Ileal Amino Acid Digestibility Research Articles

155 Standardized ileal digestibility of amino acids in soybean meal, fermented soybean meal, and soy protein concentrate fed to nursery pigs

Abstract Accurate information of amino acid (AA) digestibility in protein supplements is critical in formulating diets for nursery pigs. Soybean products are widely used in nursery pig diets due to the high crude protein (CP) concentrations. The objective of the present study was to determine the standardized ileal digestibility (SID) of AA in soybean meal, 3 sources of fermented SBM (FSBM), and soy protein concentrate (SPC) fed to nursery pigs. Ten barrows with an initial body weight of 10.5 kg (standard deviation = 0.9) were surgically fitted with T-cannulas at the distal ileum. The animals were assigned to a replicated 5 × 5 Latin square design with 10 animals, 5 experimental diets, and 5 periods to obtain 10 observations per diet. Five diets were prepared to contain SBM (48.5% CP), 3 sources of FSBM (A, B, and C; 52.6% CP, 55.1% CP, and 49.8% CP, respectively), or SPC (58.4% CP) as the sole source of AA. Each period consisted of 4 d of adaptation period and 3 d of ileal digesta collection period. The values of basal endogenous losses of AA reported in the literature were used to calculate the SID of AA by correcting the apparent ileal digestibility (AID) values. Additionally, a 2-step in vitro procedure modified for nursery pigs was conducted to determine the in vitro ileal disappearance of CP in the 5 ingredients. The AID of all indispensable AA except His and Lys in FSBM-A and FSBM-B was greater (P < 0.05) than that in SBM, whereas AID values for all AA except Trp in SPC did not differ from the values in SBM. The SID of Leu and Trp in FSBM-A and FSBM-B was greater (P < 0.05) than that in SBM or SPC. The SID of all AA in SPC was not different from that in SBM. In vitro ileal disappearance of CP in 3 sources of FSBM was greater (P < 0.001) than that in SBM or SPC. In conclusion, in vitro ileal disappearance of protein was greater in fermented soybean meal compared with soybean meal or soy protein concentrate whereas the standardized ileal digestibility of most amino acids was comparable among the soybean-derived ingredients.

Standardized ileal digestibility of amino acids and metabolizable energy in three sources of high-protein corn distillers dried grains fed to weanling pigs

Two experiments were conducted to test the null hypothesis that there are no differences in the standardized ileal digestibility (SID) of amino acids (AA) and metabolizable energy (ME) among three sources of high-protein distillers dried grains (HP-DDG) fed to weanling pigs. The three sources included an experimental HP-DDG product and two commercial HP-DDG products (i.e., HP-DDG 40 and HP-DDG 50) that were fed to weanling pigs. In experiment 1, eight barrows (initial body weight: 11.09 kg) were allotted to one of four diets using a replicated 4 × 4 Latin square design with four diets and four periods of seven days in each square. A nitrogen-free diet and three diets containing each source of HP-DDG as the sole source of AA were prepared. Results indicated that values for the SID of Lys in the experimental HP-DDG; HP-DDG 50, and HP-DDG 40 were 0.524, 0.638, and 0.642, respectively. The SID of most AA in the experimental HP-DDG was less (P < 0.05) than in the other sources of HP-DDG, but no differences were observed between HP-DDG 40 and HP-DDG 50. In experiment 2, thirty-two weanling pigs (initial body weight: 18.0 kg) were randomly allotted to one of four diets. A corn diet was formulated to contain corn as the sole source of energy and three additional diets contained corn and each source of HP-DDG. Pigs were housed individually in metabolism crates and feces and urine were collected separately for four days after five days of adaptation. Digestible energy (DE) and ME in the three sources of HP-DDG were calculated by difference. Results from experiment 2 indicated that the apparent total tract digestibility (ATTD) of gross energy (GE) in the corn diet was greater (P < 0.05) than in the diets containing the experimental HP-DDG or HP-DDG 40, and the ATTD of GE in the diets containing the experimental HP-DDG or HP-DDG 50 was greater (P < 0.05) than in the diet containing HP-DDG 40. On a dry matter basis, ME in the experimental HP-DDG, HP-DDG 40, and HP-DDG 50 were 17.05, 16.72, and 18.23 MJ/kg, respectively, with the ME of HP-DDG 50 being greater (P < 0.05) than in HP-DDG 40, but not different from the ME in the experimental HP-DDG. In conclusion, the SID of most AA in HP-DDG 40 and HP-DDG 50 was greater than in the experimental HP-DDG. The DE and ME in HP-DDG 50 was greater than in HP-DDG 40, but DE and ME in HP-DDG 40 were not different from DE and ME in the experimental HP-DDG.

153 Standardized ileal digestibility of amino acids and concentration of metabolizable energy in three sources of corn protein fed to weanling pigs

