Amino Acid Digestibility Research Articles

Amino acid requirements of the infant: the amino acid composition of human breast milk.

The recommended amino acid requirements of the infant are based on the amino acid composition of mature human breast milk. The amino acid composition of breast milk is usually determined following either acid or alkaline (for tryptophan) hydrolysis. For accuracy, however, the known effect of hydrolysis time on amino acid composition should be accounted for. Also, ideally the amino acid composition of breast milk should be given in units of digested (assumed to be absorbed) amino acids. A review of the literature is presented which gives mean total amino acid concentrations in mature human milk (n = 26 studies), mean hydrolysis correction factors (n = 3 studies) and mean true ileal amino acid digestibility coefficients (n = 3 studies, suckling piglet). There were differences between the estimates of amino acid concentration corrected for hydrolysis time and digestibility, and current FAO (2013) recommendations that were not corrected for these factors. The values based on the published literature up until 2023 (mg/g true protein) corrected for hydrolysis time and digestibility gave higher values (more than 16% higher) for leucine, lysine and threonine, and considerably higher values (greater than 30%) for histidine and tryptophan. Current recommendations may need revision.

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.

PSVI-28 Interactive effects of different fiber and lipid sources on amino acid digestibility in growing pigs

Abstract A study was conducted to determine the effects of different fiber and lipid sources on the digestibility of amino acids (AA) in growing pigs. Five diets were fed in this study. The diets were corn-soybean meal-based diet with either soybean hulls (SBH) or sugar beet pulp (SBP) as fiber source and either soybean oil (SBO) or choice white grease (CWG) as lipid source in a 2 × 2 factorial arrangement; and a N-free diet. The diets were formulated to be similar in content of AA, calcium, available phosphorus, and total dietary fiber. The SBH and SBP were each included in their respective diets at 15%, whereas the SBO and CWG were each included in their respective diets at 4.5%. The 5 diets were fed to 10 ileal-cannulated pigs [5 barrows and 5 gilts; initial average body weight (BW) = 54.8 ± 5.6 kg)]in a 5 × 5 Latin square design to give 10 replicates per diet. On an as fed basis, SBH and SBP contained 11.3 and 8.8% crude protein, 66.1 and 49.8% total non-starch-polysaccharides (NSP), 54.3 and 29.5% insoluble NSP, and 11.8 and 20.3% soluble NSP, respectively. The SBO and CWG contained &amp;gt;98.5 and &amp;gt;98.5% crude fat, 14.7 and 35.6% saturated fatty acids, and 76.6 and 62.5% unsaturated fatty acids, respectively. Dietary fiber source and lipid sources did not interact on standardized ileal digestibility (SID) of AA. The SBH- and SBP-containing diets did not differ regarding SID of all AA except Met and Trp. Pigs fed SBP-containing diets had lower (P &amp;lt; 0.05) SID of Met and greater (P &amp;lt; 0.05) SID of Trp than those fed SBH-containing diets by 2.5 and 4.7%, respectively. The SBO- and CWG-containing diets did not differ regarding SID of all AA except Trp. The SID of Trp for SBO-containing diets was greater (P &amp;lt; 0.05) than that for CWG-containing diets by 2.6%. In conclusion, the lack of interaction between dietary fiber and lipid sources on the SID of AA implies that these two factors (fiber and lipid sources) may exert their effects on ileal digestibility of AA independently if the fiber and lipid sources are included in diets for growing pigs at same levels included in the diets fed in the current study. The dietary fiber source and dietary lipid source had limited effects on the digestibility of most AA, implying that replacement of one fiber source with one another fiber source or of one lipid source with another lipid source in diets for growing pigs may have limited effect on digestibility of AA if the fiber and lipid sources are included in diets for growing pigs at same levels included in the diets fed in the current study.

PSI-16 Evaluation of protein quality of defatted black soldier fly (Hermetia illucens) larvae meal compared with traditional protein sources for dogs and cats

