True ileal protein and amino acid digestibilities in wheat dried distillers’ grains with solubles fed to finishing pigs

Addition of hydrochloric acid to collection bags or collection containers did not change basal endogenous losses or ileal digestibility of amino acid in corn, soybean meal, or wheat middlings fed to growing pigs

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.

Effects of distillers dried grains with solubles on amino acid digestibility, growth performance, and carcass characteristics of growing pigs

Two experiments were conducted to compare the standardized ileal digestibility (SID) of AA by growing pigs in European distillers dried grains with solubles (DDGS) produced from wheat, maize, or wheat–maize mixtures and to test the effect of increasing the inclusion levels of wheat DDGS on growth performance of growing-finishing pigs fed diets balanced for NE and SID Lys. In Exp. 1, 12 barrows (initial BW: 23.0 ± 2.2 kg) were surgically equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 6 × 6 Latin square design with six diets and six periods. Five sources of European DDGS were used: wheat DDGS from 2011, wheat DDGS from 2012, wheat-80 DDGS (80% wheat and 20% maize), wheat-70 DDGS (70% wheat and 30% maize), and maize DDGS. Each diet contained one source of DDGS as the sole source of AA and an N-free diet was used to determine basal endogenous losses of AA. Results indicated that the SID of CP was greater (P < 0.05) in maize DDGS compared with wheat DDGS from 2011, wheat DDGS from 2012, and wheat-70 DDGS. The SID of all indispensable AA except Trp was also greater (P < 0.05) in maize DDGS compared with all other DDGS sources used in this experiment. For Trp, the SID in wheat-80 DDGS, wheat DDGS from 2011, and wheat DDGS from 2012 were not different from maize DDGS, but were greater (P < 0.05) than in wheat-70 DDGS. The SID for all indispensable AA except Ile and Trp in wheat-70 DDGS were not different from the values calculated for wheat DDGS from 2011 and wheat DDGS from 2012, and no differences between SID values for AA in wheat DDGS from 2011 and wheat DDGS from 2012 were observed. In Exp. 2, 36 growing pigs (initial BW: 38.3 ± 1.97 kg) were randomly allotted to one of four dietary treatments (one pig/pen and nine replicate pigs/treatment) in a 2-phase feeding program (35 to 65, and 35 to 105 kg BW). The four dietary treatments included diets containing 0%, 10%, 20%, or 30% wheat DDGS. Results indicated that there was no effect of wheat DDGS on pig growth performance or carcass quality. However, addition of wheat DDGS increased linearly (P < 0.015) the indole concentration in the carcasses of the pigs. In conclusion, the SID of AA in maize DDGS produced in Europe is greater than in European wheat DDGS and DDGS produced from mixtures of wheat and maize, but inclusion of 30% wheat DDGS in diets fed to growing-finishing pigs did not affect growth performance or carcass quality.

Impact of dietary fiber and immune system stimulation on threonine requirement for protein deposition in growing pigs

High dietary fiber (DF) and immune system stimulation (ISS) are thought to limit amino acid availability for protein deposition (PD) in growing pigs. A nitrogen-balance study was conducted to determine Thr requirement for optimal PD when DF and ISS were present alone and in combination. A total of 90 barrows (20.5 kg initial BW; SD = 0.75 kg) were randomly assigned to one of 10 dietary treatments (n = 9) in nine blocks. Diets consisted of a low fiber (LF; 12.5% total DF) or high fiber (HF; 18.5% total DF by adding 10% sugar beet pulp and 5% wheat bran to the LF diet) with graded levels of Thr (0.49%, 0.57%, 0.65%, 0.73%, and 0.81% standardized ileal digestible [SID]) fed at 2.2 × maintenance ME requirements. After an 8-d adaptation, two 4-d nitrogen balance collection periods (pre-ISS and ISS) were conducted. ISS was induced by repeated injections (i.m.) of increasing doses of Escherichia coli lipopolysaccharide. Blood samples were taken during both periods to assess acute phase proteins and complete blood cell count. Data were analyzed by PROC MIXED with fixed effects of period, Thr, fiber, and their interactions, with block as a random effect. Nitrogen balance was analyzed separately for each period. Threonine requirement was estimated using PROC NLIN quadratic break-point model. Serum concentration of albumin, haptoglobin, fibrinogen, whole blood white blood cell, and platelet count were affected by ISS (P < 0.001) confirming successful ISS. During pre-ISS, PD increased linearly (P < 0.01) as Thr concentration in the diet increased, with a significant interaction (P < 0.05) between fiber and Thr. During ISS, PD increased linearly (P < 0.05) as Thr concentration in the diet increased. Quadratic break-point model estimated SID Thr required to maximize PD of pigs fed LF and HF diets during pre-ISS period was 0.68% (R2 = 0.88) and 0.78% (R2 = 0.99), respectively. During ISS, the SID Thr requirement was estimated at 0.76% (R2 = 0.76) for LF diet and 0.72% (R2 = 0.95) for HF fed pigs. HF and ISS independently increased Thr requirement for maximum PD, but these effects were not additive. HF may therefore mask the effects of ISS on Thr requirement for immune response and PD.

