Basal Endogenous Losses Research Articles

Dependence of the hindgut disappearance of phosphorus in pigs on the quantity of phosphorus entering the hindgut based on a Meta-analysis

The objectives of the current study were to compare the difference between standardized ileal digestibility (SID) and standardized total tract digestibility (STTD) of phosphorus (P) in pigs using published data and investigate the factors that affect the hindgut disappearance of P in pigs. A total of 156 observations from 32 experiments that determined the apparent ileal digestibility and total tract digestibility of P in pigs were collected. SID and STTD of P were calculated by accounting for basal endogenous losses of P. Standardized hindgut disappearance (SHD) of P was determined by subtracting the STTD of P from the SID of P. The chi-square test was performed to investigate the association between SHD of P and categorical variables, including the use of phytase, the use of inorganic P sources, the use of corn-soybean meal-based diets, and body weight (BW) of pigs. To determine the effects of the SID of P on the SHD of P, a linear equation for the SHD of P was developed using the SID of P as an independent variable. The BW of pigs ranged from 10.0 to 104.8 kg and the SHD of P ranged from –22.8% to 39.8%. The STTD of P was greater than the SID of P (47.1% vs. 49.7%; P = 0.019). Based on the chi-square analysis, the supplementation of inorganic P sources tended to result in a higher occurrence of a positive value for the SHD of P (P = 0.079). In addition, the occurrence of a positive value in the SHD of P was lower when the BW of pigs was below 30 kg. However, as the BW of pigs increased, the occurrence of a positive value in the SHD of P increased (P = 0.061). A regression analysis of the SHD of P against the SID of P in pigs indicated that the SHD of P decreased as the SID of P increased in pigs (r2 = 0.17; P < 0.001). In conclusion, the STTD of P is greater than the SID of P in pigs, and the SHD of P depends on the diet composition, the amount of P entering the large intestine, and the BW of the pigs.

Comparison of Amino Acid Digestibility between Commercial Crossbred Pigs and Mini-Jeju Island Native Pigs.

The objectives of this study were to determine the apparent ileal digestibility and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in feed ingredients, compare the ileal digestibility of CP and AA between commercial crossbred pigs and mini-Jeju Island native pigs (JINP), and develop models for estimating SID of CP and AA for commercial pigs using mini-JINP data. The study involved five crossbred commercial pigs (31.5 ± 1.6 kg of body weight and 11 weeks of age; Landrace × Yorkshire) and five mini-JINP (31.0 ± 3.2 kg body weight and 20 weeks of age). The pigs were surgically equipped with a T-cannula at the end of ileum. Each pig breed was assigned to 5 dietary treatments in a 5 × 10 incomplete Latin square design with 10 periods. Four experimental diets were formulated to contain each of soybean meal, corn gluten feed, copra meal, and sesame expellers as the sole source of nitrogen. A nitrogen-free diet was also prepared to determine basal endogenous losses of CP and AA. No interaction between breed and feed ingredient was observed for the digestibility of CP and all indispensable AA. The SID of CP and all indispensable AA, except Arg, His, and Lys, did not differ between the two breeds of pigs. Prediction equations were developed for SID of CP and AA of commercial pigs using the SID values of mini-JINP: SID of CP (%) = (1.02 × SID of CP in mini-JINP) - 5.20 with r2 = 0.97 and p < 0.05; SID of Lys (%) = (1.12 × SID of Lys in mini-JINP) - 9.10 with r2 = 0.98 and p < 0.05; and SID of Met (%) = (1.08 × SID of Met in mini-JINP) - 4.27 with r2 = 0.96 and p < 0.05. The digestibility for most AA in feedstuffs for commercial pigs can be estimated using data from mini-JINP.

Proteomic Identification and Quantification of Basal Endogenous Proteins in the Ileal Digesta of Growing Pigs.