Abstract There is increased interest in the use of insects, such as black soldier fly (Hermetia illucens) larvae meal (BSFLM), as an alternative protein source in pet foods. However, additional information is needed to determine how BSFL protein quality compares with traditional pet food protein sources. Thus, the objectives of this study were to determine the chemical composition, amino acid digestibility, and protein quality of defatted BSFLM in comparison with whole egg powder (WEP) and chicken meal (CM) using the precision-fed cecectomized rooster assay. Fifteen cecectomized roosters (n = 5 per substrate) were randomly allocated to the test substrates BSFLM, CM, and WEP. After 26 h of feed withdrawal, 20 g of substrates were crop-fed and excreta were collected for 48 h. Digestible indispensable amino acid score (DIAAS)-like values were calculated using the Association of American Feed Control Officials (AAFCO), The European Pet Food Industry Federation (FEDIAF), and National Research Council (NRC) reference values for different life stages of dogs and cats. Data were analyzed using SAS Proc Mixed 9.4 with P ≤ 0.05 significance. On a dry matter basis, CM had the greatest crude protein (70.2%), followed by BSFLM (59.8%), and WEP (51.2%). In general, WEP had greater amino acid digestibility than BSFLM and CM. BSFLM (84%) and CM (84%) had comparable arginine digestibility, but less than WEP (92%). Lysine digestibility was greater for BSFLM (80%) in contrast with CM (74%), but less than WEP (91%). DIAAS-like values were calculated, revealing methionine + cysteine as the first limiting amino acids for growing puppies and adult dogs in BSFLM according to AAFCO, FEDIAF, and NRC, whereas for CM threonine was the first limiting amino acid based on AAFCO, and phenylalanine + tyrosine based on NRC and FEDIAF. NRC identified methionine and cysteine as limiting for all test substrates in adult dogs. Methionine and cysteine were limiting for growing kittens for BSFLM among AAFCO, FEDIAF, and NRC. For CM and WEP, phenylalanine and tyrosine was the first-limiting amino acid by NRC and FEDIAF. For adult cats, phenylalanine and tyrosine were the limiting amino acid for BSFLMand CM according to AAFCO and FEDIAF, with NRC identifying it as limiting across all protein sources. In summary, methionine and cysteine and/or phenylalanine and tyrosine were the primary limiting amino acids among the protein sources evaluated. In general, BSFLM had comparable indispensable standardized amino acid digestibility to CM.

PSIX-4 Standardized amino acid digestibility of defatted black soldier fly larvae meal (BSFLM) in extruded canine diets

Abstract The use of insects, such as black soldier fly (Hermetia illucens) larvae meal (BSFLM), as an alternative protein source for animal feed, including pet food, has gained attention due to their high nutritional value and sustainability attributes. The aims of the study were to determine the chemical composition and amino acid digestibility of canine diets using BSFL to partially or completely replace chicken meal (CM) at 15% or 30% inclusion using the precision-fed cecectomized rooster assay. Fifteen cecectomized roosters (n = 5 per treatment) were randomly assigned to the test diets: Control, 15% BSFLM, and 30% BSFLM. After 26 h of feed withdrawal, 20 g of substrates were crop-fed and excreta were collected for 48 h. Data were analyzed using SAS Proc Mixed 9.4 with P ≤ 0.05 significance. The chemical composition was similar among all 3 dietary treatments. On average, the diets had similar macronutrient compositions: dry matter 92 to 93.7%, organic matter 89%, crude protein (CP) 26.7 to 28.4%, acid hydrolyzed fat 14.6%, total dietary fiber (TDF) 11.5 to 13.3%, and gross energy was 4.9 kcal/g. The slight variations in CP and TDF concentrations were due to the BSFLM. Additionally, all diets had similar concentrations of indispensable and dispensable amino acids. The standardized digestibility for all indispensable amino acids was above 75% for all dietary treatments, except histidine, lysine, and methionine + cysteine for the 30% BSFLM diet. The inclusion of BSFLM at both 15% or 30%, as a partial or full replacement of chicken by-product meal, did not negatively impact the chemical composition or amino acid digestibility of the experimental diets. Overall, this study highlighted the viability of BSFLM as an alternative and sustainable protein source in canine nutrition, indicating that extruded diets formulated with BSFLM as a partial or primary protein source can sustain adult dogs’ nutritional needs similarly to diets formulated with CM.

PSVI-29 Effect of pig weight and exogenous enzyme supplementation on ileal endogenous amino acid losses and standardized ileal amino acid digestibility of soybean meal produced from Kentucky-grown soybeans

