Standardized Ileal Digestibility Of Amino Acids 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.

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 < 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 < 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.

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 < 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 < 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 < 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.

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 < 0.05) than in the two Canadian sources, and the AID of starch and NE in diets were linearly (P < 0.001) increased as particle size was reduced. The NE in U.S. peas ground to 678 µm was less (P < 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.

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 < 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 < 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 < 0.01). This increased growth was caused by a combination of increased (P < 0.01) feed intake and increased (P < 0.05) gain-to-feed and coincided with reduced (P < 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.

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 < 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 < 0.05) decreased, and the SID of Ile and Met tended to linearly (P < 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 < 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.

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 < 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.

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 < 0.001) as SBM decreased in diets, but retention of N (% of intake and % of absorbed) increased (linear, P < 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.

Evaluation of exogenous phytase in high-phytate diets for broiler chickens and pigs

There is a gap in the understanding of the relationship between dietary phytate levels and the relative efficacy of phytase to improve amino acid (AA) digestibility in pigs and chickens. Two experiments were conducted to investigate the effect of exogenous phytase on standardized ileal digestibility (SID) of AA and the apparent ileal digestibility (AID) of P in both standard- (SP) and high-phytate (HP) diets for broilers and swine. There were either 40 cages of Cobb 500 male broilers or 10 crossbred barrows (35 kg) fitted with ileal T-cannulas. Both studies were allotted to five dietary treatments (8 replicates). Treatments consisted of four corn-soybean meal-based diets arranged in a 2 × 2 factorial of standard or high phytate and exogenous phytase at 0 or 1 000 phytase units (FYT)/kg; and one N-free diet. Birds were fed a common starter diet from d 0 to 20 and fed experimental diets from d 20 to 25. Birds were euthanized on d 25 via CO2 asphyxiation, and digesta were collected from the terminal ileum. Pigs were fed for a total of four 7-d periods, where digesta were collected on d 6 and 7 of each period. Diet and digesta samples were analyzed for DM, N, Ti, AA, and P to determine AA and P digestibility. The SID of AA was determined by correcting the AID of AA for the basal endogenous losses estimated using the N-free diet. Main effects of the diet type (standard or HP) and phytase (0 or 1 000 FYT/kg), and the interaction of diet type and phytase were evaluated. For both experiments, the HP diets produced lower SID of AA compared to the SP (P < 0.001). For broilers, there was a phytase effect (P < 0.001) for the SID of all AAs evaluated regardless of the diet type. For pigs, phytase improved (P < 0.05) the SID of Met, Lys, Cys, Glu and Ser and tended to improve (P < 0.10) Arg, Leu, Thr, and Tyr. There were no significant interactions for either experiment. For both experiments, AID of P was lower for the HP diets (P < 0.01), and phytase produced greater AID of P for both diet types (P < 0.01). These data indicate that phytase greatly improves the digestibility of P for broilers and pigs and has the ability to significantly increase the digestibility of amino acids for these animals, regardless of the dietary phytate P.

Influence of particle size and origin of field peas on apparent ileal digestibility of starch and amino acids and standardized ileal digestibility of amino acids when fed to growing pigs.