The accurate estimation of basal endogenous losses (BEL) of amino acids at the ileum is indispensable to improve nutrient utilization efficiency. This study used a quantitative proteomic approach to identify variations in BEL in the ileal digesta of growing pigs fed a nitrogen-free diet (NFD) or a casein diet (CAS). Eight barrow pigs (39.8 ± 6.3 kg initial body weight (BW)) were randomly assigned to a 2 × 2 crossover design. A total of 348 proteins were identified and quantified in both treatments, of which 101 showed a significant differential abundance between the treatments (p < 0.05). Functional and pathway enrichment analyses revealed that the endogenous proteins were associated with intestinal metabolic function. Furthermore, differentially abundant proteins (DAPs) in the digesta of pigs fed the NFD enriched terms and pathways that suggest intestinal inflammation, the activation of innate antimicrobial host defense, an increase in cellular autophagy and epithelial turnover, and reduced synthesis of pancreatic and intestinal secretions. These findings suggest that casein diets may provide a more accurate estimation of BEL because they promote normal gastrointestinal secretions. Overall, proteomic and bioinformatic analyses provided valuable insights into the composition of endogenous proteins in the ileal digesta and their relationship with the functions, processes, and pathways modified by diet composition.

Prediction models for basal endogenous losses of crude protein and amino acids in pigs

Objective: The objectives were to validate a previously published equation for estimating basal endogenous losses (BEL) of crude protein (CP) in pigs fed nitrogen-free diets and to develop prediction equations for BEL of CP and amino acids (AA).Methods: A total of 139 observations from 123 experiments in 117 papers that determined the BEL of CP and AA in pigs were collected. For the validation of the previous equation for the BEL of CP, 94 observations that were not used for developing the previous equation were used. All observations were used to develop novel equations for estimating BEL of CP in pigs based on the initial body weight (IBW).Results: The validation study indicated that the slope for BEL of CP, representing a linear bias, was less than zero (–0.56; standard error [SE] = 0.130; p&lt;0.001). The intercept for BEL of CP, representing a mean bias, was less than zero (–3.21; SE = 0.488; p&lt;0.001). The models for estimating BEL of CP (g/kg dry matter intake) in pigs fed a nitrogen-free diet were developed: 20.36–0.077×IBW with R&lt;sup&gt;2&lt;/sup&gt; = 0.11 and p&lt;0.001 and 20.80×e&lt;sup&gt;(–0.00475×IBW)&lt;/sup&gt; with R&lt;sup&gt;2&lt;/sup&gt; = 0.12 and p&lt;0.001. Novel linear models for estimating BEL of AA were developed using BEL of CP as the independent variable.Conclusion: The accuracy of the previous equation for estimating BEL of CP in pigs has been improved by reflecting additional data from recent publications. In the novel linear models for estimating BEL of AA of pigs, BEL of CP was used as an independent variable.

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 &amp;lt; 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 &amp;lt; 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 &amp;lt; 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.

PSV-2 Digestible indispensable amino acid scores (DIAAS) in pork products

Abstract The “Digestible Indispensable Amino Acid Score” (DIAAS) method measures protein quality in human foods. However, values for DIAAS are not available for some pork products. Therefore, this study aimed to determine DIAAS values for nine pork products. Nine diets contained one pork product (i.e., back ribs, shoulder butt, tenderloin, Coppa ham, prosciutto ham, speck ham, chorizo, Italian sausage, and bratwurst) as the only source of crude protein (CP) and amino acids (AA). Nine ileal cannulated gilts with an initial average body weight of 50.3 ± 3.8 kg were used in a 9 × 6 incomplete Latin square with 9 diets and six 7-d periods. Ileal digesta were collected on d 6 and 7 of each period. There were, therefore, six replicate pigs per diet, but no pig was fed the same diet twice. A nitrogen-free diet was used to measure basal endogenous losses of CP and AA, and this diet was fed to all pigs in one separate 7-d period. The standardized ileal digestibility (SID) and DIAAS of each pork product were calculated. Reference ratios were used for children from 6 mo to 3 yr old and individuals older than 3 yr. Data were analyzed by ANOVA using the MIXED procedure of SAS with pig as the experimental unit. Diet was the fixed effect and replicate pig was the random effect. Results indicated that for both age groups, prosciutto ham had greater (P &amp;lt; 0.05) DIAAS than all other pork products (Table 1), which may be because prosciutto is from the hind leg of the pig, which contains less connective tissue. Prosciutto was also not smoked, which may contribute to the greater DIAAS values for this protein because smoking may reduce DIAAS. For children from 6 mo to 3 yr old, tenderloin, Coppa ham, and Italian sausage had greater (P &amp;lt; 0.05) DIAAS than chorizo and bratwurst sausages, back ribs, and shoulder butt. However, for individuals older than 3 yr, Coppa ham had greater (P &amp;lt; 0.05) DIAAS than all other pork cuts and sausages. The observation that back ribs and shoulder butt had decreased DIAAS than tenderloin is likely because tender cuts with less connective tissues tend to have greater concentrations of indispensable AA with less non-nitrogen content. In addition, for both age groups, there was no limiting AA for all pork products, except that chorizo sausage was limiting in sulfur AA for children from 6 mo to 3 yr old. In conclusion, data from this experiment demonstrated that all pork products have “good” or “excellent” protein quality for individuals older than 6 mo of age, indicating that these food ingredients may be used to complement lower-quality proteins and provide a meal with all indispensable 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.