Abstract Two experiments were conducted to test the hypothesis that the standardized ileal digestibility (SID) of amino acids (AA), apparent total tract digestibility (ATTD) of gross energy (GE), and concentrations of digestible energy (DE) and metabolizable energy (ME) are not different among three sources of corn protein (i.e., new corn protein, ANDVantage 50Y, ANDVantage 40Y) when fed to weanling pigs. In Exp. 1, ileal-cannulated barrows [n = 8; initial body weight (BW) = 11.09 kg; SD = 0.46] were fed an N-free diet or three diets containing each corn protein as the sole source of AA. Pigs were allotted to a replicated 4 × 4 Latin square design with 4 diets and 4 periods of 7 d in each square. Ileal digesta were collected for 2 d and the SID of AA was calculated. In Exp. 2, weanling pigs (n = 32; initial BW = 18.0 kg; SD = 1.21) were fed a corn-based basal diet or three diets containing corn and each source of corn protein. Pigs were housed individually in metabolism crates and feces and urine were quantitatively collected for 5 d after 7 d of adaptation. Concentrations of DE and ME in all diets were calculated and DE and ME in the three sources of corn protein were calculated by difference. Data from both experiments were analyzed using the MIXED procedure of SAS with pig as the experimental unit. In Exp. 1, the statistical model included diet as the fixed effect and square, pig, and period as random effects. In Exp. 2, the model included ingredient as the fixed effect. Results from Exp. 1 demonstrated that the SID of all indispensable AA except Arg and His in ANDVantage 40Y and ANDVantage 50Y were greater (P &amp;lt; 0.05) compared with the new corn protein, but no differences were observed between ANDVantage 50Y and ANDVantage 40Y (Table 1). Results from Exp. 2 indicated that on a dry matter basis, concentration of DE in ANDVantage 50Y was greater (P &amp;lt; 0.05) than in ANDVantage 40Y, the new corn protein, and corn, but ME in ANDVantage 50Y was not different from the ME in the new corn protein (Table 2). Concentration of ME in the new corn protein was not different from ME in corn, ANDVantage 40Y, or ANDVantage 50Y. In conclusion, the new source of corn protein had concentrations of AA that were not different from ANDVantage 50 Y, but this new corn protein had decreased digestibility of AA compared with other corn proteins. The new corn protein also had less DE compared with ANDVantage 50Y, but ME in the new corn protein was not different from corn, ANDVantage 40Y, or ANDVantage 50Y.

36 Effects of grinding method on ileal digestibility of amino acids in different short-season corn cultivars fed to growing pigs

Abstract Decreased corn production was previously observed in Manitoba due to the low climatic temperatures; however, corn production has increased by developing corn hybrids that require low corn heat units, and therefore can grow in areas with decreased heat units. Milling technology affects feed particle size and shape, which may affect the digestibility of nutrients and growth performance of pigs. Therefore, this study aimed to determine the effects of grinding methods on the apparent (AID) and standardized (SID) ileal digestibility of amino acids (AA) in selected short-season corn cultivars fed to growing pigs. A total of 18 ileal cannulated barrows (56.8 ± 2.9 kg) were assigned to 1 of 6 dietary treatments in a triplicate 6 × 2 incomplete Latin square design with 6 diets and 2 periods to give 6 observations per treatment. Dietary treatments were arranged in a 3 × 2 factorial design with three different corn cultivars [two Manitoba-origin short-season corns (A or B) or a US-origin corn] and two grinding methods [hammer mill or roller mill]. Each ingredient was included as the sole source of protein in the diets. All diets contained 0.3% titanium dioxide as an indigestible marker. Each experimental period lasted 7 d including the first 5 d for adaptation and the last 2 d for ileal digesta collection. After feeding the experimental diets, all pigs were fed a low-protein diet for 7 d to quantify endogenous losses of N and AA for determining the SID of N and AA. Pigs were fed the diets at 2.8 times the maintenance energy requirement based on their body weight at the beginning of each period. Data were analyzed using the PROC MIXED of SAS. The statistical model included diet as fixed effect and replication, animal within replication, and period within replication as random effects. The AID of Arg, Ala, Ser, and Gly were greater (P &amp;lt; 0.05) in short-season corn B compared with US-origin corn. The AID and SID of His in both short-season corns were greater (P &amp;lt; 0.05) than in US-origin corn. The AID of His and SID of Thr in hammer-milled corns were greater (P &amp;lt; 0.05) than in roller-milled corns. A significant interaction was found whereby AID of Ile in hammer-milled corn was not different between short-season corn B cultivar and US-origin corn but in roller-milled corn, short-season corn B cultivar had a greater (P &amp;lt; 0.05) digestibility than US corn. In conclusion, the digestibility of AA was greater in short-season corn than in US corn, and pigs had greater digestibility of AA in hammer-milled corn than roller-milled corn.

PSI-12 Dietary isoacids modulate nutrient digestibility and fermentation products in ileal digesta and feces of growing pigs fed corn-soybean meal diets

Abstract Branched-chain fatty acids, or isoacids, are the product of branched-chain amino acid fermentation and have been associated with benefits on the productivity of ruminants, primarily by positively modulating gut microbes and promoting gastrointestinal health. The objective of this study was to determine the optimal inclusion level of isoacid blend product based on apparent ileal digestibility (AID), apparent total tract digestibility (ATTD) of nutrients, and fermentation products in growing pigs fed corn-soybean meal diets. Twelve cannulated pigs [body weight (BW) = 20.9 + 0.6 kg] were used in a 5-period switch-back design with 6 diets and 2 replicate pigs in each period (n = 10 observations per dietary treatment). Experimental diets consisted of increasing levels (0%, 0.5%, 0.75%, 1%, 1.25%, and 1.5%) of an isoacid blend (isobutyrate, isovalerate, and 2-methyl butyrate, 1:1:1) added to a corn-soybean meal basal diet containing titanium dioxide as an indigestible marker. Each experimental period lasted 14 d: 10 d for acclimatization to the diets, 2 d for fecal collection, and 2 d for digesta collection. Diets, fecal, and ileal digesta samples were analyzed for gross energy (GE), crude protein (CP), fiber composition, amino acids (AA), and titanium. The concentration of short-chain fatty acids and ammonia were analyzed in digesta and fecal samples. Orthogonal polynomial contrasts were used to determine the linear and quadratic effects of increasing levels of isoacids. Dietary supplementation of isoacids improved (P &amp;lt; 0.1, linear and/or quadratic) AID of crude fiber and hemicellulose and most of the indispensable AA (except Met+Cys, Trp, and Val) as well as ATTD of CP, GE, neutral detergent fiber, and hemicellulose. In addition, ATTD of Arg, His, Ile, Leu, Met+Cys, Phe, Thr, Trp, and Val increased quadratically (P &amp;lt; 0.1). Collectively, 1% isoacid inclusion promoted the greatest responses in most measured variables (% increase: unsupplemented vs. 1%): AID of Lys (9.3%), Met (5.7%), Thr (17.8%), Leu (7.4%), Ile (9.2%), Phe (7.8%), His (5.9%), Arg (4.9%); ATTD of CP (2.1%), GE (1.3%), NDF (3.9%), hemicellulose (&amp;gt;50%), overall indispensable AA (9.5%), overall dispensable AA (8.6%). On the other hand, the inclusion of isoacids quadratically increased (P = 0.071) the concentration of ammonia and decreased (P &amp;lt; 0.1) the concentration of acetic acid, iso-valeric acid, and total VFA in ileal digesta samples. In fecal samples, the proportion of acetic acid decreased (P &amp;lt; 0.05) quadratically while the proportion of propionic, valeric, and caproic acids increased (P &amp;lt; 0.1). In conclusion, dietary supplementation of isoacids at 1% can improve dietary nutrient digestibility, particularly ileal AA digestibility. Based on the changes in fermentation products, the modulation of intestinal microbiota through the gastrointestinal tract could be potentially related to the effects of isoacids on nutrient digestibility. However, the effects of isoacids supplementation on intestinal microbiota must be determined.