The objective was to test the hypothesis that particle size and origin of field peas influence the apparent ileal digestibility (AID) of starch, crude protein (CP), and amino acids (AA) and the standardized ileal digestibility (SID) of AA. Three sources of field peas were procured. One source was from the United States and two sources were from Canada. The U.S. source and one of the sources from Canada (i.e., Canada 1) were each divided into two batches and ground to achieve a target particle size of 250 or 450µm, whereas the other source from Canada (i.e., Canada 2) was only ground to a target particle size of 250µm. Each batch of field peas was included in one diet as the only source of AA. An N-free diet was used to determine the basal endogenous losses of CP and AA. Six barrows (initial weight: 50.5kg; SD = 3.7) that had a T-cannula installed in the distal ileum were randomly allotted to a 6 × 6 Latin square design with six diets and six 7-d periods. Ileal digesta from pigs were collected for 2d after 5d of adaptation. Data were analyzed using a statistical model that included batch of field peas as the fixed effect and animal and period as the random effects. Contrast statements were used to analyze the effects of particle size, origin, and the interaction between particle size and origin. Results indicated that the AID of starch was increased by reducing the particle size in the U.S. source of field peas, but that was not the case for the Canada 1 source (interaction; P < 0.001). Particle size did not influence the AID of CP or AA, but the Canada 2 source of field peas had greater (P < 0.05) AID of Trp, Ala, Cys, Gly, and Tyr than the field peas from the United States. The SID of CP and AA was also not affected by the particle size of field peas. The SID of CP and Trp was greater (P < 0.05), and the SID of His, Ile, and Thr tended (P < 0.10) to be greater in the Canada 2 source compared with the U.S. source, but no differences between the two Canada sources were observed. In conclusion, a few differences in SID of AA between field peas produced in the United States and peas produced in Canada were observed, but there was no effect on SID of AA of reducing the particle size of field peas from 450 to 250µm, whereas the AID of starch increased by reducing the particle size only in the field peas from the United States.

300 Metabolizable Energy and Amino Acid Digestibility by Growing Pigs may be Reduced if Excessive Heat is Applied During Drying of Corn

Abstract Two experiments were conducted to test the hypothesis that both drying temperature and drying time affect the standardized ileal digestibility (SID) of amino acids (AA) and metabolizable energy (ME) in corn fed to growing pigs. A single source of corn was divided into 11 batches that were dried using a “drying chamber” at 80ºC for 1.5, 3.0, 24, or 48 h or at 130ºC for 1.5, 3.0, 6.0, 9.0, 12, 24, or 48 h. Exp. 1 was designed to determine the concentrations of ME in the 11 batches of corn. Eleven diets based on each batch of corn were formulated. Growing barrows (n = 88; BW = 20.6 ± 1.2 kg) were allotted to the 11 diets in a randomized complete block design with 8 blocks of 11 pigs. Urine and fecal samples were collected for 4-days after 7-days of adaptation. Contrast statements were used to determine effects of temperature and drying time within temperature. Exp. 2 was designed to determine the SID of AA in the 11 batches of corn. An N-free diet and 11 diets that each contained one of the 11 batches of corn as the sole source of AA were formulated. All diets contained 0.40% chromic oxide as an indigestible marker. Twenty-four growing pigs (22.8 ± 5.1 kg) that had a T-cannula installed in the distal ileum were allotted to a replicated 12 × 4 Youden square with 12 diets and four 7-day periods in each square. Therefore, there were 8 replicate pigs per diet. Ileal digesta were collected on days 6 and 7 of each 7-days period. Data were analyzed as described for Exp. 1. Results indicated that ME (dry matter basis) was greater (P &amp;lt; 0.01) if corn was dried at 130ºC than at 80ºC (Table 1). The ME (dry-matter basis) increased (quadratic, P &amp;lt; 0.04) with drying time at 80ºC, whereas it decreased at 130°C (quadratic, P &amp;lt; 0.05). The SID of AA did not differ between corn dried at 80°C and 130°C, except that the SID of Lys was less (P &amp;lt; 0.05) if corn was dried at 130°C than at 80°C. The SID of most AA decreased (linear or quadratic, P &amp;lt; 0.05) as time of drying increased at 130°C. In conclusion, the SID of AA and ME in corn are not reduced by extending the time of drying at 80°C. However, the digestibility of AA is reduced if corn is dried at 130°C and the longer the time of drying the more the SID of AA is reduced. Values for ME in corn are increased if corn is dried at 130°C rather than 80°C.

