesis that an increased inclusion rate of fiber decreases the contribution of DE and ME from hindgut fermentation. Twenty ileal-cannulated pigs (BW: 30.64 ± 2.09 kg) were allotted to a replicated 10 × 4 incomplete Latin Square design with 10 diets and 4 26-d periods. A basal diet based on corn and soybean meal (SBM) and a corn-SBM diet with 30% corn starch were formulated. Six additional diets were formulated by replacing 15 or 30% corn starch by 15 or 30% corn germ meal (CGM), sugar beet pulp (SBP), or wheat middlings (WM), and 2 diets were formulated by including 15 or 30% canola meal (CM) in a diet containing corn, SBM, and 30% corn starch. Effects of adding 15 or 30% of each fiber source to the corn starch diet were analyzed using orthogonal polynomial contrasts. Two-independent-sample t-tests were used to compare inclusion rates within each ingredient. Results indicated that concentration of ME (kcal/kg) linearly decreased (P < 0.001) from 3,420 kcal/kg in the corn starch diet to 3,348 and 3,305, 3,290 and 3,221, 3,316 and 3,125 and 3,310 and 3,213 kcal/kg as 15 or 30% CM, CGM, SBP, or WM was added to the diet. However, inclusion rate did not affect DE and ME of the ingredients (Table 1). This indicates that DE and ME in ingredients were independent of inclusion rates and utilization of energy from test ingredients was equally efficient in diets with 30% inclusion compared with diets with 15% inclusion. In conclusion, fiber had a negative effect on DE and ME in the diet, but inclusion rate does not affect calculated values for DE and ME in feed ingredients with relatively high concentration of fiber indicating that the microbial capacity for fermentation of fiber in pigs is not overwhelmed by inclusion of 30% high-fiber ingredients in the diets. Table 1. Concentration of DE and ME in canola meal, corn germ meal, sugar beet pulp, and wheat middlings Item, kcal/kg DM Inclusion rate SEM P-value 15% 30% Digestible Energy Canola meal 3,257 3,517 198 0.218 Corn germ meal 3,254 3,314 165 0.722 Sugar beet pulp 3,027 2,839 197 0.357 Wheat middlings 3,181 3,319 198 0.495 Metabolizable Energy Canola meal 3,235 3,377 167 0.410 Corn germ meal 3,024 3,290 182 0.165 Sugar beet pulp 3,032 2,729 190 0.136 Wheat middlings 3,197 3,244 198 0.817 [ABSTRACT FROM AUTHOR]

The current paper reviews the content and variation of fiber fractions in feed ingredients commonly used in swine diets. Carbohydrates serve as the main source of energy in diets fed to pigs. Carbohydrates may be classified according to their degree of polymerization: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Digestible carbohydrates include sugars, digestible starch, and glycogen that may be digested by enzymes secreted in the gastrointestinal tract of the pig. Non-digestible carbohydrates, also known as fiber, may be fermented by microbial populations along the gastrointestinal tract to synthesize short-chain fatty acids that may be absorbed and metabolized by the pig. These non-digestible carbohydrates include two disaccharides, oligosaccharides, resistant starch, and non-starch polysaccharides. The concentration and structure of non-digestible carbohydrates in diets fed to pigs depend on the type of feed ingredients that are included in the mixed diet. Cellulose, arabinoxylans, and mixed linked β-(1,3) (1,4)-d-glucans are the main cell wall polysaccharides in cereal grains, but vary in proportion and structure depending on the grain and tissue within the grain. Cell walls of oilseeds, oilseed meals, and pulse crops contain cellulose, pectic polysaccharides, lignin, and xyloglucans. Pulse crops and legumes also contain significant quantities of galacto-oligosaccharides including raffinose, stachyose, and verbascose. Overall, understanding the structure, characteristics and measurable chemical properties of fiber in feed ingredients may result in more accurate diet formulations, resulting in an improvement in the utilization of energy from less expensive high-fiber ingredients and a reduction in reliance on energy from more costly cereal grains. [ABSTRACT FROM AUTHOR]