PSIV-21 Ileal digestibility of amino acids in feed ingredients for 22-, 56-, and 87-kilogram pigs

Abstract The objective of the present study was to test the hypothesis that the apparent ileal digestibility (AID) of amino acids (AA) in feed ingredients is not constant in pigs with 3 different body weights (BW). Eight pigs with initial BW of 22.2 ± 1.2 kg cannulated at the distal ileum were used. Two experimental diets contained corn distillers dried grains with solubles (DDGS) and soybean meal-wheat mixture (SBM-W; 70% soybean meal + 30% wheat) as the sole source of nitrogen, respectively. The diets were assigned to the animals in a 2-period cross-over design. Each period consisted of a 5-d adaptation period and a 2-d ileal digesta collection period. The animals, diets, and experimental design for 50 kg pigs (initial BW = 55.6 ± 3.3 kg) and 80 kg pigs (initial BW = 86.9 ± 5.1 kg) were identical to those used for 22 kg pigs. Orthogonal polynomial contrasts were used to determine the effect of ingredient type (corn DDGS or SBMM) and BW of pigs (from 22 to 87 kg) and the interaction between these 2 main effects. The AID of crude protein, lysine, and methionine in both corn DDGS and SBM-W linearly or quadratically increased (P &amp;lt; 0.05) with an increase in pig BW. An interaction between ingredient type and linear effect of BW was observed (P &amp;lt; 0.05) in histidine, isoleucine, leucine, phenylalanine, threonine, and valine. Specifically, a linear increase in AID of these AA with increasing BW of pigs was greater in SBM-W compared with corn DDGS. In conclusion, the AID values of most AA differed between the BW range of 22 to 87 kg, and these patterns varied among different ingredients.

157 Effects of increasing dietary protein concentration on digestibility of amino acids by growing pigs

Abstract Two experiments were conducted to test the hypothesis that the standardized ileal digestibility (SID) of amino acids (AA) by growing pigs is not influenced by dietary protein concentration if all AA are supplied by soybean protein isolate (SPI) or casein. In Exp. 1, cannulated pigs [n = 12; average body weight (BW) = 39.22 kg; SD = 3.96] were allotted to a replicated 6 × 3 Youden square design with the 6 diets and 3 periods. Five diets were formulated to contain 7 to 35% SPI. An N-free diet was also used. In Exp. 2, cannulated pigs (n = 24 average BW = 23.12 kg; SD = 2.89) were allotted a quadruplicated 6 × 2 Youden square design with the 6 diets and 2 periods. Five diets were formulated to contain 6.75 to 33.75% casein. An N-free diet was also used. Ileal digesta were collected and analyzed for dry matter (DM), Cr, and AA. The statistical models included diet as a fixed variable and square, animal, and period as random effects. Polynomial contrasts were used to test linear and quadratic effects of increasing dietary protein. Results from Exp. 1 indicated that the apparent ileal digestibility (AID) of DM linearly (P = 0.001) decreased and the AID of all AA quadratically (P &amp;lt; 0.05) increased as the inclusion of SPI increased in the diets (Table 1). The SID of His and Trp was not affected by the inclusion of SPI in the diets. However, the SID of Arg, Leu, Lys, Phe, Thr, and Val linearly (P &amp;lt; 0.05) decreased, and the SID of Ile and Met tended to linearly (P &amp;lt; 0.10) decrease as the inclusion of SPI in the diets increased. Results from Exp. 2 indicated that the AID of DM tended to linearly decrease (P = 0.089) as the inclusion of casein increased in the diets (Table 2). The AID of most AA increased quadratically (P &amp;lt; 0.01) and the AID of Trp tended to increase (quadratic, P = 0.068) with increasing inclusion rate of casein. The SID of most AA was independent of casein levels. In conclusion, the anti-nutritional factors may have been increased in the diets as the inclusion of SPI increased and thus resulted in reduced SID values. However, the SID values were not influenced by increasing dietary protein if all AA were supplied by casein that does not contain anti-nutritional factors. Therefore, it is concluded that pigs have the capacity to absorb peptides and AA with the same efficiency if the protein concentration is 30% as if it is 6%. Dietary protein concentration itself, therefore, is not likely to limit AA absorption. However, even small amounts of anti-nutritional factors appear to negatively impact the SID of AA.