305 Dietary Carbohydrase Mixture Supplementation and Fiber Levels on Ileal Digestibility of Nutrients in Diets for Gestating Sows

Abstract Supplementation of multi-carbohydrase enzyme cocktails can increase nutrient digestibility of fibrous diets in grower pigs, particularly acting on dietary non-starch polysaccharides (NSP). Although NSP degrading enzymes are extensively used in sow diets, there is little data characterizing the NSP enzyme effects. Our previous work demonstrated a 10% increase in nutrient digestibility in diets fed to gestating sows. The objective of this study was to evaluate the effect of a carbohydrase mixture (CM) and dietary fiber level on standardized ileal digestibility (SID) of protein and amino acids (AA) and apparent ileal digestibility (AID) of NSP in gestation diets fed to pregnant sows. Ileal cannulas were placed in 12 gestating sows (Parity 0 to 2) who were allowed to recover for 1 week, then assigned to either a high (HF; 17.5% NDF) or low fiber (LF; 10% NDF) diet with one of 3 levels of CM supplementation (‘0’, ‘0.08’, and ‘0.10’%) or a nitrogen-free diet to determine ileal endogenous AA losses. Diets were corn-soybean meal based with soyhulls and corn DDGS as fiber sources and formulated to reflect industry-relevant diets. Thus, oil was included at 3% in HF to maintain similar formulated metabolizable energy content. Sows were fed once daily at 2.2 kg/d. Ileal digesta samples were collected for 12 h on 2 successive days following a 7-day adaptation period. At the end of digesta collection, sows were assigned a different diet in a new adaptation/digesta collection period. There were 5 collection periods for a total of 8 observations/diet. Digesta was analyzed for crude protein, amino acids, NSP, and titanium as the indigestible marker to determine AID and SID. There was no interaction between diet fiber level and CM supplementation. Carbohydrase mixture supplementation to gestating sow diets did not impact SID of crude protein and AA regardless of dietary fiber level. The SID of His, Ile, Lys, Phe, Thr, Trp, and Val were 3 to 6% lower (P &amp;lt; 0.09) in HF than LF independent of CM. There was no impact of fiber level on the average SID of amino acids in gestating sow diets which was 83.5%. Supplementation of CM did not impact AID of NSP components, but sows fed HF had greater AID of arabinose (LF: 26.5% vs HF: 40.6%), xylose (LF: 3.5% vs HF: 40.9%), and total NSP (LF: 25.9% vs HF: 40.0%) compared with sows fed LF (P &amp;lt; 0.05). Inclusion of CM in high fibrous gestating sow diets did not increase the SID of AA or AID of NSP, but a high fiber gestation diet reduced SID of AA. As such, differences in SID of AA should be considered when formulating high fibrous diets for gestating sows.

303 Interactive Effects of Pelleting and Particle Size Reduction of Corn on Ileal Digestibility of Starch and Amino Acids in Corn-Soybean Meal Diets Fed to Pigs

Abstract The objective was to determine the interactive effects of particle size reduction and pelleting on the apparent ileal digestibility (AID) of starch and the standardized ileal digestibility (SID) of amino acids (AA) in corn-soybean meal diets fed to pigs. Six corn-soybean meal based diets were arranged in a 3 × 2 factorial with 3 particle sizes of corn (i.e., 700, 500, or 300 μm) and 2 diet forms (i.e., meal or pelleted). An N-free diet was also used and there were, therefore, a total of 7 diets. Pigs were allowed ad libitum access to feed and water. Pigs (n = 7; initial body weight = 59.30 kg; SD = 2.77) that were equipped with a T-cannula in the distal ileum were allotted to the 7 diets using a 7 × 7 Latin square design with 7 periods. Ileal digesta were collected for 2 days after 5 days of adaptation. The statistical model included diet as fixed effect and pig and period as random effects. Contrast coefficients were used to determine effects of diet form, linear effects of particle size, and the interaction. Results indicated that the AID of starch was linearly increased (P = 0.001) with reduced particle size of corn and pelleted diets had greater (P = 0.029) AID of starch than meal diets (Table 1). The SID of Leu, Lys, Met, Phe, Thr, and Val linearly increased with reducing particle size, but the increase was greater in pelleted diets than in meal diets (interaction, P &amp;lt; 0.05). The SID of Arg, His, Ile, and Val also linearly increased (P &amp;lt; 0.05) as the particle size of corn was reduced, and the SID of all indispensable AA except Trp was greater (P &amp;lt; 0.05) in pelleted diets than in meal diets. In conclusion, reducing the particle size of corn from 700 to 300 μm increased the AID of starch and the SID of AA, but the AID of starch and the SID of most indispensable AA was greater in pelleted diets than in meal diets. If there were interactions, the effects of reducing particle size were greater when corn particle size was reduced from 500 to 300 μm in meal diets and from 700 to 500 μm in pelleted diets.