Effects of ileal digesta collection time on standardized ileal digestibility of amino acids in corn, soybean meal, and distiller's dried grains with solubles fed to growing pigs

The objective of this experiment was to determine the minimum collection time needed to obtain representative samples of ileal digesta from pigs fed different types of diets. Eight barrows with an initial BW of 34.6 kg (SD 2.1) were individually fitted with a T-cannula in the distal ileum and randomly allotted to a replicated 4 × 4 Latin square design with 4 diets and 4 periods per square. Three diets contained corn, soybean meal (SBM), or distiller's dried grains with solubles (DDGS) as the sole source of CP. An N-free diet was also prepared. All diets contained 0.5% chromic oxide as an indigestible marker. Equal meals were provided at 0800 and 2000 h. Ileal digesta samples were collected in 2-h intervals from 0800 to 2000 h during the last 3 d of each 7-d period. When pigs were fed the corn diet, the standardized ileal digestibility (SID) of most indispensable AA and dispensable AA increased and then decreased (quadratic, < 0.05) during each of the six 2-h periods. The SID of most AA were less ( < 0.05) if the ileal digesta samples were collected from 1800 to 2000 h or from 1600 to 2000 h compared with the SID values from the ileal samples collected over the entire 12-h period. When pigs were fed the SBM diet, the SID of Ile, Leu, Thr, Trp, Val, Ala, and Cys increased and then decreased (quadratic, < 0.05) but the SID of all other AA linearly decreased ( < 0.05) during the six 2-h periods. The SID of almost all AA were greater ( < 0.05) if the ileal samples were collected from 0800 to 1000 h, from 0800 to 1200 h, from 1000 to 1400 h, or from 0800 to 1400 h but less ( < 0.05) if collected from 1600 to 1800 h, from 1800 to 2000 h, from 1600 to 2000 h, or from 1400 to 2000 h compared with the SID values from the ileal samples collected over the entire 12-h period. When pigs were fed the DDGS-based diet, the SID of Ile, Leu, Lys, Phe, Trp, Val, and Tyr increased and then decreased (quadratic, < 0.05) during the six 2-h periods. The SID of most AA were less ( < 0.05) if the ileal samples were collected from 1800 to 2000 h compared with the SID values from the ileal samples collected over the entire 12-h period. In conclusion, diurnal variations in SID of AA in pigs indicate that 6 h of ileal sample collection starting 4 or 6 h after feeding may provide representative samples of ileal digesta from pigs fed different types of diets.

Xylanase increased the ileal digestibility of nonstarch polysaccharides and concentration of low molecular weight nondigestible carbohydrates in pigs fed high levels of wheat distillers dried grains with solubles