160 Awardee Talk: Impact of indigestible protein on coccidiosis and meat and bone meal autoclaving time-related reduction in amino acid digestibility for broiler chickens and growing pigs

Abstract Meat and bone meal (MBM) is a byproduct of the processing of livestock in the rendering industry. Because of its highly digestible protein and balanced amino acid profile, MBM is a valuable protein source in swine and poultry diets. Rendering may reduce amino acid digestibility of MBM because of heat damage to MBM, and the effect of heat damage on amino acid digestibility in MBM may be different between broiler chickens and growing pigs. For this reason, the objective of this study was to determine the effect of autoclaving on standardized ileal digestibility (SID) of amino acid in MBM fed to broiler chickens and growing pigs. Meat and bone meal from the same batch was autoclaved at 134°C for 0, 30, 60, 90, 120, 150, or 180 min, generating 7 samples. Eight experimental diets consisted of 7 diets containing each MBM sample as a sole source of nitrogen and a nitrogen-free diet. In Exp. 1, male broiler chickens [n = 656; initial body weight (BW) = 777 ± 69 g] at d 18 post hatching were assigned to the 8 diets in a randomized complete block design with BW as a blocking factor. On d 23, birds were euthanized by CO2 asphyxiation and dissected for the collection of ileal digesta. In Exp. 2, barrows (n = 16; initial BW = 25.7 ± 1.0 kg) surgically fitted with T-cannulas at the distal ileum were allotted to duplicate 8 × 4 incomplete Latin square design with the 8 diets and 4 periods. Each experimental period consisted of 5-d adaptation and 2-d ileal digesta collection periods. Data for Exp. 1 and 2 were pooled as a 2 × 7 factorial treatment arrangement with the effects of species (i.e., broiler chickens or pigs) and autoclaving time (i.e., 0 to 180 min). The basal endogenous losses of most AA in growing pigs were greater (P &amp;lt; 0.05) compared with broiler chickens. The SID of nitrogen and tryptophan in MBM linearly decreased (P &amp;lt; 0.05) in both species with increasing autoclaving time. An interaction between species and quadratic effect of autoclaving time was observed (P &amp;lt; 0.05) in SID of arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, and valine in MBM. Specifically, the SID of lysine both linearly and quadratically decreased (P &amp;lt; 0.05) in broiler chickens (85.0 to 56.0%), whereas the SID of lysine only linearly decreased (P &amp;lt; 0.05) in growing pigs (79.5 to 46.7%) as autoclaving time increased. In conclusion, given the species differences in amino acid digestibility response to the severity of heat damage, target species should be considered when using amino acid digestibility value of MBM in diet formulation.

54 Effects of a new biosynthetic 6-phytase supplementation on nutrient digestibility, phytate disappearance and growth efficiency in weaning piglets fed low in calcium and digestible phosphorus diets

Abstract The objective of this study was to investigate the influence of adding graded levels of a new biosynthetic bacterial 6-phytase on nutrient digestibility, phytate disappearance and growth performance in weaned piglets. A total of 192 male weaned piglets with initial body weight of 8.70 ± kg, distributed in a randomized block design with four treatments and 24 replicate pens with 2 animals each for 42 d. The experimental diets included a phosphorus and Ca deficient diet (STTD of P/Ca = 0.21%/0.58% and 0.19%/0.54%, respectively, in post-weaning 1 and 2 diets) containing 0 (a control diet), 500, 1,000 or 1,500 FTU/kg diet. The diets were fed into 2 phases: post-weaning 1 and 2 from 1 to 14 and 15 to 42 d, respectively. Body weight and feed intake were measured at the end of each phase, and average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) were calculated for the overall experimental period. On d 42, ileal digesta samples were collected from 1 piglet/pen (n = 12 samples/treatment) for apparent ileal digestibility (AID) of Ca, P, and amino acids and phytate disappearance determination. Supplementation of diet with phytase from 0 to 1500 FTU/kg diet linearly improved (P &amp;lt; 0.01) AID of Ca. Both linear and quadratic effects (P &amp;lt; 0.001) was observed for AID of P and phytate-P. Increasing level of phytase supplementation resulted in linear and quadratic increases of Arg, His, Ile, Leu, Lys, Phe, Thr, Trp, Val, Ala, Asp, Cys, Glu, Ser, Tyr and total amino acids. Phytase supplementation increased (P &amp;lt; 0.0001) linearly Met and Pro, with an AID of Met showing a tendency (P = 0.09) for a quadratic increase. In addition, increasing phytase dose linearly increased (P = 0.006) the overall ADFI and ADG and decreased (P &amp;lt; 0.001) F:G ratio. Also, a tendency (P = 0.07) for quadratic effect of phytase was also observed on F:G ratio. These findings highlight that the supplementation of diets with the new bacterial 6-phytase significantly enhanced the utilization of nutrients, disappearance of phytate and performances of weaned piglets in a dose dependent manner.

