Amino Acid Digestibility Research Articles

Evaluation of protease plus a precision-biotic on body weight gain and feed conversion ratio in broilers from 0 to 42 days of age

This study aims to evaluate the effects of a protease combination with a precision biotic on body weight gain (BWG) and feed conversion ratio (FCR) of broilers from day 0 to 42. 1,400 Cobb 500 male chicks were reared on seven different diets, including an unrestricted positive control (PC–Diet 1) and a negative control (NC–Diet 2) with slightly reduced crude protein, apparent metabolizable energy (AME), and digestible amino acids. Five additional treatment diets were formulated using the negative control and varying concentrations of a protease (Diets 3-4; 33ppm and 50ppm, respectively) and in combination with a precision biotic (Diets 5-7; 33ppm + 700ppm; 50ppm + 500ppm; and 50ppm + 700ppm, respectively). The PC treatment showed significantly different feed intake and FCR compared to all other treatments in all production phases (P < 0.05). There are no significant differences in non-PC treatments in all production phases for BWG and FCR (starter p=0.230 and 0.300; grower p=0.443 and 0.237; finisher p=0.450 and 0.896; overall p=0.111 and 0.497, respectively), nor is there any in terms of mortality (p=0.800). These findings may provide valuable information to producers to optimize flock performance efficiently and cost-effectively.

Standardized Ileal Digestibility of Amino Acids in Hybrid Rye Ground to Two Particle Sizes and Fed With or Without Multienzyme Supplement to Young Growing Pigs.

A newly developed hybrid rye with enhanced ergot resistance has potential as an alternative energy source for pigs. An experiment was conducted to evaluate the effects of particle size (PS) and multienzyme supplement (MES) on the apparent total tract digestibility (ATTD) of energy and nutrients and the standardized ileal digestibility (SID) of amino acids (AA) in hybrid rye fed to growing pigs. Bono and Gatano, two hybrid rye varieties, were ground to either a coarse (1111 and 1210 μm) or a fine (594 and 717 μm) PS using a hammer mill. Eighteen ileal-cannulated barrows (initial BW = 18.2 ± 1.0 kg) were randomly assigned to 1 of 9 dietary treatments in a replicated 9 × 3 incomplete Latin square design to give six observations per treatment. Among the nine experimental diets, eight featured two hybrid rye varieties (Bono or Gatano), either coarsely or finely ground, as the only source of AA with or without MES, while an N-free diet was used to estimate the endogenous losses of AA at the distal ileum. All diets contained titanium dioxide as an indigestible marker. Each period lasted 9 days, with the first 5 days being for adaptation followed by 2 days each for faecal and ileal digesta collection. Data were analysed using the MIXED procedure of SAS, with the final model having variety, PS, MES, their two-way interactions, and a three-way interaction. No interactions were noted except that the apparent ileal digestibility and SID of crude protein (CP) and most AA in Gatano had greater effects of MES than Bono (Variety × MES; p < 0.05). The ATTD of dry matter (DM), gross energy (GE) and CP were greater (p < 0.05) in Bono diets than in Gatano diets. Finely ground hybrid rye diets had higher (p < 0.05) ATTD of neutral detergent fibre assayed with a heat stable amylase and expressed inclusive of residual ash (NDF) and ether extract compared to coarsely ground hybrid rye diets. Dietary MES supplementation increased (p < 0.05) the ATTD of DM, GE, CP, NDF, acid detergent fibre expressed inclusive of residual ash, and ash in hybrid rye diets. In conclusion, the nutrients digestibility of hybrid rye can be affected by its variety. PS reduction improved the nutrient digestibility in hybrid rye, and MES supplementation improved the energy and AA digestibility in hybrid rye fed to growing pigs.

Effect of temperature on the digestibility of non-starch polysaccharide-rich ingredients in Nile tilapia (Oreochromis niloticus)

This study aimed to investigate the interaction effect of NSP-rich ingredient and rearing temperature on nutrient digestibility of the ingredients in Nile tilapia. Seven NSP-rich ingredients were tested: insect meal, wheat bran, palm kernel meal, rapeseed meal, sunflower meal, dried distillers grains with solubles (DDGS) from corn, and rice bran. A balanced control diet was formulated followed by the formulation of seven test diets by mixing 30 % of each test ingredient with 70 % of the control diet and fed to fish reared at 24 or 32 °C. At each temperature, 35 all male Nile tilapia with an initial mean weight of 45.0 g at 24 °C and 43.8 g at 32 °C were housed in each of 24 glass-tanks, each containing 60 L of water. The diets were administered to the fish groups in triplicate over 42 d in a recirculating aquaculture system. Fecal samples were collected and analyzed alongside the diets to determine nutrient digestibility. Digestibility of all nutrients differed between ingredients (P < 0.001) at both temperatures. Wheat bran had the lowest NSP digestibility at both 24 (1.9 %) and 32 °C (9.7 %). At 24 °C, DDGS showed the highest NSP and protein digestibility (41.4 and 90.3 %), while at 32 °C insect meal showed the highest NSP and fat digestibility (59.8 and 97.5 %). Insect meal showed the highest fat digestibility (97.4 %) also at 24 °C. An interaction effect between ingredient and temperature was observed for the digestibility of NSP, carbohydrate, protein, amino acids, magnesium, and dry matter (P ≤ 0.035). Some nutrients showed reduced digestibility for some ingredients at the higher temperature, but in most of the cases temperature increased nutrient digestibility, with insect meal exhibiting a 20 % increase in NSP digestibility. In conclusion, water temperature affect nutrient digestibility, but the extend of the temperature effect differs between ingredients.