The objective was to study the effect of a commercially available xylanase (CAX), an experimental xylanase (EX), and EX in combination with protease (EXP) on the degradation of nondigestible carbohydrates (NDC) and apparent ileal digestibility (AID) of nutrients in wheat distillers dried grains with solubles (wDDGS). The control and 3 enzyme diets contained 96% wDDGS supplemented with vitamins, minerals, L-lysine, and chromic oxide as a digestibility marker in addition to enzyme premix. Eight ileal cannulated pigs were fed 4 experimental diets containing 96% wDDGS-a control diet or 1 of 3 diets with CAX, EX, or EXP-in a double 4 × 4 Latin square design. The experimental period lasted 7 d; adaptation lasted 4 d, and the ileal digesta were collected for 8 h on d 5 and 7, when spot samples of feces were also collected. Digesta samples were analyzed for NDC, total and soluble nonstarch polysaccharides (NSP), low molecular weight (LMW) NDC, OM, CP, fat, starch, and marker. Compared with the control diet, addition of CAX, EX, and EXP increased the AID of arabinoxylan by 32 (P < 0.001), 28 (P = 0.001), and 24% (P = 0.004), respectively. In addition, EXP increased the AID of noncellulosic polysaccharide glucose by 21% compared with the control (P = 0.005). Compared with the control, addition of EX, EXP, and CAX decreased the concentration of soluble arabinoxylan in ileal digesta by 40 (P < 0.0001), 40 (P < 0.0001), and 21% (P = 0.022), respectively. Furthermore, addition of CAX, EXP, and EX increased the concentration of LMW arabinoxylan in ileal digesta by 40 (P = 0.0001), 36 (P = 0.0006), and 24% (P = 0.023), respectively, compared with the control. Addition of EX and EXP decreased the concentration of soluble NSP of ileal digesta by 25 (P = 0.001) and 26% (P < 0.001), respectively, compared with the control diet. Addition of CAX (P < 0.0001) and EXP (P = 0.013) increased the arabinose-to-xylose ratio in the insoluble arabinoxylan fraction in ileal digesta compared with the control diet, and CAX increased the uronic acid-to-xylose ratio of the ileal insoluble NSP fraction (P < 0.0001) compared with the control diet. Enzyme addition did not affect AID of OM, CP, starch, and fat (P > 0.3). In conclusion, addition of xylanases to wDDGS diets increased the ileal digestibility of NSP and generated LMW NDC components in the small intestine of pigs but did not affect ileal digestibility of nutrients in the current study.

Apparent and standardised ileal amino acid digestibility of wheat distillers dried grains with solubles with or without exogenous protease in broilers and turkeys

The apparent (AIAAD) and standardised ileal amino acid digestibility (SIAAD) of wheat distillers dried grains with solubles (wheat-DDGS) was determined for broilers and turkeys at 28 d using two experiments. A total of 84 male Ross 308 broiler chicks (Experiment 1) or 84 male BUT 10 turkey poults (Experiment 2) were offered a nutrient-adequate diet from d 1 to 23. On d 23, birds in each experiment were allocated to 4 treatments consisting of a nitrogen-free diet (NFD) (with or without protease) and an assay diet containing wheat-DDGS as the only source of amino acids (with or without protease) in a randomised complete block design. In Experiments 1 and 2, the coefficient of AIAAD or SIAAD of Lys and Asp were low irrespective of protease. In Experiment 1, the coefficient of AIAAD ranged from 0.35 (Ala) to 0.75 (Pro) without protease, whereas the range was 0.42 (Thr) to 0.82 (Pro) with protease. Protease improved the coefficient of AIAAD for Arg and Pro and tended to improve the coefficient of AIAAD for Met. Without protease, the coefficient of SIAAD ranged from 0.51 (Ala) to 0.84 (Pro), whereas the range was from 0.65 (Ala) to 0.93 (Pro) with protease. Protease improved the coefficient of SIAAD of Arg, Leu, Phe, Met, Val and Pro. In Experiment 2, the coefficient of AIAAD was lower than 0.50 for all amino acids except for Glu (0.70) and Pro (0.81) without protease. On the other hand, the coefficient of SIAAD ranged from 0.41 (Thr) to 0.89 (Pro) without protease, whereas the range was from 0.56 (Arg) to 0.88 (Pro) with protease supplementation. With the exception of Cys and Pro, protease improved the coefficient of AIAAD and SIAAD of all other amino acids by 0.05-0.19. It was concluded that the AIAAD and SIAAD of wheat-DDGS are variable and are generally greater in broilers compared to turkeys at 28 d of age. Protease improved the ileal digestibility of a large number of amino acids in wheat-DDGS for broilers and turkeys.