154 Reduction of particle size of field peas increases net energy and digestibility of starch when fed to growing pigs

Abstract Two experiments were conducted to test the hypothesis that particle size of field peas and location of production may affect the apparent ileal digestibility (AID) of starch, the standardized ileal digestibility (SID) of amino acids (AA), and net energy (NE). One source of peas from the U.S., and two sources from Canada were procured. The U.S. peas were ground to 265, 457, or 678 µm, whereas the two Canadian peas were ground to 411 and 415 µm, respectively. A basal diet containing corn and soybean meal as the sources of energy, starch, and AA, and five diets containing corn and soybean meal and 50% of each source of peas were formulated. Pigs were fed the same diets in Exp. 1 and 2, but an N-free diet was also used in Exp. 1. In Exp. 1, barrows [n = 7; initial body weight (BW) = 60.6 kg; SD = 2.1] that had a T-cannula installed in the distal ileum were allotted to a 7 × 7 Latin square design with seven diets and seven periods. Ileal digesta were collected and analyzed for Cr and AA. In Exp. 2, pigs (n = 24; initial BW = 30.8 kg; SD = 1.0) were used in a 6 × 6 Latin square design with six calorimetry chambers and six periods. To determine NE, feces and urine were quantitatively collected and O2 consumption and CO2 and CH4 productions were measured. In both Exp. 1 and 2, the statistical model included diet as the main effect and pairwise comparisons were used to separate the means. Contrast coefficients were also used to determine linear effects of particle size within the U.S. peas. Results from Exp. 1 indicated that the SID of AA was not influenced by the origin of the peas or by particle size, except that the SID of Arg was linearly (P = 0.042) increased (Table 1) as particle size of U.S. field peas was reduced. The AID of starch in the U.S. peas ground to 265 µm was greater (P &amp;lt; 0.05) than in the two Canadian sources, and the AID of starch and NE in diets were linearly (P &amp;lt; 0.001) increased as particle size was reduced. The NE in U.S. peas ground to 678 µm was less (P &amp;lt; 0.05) than in all other pea samples. In conclusion, AID of starch, SID of AA, and NE did not differ between field peas grown in Canada and peas grown in the U.S., but reducing the particle size of field peas resulted in improved digestibility of starch and energy by pigs.

PSII-17 Effect of protease supplementation on amino acids digestibility of soybean meal fed to growing pigs of different ages

Abstract Protease supplementation can increase amino acids (AA) availability; however, the effectiveness of protease in swine diets varies and has been associated with the type and dose of protease, dietary ingredients, and potentially animal age. This study investigated the interactive effect of protease inclusion level and pig age on standardized ileal digestibility (SID) of protein (CP) and AA of soybean meal (SBM) fed to growing pigs. A corn starch–based diet was formulated with SBM as the sole source of AA and containing titanium as an indigestible marker. Protease was supplemented at 0, 15,000; 30,000 and 45,000 NFP/kg of feed (ProAct 360). An N-free diet was used to estimate basal ileal endogenous AA losses. Ten cannulated pigs (body weight = 21 kg ± 2 kg) were assigned to experimental diets in a duplicate 5 × 5 Latin square design. In Phase I (23 to 30 kg-pigs, 90 ± 17 d of age), ileal digesta was collected in 5 periods of 7 d (5 d adaptation and 2 d ileal digesta collection). In Phase II (50 to 65 kg-pigs. 140 ± 17 d of age), using the same diets, ileal digesta was collected in 5 more periods of 7 d. Pigs were fed at 4% of body weight (BW) adjusted at the end of each period. Diets and ileal digesta were analyzed for CP, AA, and titanium and SID was calculated. Orthogonal polynomial contrasts were used to determine the linear and quadratic effects of protease supplementation. The combined data were analyzed as 4 x 2 factorial, including the fixed effects of protease inclusion (excluding N-free diet), age, and their interactions. In phase I, increasing levels of protease resulted in linear improved (P &amp;lt; 0.1) of SID for the majority of indispensable AA (Except Arg, His, Met + Cys, and Trp) and the average of dispensable AA. In phase II, the SID of Ile, Leu, Met, Met + Cys, Val, the average of indispensable AA, and the majority of dispensable AA was quadratically improved. Overall (Phase I and II), the SID of Ile, Leu, Met + Cys, Val, Cys, Glu, Tyr, and the average of dispensable AA was quadratically improved (P &amp;lt; 0.1). In most cases, the supplementation of 30,000 NFP/kg of feed resulted in the greatest AA digestibility improvements. However, the linear response in the first phase for some AA suggests that diets for younger pigs could be supplemented with a greater level (45,000 NFP/kg of feed). There were no interactions between protease levels and age. Younger pigs had improved (P &amp;lt; 0.1) SID of CP and most AA (Except Cys, Gly, and Ser). In conclusion, dietary protease supplementation can improve SID of AA in soybean mean independent of pig age. Pigs age can influence AA digestibility where younger pigs have greater AA digestibility.

64 Effect of feeding intact protein from soybean meal instead of crystalline amino acids on growth performance, protein synthesis, and immune response of growing pigs

Abstract The objective was to test the hypothesis that feeding intact protein from soybean meal (SBM) instead of crystalline amino acids (AA) does not affect growth performance, protein synthesis, intestinal morphology, or immune response of growing pigs. A control corn-SBM diet was used. Three additional diets were formulated by reducing the inclusion rate of SBM and adding 3, 4, or 5 crystalline AA (i.e., Lys, Met, Thr, Trp, Val) to the diets, which resulted in reducing the protein concentration from 20.0% to 13.4%. All diets were formulated to meet requirements for standardized ileal digestible indispensable AA. A total of 176 pigs [initial body weight (BW) = 32.2 kg; SD = 4.2] were used. On d 1, 16 randomly chosen pigs were euthanized and body nutrient composition was determined. The remaining 160 pigs were allotted to the 4 diets using a randomized complete block design with 4 pigs per pen and 10 replicate pens per diet. Starting BW was the blocking factor. Individual pig BW and feed consumption were recorded. On d 28, one pig per pen was slaughtered and blood, carcass, and viscera were collected and analyzed for N, fat, and energy to calculate deposition in the body. Ileal mucosa, ileum and colon tissue and digesta were analyzed for blood characteristics, cytokines, tissue morphology, ammonia, and gene expression. Contrasts coefficients were used to determine linear and quadratic effects of reducing dietary protein. Results indicated that average daily gain, average daily feed intake, gain to feed ratio, carcass characteristics, and protein, lipid, and energy depositions were not affected by reducing SBM and increasing crystalline AA in diets (Table 1). However, energy efficiency tended to decrease (quadratic, P = 0.083) by reducing dietary protein. Blood urea N was reduced (linear, P &amp;lt; 0.001) as dietary protein was reduced, but blood total protein was not affected by dietary treatment. Cytokines, ileal and jejunal morphologies, and gene abundance of AA transporters in the ileal mucosa were not affected by dietary protein. Ammonia concentrations in ileal digesta increased and then decreased (quadratic, P = 0.043) and colon digesta tended to increase and then decrease (quadratic, P = 0.074) as dietary protein was reduced. Bacteria protein in colon digesta was reduced (linear, P = 0.030) by reducing dietary protein. In conclusion, providing AA from intact protein from SBM or from crystalline AA did not affect growth performance, intestinal morphology, and immune response of pigs. However, SBM in diets can provide energy that may be utilized more efficiently than energy from diets with less SBM and crystalline AA. Further research is suggested to elucidate if SBM improves utilization of other nutrients in diets for pigs.