Effects of feed particle size, calcium concentration and phytase supplementation on InsP6 degradation in broiler chickens fed pelleted diets

ABSTRACT 1. The objective of the trial was to study the single and interactive effects of feed particle size in pelleted feed, dietary calcium (Ca) concentration and microbial phytase supplementation in broiler chickens. The studied traits were myo-inositol (1,2,3,4,5,6) hexakis (dihydrogen phosphate) (InsP6) degradation, pre-caecal digestibility of phosphorus (P), Ca and amino acids (AA) and retention of P, Ca and nitrogen (N). 2. Male Ross 308 broiler chickens were housed in metabolism units in groups of 10 and allocated to one of eight diets with seven pen replicates per diet. The 2 × 2 × 2-factorial arrangement included coarse and fine feed particle size (309 or 222 µm), low and high Ca concentration (4.9 and 7.2 g/kg) and without or with phytase supplementation (1,000 FTU/kg). 3. Pre-caecal InsP6 disappearance was higher with coarse than fine feed particle size when no phytase was added (54 vs. 48%) but not when phytase was added (74%; p = 0.046). High dietary Ca feeds decreased pre-caecal InsP6 disappearance (67 to 59%) and P digestibility (65 to 55%; p < 0.001). Gizzard pH was lower with coarse than fine feed particle size and higher with high Ca than low Ca (p < 0.001). Pre-caecal digestibility of most AA was approximately 3.5%-points lower with high Ca without phytase compared to the other treatments (p ≤ 0.047). Coarse feed particle size caused higher pre-caecal AA digestibility than fine particle size (~2%-points; p ≤ 0.031). InsP6 disappearance in the crop increased at high Ca concentration when phytase was added (22 vs. 37%; p = 0.011). 4. Coarser feed particle size in pellets increased gastrointestinal InsP6 degradation and nutrient digestibility, likely owing to effects on the gizzard functions. Additional Ca supply exerted antinutritive effects that was not compensated for by using coarser feed particles.

Potential new methods to analyze basal and total endogenous protein losses of host and bacterial origin in pigs. Methods to analyze endogenous protein in pigs.

BackgroundCurrent systems for assessing protein quality such as the Digestible Indispensable Amino Acid Score (DIAAS) correct apparent amino acid digestibility for basal endogenous protein losses (bEPL), ignoring the potential influence of the diet on these losses. However, the quantification of total endogenous protein losses (tEPL) poses a challenge. ObjectiveTo evaluate different methods for quantifying tEPL and bEPL, and to assess their potential in discriminating between tEPL originating from bacteria and host. MethodsUsing an incomplete Youden square design, twelve ileal cannulated pigs received ten different protein sources, and a nitrogen-free (NF) diet. Ileal digesta were collected on days 6 and 7 of each 1-week feeding period, to quantify endogenous protein losses (EPL) and analyze apparent ileal digestibility. Ileal EPL were estimated based on 1) 16S-+18S gene copy qPCR, 2) diaminopimelic acid (DAPA)+18S, 3) differential AA profiles in digesta, EPL and bacteria, equaling tEPL, and 4) an NF diet and 5) whey protein isolate (WPI), equaling bEPL. ResultsIleal bEPL based on the NF and WPI method correlated moderately-highly (r=0.69, P<0.05), but the NF method probably underestimated bEPL. In pigs fed the WPI diet, EPL based on the WPI and AA profile method were highly correlated (r=0.88, P<0.01). Overall, tEPL based on the AA profile method were moderately correlated with the 16S+18S method (r=0.58, P<0.001), and DAPA+18S (r=0.57, P<0.001). Low correlations were observed between bacterial tEPL based on the AA profile method and 16S or DAPA. Host tEPL based on the AA profile method and 18S were weakly correlated (r=0.39, P<0.001). ConclusionsThe AA profile method seems the most appropriate method for tEPL quantification, while the WPI method is preferred for bEPL quantification. Despite challenges in distinguishing between bacterial and host EPL, it is evident that bacterial proteins substantially (on average 37-83%, depending on method) contribute to the EPL.