Abstract There is increasing interest in using locally sourced soybeans and soybean meal. Ileal amino acid digestibility (IAAD) of soybean meal from Kentucky-grown soybeans was evaluated in 25- and 50-kg cannulated pigs. The experiment used sixteen pigs in a randomized complete block design consisting of four treatments with 4 pigs per treatment. This was repeated in time resulting in eight replicates per treatment for both body weight (BW)groups. After cannulation at about 20 kg BW, all pigs were allowed to recover from the surgery and were fed a corn-SBM-based diet that met all nutrient and energy requirements. The experimental diets consisted of two nitrogen-free diets [NFD] with or without exogenous enzyme supplementation (phytase and a combination of phytase and carbohydrase enzymes) and two semi-purified diets containing soybean meal from Kentucky-grown soybeans as the only source of protein with or without exogenous enzyme supplementation. Each diet was fed for 7 consecutive d with 10-h ileal digesta collection on d 6 and 7. The same diets were fed to the same set of pigs at about 50 kg BW. Data were analyzed as a factorial arrangement of treatments (BW x diet) for ileal endogenous amino acid losses (IEAAL), apparent IAAD and standardized IAAD (SIAAD). Data from the NFD were used to determine the SIAAD from the AIAAD values. Exogenous enzyme supplementation increased (P &amp;lt; 0.05) IEAAL except for Gly and Pro while samples collected during phase 2 had greater (P &amp;lt; 0.05) IEAAL (10 amino acids). Pig BW did not influence IEAAL. Enzyme supplementation did not increase AIAAD except for Arg, Ala, Gly, N, and total AA while apparent ileal N, Met, Thr, and Val digestibility was greater (P &amp;lt; 0.05) in 50 kg pigs. Interactions between BW and diets showed that 50 kg pigs fed the SBM diet containing enzyme supplementation had greater (P &amp;lt; 0.05) N, Arg, and total AA digestibility compared with 50 kg pigs without enzyme supplementation. Digestibility of Val and Asp was greater (P &amp;lt; 0.05) in samples collected during phase 2. After correction for basal IEAAL, 50 kg pigs had greater (P &amp;lt; 0.05) SIAAD values for 12 of the AA analyzed while exogenous enzyme supplementation resulted in greater (P &amp;lt; 0.05) SIAAD for 9 of the AA analyzed. The SIAAD values for four AA (His, Phe, Val, and Asp) were greater (P &amp;lt; 0.05) for samples collected in phase 2. Results from this study showed that exogenous enzyme supplementation increased IEAAL and that IAAD of SBM produced from Kentucky-cultivated soybeans was high and that exogenous enzyme supplementation improved the SIAAD values of several amino acids. The IAAD values of SBM produced from soybeans cultivated in KY was high and are similar to values reported in the literature.

376 Effects of multi-carbohydrase and protease supplementation on ileal digestibility of amino acids in expeller-pressed canola meal fed to growing pigs

Abstract Expeller-pressed canola meal (ECM) is a co-product obtained from expeller-pressing canola seeds to obtain canola oil, and it has potential as a cost-effective feedstuff in swine diets. Also, ECM may be a superior protein source compared with solvent-extracted canola meal due to its greater digestible amino acid (AA) contents. However, limited information is available on the effects of enzyme supplementation on AA digestibility in ECM for pigs. Therefore, the objective of this study was to determine the effects of multi-carbohydrase (MC) and protease supplementation on the apparent (AID) and standardized ileal digestibility (SID) of AA in ECM when fed to growing pigs. A total of 12 barrows (65.9 ± 5.0 kg initial body weight), each fitted with a T-cannula in the distal ileum, were allocated for 2 studies: the current study (4 treatments) and another study with 8 treatments. Pigs were arranged in a 12 × 6 incomplete Latin square design with 12 diets and 6 periods, resulting in 6 observations per dietary treatment. Four dietary treatments were: 1) basal ECM diet; 2) ECM diet with MC supplementation (1 kg/tonne); 3) ECM diet with protease supplementation (250 g/tonne); and 4) ECM diet with both MC and protease supplementation. A casein diet was fed to all 12 pigs for 1 wk after feeding experimental treatments to quantify endogenous losses of AA. All diets contained 0.3% titanium dioxide as an indigestible marker. Pigs were fed 1 of the 4 diets during each of the 7-d periods, and ileal digesta were collected on d 6 and 7 from 0800 to 1700 h. Pigs were fed the diets at 2.8 times maintenance energy requirement based on their body weight at the beginning of each period. Data were analyzed using the PROC MIXED of SAS. The statistical model included MC, protease, and their interaction as fixed effects, and replication, animal within replication, and period within replication as random effects. Protease supplementation did not affect AID or SID of AA in ECM. Similarly, no significant differences were observed in MC supplementation on AID and SID of AA, except for a significant increase (P &amp;lt; 0.05) in the AID of Gly with MC supplementation compared with the non-supplemented diet. No interactive effects were found between MC and protease supplementation on the AID and SID of AA in growing pigs. In conclusion, the digestibility of AA in ECM fed to growing pigs with and without enzyme supplementation did not differ, and no interactive effects were observed. Future studies will aim to investigate the dose-effect to accurately determine whether the absence of an effect was attributable to improper enzyme-to-substrate ratio.