301 Effects of Different Sources and Particle Sizes of Field Peas on Ileal Digestibility of Amino Acids and Starch by Growing Pigs

Abstract The objective was to test the hypothesis that particle size and origin influence the apparent ileal digestibility (AID) of starch and the standardized ileal digestibility (SID) of amino acids (AA) in field peas. Three sources of field peas were procured. One source was from the U.S. and 2 sources were from Canada. The U.S. source and 1 of the sources from Canada (i.e., Canada 1) were each divided into 2 batches and ground at 200 or 400 µm, whereas the other source from Canada (i.e., Canada 2) was only ground at 200 µm. Each source of field peas was included in one diet as the only source of AA. An N-free diet was used to determine the basal endogenous losses of crude protein (CP) and AA. Barrows (n = 6; initial body weight: 50.5 kg; SD = 3.7) that had a T-cannula installed in the distal ileum were randomly allotted to a 6 × 6 Latin square design with 6 diets and six 7-d periods. Ileal digesta from pigs were collected for 2 days after 5 days of adaptation. The statistical model included source as the fixed effect and animal and period as the random effects. Contrast statements were used to analyze effects of particle size, origin, and the interaction between particle size and origin. Results indicated that the AID of starch was increased by reducing the particle size of the U.S. source, but that was not the case for the Canada 1 source (interaction; P &amp;lt; 0.001; Table 1). No interactions were observed for the SID of CP or AA. The SID of CP and AA was not affected by particle size of field peas. The SID of CP and Trp was greater (P &amp;lt; 0.05) and the SID of His, Ile, and Thr tended to be greater in the Canada 2 source (P &amp;lt; 0.10) than in the U.S. source. In conclusion, a few differences in the SID of AA in field peas produced in the U.S. or Canada were observed, but there was no effect on SID of AA of reducing the particle size of field peas from 400 to 200 µm. However, the effect of particle size on the AID of starch was greater in field peas from the U.S. compared with field peas from Canada.

298 Comparison of Amino Acid Digestibility in Pulses Between Broiler Chickens and Pigs

Abstract The difference in capacity and structure of the gastrointestinal tract of broiler chickens and pigs could influence the digestibility of amino acids (AA) in feed ingredients. Therefore, two experiments were carried out to compare the standardized ileal digestibility (SID) of AA in faba beans (FB) and three field peas (FP) cultivars between broiler chickens (Exp.1) and pigs (Exp.2). Four diets were prepared to contain FB, FP DS-Admiral (FPD), FP Hampton (FPH), or FP 4010 (FP4) as the sole source of nitrogen. A nitrogen-free diet (NFD) was also prepared to estimate the basal endogenous losses of AA. On day 21 post-hatch, 416 male broiler chickens with an initial body weight (BW) of 951 ± 111 g were allotted to 5 diets in a randomized complete block design with BW as a blocking factor in Exp.1. There were 8 replicate cages with 10 birds per cage for diets containing the test ingredients and 12 birds per cage for the NFD. All birds were fed the diets for 5 days. On day 26 post-hatch, birds were euthanized by CO2 asphyxiation and digesta contents from the distal two-thirds of the ileum were collected. Barrows (n = 20) with an initial BW of 30.2 ± 1.58 kg, surgically fitted with T-cannulas at the distal ileum, were used in Exp.2. The pigs were divided into 4 blocks based on BW and assigned to a 5 × 2 incomplete Latin Square design consisting of 5 dietary treatments and 2 experimental periods. The daily feeding allowance was calculated at 4% of the mean BW of the pigs in each block. The adaptation period was 5 days, followed by a 2-day collection of ileal digesta samples. Data from Exp.1 and 2 were pooled and analyzed as a 2 × 4 factorial treatment arrangement with the effect of species and test ingredients. There were no interactions (P &amp;gt; 0.05) between diet and species. For broiler chickens, the SID of Lys in FB, FPD, FPH, and FP4 were 91.3, 91.0, 92.5, and 85.1%, respectively, whereas for pigs the SID of Lys were 82.4, 85.7, 87.0, and 78.9%, respectively. The respective SID of Met in FB, FPD, FPH, and FP4 were 84.1, 87.3, 89.8, and 72.1% for broiler chickens. Furthermore, the SID of Met in FB, FPD, FPH, and FP4 for pigs were 71.5, 80.4, 81.8, and 68.1%, respectively. Field peas 4010 had significantly less (P &amp;lt; 0.05) SID of indispensable AA compared with the other ingredients, except for the SID of Trp. In conclusion, the SID of AA were significantly greater (P &amp;lt; 0.05) in broiler chickens compared with pigs, except for the greater (P &amp;lt; 0.05) SID of Pro in pigs and similar SID of Arg between both species.