Assessment of two diet types in reduced-crude protein diets with or without phytase supplementation – implications on key phenotypic responses in 21-day-old broiler chickens

ABSTRACT 1. Two concurrent experiments were conducted to investigate the effect of using the crude protein (CP) value of supplemental amino acids (AA) in formulating reduced-crude protein (RCP) diets. The RCP diets formulated without accounting for CP values of supplemental AA (RCPN) or otherwise (RCPY) or a positive control (PC) diet were fed without (Experiment 1) or with (Experiment 2) phytase. 2. Each experiment utilised 105 male broiler chicks. Birds were provided a common starter diet from d 0–7. On d 21, ileal digesta were collected from the distal half of the ileum. For mRNA expression analysis, tissues were collected from the mid-jejunum and the liver. Excreta grab samples were collected for analysis for N content. 3. In Experiment 1, there was a stepwise decrease (p < 0.01) in weight gain and excreta N for birds receiving PC, RCPN and RCPY diets. The coefficients of ileal digestibility of His, Leu, Phe and Trp were greater (p < 0.05) in birds that received RCPY rather than the PC diets. The relative mRNA expression of CAT1 was greater (p < 0.05) for birds that received the PC diet. 4. In Experiment 2, growth performance and excreta N were not different between the PC and RCPN diets, but weight gain, feed intake and excreta N were greater (p < 0.01) in birds receiving PC or RCPN diets. The coefficients of digestibility were greater (p < 0.01) in RCP than PC diets for Lys, Thr, Cys, Gly and Ser. The mRNA expression for S6kinase and PRKAβ2 was greater (p < 0.05) for birds fed RCPN compared to PC. 5. In conclusion, accounting for the N content of supplemental AA during feed formulation for RCP diets will influence the effect of CP reduction on growth performance and ileal amino acid digestibility.

Energy Values and Standardized Ileal Digestibility of Amino Acids in Fermented Soybean Meal Fed to Growing Pigs.

This study aimed to evaluate the digestible energy (DE), metabolizable energy (ME), and standardized ileal digestibility (SID) of amino acids (AA) in fermented soybean meal (FSBM) fed to growing pigs. In experiment 1, twenty-two growing pigs (Duroc × Landrace × Yorkshire; 32.0 ± 4.2 kg BW) were fed one of 11 diets in a replicated 11 × 3 incomplete Latin square design to determine the DE and ME of FSBM. The diets included a corn-based diet and 10 experimental diets formulated by replacing the corn with 29.10% FSBM. In experiment 2, eleven growing pigs (Duroc × Landrace × Yorkshire; 24.3 ± 2.3 kg BW) were surgically equipped with a T-cannula and arranged in an 11 × 6 incomplete Latin square design with 11 diets and six periods. The diets included an N-free diet and 10 experimental diets containing 40% FSBM as the sole source of AA. The results showed that the contents of dry matter (DM), gross energy, crude protein, crude fiber, neutral detergent fiber, acid detergent fiber, calcium, and phosphorus averaged 91.83% (ranging from 89.24 to 94.55%), 18.44 MJ/kg (ranging from 18.00 to 18.95 MJ/kg), 50.63% (ranging from 50.00 to 51.81%), 4.51% (ranging from 3.41 to 5.40%), 9.17% (ranging from 7.02 to 10.30%), 6.38% (ranging from 4.97 to 7.45%), 0.32% (ranging from 0.29 to 0.34%), and 0.67% (ranging from 0.61 to 0.84%), respectively. The average DE and ME were 17.55 and 16.33 MJ/kg DM, respectively, with ranges of 15.72 to 18.80 MJ/kg DM and 14.30 to 17.72 MJ/kg DM, respectively. Significant differences were observed in the SID of essential AA (p < 0.05), except for Thr and Arg. The SID of Lys, Met, Trp, and Thr ranged from 68.13 to 83.27% (mean = 76.62%), 62.23 to 89.30% (mean = 75.25%), 72.30 to 90.29% (mean = 80.96%), and 74.17 to 84.41% (mean = 77.90%), respectively. These results indicate significant variability in chemical composition, energy content, and the SID of AA among the selected FSBM samples. The chemical composition of FSBM can be used to predict DE and ME values.