Nutritive value of wheat concentrated distillers solubles in diets for growing pigs

Two experiments (Exp.) were conducted to determine the nutritive value of wheat-derived wet concentrated distillers solubles (CDS) for growing pigs. In Exp. 1, standardised ileal digestibility (SID) of amino acids (AA) was determined by the difference method, using six ileally cannulated barrows (initial bodyweight (BW) of 31 ± 2.9 kg). The pigs were fed a casein-corn starch-based diet supplemented with wheat CDS so that about half of the crude protein (CP) originated from either wheat CDS or from casein. In Exp. 2, 12 barrows with an initial BW of 17 ± 0.9 kg were used to determine digestible energy (DE) content, and to calculate metabolisable energy (ME) and net energy (NE) content of wheat CDS. Animals were fed either a casein-corn starch-based basal diet or a CDS diet containing 470 g/kg of the basal diet and 530 g/kg wheat CDS on a dry matter (DM) basis. Values of SID of CP and AA in Exp. 1 amounted to 85, 74, 83 and 70% for CP, lysine, methionine and threonine, respectively. The DE, ME and NE contents of wheat CDS were 16.8, 15.8 and 11.1 MJ/kg DM, respectively. It can be concluded that SID of CP and AA and also the energy content in wheat CDS are substantially higher than corresponding values reported in international tables with information on nutritional value of dried co-products of bioethanol production.

Dry fractionation creates fractions of wheat distillers dried grains and solubles with highly digestible nutrient content for grower pigs

Nutrient digestibility in distillers dried grains with solubles (DDGS) is limited by constraints such as particle size and fiber. Wheat DDGS contains more fiber than corn DDGS that may reduce its nutritional value in swine feeds. Dry fractionation may create DDGS fractions with low and high fiber content; therefore, wheat DDGS was processed sequentially using a vibratory sifter and gravity table. Sufficient material was obtained from 3 wheat DDGS fractions that differed in particle size from fine to coarse (Fraction A [FA], Fraction C [FC], and Fraction D [FD]). Five cornstarch-based diets were mixed that contained either 40% wheat DDGS, 30% FA, 30% FC plus 10% soybean meal (SBM), 30% FD plus 15% SBM, or 35% SBM. A sixth, N-free diet served to subtract basal endogenous AA losses and as control for energy digestibility calculations. Six ileal-cannulated barrows (29 kg BW) were fed 6 diets at 2.8 times maintenance for DE in six 9-d periods as a 6 × 6 Latin square. Feces and ileal digesta were collected sequentially for 2 d each. Wheat DDGS FA, FC, and FD were 258, 530, and 723 μm in mean particle size and contained 44.8, 39.3, and 33.8% CP and 29.1, 35.1, and 37.5% in NDF, respectively. The apparent total tract digestibility (ATTD) of GE was greater (P < 0.05) for SBM than wheat DDGS, was greater (P < 0.05) for FA than wheat DDGS, and did not differ between FC, FD, and wheat DDGS. The standardized ileal digestibility (SID) did not differ between SBM and wheat DDGS (P > 0.05) for most AA. The SID of Arg, Lys, Trp, and available Lys was greater (P < 0.05) for FD than wheat DDGS but was similar for FA, FC, and wheat DDGS and was greater (P < 0.05) for FD than SBM. The DE and NE value was greater (P < 0.05) for SBM, FA, and FC than wheat DDGS and did not differ between FD and wheat DDGS. The SID content of indispensable AA and available Lys was greater (P < 0.05) for SBM than wheat DDGS. The SID content of Ile, Leu, Met, Phe, and Val was greater (P < 0.05) for FA than wheat DDGS but did not differ for indispensable AA between FC and wheat DDGS. The SID content of His, Ile, Leu, Met, and Phe was lower (P < 0.05) for FD than wheat DDGS. In conclusion, dry fractionation creates DDGS fractions with a differing chemical composition. Fine particle fractions contain less fiber and more CP than coarse particle fractions, but their AA digestibility was lower, likely due to most of the solubles being fine particles that are more susceptible to AA damage than protein entrapped in particles of larger size.