154 The Effect of a Novel Consensus Bacterial 6-Phytase Variant on Ileal Digestibility of Energy in Growing Pigs: Meta-Analysis of 4 Trials

Abstract This meta-analysis evaluated the effect of a novel consensus bacterial 6-phytase variant (PhyG) on the apparent ileal digestibility (AID) of energy in growing pigs. It was hypothesized that increasing phytase doses improves energy digestibility. The database was constructed using 4 studies (PIC, L 800 × Camborough sows or TN Tempo × TN70 breeds; average body weight of 26.5 kg at sampling), contributing 220 data points. Pigs were fed corn or corn-wheat based diets with soybean meal, canola meal, rice bran, wheat middlings or DDGS. All studies had a negative control (NC) diet deficient in total Ca, dig P, standardized ileal digestible amino acids and without feed phosphates. The analyzed total Ca, total P, phytate P and calculated net energy ranged from 0.46 to 0.53%, 0.37 to 0.43%, 0.24 to 0.30%, and 2,441 to 2,472 kcal/kg, respectively. The NC was supplemented with PhyG at 250, 500, 1,000 or 2,000 FTU/kg. Digesta were collected using ileal T-cannulation (9-10 replicates/treatment, Latin square design). Data were analyzed using the Fit Model platform of JMP 14.0 with trial code as a random effect. Phytase dose response (using analyzed phytase activity) was analyzed with exponential curve fitting. The AID of gross energy and the ileal digestible energy (DE, kcal/kg) improved with 1,000 or 2,000 FTU/kg PhyG treatments vs. NC (P &amp;lt; 0.05, Table 1). Increasing the PhyG dose exponentially increased (P &amp;lt; 0.1) the AID of gross energy (%) and the ileal DE. Ileal DE improvement above NC increased exponentially (P &amp;lt; 0.06) up to 120.8 and 132.6 kcal/kg at 1,000 and 2,000 FTU/kg, respectively. In conclusion, PhyG supplementation improved ileal DE in growing pigs in a dose-dependent manner.

PSIII-17 Evaluation of Cheese co-Products in Comparison with Specialty Proteins on Growth Performance of Weaned Pigs