136 Effects of acid-binding capacity in low-zinc diets on growth performance of weaned pigs

Abstract Post-weaning diarrhea (PWD) of piglets remains a concern in the pork industry. Historically, PWD has been controlled with dietary solutions such as antibiotics as growth promotors and high dietary inclusion of ZnO. However, such use of antibiotics is not permitted any longer and such use of ZnO has already been banned in the EU. In the present trial, the objective was to study the effects on growth performance of acid binding capacity (ABC) as dietary solution in low zinc diets compared to control diet with high zinc. In total, 1,445 pigs (Camborough F1 female x 800 boar line; PIC Canada) were weaned at 20 ± 1 d of age, comprising of equal number of gilts and barrows, and were randomly placed into one of 50 mixed-gender pens (50% barrows and 50% gilts) in two rooms filled four d apart, for 28 or 29 pigs per pen. In total, five dietary regimes were tested during Phase 1 (d 0-7) and 2 (d 7-21): one high in Zn (2,000-3,000 ppm ZnO; 412 mEq/kg ABC-4) and 4 low in Zn (150 ppm) with incremental reductions in ABC-4 from 326 to 150 mEq/kg. Reductions in ABC-4 were accomplished using a combination of changes; added organic acids (formic, fumaric, benzoic), Ca formate to replace limestone, and a low ABC-4 soy protein concentrate to replace regular soy protein concentrate. Pigs were fed a common diet during Phase 3 (d 21-42). For each feeding phase all diets were formulated to equal net energy and standardized ileal digestible amino acids and contained phytase. At d 21, pigs fed high Zn were 1.6 kg heavier (11.3 vs 9.7 kg; P &amp;lt; 0.01) than pigs fed low Zn with greatest ABC-4. Within low Zn diets, reducing ABC-4 linearly increased body weight (BW; 9.7 vs. 10.1 kg). These differences continued until d 42: pigs fed high Zn were 1.8 kg heavier (24.1 vs 22.3 kg; P &amp;lt; 0.01) than pigs fed low Zn with greatest ABC-4). Within low Zn diets, reducing ABC-4 for the first 3 wk after weaning linearly increased BW (22.9 vs. 22.3 kg; P &amp;lt; 0.01). This increased growth was caused by a combination of increased (P &amp;lt; 0.01) feed intake and increased (P &amp;lt; 0.05) gain-to-feed and coincided with reduced (P &amp;lt; 0.01) incidence of scours. In conclusion, weaned pigs fed high Zn diets grew more than pigs fed low Zn diets. Dietary ABC-4 is a dietary solution to consider for ameliorating the reduced growth by pigs fed low Zn diets: 33% of the reduced growth could be compensated for by feeding diets low in dietary ABC-4 during the first 3 wk after weaning.

PSI-15 Effect of feeding intact protein from soybean meal instead of crystalline amino acids on energy and nitrogen balance by growing pigs

Abstract The objective was to test the hypothesis that feeding intact protein from soybean meal (SBM) to growing pigs instead of crystalline amino acids (AA) increases nitrogen (N) retention, digestible energy (DE), and metabolizable energy (ME). A control corn-SBM diet and three diets, in which the inclusion rate of SBM was reduced and 3, 4, or 5 crystalline AA (i.e., Lys, Met, Thr, Trp, Val) were added, were formulated. The concentration of standardized ileal digestible AA was constant among diets, but crude protein was reduced as crystalline AA were added. Pigs were limit fed at 3.2 times the ME requirement for maintenance. Forty pigs (initial body weight = 20.5 kg; SD = 2.4) were allotted to the 4 diets using a randomized complete block design with 2 blocks of 20 pigs with five pigs per diet in each block. Pigs were housed in metabolism crates with pans and screens that allowed for quantitative collection of feces and urine for 4 d after 5 d of adaptation. Samples of diets, feces, and urine were analyzed for gross energy (GE) and N. The statistical model included diet as fixed effect and block as random effect, and pig was the experimental unit. Contrasts coefficients were used to determine linear and quadratic effects of reducing dietary protein. Results indicated that apparent total tract digestibility (ATTD) of dry matter (DM) decreased (quadratic, P = 0.027) and ATTD of GE tended to decrease (quadratic, P = 0.076; Table 1) as SBM inclusion was reduced in the diets. Absorbed N, retained N (g/d), and ATTD of N were decreased (linear, P &amp;lt; 0.001) as SBM decreased in diets, but retention of N (% of intake and % of absorbed) increased (linear, P &amp;lt; 0.001) as SBM decreased in diets. The DE decreased (linear, P = 0.007) as SBM decreased in diets, whereas SBM had no effect on ME. Dietary SBM also had no effect on ME to GE ratio, but ME to DE increased (linear, P = 0.008) by reducing SBM in diets. In conclusion, diets containing intact protein from SBM had greater ATTD of GE and N, and greater DE, but reduced N retention rate when compared with diets containing crystalline AA. However, daily protein retention could not be maintained when crystalline AA rather than SBM were used to furnish the digestible AA in the diets, which may have negative consequences on carcass quality.