Nutrient digestibility and growth performance of pigs fed diets with different levels of canola meal from Brassica napus black and Brassica juncea yellow

Nutrient digestibility and the effect of high dietary inclusion of canola meals from Brassica napus black (BNB) and Brassica juncea yellow (BJY) on growing and weaned pigs performance were determined. In Exp.1, 6 ileal cannulated barrows (initial BW = 20.7 ± 1.5 kg) were used to determine the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA in BNB and BJY. Pigs were allotted to diets containing either BNB or BJY as the sole source of protein in a crossover design to give 6 replicates per diet. The SID of all AA in BNB and BJY were similar. In Exp. 2, 168 weaned pigs (initial BW = 7.61 ± 0.76 kg) were assigned in a randomized complete block design to 7 diets (n = 24) consisting of a wheat-soybean meal-based control diet and 6 diets containing 5, 10 or 15% of canola meal derived from either BNB or BJY to determine the effect of different dietary inclusion on growth performance over a 28-d period postweaning. Diets were formulated to contain similar NE and SID of Lys. There were no differences in growth performance among treatments. In Exp. 3, 162 weaned pigs (initial BW = 7.26 ± 0.70 kg) were used to determine the effect of high BNB and BJY inclusion level without or with multicarbohydrase supplementation on growth performance and apparent total tract digestibility (ATTD) of CP, DM, and GE. A wheat-soybean meal-based control diet and 8 diets containing 20 and 25% of either BNB or BJY without or with added multi-carbohydrase were formulated (n = 18) to contain comparable NE and similar SID of Lys contents. Feeding the diets containing 25% of BNB or BJY supported similar growth performance as those containing 20%. The multi-carbohydrase had no effect on growth performance but improved (P < 0.05) the ATTD of DM, CP, and GE compared with those fed nonsupplemented diets irrespective of canola meal type. Diets containing 25% canola meal had lower (P < 0.05) ATTD of DM, CP, and GE regardless of canola meal type compared with the 20% canola meal diets. There was an interaction (P < 0.05) between canola meal type and inclusion level on ATTD of DM in which ATTD of DM decreased with increasing inclusion of both canola meal types. Results of the current study indicate that both BNB and BJY can be included up to 25% in weaned pig diets without compromising performance as long as the diets are formulated on an NE and SID of Lys basis. Also, enzyme addition improved the ATTD of CP, DM, and GE in weaned pigs in both BNB and BJY diets.

Nonruminant Nutrition Symposium: Controlling feed cost by including alternative ingredients into pig diets: a review

Sustained price increases for traditional cereal grain and protein meal feed commodities have forced the pork industry to consider the dietary inclusion of alternative feedstuffs. Crop seed may serve as feedstuffs but their demand as feedstock for human food, biofuel, and bioindustrial products has increased. Together with these products, coproducts such as distillers dried grains with solubles, wheat millrun, and canola meal are produced. As omnivores, pigs are ideally suited to convert these non-human-edible coproducts into high-quality food animal protein. Therefore, coproducts and other low-cost alternative feedstuffs such as pulses and oilseeds can be included in pig diets to reduce feed cost per metric ton of feed. However, inclusion of alternative feedstuffs in pig diets does not necessarily reduce feed cost per kilogram of gain. Therefore, the use of novel and existing feedstuffs in pig diets must be optimized following their characterization for energy and AA profile. Alternative feedstuffs generally have a high content of at least 1 of the following antinutritional factors (ANF): fiber, tannins, glucosinolates, and heat-labile trypsin inhibitors. Several methods can optimize nutrient use of pigs fed alternative feedstuffs by reducing effects of their ANF. These methods include 1) particle size reduction to increase nutrient digestibility, 2) dehulling or scarification to reduce tannin and fiber content of pulses and oilseeds, 3) air classification to create fractions that have a greater content of nutrients and lower content of ANF than the feedstock, 4) heat treatments such as extrusion, toasting, roasting, and micronization to reduce heat-labile ANF, 5) dietary supplementation with fiber-degrading enzymes or predigestion of fibrous feedstuffs or diets with fiber-degrading enzymes to increase dietary nutrient availability, and 6) formulation of diets based on bioavailable AA coefficients. In conclusion, the feeding of alternative ingredients may reduce feed cost per unit of pork produced provided that their price per unit NE or digestible lysine is less than that of the traditional feedstuffs and that negative effects of their ANF are controlled.