492 Effects of particle size and protease supplementation on amino acids digestibility in peas fed to growing pigs

Abstract This study aimed to determine the effects of particle size and protease supplementation on amino acid (AA) digestibility in peas fed to growing pigs. A total of 8 barrows (65.9 ± 5.0 kg initial body weight), each fitted with a T-cannula in the distal ileum, were allocated in an 8 × 7 incomplete Latin square design. Eight experimental diets were arranged in a 2 × 2 × 2 factorial design, consisting of two varieties of field peas (Amarillo, Meadow peas), two particle sizes (400, 700 μm), and without or with protease supplementation (0, 250 g/ton). The Amarillo and Meadow peas were similar in crude protein (20.6 vs 21.3%). Field peas were included in the diets as the only source of AA, with a 96.1% inclusion rate. All diets contained 0.3% titanium dioxide as an indigestible marker. A casein diet was used to estimate basal endogenous N and AA losses. The experiment was conducted for seven consecutive periods. Each experimental period lasted 7 d, including 5 d of adaptation and the last 2 d for ileal digesta collection from 0800 to 1700 h. Data were analyzed using the PROC MIXED of SAS. The statistical model included variety, enzyme, particle size, and their interaction as fixed effects, and replication, animal within replication, and period within replication as random effects. There was no 3-way interaction between variety, enzyme supplementation, and particle size on apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA in diets. Moreover, there were no differences in AID and SID between different varieties of field peas except for Cys where AID (66.2 vs 63.4%) and SID (71.9 vs 69.0%) were greater (P &amp;lt; 0.05) in Amarillo peas than in Meadow peas. Similarly, no difference was found between the diets with and without enzyme supplementation except for AID of Pro (71.9 vs 75.4%), which was less (P &amp;lt; 0.05) when protease was included. Also, no effects of particle size were observed except for SID of Ala (80.0 vs 77.0%), which was greater as particle size was reduced to 400 μm. The average SID values for essential AA were Arg (88.3%), His (80.9%), Ile (77.7%), Leu (78.7%), Lys (83.9%), Met (75.8%), Phe (79.3%), Thr (72.9%) and Val (74.9%). In conclusion, the variety of field peas, enzyme supplementation, or particle size did not affect the AID and SID of the field peas, and no interaction was observed among the factors. Future studies will investigate dose-response relationships to determine whether the observed enzyme effect was due to inadequate ratios between enzyme and substrate.

304 Amino acid digestibility and protein quality of fermented soybean-based ingredients using the precision-fed cecectomized rooster assay

Abstract Fermented soybean-based ingredients may serve as an alternative protein source for pet foods because of their high-quality protein content. The amino acid (AA) content and protein quality of fermented soybean-based ingredients may vary depending on their composition and processing, however, so testing is required. Our objective was to measure the AA composition, AA digestibility, and protein quality of fermented soybean-based ingredients using the precision fed cecectomized rooster assay. The University of Illinois Institutional Animal Care and Use Committee approved all animal procedures prior to experimentation. Cecectomized roosters (n = 36; six roosters per substrate) were randomly allotted to one of five test substrates: 1) autoclaved soybean (ASB); 2) fermented soybeans (FSB); 3) fermented soybeans with probiotics (FSBP); 4) fermented soybean meal (FSBM); 5) fermented soybean meal with probiotics (FSBMP). After 26 h of feed withdrawal, roosters were tube-fed test substrates. Following crop intubation excreta samples were collected 48 h. Endogenous loss corrections for AA were made by using five additional cecectomized roosters. All data were analyzed using SAS version 9.4. All substrates had increased AA digestibilities, with all indispensable AA digestibilities being &amp;gt;80% except for lysine (78.1% to 86.9%). Tryptophan digestibility was less (P &amp;lt; 0.05) in FSB than other substrates, but other AA digestibilities were not different. Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality according to nutritional guidelines for adult dogs, adult cats, growing puppies, and growing kittens. The most limiting AA was the same for all ingredients. In adult dogs, methionine was the most limiting AA based on National Research Council (NRC; DIAAS: 33.4-35.1), European Pet Food Industry Nutritional Guidelines (FEDIAF; DIAAS: 49.6-52.1), and Association of American Feed Control Officials (AAFCO; DIAAS: 60.2-63.2) guidelines. In adult cats, phenylalanine was the most limiting AA (DIAAS: 59.5-63.2) when using NRC guidelines, but DIAAS were above 100 for FEDIAF and AAFCO guidelines. In growing puppies, methionine was most limiting according to NRC (DIAAS: 56.7-59.6) and FEDIAF (DIAAS: 78.8-82.7) guidelines, but threonine was most limiting according to AAFCO (DIAAS: 68.8-72.3) guidelines. In growing kittens, methionine was most limiting according to NRC (DIAAS: 70.9-74.4) and AAFCO (53.4-56.0) guidelines, but phenylalanine was most limiting according to FEDIAF (DIAAS: 66.7-70.8) guidelines. Our results demonstrate that fermented soybean-based ingredients are high-quality protein sources. Even though they have one or more limiting AA, they would serve as strong complementary proteins for pet foods. Further research in dogs and cats is necessary to confirm sufficient palatability and digestibility, but these data suggest that they are valuable sources of protein for pet food.