Determination of apparent and standardized ileal digestibility of amino acids in corn HP-DDG fed to growing pigs

The corn-based ethanol production industry provides co-products with potential value as animal feed. However, the nutritional value of these co-products should be adequately determined for their sustainable implementation in swine diets. Therefore, a study was conducted to determine the concentration of amino acids (AA), apparent ileal digestible amino acids (AID), standardized ileal digestible amino acids (SID), and crude protein (CP) in corn distillers dried grains with high protein content (corn HP-DDG) for pigs. Six growing pigs (initial body weight: 46.30 ± 2.14 kg) were surgically fitted with a T-cannula at the distal ileum and allotted to a duplicate 2 × 3 incomplete Latin Square Design. Diets containing corn HP-DDG as the only AA source and a nitrogen-free diet (NFD) were formulated. Corn HP-DDG was used as a test ingredient to replace 40% of the starch in NFD, and titanium dioxide (0.5%) was added as an indigestible marker to both diets. Pigs were fed between 08:00 and 18:00 h during five days of adaptation and a sequence of two days of ileal digesta collection. On an as-fed basis, the chemical composition of corn HP-DDG was 40.41% CP, 1.39% lysine, 1.57% methionine + cysteine, 1.61% threonine, 0.23% tryptophan, and 2.15% valine. The AID and SID values of corn HP-DDG were 74.04% and 80.87% for CP; 76.32% and 79.15% for lysine; 84.75% and 86.52% for methionine + cysteine; 71.97% and 78.30% for threonine; 83.86% and 92.44% for tryptophan; and 76.34% and 80.47% for valine, respectively. In conclusion, the SID CP and AA in corn HP-DDG were within the previously published values, and the determined SID coefficients should be used to formulate accurate diets for pigs.

Determination and prediction of standardized ileal amino acid digestibility of wheat bran in broiler chickens.

The objective of this experiment was to determine the standard ileal digestibility (SID) of amino acid (AA) in 10 different sources of wheat bran fed to broilers and establish the SID AA prediction based on the chemical composition. A total of 660 1-day-old broilers were randomly divided into 11 treatments with 6 replicates of 10 chickens each. Diets included 10 semi-purified mash diets and 1 nitrogen-free diet. Titanium dioxide (TiO2) 0.50% was used as an indigestible index. On day 13, 6 chickens from each replicate were selected for slaughter to collect ileal contents. On day 28, 4 chickens from each replicate were selected for slaughter to collect ileal contents. Results showed that the coefficient of variation of the conventional nutrients (except for gross energy, and dry matter) and all amino acids was greater than 8.00%. The average SID of essential AA in wheat bran for 13-day-old broilers was 37.24% and the average SID of nonessential AA was 42.02%; the average SID of essential AA for 28-day-old broilers was 67.13% and the average SID of nonessential AA was 69.51%. A correlation was observed (P<0.05) between most SID AA and crude protein (CP), crude fiber (CF), acid detergent fiber (ADF), and ash at day 13. A correlation was observed (P<0.05) between most SID AA and CF, and ADF at day 28. The R2 value of stepwise regression equations for predicting the SID AA at day 13 and day 28 was best for glutamic acid (R2 = 0.97 using CP, ash, CF, ether extract (EE), and neutral detergent fiber (NDF)) and lysine (R2 = 0.74 using ash, ADF, EE, and NDF), respectively. In conclusion, broiler age had a significant effect on the SID AA values of wheat bran. The chemical composition of wheat bran varied widely between sources, and CP, CF, ADF, NDF, and ash were reasonable predictors of the SID AA of wheat bran.

Determination and prediction of amino acid digestibility in brown rice for growing-finishing pigs.

The experiment aimed to determine the standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in 10 brown rice samples fed to pigs, and to construct predictive models for SID of CP and AA based on the physical characteristics and chemical composition of brown rice. Twenty-two cannulated pigs (initial body weight: 42.0±1.2 kg) were assigned to a replicated 11×3 incomplete Latin square design, including an N-free diet and 10 brown rice diets. Each period included 5 d adaptation and 2 d ileal digesta collection. Chromic oxide was added at 0.3% to all the diets as an indigestible marker for calculating the ileal CP and AA digestibility. The coefficients of variation of all detected indices for physical characteristics and chemical composition, except for bulk weight, dry matter (DM) and gross energy (GE), in 10 brown rice samples were greater than 10%. The SID of CP, lysine (Lys), methionine (Met), threonine (Thr) and tryptophan (Trp) in brown rice was 77.2% (62.6% to 85.5%), 87.5% (80.3% to 94.3%), 89.2% (78.9% to 98.9%), 55.4% (46.1% to 67.6%) and 92.5% (86.3% to 96.3%), respectively. The best prediction equations for the SID of CP, Lys, Thr and Trp were as following, SIDCP=﹣664.181+8.484×DM (R2=0.40), SIDLys=53.126+6.031×ether extract (EE) +0.893×thousand-kernel volume (R2=0.66), SIDThr=39.916+7.843×EE (R2=0.41) and SIDTrp=﹣361.588+4.891×DM+0.387×total starch (R2=0.85). Overall, a great variation exists among 10 sources of brown rice, and the thousand-grain volume, DM, EE, and total starch can be used as the key predictors for SID of CP and AA.