Ileal digestibility of amino acids in pea protein isolates, wheat-corn distillers dried grains with solubles, and short-season corn fed to broiler chicks

The apparent ileal digestibility (AID) of amino acids (AA) in 4 pea protein isolates [PPI; experiment (Exp.) 1], 5 wheat- and corn-derived distillers grains with solubles (wcDDGS; Exp. 2), and 5 short-season corn (Exp. 3) samples for broiler chickens were determined. In addition, a reference wheat sample was included in each experiment to measure the repeatability of the ileal digestibility assay used. Birds (n = 180 for Exp. 1 and n = 216 for Exp. 2 or 3) were fed test diets from d 15 to 21 of age. Reference wheat and PPI were included in test diets at 91.7 and 25%, respectively, as the sole source of AA, whereas wcDDGS and corn were combined with wheat in test diets at 47.7% test ingredient (wcDDGS or corn) and 51% wheat as the sources of AA. Chromic oxide at 0.3% was added in all diets as the indigestible marker. Each test diet was randomly assigned to 6 cages of 6 male birds each. On d 21, birds were killed and ileal digesta were collected to determine the AID of AA. The mean AID values for indispensable AA ranged from 86.0% (Thr) to 94.7% (Arg) for PPI, 50.7% (Lys) to 79.8% (Leu) for wcDDGS, and 73.9% (Thr) to 95.3% (Arg) for corn. Overall, the CV range for AID of AA was widest for wcDDGS (8.1% for Met to 29.4% for Lys) followed by corn (3.0% for Met to 10.7% for Thr) and then PPI (2.7% for Lys to 6.1% for Thr). For wcDDGS and corn, the within-sample variation (assay condition) was more than between-sample variation (feed differences), whereas the reverse was true for PPI. No differences were detected in the AID of CP and AA for reference wheat among experiments.

Effect of a carbohydrase mixture on ileal amino acid digestibility in extruded full-fat soybeans fed to finishing pigs

Extrusion technology has been used successfully to improve the nutritive value of full-fat oilseeds via shear force and heat applied during passage through the extruder, exposing more peptide bonds to enzymatic hydrolysis. However, the fibrous portion of the seeds is largely intact after extrusion. Therefore, application of carbohydrase mixtures targeting nonstarch polysaccharides might further improve the nutritive value of extruded full-fat oilseeds. This hypothesis was investigated in a study involving 6 ileal-cannulated barrows (average initial BW = 75.0 kg) fed extruded full-fat, soybean- (FFSB) based diets, without or with a carbohydrase mixture (CM) to determine apparent ileal digestibility (AID) of energy and standardized ileal digestibility (SID) of AA. The CM supplement provided 500, 50, 400, 1200, 450, and 45 units of pectinase, cellulase, mannanase, xylanase, glucanase, and galactanase, respectively, per kilogram of diet. A basal diet was formulated to contain FFSB as the sole source of AA, whereas the CM diet was formulated by supplementing the basal diet with CM. Diets contained titanium dioxide as an indigestible marker. Diets were fed in a 2-period crossover design to give 6 observations per diet. Each experimental period lasted 7 d, including a 5-d adaptation period and 2-d ileal digesta collection period. The SID of N and AA were calculated using published values for ileal endogenous N and AA losses from our laboratory. Enzyme supplementation increased (P < 0.01) AID values of DM (68.7 vs. 65.7%), GE (74.6 vs. 70.5%), and N (64.2 vs. 58.5%). Greater (P < 0.05) AID values were recorded for Leu, Met + Cys, Thr, Cys, Ser, and Tyr in the CM diet compared with the basal diet. Compared with the basal diet, the CM diet had greater SID values for N (73.7 vs. 68.6%; P < 0.01), Met + Cys (59.9 vs. 52.2%; P < 0.05), and Thr (66.3 vs. 61.2%; P < 0.05). The average SID for indispensable and total AA increased by 3.4% and 3.8% units, respectively, after enzyme supplementation. In conclusion, enzyme supplementation increased the nutritive value of extruded FFSB for finishing pigs.