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.

Effects of different protein sources in low-phosphorus diets on calculated basal endogenous loss of phosphorus by growing pigs

The objective of this experiment was to test the hypothesis that the basal endogenous loss (BEL) of P from pigs fed a diet containing spray dried plasma, casein, or potato protein concentrate is not different from that of pigs fed a diet containing gelatin. Forty pigs (body weight: 19.34 kg; SD = 0.80) were housed individually in metabolism crates and allotted to four low-P diets using a completely randomized block design with two blocks of 20 pigs and five pigs per diet in each block. Diets were based on cornstarch and sucrose and contained 200 g/kg gelatin, 200 g/kg spray dried plasma, 185 g/kg casein, or 200 g/kg potato protein concentrate. With the exception of Ca and P, diets were formulated to meet requirements of all nutrients. Feces and urine samples were collected for 4 d following a 5-d adaptation period. Fecal samples were dried and ground, and fecal and urine samples were analyzed for P. Data were analyzed using a model that included diet as fixed effect and block as random effect. Results indicated that feed intake and fecal excretion of dry matter were greater (P < 0.05) in pigs fed diets containing spray dried plasma, casein, or potato protein concentrate compared with pigs fed the gelatin diet, with pigs fed potato protein concentrate having the greatest (P < 0.05) excretion. The apparent total tract digestibility (ATTD) of dry matter was least (P < 0.001) in pigs fed the diet containing potato protein concentrate, but there were no differences among gelatin, spray dried plasma, and casein diets. The ATTD of P was greater (P < 0.001) in pigs fed diets containing spray dried plasma or casein compared with pigs fed gelatin or potato protein concentrate diets. The BEL of P was not different between the gelatin and casein diets (i.e., 176 and 234 mg/kg dry matter intake), but pigs fed diets containing spray dried plasma or potato protein concentrate had greater (P < 0.001) BEL of P (i.e., 338 and 374 mg/kg dry matter intake) compared with pigs fed gelatin or casein diets. In conclusion, the BEL of P was greater if calculated from diets containing spray dried plasma or potato protein concentrate compared with gelatin. However, casein may be an alternative to gelatin to estimate the BEL of P because casein provides a greater amount of P compared with gelatin, which compensates for the deficient level of P in gelatin, but does not affect the BEL of P.

Reduction of particle size of field peas (Pisum sativum L.) increases net energy and digestibility of starch when fed to growing pigs, but there is no difference in nutritional value between peas from the United States and peas from Canada.