379 Application of an energy and nutrient matrix to a diet supplemented with a novel phytase achieved a production and sustainability benefit in pigs

Abstract The capacity of a novel consensus bacterial 6-phytase variant (PhyG) to maintain growth performance and production benefits of pigs when added to an energy and nutrient-reduced mixed cereal diet was assessed. Two experiments were conducted. In Exp. 1 (wean to finish), weaned pigs [n = 192; initial body weight (BW) 7.18 ± 0.38 kg] were randomized to 4 treatments from weaning until market weight. Diets were provided in 5 phases. Treatments included: 1) a nutritionally sufficient positive control (PC); 2) a negative control (NC1) without added inorganic phosphate, reduced (based on specific PhyG dose) in net energy (NE), calcium (Ca), digestible amino acids (AA) and sodium (Na) vs. PC, supplemented with PhyG at 1,000, 1,000, 750, 500 and 500 FTU/kg in each phase, respectively (NC1+low PhyG); 3) a negative control (NC2) as NC1 supplemented with PhyG at 2,000, 2,000, 1,000, 750 and 750 FTU/kg in each phase and further reduced in energy and nutrient based on specific PhyG dose (NC2+high PhyG), and; 4) a negative control (NC3) as 2) and supplemented with xylanase–β-glucanase (XB) to provide 2,400 U/kg xylanase and 304 U/kg β-glucanase, with additional reduction in NE and digestible AA based on the contribution of XB (NC3+low PhyG + XB). In Exp. 2 (nursery), weaned pigs (n = 360; initial BW 8.40 ± 0.78 kg) were assigned to 3 dietary treatments from weaning up to 35 d. Diets were offered in 2 phases. Treatments included a nutritionally adequate positive control (PC) and 2 PhyG-supplemented diets, reduced in digestible phosphorus, Ca, Na, NE and digestible AA vs. PC, according to the expected contribution of PhyG added at 1,000 FTU/kg (NC1) or 2,000 FTU/kg (NC2), respectively. Data were analyzed by ANOVA. Means separation was by Tukey’s HSD test. In Exp. 1, overall growth performance (114 d) in all enzyme-supplemented diets was maintained or improved compared with PC. Compared with PC, feed cost per kg BW gain was significantly reduced by 7.3% and total carbon footprint (CFP; CO2 eq. g/kg BW gain) was reduced by 6.8% with PhyG + XB combination. In Exp.2, overall growth performance (35 d), in all PhyG-supplemented, nutrient-reduced, treatments, were either not different from, or were improved, vs. PC. Total feed costs and estimated CFP per kg BW gain were reduced in all PhyG-supplemented, nutrient- and NE-reduced treatments vs. PC. In conclusion, the application of a full energy and nutrient matrix maintained the overall growth of pigs in both 114- and 35-d studies with the novel phytase. The addition of XB further improved the overall growth of market pigs. Moreover, full matrix application with PhyG achieved reductions in total feed cost and carbon footprint in both studies.

165 Characterizing protein quality with in vitro methodologies

Abstract Nutritional assessment of the quality of a protein source is a complex process with different requirements depending on the jurisdiction being discussed. The Protein Efficiency Ratio (PER) is a growth measurement required in Canada, whereas the United States uses the Protein Digestibility Corrected Amino Acid Score (PDCAAS), which requires the determination of the amino acid profile and digestibility of the protein source. Notably both PER and PDCAAS are in vivo methods, necessitating the use of animals for measurement of growth and protein digestibility. Understandably there is significant interest from both industry and consumers to reduce reliance on animal experimentation for content claims. It is notable that outside of North America there are multiple examples of in vitro protein quality assessment. In Europe protein content claims are based on whether the protein content contributes &amp;gt;12% of the total energy, and in Australia content claims begin at 5 g of protein per serving. As the use of in vitro techniques for protein quality assessment has not led to indices of protein malnutrition in Europe and Australia, should be possible to use in vitro techniques in methods such as PER and PDCAAS thereby removing the reliance on animal use for quality assessment in North America. This can be accomplished by using in vitro methods in the assessment of protein digestibility and relying on recent changes by Health Canada to allow for calculation of PER from PDCAAS values. This presentation will introduce how protein quality is calculated via PER/PDCAAS, and subsequently discuss modifications of these methods to incorporate in vitro techniques to generate values indicating their nutritional quality with positive correlations to in vivo data.