Amino acid and fiber digestibility, intestinal bacterial profile, and enzyme activity in growing pigs fed dried distillers grains with solubles-based diets

The aim of this study was to determine ileal AA and fiber digestibility in new-generation dried distillers grains with solubles (DDGS) derived from wheat (wDDGS), a wheat-corn blend [wcDDGS, wheat and corn were fermented in a 7:3 wt/wt ratio], or corn (cDDGS) and to determine the effects of diets containing DDGS on gut bacteria and bacterial and digestive enzyme activities. Experimental diets contained one of the DDGS samples as the sole source of protein, and a low protein diet (5% casein) was included to estimate basal endogenous ileal CP and AA losses. Chromic oxide (0.3%) was added as an indigestible marker to all diets. Twelve cannulated barrows with an initial BW of 20.2 +/- 1.3 kg were allotted to the 4 experimental diets in a 2-period crossover design, which provided 6 observations per diet. Pigs were acclimatized to their diets for 5 d followed by a continuous 12-h digesta collection on d 6 and 7. Diet had no effect on the apparent ileal digestibility (AID) of CP (P = 0.58). The wDDGS diet generally had decreased (P < 0.05) AID of AA compared with the wcDDGS or cDDGS diet. Similarly, the values for standardized ileal digestibility of CP and most AA were smaller (P < 0.05) for the wDDGS diet compared with the other 2 DDGS diets. The Lys and Thr were the least digestible AA among the indispensable AA across the 3 DDGS samples. The digestibilities of nonstarch polysaccharides and NDF were not affected by diet (P = 0.80 and 0.40, respectively); however, the ileal digesta viscosity was greater (P < 0.05) for the wcDDGS diet than the wDDGS and cDDGS diets. The counts of Lactobacillus (P = 0.09) and Enterobacteriaceae (P = 0.05) were greater for the cDDGS diet compared with the other 2 diets. Accordingly, the cDDGS diet elicited a greater (P < 0.05) lactic acid concentration in digesta than the wDDGS diet. The activities of bacterial (P = 0.86 to 0.91) and digestive enzymes (P = 0.31 to 0.80) did not differ among the diets. The results indicate that the wDDGS had generally less protein and AA ileal digestibilities compared with the wcDDGS and cDDGS samples and that nonstarch polysaccharides and NDF digestibilities were similar among diets. Although diet influenced digesta bacterial counts, no effects were observed on the activities of bacterial and digestive enzymes.

Board-invited review: the use and application of distillers dried grains with solubles in swine diets

Distillers dried grains with solubles (DDGS) may be included in diets fed to pigs in all phases of production. The concentrations of DE and ME in DDGS are similar to those in corn. Phosphorus in DDGS is highly digestible to pigs and apparent total tract digestibility values of approximately 60% have been reported. The concentration of starch in DDGS is low (i.e., between 3 and 11%), but the concentration of fat in DDGS is approximately 10% and the concentrations of ADF, NDF, and total dietary fiber in DDGS are approximately 3 times greater than those in corn (9.9, 25.3, and 42.1%, respectively). The apparent total tract digestibility of dietary fiber is less than 50%, which results in reduced digestibility values for DM and energy in DDGS. The concentrations of most AA in DDGS are approximately 3 times greater than those in corn, but the standardized ileal digestibility of most AA is approximately 10 percentage units less than in corn. Nursery pigs from 2 to 3 wk postweaning, and growing and finishing pigs may be fed diets containing up to 30% DDGS without any negative impact on growth performance. However, the carcass fat in pigs fed diets containing DDGS has a greater iodine value than the carcass fat in pigs not fed DDGS. It may, therefore, be necessary to withdraw DDGS from the diet of finishing pigs during the final 3 to 4 wk before slaughter to achieve the desired pork fat quality. Lactating sows can also be fed diets containing up to 30% DDGS, and DDGS can replace all the soybean meal in diets fed to gestating sows without negatively affecting sow or litter performance. Inclusion of DDGS in diets fed to pigs may improve immune system activation, but more research is needed to elucidate the mechanisms responsible for these effects. Manure volume will increase when DDGS is included in the diets because of the reduced digestibility of DM in DDGS. Nitrogen excretion may also increase, but this can be prevented by the use of crystalline AA in diets containing DDGS. In contrast, P excretion can be reduced in diets containing DDGS if the total dietary concentration of P is reduced to compensate for the greater digestibility of P in DDGS. In conclusion, DDGS can be included in diets fed to growing pigs in all phases of production, beginning at 2 to 3 wk postweaning, in concentrations of up to 30% DDGS, and lactating and gestating sows can be fed diets containing up to 30 and 50%, respectively, without negatively affecting pig performance.