Two experiments were conducted to test the hypotheses that particle size of field peas and location where peas are grown do not affect apparent total tract digestibility of nutrients and gross energy, digestible energy (DE), metabolizable energy (ME), and net energy (NE), apparent ileal digestibility (AID) of starch, or standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA). In both experiments, 3 sources of field peas were used. One source was obtained from the United States and 2 sources were obtained from Canada (i.e., Canada 1 and Canada 2). The U.S. field peas were ground to 678, 457, or 265 µm, whereas the 2 sources of Canadian peas were ground to 411 and 415 µm, respectively. Therefore, 5 batches of field peas were used in both experiments. A basal diet contained corn and soybean meal as the only source of energy, starch, and AA, and 5 diets containing corn and soybean meal and 50% of each source of field peas were also formulated. The ratio between corn and soybean meal was 1.92:1 in all diets. In experiment 1, an N-free diet was also used to calculate basal endogenous losses of AA and CP, but in experiment 2, no N-free diet was used. In experiment 1, 7 barrows (initial body weight = 60.6 ± 2.1kg) that had a T-cannula installed in the distal ileum were allotted to a 7 × 7 Latin square design with 7 diets and 7 periods. In experiment 2, 24 pigs (initial body weight = 30.8 ± 1.0kg) were housed in 6 calorimeter chambers with 4 pigs per chamber. The 6 chambers were allotted to one of the 6 diets using a 6 × 6 Latin square design with 6 consecutive periods of 15 d. Results of experiment 1 demonstrated that the SID of CP and AA was not influenced by the origin of the peas or by the particle size, but the AID of starch increased (linear, P < 0.001) as particle size was reduced from 678 to 457 or 265 µm. Results of experiment 2 indicated that growing location did not affect concentrations of DE, ME, or NE of field peas, but concentrations of DE, ME, and NE increased (linear, P < 0.05) when particle size was reduced from 678 to 457 or 265 µm. In conclusion, field peas grown in Canada or the United States have the same nutritional value, but starch digestibility and NE increase if the particle size of field peas is reduced.

The pig is an excellent model to determine amino acid digestibility of human foods and to generate data needed to meet human amino acid requirements.

The protein value of any food item is determined by the quantity and ileal digestibility of indispensable amino acids in that food. To determine the ileal digestibility of amino acids, an animal model needs to be used, and the pig is the preferred model because values for ileal digestibility obtained in pigs are representative of values obtained in humans. In addition, pigs are omnivorous animals like humans, they are meal eaters, they consume most diets that humans consume, they are easy to work with, and they can be used for repeated determinations of digestibility in many foods. It is, therefore, possible to use pigs to establish a database with digestibility values for human foods and by correcting digestibility values obtained in pigs for the basal endogenous losses of amino acids, it is possible to calculate true ileal digestibility values that are additive in mixed meals. As a consequence, the protein quality of a meal consisting of several food items can be calculated based on digestibility values obtained in pigs. Future work needs to focus on expanding existing databases for amino acid digestibility in foods to include more food items, which will make it possible to estimate the amino acid value of more mixed meals. It is also necessary that the amino acid values in mixed meals be related to requirements for digestible indispensable amino acids in the individuals consuming the meals. The current contribution describes the basic steps in determining amino acid digestibility in human foods using the pig as a model and also outlines future steps needed to further improve amino acid nutrition in humans.

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.

123 Effects of Different Protein Sources Containing Highly Digestible Phosphorus on the Basal Endogenous Loss of Phosphorus

Abstract The objective of this experiment was to test the hypothesis that the basal endogenous loss of P from pigs fed a diet containing blood plasma, casein, or potato protein concentrate is not different from that of pigs fed a diet containing gelatin. Pigs (n = 40; body weigh =: 19.34 kg) were housed in metabolism crates and were randomly allotted to four low-P diets containing 20% gelatin, 20% blood plasma, 18.5% casein, or 20% potato protein concentrate. With the exception of Ca and P, diets were formulated to meet the requirements for 11 to 25 kg pigs. Feces and urine samples were collected separately for 4 d following a 5-d adaptation period. Feces samples were dried, ground, and analyzed for Ca and P, and urine samples were also analyzed for Ca and P. Data were analyzed using a model that included diet as fixed effect and replicate as random effect. Results indicated that feed intake and fecal excretion of dry matter were greater (P &amp;lt; 0.05) in pigs fed diets containing blood plasma, casein, and potato protein concentrate compared with pigs fed the gelatin diet, with pigs fed potato protein concentrate having the greatest (P &amp;lt; 0.05) excretion (Table 1). The apparent total tract digestibility of dry matter was least (P &amp;lt; 0.001) in pigs fed the diet containing potato protein concentrate, but there were no differences among gelatin, blood plasma, and casein diets. No differences were observed in the standardized total tract digestibility of P among diets. Basal endogenous loss of P was not different between the gelatin and casein diets, but pigs fed diets containing blood plasma or potato protein concentrate had greater (P &amp;lt; 0.001) basal endogenous loss of P compared with pigs fed gelatin or casein diets. In conclusion, the basal endogenous loss of P was greater in diets containing blood plasma and potato protein concentrate compared with gelatin. However, casein could be an alternative to gelatin to estimate the basal endogenous loss of P because casein provides a greater amount of P compared with gelatin that compensates for the deficient level of P in gelatin, but does not affect values for the basal endogenous loss of P.