244 Comparative crude protein solubilization in yellow pea and fava bean protein concentrates in a simulated porcine gastric and intestinal digestion model

Abstract Pulses are valuable protein ingredients but unique characteristics among them are known to influence protein quality and utilization. We determined crude protein solubilization (CPS) in yellow pea (YP) and fava bean (FB) protein concentrates using simulated porcine gastric and intestinal model (Table 1). For each ingredient, 500 mg CP equivalent was incubated in triplicate with pepsin at either pH 3.5 or 4.5 for 0, 0.5, 1, and 1.5 h at 39°C and 200 r.p.m. for gastric CPS. For intestinal CPS, gastric samples (derived at pH 3.5 for 1.5 h) were incubated with pancreatin and bile extract at pH 6.8 for 0, 0.5, 2, 4 and 6 h. Intestinal CPS was categorized as CPfast, CPslow and CPresistant corresponding to CPS within the first 0.5 h, 0.5 to 4 h, and undigested after 4 h, respectively (Table 2). The concentration of CP in the supernatant was equated to CPS. Data were subjected to Proc GLIMIXX of SAS while Gompertz equation was used to describe the gastric and intestinal solubilization kinetics (A-maximum solubilized CP, Wo- initial CP solubility, Ku- solubilization rate, Ti- time to inflection). The model for gastric CPS had fixed effects of protein, incubation time, stomach pH and their interaction at 1.5 h and while fixed effects of protein was evaluated in intestinal CPS kinetics. The analyzed CP in FB and YP were 712.7 and 599.1, g/kg DM, with 3 and 4% of CP bound to NDF, respectively. Gastric CPS in FB was not influenced (P &amp;gt; 0.05) by pH and incubation time; however, at 1.5 h gastric CPS in FB was 40.9 and 28.44% at pH 3.5 and 4.5, respectively. Gastric CPS in YP was influenced by incubation time (P &amp;lt; 0.05) with increase at pH 3.5 after 1 h and at pH 4.5 after 0.5 h compared with 0 h. After 1.5 h, gastric CPS in YP was 50.0% at pH 3.5 and 33.2% at pH 4.5. Whereas YP gastric CPS at pH 3.5 and 1.5h was greater compared with FB, there were no differences (P &amp;gt; 0.05) between the FB and TP at pH 4.5. However, intestinal CPS tended (P &amp;lt; 0.10) to be greater for FB (91.7%) compared with YP (89.4%). The FP was solubilized faster (Ku; P &amp;lt; 0.05) than YP, supported by a (P &amp;lt; 0.05) higher CPfast of FB (87.8%) compared with YP (75.9%). CPresistent was found to be greater (P &amp;lt; 0.05) for YP (12.0%) than for FB (6.6%; Figure 1). In conclusion, fava, and pea protein concentrates had gastric protein solubilization that was dependent on pH. The less resistant protein in FB suggested a greater nutritive value than YP. Further research should determine ileal amino acids digestibility and the impact of incorporation in practical diets to characterize animal performance, health, and environment impact.

491 Processing and stomach pH influenced in vitro gastric protein solubilization kinetics in sunflower meal

Abstract The study aimed to evaluate the effect of processing and pH on gastric protein solubilization kinetics in sunflower meal (SFM) products using porcine digestion simulation model. The SFM samples were derived from diverse processing approaches: 1) dehulled-cold pressed (SFM_CP), 2) dehulled-solvent-extracted (SFM_SE), and 3) application of electrostatic separation technology on SFM_SE to generate high crude protein (CP) version (SFM_SEP). Soybean meal (SBM) was included for reference comparison (Table 1). Considering the complex factors influencing retention time, gastric pH, and pepsin secretion, the study employed multiple sampling times, and pH levels. A total of 500 mg CP equivalent of each sample (in triplicates) was mixed with 25 mL of 0.1 M phosphate buffer (pH 6.0) and 2 mL of pepsin (27 mg/mL). The pH was adjusted to either 1.5, 2.5, 3.5 or 4.5 using 1 M HCl and placed in incubator shaker (200 rpm) at 39°C. Samples were taken at 0, 30, 60, and 90 min, snap-frozen in liquid nitrogen, stored frozen, later thawed at 4°C, centrifuged (15,000 × g for 10 min) and supernatants analyzed for CP. The data were analyzed using Proc GLIMIXX in SAS while Gompertz equation was used to describe the gastric protein solubilization kinetics. The model included the fixed effects of protein source or processing, stomach pH and their interaction on the gastric CP solubility at 90 min and gastric protein solubility kinetics (A-maximum solubilized CP, Wo- initial CP solubility, Ku- solubilization rate, Ti- time to inflection). The analyzed CP SBM, SFM_CP, SFM_SE, and SFM_SEP, were 514.4, 524.4, 393.5, and 484.2 g/kg DM, respectively. Gastric CP solubility increased with lower pH and longer incubation time (P &amp;lt; 0.05), which corresponded well with the optimum pH of pepsin activity around 2. Compared with SFM, SBM had the least (P &amp;lt; 0.05) gastric CP solubility at pH 4.5 and 3.5, and the least predicted maximum gastric CP solubility (A) at pH 4.5, 3.5 and 2.5 (P &amp;lt; 0.05; Table 2). SFM_CP showed the greatest predicted initial gastric CP solubility at 0 h (Wo) and A (P &amp;lt; 0.05). Electrostatic fractionation of SFM_SE (SFM_SEP) enhanced gastric CP solubility at pH 3.5 and 2.5 and reduced the solubility time to inflection point (Ti; P &amp;lt; 0.05). In conclusion, data indicated that cold pressing SFM increased gastric CP solubility relative to solvent extraction. However, electrostatic fractionation of SFM_SE improved protein gastric solubility. While SBM remains a standard, incorporating the studied sunflower meals with their fast CP digestion kinetics in feed formulation could improve protein utilization in young animals with high stomach pH. In vivo studies, particularly on ileal amino acid digestibility, are crucial to validate these findings. Sunflower meal tables_FMN.pdf