Abstract Plant protein, animal protein, and milk protein are common protein sources in nursery diets. To ensure growth performance of pigs and profitability of feeding programs, specialty protein ingredients are strategically selected by nutritionists primarily based on energy value, digestible amino acid (AA) content, nutrient variability, and cost. Indeed, standardized ileal digestibility of AA and metabolizable energy are greater in cheese co-products than fishmeal or enzymatic-treated soybean meal (ESBM). Therefore, two experiments were conducted to determine if replacing specialty protein sources with a novel cheese co-product in nursery diets could improve growth variables and profitability. In experiment 1, a total of 540 pigs (PIC 800 x Camborough; 7.1 kg) were blocked by body weight and allotted to 3 treatments, 10 replicates per treatment, and 18 pigs per pen. The three dietary treatments were a control diet containing ESBM and microbial biomass (MB) or 5% of cheese co-product from manufacturer A or B added to the basal diet with replacement of ESBM and MB. In experiment 2, a total of 1,080 pigs (PIC 800 x Fast 276; 6.7 kg) were blocked by body weight and allotted to 4 treatments, 15 replicates per treatment, and 18 pigs per pen. The four treatments were a control diet with ESBM and MB, control with 5% of cheese co-product by replacing ESBM; control with 0.5% of functional protein; control with 4% of bovine plasma. All experimental diets were formulated on an equal SID Lys basis and a common diet was provided after approximately 3 weeks post-weaning. Data were analyzed using generalized linear mixed models with treatment as a fixed effect and block as a random effect. Results from experiment 1 showed that pigs fed cheese co-products regardless of the source had greater ADG (P &amp;lt; 0.05) by 4.4% than those fed control. Results from experiment 2 showed that pigs fed cheese co-product had greater (P &amp;lt; 0.05) intake in week 2 and week 3, which resulted in an overall increase in feed intake by 7.5% compared with those fed functional protein. However, there were no difference in overall gain, ADG, and feed efficiency during the entire 40-day study. Economic assessment showed that pigs fed cheese co-products had better income over feed cost than control in experiment 1 and had an equivalent income over feed cost compared with control in experiment 2. These results suggest that the novel cheese co-products can effectively substitute for ESBM and other specialty proteins in nursery diets and provide some flexibility to substitute expensive protein sources without jeopardizing growth and profitability.

153 Effect of Exogenous Phytase on the Digestibility of Amino Acids and Phosphorus in Standard and High Phytin Swine Diets

Abstract The objective of the following study was to investigate the effect of exogenous phytase (Hiphorius 40, DSM Nutritional Products) on the standardized ileal digestibility (SID) of amino acids (AA) and the apparent ileal digestibility (AID) of P in both standard and high phytin (HP) swine diets. The study consisted of 4 diets arranged in a 2 x 2 factorial of standard or high phytin and exogenous phytase at 0 or 1,000 FYT/kg; and one N-free diet. Ten crossbred male pigs fitted with ileal T-cannulas were allotted to the 5 dietary treatments in duplicate 5 x 4 incomplete Latin-square design. Pigs were fed for a total of four 7-d periods, where digesta was collected on d 6 and 7 of each period. Diet and digesta samples were analyzed for dry matter, N, Ti, AA, and P to determine AA and P digestibility. The SID of AA was determined by correcting the AID of AA for the basal endogenous losses estimated using the N-free diet. Data were subjected to an ANOVA where main effects of the diet type (standard vs. HP) and phytase were evaluated as well as the interaction of diet type and phytase. If the ANOVA was significant the means were separated by Tukey’s method. The basal endogenous AA losses of pigs in this study ranged from 0.115 (Met) to 0.921 (Thr) g/kg DM and 0.308 (Cys) to 9.455 (Pro) g/kg DM for indispensable and dispensable AA, respectively. The HP diets produced less SID of all AA compared with the standard diets (P &amp;lt; 0.001) with an average SID reduction of 6.5% for indispensable AA. Phytase improved (P &amp;lt; 0.05) the SID of Met, Lys, Arg, Cys, Glu and Ser and tended to improve (P &amp;lt; 0.10) Leu, Thr, and Tyr. There were no significant diet type*phytase interactions. The AID of P was less (P &amp;lt; 0.01) for the HP diets relative to the standard (39.12% vs. 45.84%), and phytase produced greater (P &amp;lt; 0.01) AID of P for both diet types (25.62% vs. 59.34%). These data indicate that phytase can improve the digestibility of many AA and P in both standard and HP diets for growing pigs.