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.

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.

Standardized ileal amino acid digestibility of high-oleic full-fat soybean meal in broilers

High-oleic (HO) soybean may serve as a value-added feed ingredient to enrich poultry meat due to its fatty acid content. However, the amino acid (AA) nutrient digestibility of soybean meal (SBM) made from these soybeans has yet to be determined. The objective of this study was to determine apparent ileal AA digestibility (AID) and standardized ileal AA digestibility (SID) of high-oleic full-fat (HO-FF) SBM compared to normal oleic full-fat (NO-FF), normal oleic extruded expeller (NO-EE), and solvent-extracted SBM (SE-SBM) in broilers. A nitrogen-free basal diet (NFD) was fed to 1 treatment group with 10 chicks/cage to determine basal endogenous losses (BEL). Titanium dioxide was used as an inert marker. The test diets contained 57.5% of the basal NFD and 42.5% of 1 of the 4 soybean sources. A total of 272 Ross-708 male broilers were placed in 40 battery cages with 5 treatments and 8 replicates per treatment. A common starter diet was provided to all the chickens for 14 d. Experimental diets were provided as a mash for 9 d before sample collection. Chickens were euthanized with CO2 on d 23, and contents of the distal ileum were collected, frozen, and freeze-dried. The BEL were similar to the values found in the literature. At d 23, broilers fed the SE-SBM had the highest body weight gain and best FCR compared to chickens fed the HO-FF and NO-FF treatments (P < 0.001). Broilers fed the SE-SBM and NO-EE experimental diets had (P < 0.001) higher apparent ileal AA digestibility and AA SID than broilers fed the HO-FF and NO-FF treatments. In conclusion, the SID of AA from HO-FF is similar to the digestibilities of other full-fat soybeans found in the literature and is lower than that of NO-EE and SE-SBM.

Comparison of methods for estimating basal endogenous losses of amino acids and additivity of digestibility of amino acids in corn and soybean meal for broilers

This study was to compare the estimates of basal endogenous losses (BEL) of amino acids (AA) determined by 3 methods including feeding a nitrogen-free diet (NFD) or a low-casein diet (LCD, containing casein at 30 g/kg diet) or using the regression method. Another objective was to investigate whether the ileal AA digestibility of corn calculated from a casein-supplemented corn diet is additive for a corn-soybean meal (SBM) mixed diet in broilers. On d 31 of age, 168 Ross 308 male broilers were assigned to 8 dietary treatments with 6 replicates in a randomized complete block design. An NFD and 3 diets containing 30, 60, or 90 g/kg of casein were formulated to determine the BEL of AA and ileal AA digestibility of casein. The other 4 diets consisted of a corn diet, SBM diet, casein-supplemented corn diet, and corn-SBM mixed diet. On d 35 of age, digesta from the distal section of the ileum were collected. The BEL of AA in birds fed the LCD were greater (P < 0.05) than those of the NFD and the regression method. There were no differences in the BEL of AA determined between the NFD and the regression method. Apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA for corn calculated from the casein-supplemented corn diet were greater (P < 0.05) than those of the corn diet. The predicted AID of Thr in the corn-SBM mixed diet based on the AID of AA for corn in the corn diet was lower (P < 0.05) than the measured AID. However, the predicted AID of AA in the mixed diet based on the AID of AA for corn in the casein-supplemented corn diet did not differ from the measured AID. The predicted SID of AA in the mixed diet did not differ from the measured SID irrespective of casein supplementation. In conclusion, feeding an NFD or using the regression method yields similar BEL of AA, but not feeding an LCD. Casein supplementation in the corn diet increases the ileal AA digestibility for corn, which is additive for the corn-SBM mixed diet.