494 Long-term effects of canola meal inclusion in gestation and lactation diets on sow and piglet performance over two reproductive cycles

Abstract The experiment was conducted to determine the long-term effects of dietary canola meal (CM) inclusion as the main protein source in gestation and lactation diets on sow and litter performance. Sows (n = 68) from two baches were randomly allotted 1 of 2 diets on d 80 of pregnancy. The two diets were a corn-barley and soybean meal control diet (CTRL) and a corn-barley and CM treatment diet (CCM). All diets were formulated to be similar in standardized ileal digestible amino acid and net energy contents. Sow body weight (BW) and backfat (BF) thickness were determined on d 1, 35, 80, and 111 of pregnancy, on d 1 and 21 post-farrowing. Piglets were weighed on d 0 and at weaning (d 21). Data were analyzed using the PROC MIXED procedure of SAS 9.4 for a randomized complete block design with repeated measures. Over the two reproductive cycles, dietary treatments did not influence sow BW and BF thickness on d 80 and 111 of pregnancy, as well as d 1 and 21 post-farrowing (P &amp;gt; 0.10). However, sows fed the CCM diet had less (P &amp;lt; 0.05) BW and BF thickness on d 1 and 35 of pregnancy in the second reproductive cycle than sows fed the CTRL diet. The CCM diet decreased gestation gain from d 80 to d 111 of pregnancy compared with the CTRL diet over the two reproductive cycles (P &amp;lt; 0.05). No dietary effect on litter size or litter performance was found during the experimental period (P &amp;gt; 0.10). However, reproductive cycle had significant effects (P &amp;lt; 0.05) on BW gain and BF thickness from d 80 to 111 of pregnancy as well as BW and BF thickness on d 1 of lactation. In addition, litter weight at birth and after cross-fostering were significantly improved during the second reproductive cycle compared with the first cycle (P &amp;lt; 0.05). An interaction between dietary treatment and reproductive cycle on BW gain and BW on d 1 of lactation was observed (P &amp;lt; 0.05). In conclusion, feeding gestation and lactation diets containing CM as the main protein source to sows over two reproductive cycles supported similar sow reproductive and litter performance as the control.

Prediction of the apparent ileal digestible amino acid contents of canola meal for broilers from crude protein content

Context Canola meal is a protein-rich feedstuff with an amino acid profile that is reasonably well balanced and has the potential to replace soybean meal in poultry diets. Aim The objective of the present study was to investigate the relationship between the crude protein content and apparent ileal digestible amino acid contents of Australian canola meals. Methods Thirteen canola meal samples, processed by expeller or solvent extractions, were collected. The digestibility assay diets were based on dextrose and contained canola meal as the sole source of protein. The proportions of dextrose and canola meal were varied in each diet to obtain ~200 g/kg crude protein. Each diet was fed to three cages of six 35-day-old broilers for 7 days. At the end of the assay, digesta from the terminal ileum was collected for digestibility determination. Key results Crude protein contents were positively correlated with amino acid contents (P &lt; 0.05 to 0.001), except that of serine (r = 0.43; P = 0.11). Significant correlations between the crude protein content and ileal digestible contents were observed for most of amino acids, with coefficients of &gt;0.80 (P &lt; 0.05 to 0.001). Low correlation coefficients were observed for lysine (r = 0.48; P = 0.11) and serine (r = 0.55; P = 0.06). The poor correlation for lysine may be reflective of reduced lysine availability during processing. Conclusions The results showed that the crude protein content of canola meal could serve as a predictor of apparent ileal digestible content of most amino acids for broiler chickens. Implications Regression equations developed in the present study could be used to predict the content of ileal digestible amino acids in canola meal by using analysed crude protein contents.

Evolution and significance of amino acid scores for protein quality.

Amino acid scores have become very popular protein quality scores since their definition and recommendation by FAO expert groups. The chemical score is the central pillar of this method, and has been refined with digestibility correction factors, such as protein digestibility for the PD-CAAS and amino acid digestibility for the DIAAS. Several elements need to be taken into account to properly determine these scores, not only from a methodological point of view but also in order to reconcile regulation, pragmatism, accuracy and also biological significance. This review offers a reminder of the main points raised in the FAO reports on protein and AA requirements in 1995 and 2007, and on protein quality in 1991 and 2013. It also highlights the factors that most impact score metrics, and in particular the choice of reference pattern and protein determination in the food. Lastly, the scores are compared, and versus another quality score based on the physiological response, the protein efficiency ratio.