Apparent metabolizable energy and ileal amino acid digestibility of commercial soybean meals of different origins in broilers

We studied the chemical composition and the in vivo AMEn content and apparent (AID) and standardized (SID) ileal digestibility of CP and amino acids (AA) of 27 samples of soybean meals (SBM) from Argentina (ARG), Brazil (BRA), and USA, collected in Spain. On 88% DM basis, the BRA meals had more CP (46.9 vs. 46.0 and 45.9%; P < 0.05) and less sucrose (5.21 vs. 6.28 and 6.47%; P < 0.001) and stachyose (4.20 vs. 4.66 and 4.78%; P < 0.05) than the USA and ARG meals. Urease activity, protein dispersibility index, KOH protein solubility, and trypsin inhibitor activity values, were higher for the USA meals than for the South American meals (P < 0.05). In the in vivo trial, broilers received a common crumble diet from 0 to 16 d of age and then, their respective experimental diets (53% of a N-free diet and 47% of each of the 27 SBM tested) in mash form, for 5 d. The AMEn (2,334 vs. 2,282 and 2,277 kcal/kg; P = 0.062) and the AID (87.3 vs. 86.7 and 86.4%; P = 0.054) and SID (91.9 vs. 91.2 and 90.8%; P < 0.05) of the protein, were greater for the USA meals than for the ARG and BRA meals. In fact, the SID of Lys (93.5 vs. 93.0 and 92.1%; P < 0.001) and of the sum of Lys, Met, Thr, Trp, and Cys (91.4 vs. 91.0 and 90.2%; P < 0.05) were greater for the USA meals than for the ARG and BRA meals. In summary, the chemical composition, protein quality indicators, AMEn content, and ileal digestibility of the CP and the AA of the SBM, varied with the country of origin of the soybeans. In order to increase the accuracy of the feed formulation process, the composition and nutrient content of commercial batches of SBM, by country of origin should be controlled and periodically updated.

Standardized ileal digestibility of amino acids in Chinese fermented soybean meal from different sources fed to mid and late-gestating sows.

We determined apparent ileal digestibility (AID) and standardized ileal digestibility (SID) values of crude protein (CP) and amino acids (AA) in fermented soybean meal from five different sources (FSBM 1 to 5) in China when fed to mid and late-gestating sows. Twenty-four parity four sows (12 at 30 d in gestation and 12 at 80 d in gestation) were fitted with a T-cannula in the distal ileum and used in this experiment. Sows were randomly assigned to a replicated 6 × 3 Youden square design including six diets and three periods. Six diets were provided for sows in mid and late gestation, including a nitrogen-free diet and five test diets containing 26% FSBM from different sources. Results showed that there were differences in AID and SID of CP among the different FSBM samples, but no differences between sow physiological stages were observed. Specifically, when mid-gestating sows were fed FSBM 2, the AID of CP was the lowest, whereas FSBM 3 exhibited a greater AID of CP when compared to the other FSBM samples (P < 0.01). Furthermore, during late gestation, FSBM 3 consistently had greater SID of CP when compared to other FSBM samples (P < 0.01). The ileal digestibility of most AA varied with different FSBM samples. In both mid and late gestation, differences (P < 0.05) were observed for AID of lysine, tryptophan, histidine, and arginine across different FSBM samples. Similarly, the AID of dispensable AA (cysteine, glutamine, and serine) also exhibited differences (P < 0.05) across different FSBM samples in both mid and late-gestating sows. For mid-gestating sows, SID differences relating to lysine, phenylalanine, tryptophan, threonine, and arginine were observed among different diets (P < 0.05). In late-gestating sows, SID values for lysine, tryptophan, leucine, and arginine differed across diets (P < 0.05). Furthermore, the ileal digestibility of some dispensable AA was influenced by physiological stage, as evidenced by greater AID and SID values for glycine, glutamine, cysteine, and serine in late-gestating sows when compared to mid-gestating sows (P < 0.01). In summary, our study determined AA ileal digestibility of different FSBM fed to mid and late-gestating sows. We observed that the AA ileal digestibility differed among five FSBM samples, but the physiological stage of sows did not affect the ileal digestibility of CP and most AA. Additionally, when formulating diets for sows, it is crucial to consider the nutritional value differences of FSBM.

Influence of graded levels of maize distillers dried grains with solubles (mDDGS) on the performance, digestive tract development and carcass characteristics of broilers

Abstract The present study investigated the feeding value of maize distillers dried grains with solubles (mDDGS) for broiler chickens. As the first step, the nutrient composition, apparent metabolisable energy (AME) and apparent ileal amino acid digestibility of mDDGS were determined. These values were used to formulate iso-nutrient and isocaloric diets to evaluate the influence of graded levels of mDDGS on broiler performance, digestive tract development and carcass characteristics. Five maize-soybean based diets containing 0 or 5, 10, 15 and 20% of mDDGS, were formulated and cold-pelleted at 65 °C. Each diet was offered ad libitum to six replicates (eight birds per replicate cage) during starter (day 1–21) and finisher (day 22–35) phases. The mDDGS was analysed to contain (% dry matter (DM) basis): CP, 27.8; total non-starch polysaccharides, 28.6 and soluble non-starch polysaccharides, 5.6. The AME was determined to be 10.23 MJ/kg DM. The average ileal digestibility coefficient of indispensable AA was 0.826. The Inclusion of 20% mDDGS resulted in poorer (P &lt; 0.05) feed per gain (quadratic effect, P &lt; 0.05) during the starter period, but no negative effects (P &gt; 0.05) were observed finisher period and the overall production period (day 1–35). Feed intake and feed per gain (linear effect, P &lt; 0.05) decreased with increasing inclusions of mDDGS during finisher period and overall period. A tendency (P = 0.06) for linear improvement in excreta quality was observed with increasing inclusion levels of mDDGS. Relative digestive tract weights and carcass and breast meat yields were not influenced (P &gt; 0.05) by dietary treatments. A linear (P &lt; 0.05) decrease was observed for the relative lengths of jejunum, ileum and the small intestine. The results indicated that, when balanced for metabolisable energy and digestible amino acids, mDDGS can be incorporated into broiler starter and finisher diets up to 15 and 20%, respectively, with no adverse effects on live performance, carcass characteristics or excreta quality.