The objective was to determine the apparent ileal digestibility (AID), apparent hindgut disappearance (AHD), and the apparent total tract digestibility (ATTD) of DM, energy, and nutrients by growing pigs fed mixed diets containing increasing concentrations of dietary fiber. Twenty ileal-cannulated pigs (BW: 30.64 ± 2.09 kg) were allotted to a replicated 10 × 4 incomplete Latin Square design with 10 diets and 4 26-d periods. A basal diet based on corn and soybean meal (SBM) and a corn-SBM diet with 30% corn starch were formulated. Six diets were formulated by replacing 15 or 30% corn starch by 15 or 30% corn germ meal (CGM), sugar beet pulp (SBP), or wheat middlings (WM). Two additional diets were formulated by including 15 or 30% canola meal (CM) in a diet containing corn, SBM, and 30% corn starch. Effects of adding 15 or 30% of each fiber source to the corn starch diet were analyzed using orthogonal polynomial contrasts. Results indicated a linear reduction (P < 0.001) of AID of DM from 76.8% in the corn starch diet to 73.7 and 65.6%, 65.9 and 56.0%, 61.4 and 48.6%, and 66.1 and 62.1% in diets containing 15 and 30% CM, CGM, SBP, or WP. The ATTD of DM linearly decreased (P < 0.05) from 93.6% in the corn starch diet to 90.3 and 87.7%, 89.7 and 86.2, 90.7 and 86.8%, and 89.5 and 85.7% as CM, CGM, SBP, or WM were included by 15 or 30% in the diets. The AID of CP was linearly reduced (P < 0.05) by the inclusion of 15 and 30% CM (76.8 and 70.1%), CGM (73.6 and 66.6%), SBP (74.6 and 70.0%), and WM (74.9 and 71.0%) compared with the corn starch diet (79.6%). The ATTD of CP was also reduced (Linear, P < 0.05) with increasing inclusion of test ingredients in the diet. The AHD of DM linearly increased (P < 0.05) from 16.6% in the corn starch diet to 16.5 and 22.2%; 24.0 and 30.1%, 29.2 and 38.1%, and 23.3 and 21.3% as CM, CGM, SBP, or WM were included by 15 or 30% in the diets. In conclusion, increasing concentrations of fiber in the diet may result in increased hindgut fermentation of some nutrients but this may also reduce AID and ATTD of DM and CP. [ABSTRACT FROM AUTHOR]

An experiment was conducted to determine the standardized ileal digestibility (SID) of AAby pigs in 6 sources of meat and bone meal (MBM). Eighteen ileal-cannulated barrows (initial BW: 69.3 ± 4.4 kg) were randomly allotted to a replicated 4x9 incomplete Latin square design with 4 periods and 9 diets, therefore, a total of 8 replications per diet. One diet included 33% soybean meal (SBM) as the sole source of AA and 6 diets contained 1 source of MBM included at 9% and SBM included at 22% as the only AA containing ingredients. A N-free diet was used to determine basal endogenous losses of AA. The last diet was unrelated to the experiment. The SID of AA was calculated using the direct procedure for the SBM diet. The difference procedure was used to calculate the SID of AA for all sources of MBM. The SID of Lys was greater (P < 0.05) in MBM 4 than in MBM 2, MBM 3, and MBM 6, but not different from MBM 1 and MBM 5. The SID of Met was greater (P < 0.05) in MBM 1 and MBM 4 than in MBM 3 and MBM 6, but not different from MBM 2 and MBM 5. The SID of Thr was greater (P < 0.05) in MBM 1 than in MBM 2, MBM 3, and MBM 6, but not different from MBM 4 and MBM 5. The SID of Trp was the least (P < 0.05) in MBM 3 among MBM sources. In conclusion, the SID of indispensable AA varies widely among MBM sources. [ABSTRACT FROM AUTHOR]