Pig True Ileal Digestible Amino Acid Contents of Individual Ingredients are Additive in Mixed Meals and Allow Accurate Predictions of Digestible Indispensable Amino Acid Score Values

BackgroundAlthough not every food protein contributes sufficient quantities of all of the indispensable amino acids (AAs) required for human health, the human diet is a mixture of foods. It is therefore important to evaluate protein quality in mixed meals. ObjectivesThe hypothesis was that the true ileal digestible AA content of mixed meals can be predicted from the amounts of digestible AA determined for individual food ingredients, allowing further prediction of the digestible indispensable amino acid score (DIAAS) for meals. MethodsFour diets contained either pea protein isolate (PPI), whey protein concentrate (WPC), or mixtures of PPI:WPC at a ratio of 25:75 (PP25) or 75:25 (PP75). Six ileal cannulated pigs were allocated to a 4 × 6 Latin Square design. Experimental diets at 10% protein and a protein-free diet were fed for 7 d with ileal digesta collection on days 6 and 7. True ileal digestibility (TID) of AA, amount of digestible AA, and DIAAS were calculated for each diet and predicted for the 2 mixed meals. ResultsPredicted and determined digestible AA contents of the mixed diets were not different. The predicted values fell within the confidence interval (95%) of the determined values. DIAAS for PPI was 61% and for WPC it was 96%. DIAAS calculated based on the predicted amounts of digestible AA for PP25 was 104% and for PP75 83%. These values were nearly identical to the determined values of 104% and 84% for PP25 and PP75, respectively. ConclusionsThe amount of digestible AA and DIAAS can be accurately predicted in mixtures of PP and WPC from the AA digestibility values for the individual ingredients.

PSII-22 Effects of protease supplementation on ileal digestibility of amino acids in pulse grains fed to growing pigs

PSII-22 Effects of protease supplementation on ileal digestibility of amino acids in pulse grains fed to growing pigs

Pork cuts, hams, and sausages have digestible indispensable amino acid scores (DIAAS) close to or over 100

AbstractBackgroundThe “Digestible Indispensable Amino Acid Score” (DIAAS) method measures protein quality in human foods. Animal‐based products generally have high protein quality, but DIAAS values for some pork products are not available. Therefore, the objective of this experiment was to determine standardized ileal digestibility (SID) of amino acids (AA) and DIAAS values for pork products, including three types of pork cuts, Italian hams, and sausages, and to test the hypothesis that all pork products have DIAAS equal to or greater than 100.ResultsThe mean SID of the indispensable AA in all pork products was above 90% and indicated excellent digestibility. For children from 6 months to 3 years old and individuals older than 3 years, prosciutto had greater (p &lt; 0.05) DIAAS than all other pork products. Tenderloin and Coppa had greater (p &lt; 0.05) DIAAS than back ribs, shoulder butt, chorizo, and bratwurst. There were no limiting AA in any of the pork products (DIAAS &gt;100) with the exception that sulfur AA (SAA: methionine + cysteine) were limiting in chorizo for children from 6 months to 3 years old (DIAAS = 99).ConclusionWith the exception of chorizo for children less than 3 years old, all pork products have “excellent” protein quality for individuals older than 6 months of age, with DIAAS greater than 100. Pork proteins can, therefore, complement proteins with low quality to produce a meal that is adequate in all AA.

Apparent metabolizable energy concentration and ileal amino acid digestibility in cereal grains fed to broiler chickens.

This study aimed to determine apparent metabolizable energy concentrations and ileal amino acid (AA) digestibility in cereal grains and to compare those metabolizable energy values between the total collection and index methods for 21-day-old broilers. On day 17 post-hatch, a total of 336 Ross 308 male broilers were assigned to 6 dietary treatments with 8 replicate cages (7 birds/cage). Five experimental diets were formulated to incorporate non-extruded corn, extruded corn, wheat, wheat flour, and barley as the sole source of AA and energy. Retention of dry matter and nitrogen, and energy concentrations in cereal grains determined by the total collection method were greater (p<0.05) than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater (p<0.05) than those of wheat, wheat flour, and barley. Wheat flour exhibited greater (p<0.05) ileal AA digestibility than non-extruded and extruded corn. Extruded corn and wheat showed comparable ileal AA digestibility values, whereas barley had the lowest among cereal grains. Energy concentrations of cereal grains determined by the total collection method were greater than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater compared to wheat, wheat flour, and barley, irrespective of the method used. The ileal AA digestibility in wheat flour was the greatest, followed by non-extruded corn, extruded corn, wheat, and barley in broilers.