Determination of ileal digestibility of tryptophan in tryptophan biomass for broilers using the direct and regression methods

A total of 372 Ross 308 male broilers were used in a 2-day trial to determine the ileal digestibility of tryptophan in tryptophan biomass using the direct and regression methods, and to compare the digestibility between the 2 methods. A nitrogen-free diet was prepared to estimate the basal endogenous losses of amino acids of birds. Two semi-purified diets were formulated to contain tryptophan biomass as the sole source of amino acids. Five corn-soybean meal-based diets consisted of a basal diet and 4 assay diets containing either 30 or 60 g/kg of tryptophan biomass A or B (TBA or TBB) at the expense of corn and soybean meal in the basal diet. The ratio of corn and soybean meal remained consistent across the basal and assay diets. Birds received a standard starter diet (193 g/kg crude protein) from day 0–19 post-hatch and 8 experimental diets for 2 days from day 19. On day 21 post-hatch, birds were asphyxiated with carbon dioxide and digesta samples from the distal section of the ileum were collected. The linear regression of tryptophan biomass-associated digested tryptophan against tryptophan biomass-associated tryptophan intake was conducted to determine the ileal tryptophan digestibility in tryptophan biomass. The apparent and standardized ileal digestibility of tryptophan determined by the direct method were 0.993 and 0.993 in TBA, and 0.995 and 0.996 in TBB, respectively. The apparent ileal digestibility of amino acids in corn-soybean meal-based diets quadratically increased (P < 0.05) as dietary levels of tryptophan biomass increased. The ileal digestibility of tryptophan determined by the regression method was 1.013 and 1.009 for TBA and TBB, respectively. The ileal digestibility of tryptophan in TBA derived from the regression method was greater (P = 0.033) than that of determined using the direct method, but no difference (P = 0.193) was observed in TBB. However, the ileal digestibility of tryptophan in the tryptophan biomass was close to 100 % irrespective of the method used.

Research Note: Evaluation of standardized ileal amino acid digestibility in feed ingredients for Pekin ducks

The digestibility of crude protein (CP) and amino acids (AA) in feedstuffs including corn, soybean meal (SBM), and corn distillers dried grains with solubles (DDGS) was investigated in White Pekin ducks. The test ingredients were the sole source of AA and CP. A nitrogen-free diet was also formulated for determining endogenous losses of AA and nitrogen. Birds were fed a standard starter diet for the first 15 d posthatch. On d 16, 96 ducklings (860 ± 50 g BW) were selected and allocated into 1 of 4 dietary treatments containing the test ingredients with 6 replicates per treatment in a randomized complete block design. All the crumbled assay diets were offered ad-libitum for 5 d and contained chromic oxide as an indigestible marker at 0.05%. On d 21, ducks were euthanized to collect the ileal digesta for digestibility analysis. Basal endogenous losses were abundant in glutamine, aspartic acid, leucine, proline, and serine, consecutively. For apparent ileal digestibility (AID), lysine and methionine were the highest (P < 0.05) in SBM, followed by corn and DDGS. For threonine, the highest values (P < 0.05) were similarly noted for SBM, followed by DDGS and corn; the values were 80.44, 69.88, and 64.89%, consecutively. Considering standardized ileal digestibility (SID), higher values (P < 0.05) for SBM were similarly noted for all the amino acids including lysine, methionine, and threonine; the values were 89.40, 93.58, and 86.50%, respectively. Conclusively, improved AA and CP digestibility was noted with SBM. Dietary protein source affected the extent of digestibility at the distal ileum; and the utilization of digestible amino acid coefficients during ducks' feed formulation is emphasized.