Dietary superdosing of phytase positively affects growth, mineral utilization and amino acid availability of channel catfish (Ictalurus punctatus)

The present study investigated the effects of supplementing high levels (superdosing) of dietary phytase on growth performance, mineral utilization and digestibility of amino acids in different regions of the gastrointestinal (GI) tract of fingerling channel catfish. The negative control (NC) diet was formulated with primarily soybean meal as a protein feedstuff which contributed 0.61 % total phosphorus (P) but was deficient in available P at 0.11 % of diet. Five other diets were formulated either with supplemental monocalcium phosphate at 1 % of diet in the positive control (PC), or supplemented with Quantum Blue phytase (AB Vista, Plantation, Florida) at 1000, 2000, 4000, or 8000 phytase units (FTU)/kg of diet. Groups of 20 catfish were each stocked into 24 aquaria operated as a closed, recirculating system with biological and mechanical filtration. All dietary treatments were assigned randomly to quadruplicate aquaria and initially fed at 6 % of total body weight per day. Feed quantities were adjusted weekly after weighing all fish in each aquarium as a group, and feeding levels were maintained close to apparent satiation throughout the 8-week feeding trial. Phytase supplementation significantly (P < 0.05) increased various responses of channel catfish including weight gain, feed efficiency, and protein retention compared to catfish fed the NC diet, resulting in values that were similar to catfish fed the PC diet. Moreover, catfish fed the phytase-supplemented diets had higher bone ash, calcium (Ca), magnesium (Mg), P, manganese (Mn), and zinc (Zn), as well as retention of Ca, Mg, P, iron (Fe), Mn, and Zn in whole-body tissues. Additionally, apparent availability of P from the posterior intestinal region increased with dietary phytase supplementation, with reduced excretion of nitrogen, Ca, Mg, P, copper (Cu), Mn, and Zn observed in comparison to fish fed the NC diet. Apparent digestibility coefficients for many of the indispensable and dispensable amino acids were increased by phytase supplementation, except for histidine, methionine, threonine, and taurine. This improvement in amino acid availability occurred only in the posterior region of the gastrointestinal tract. Channel catfish fed the diet containing 4000 FTU/kg diet had the highest postprandial plasma phosphorus level most of the time, except at 24 h after feeding. Based on these various responses, the optimal dietary phytase dosage was determined to average 5492 FTU/kg diet.

An Estimation of the Requirements of the Standardized Ileal Digestible Tryptophan, Valine, Isoleucine and Methionine on Young Pigs’ (Up to 50 kg) Feed Efficiency: A Meta-Regression Analysis

Currently, the NRC amino acid (AA) requirements for pigs published in 2012 are used as a reference in variable swine industries. However, recent results in several articles suggest that the standardized ileal digestible (SID) AA–lysine (Lys) ratio significantly evolved over the last two decades, while some publications report inconsistent outcomes. Therefore, the present study used a meta-regression analysis to assess the relative ratio to lysine to maximize the feed efficiency of four essential amino acids (tryptophan, valine, isoleucine, and methionine) in pig diets. According to the PRISMA guidelines, articles examining the target AA requirement using a basal diet supplemented with varying levels of crystalline AA (tryptophan, valine, isoleucine, or methionine) were identified across Scopus, PubMed, and Science Direct. As a result, 23, 22, 16, and 9 articles using tryptophan, valine, isoleucine, and methionine were selected and categorized into experiments for inclusion in our meta-analysis. The results suggested that the requirements of tryptophan, valine, isoleucine, and methionine in our meta-regression analysis were superior to NRC recommendations, regardless of the regression models and the growth phases with significant RSQ values (RSQ ≈ 1). Also, the QUAD and CLP regression models emphasized higher requirements than the LP model for the great majority of amino acids and growth phases. The results of the QUAD and CLP models were selected as estimations of the amino acid requirements for pigs under challenged conditions, whereas the LP model was chosen to estimate the amino acid requirements of genetically improved pigs under a modern housing system. The results of this meta-regression analysis could be used to refresh the information on the NRC amino acids (AA) requirements for swine.

The Impact of Thermal Treatments up to 140 °C on Amino Acid Digestibility of Fish Meal in Rainbow Trout (Oncorhynchus mykiss)

Fish meal (FM) is an essential ingredient in fish feeds, but the thermal treatments used during its production might affect its nutrient availability. Therefore, an in vivo digestibility trial was conducted with three different thermal treated FM, at no heat treatment (control), 70, and 140 °C. A total of 216 rainbow trout (230 ± 6.0 g) were randomly assigned to 12 tanks, and feces samples were collected by stripping. FM was produced by lyophilizing mackerel. The lyophilized FM (94% DM) was then divided into three groups: FM Control, which was not exposed to thermal treatments, and FM 70 °C and FM 140 °C, which were exposed for 1 h to the respective temperatures of its descriptions. A conventional FM-based (FM with 64% CP produced at 110 °C) control diet was used as a basal diet. In the experimental groups, 30% of the basal diet was replaced by one of the tested FMs. No differences in apparent total tract digestibility (ATTD) were observed between FM Control and 70 °C. Protein ATTD of FM 140 °C as well as Arg ATTD were lower compared to FM Control and 70 °C. The same effect was observed for His and Asp ATTD. The current study showed that thermal treatment affects FM macronutrient and amino acid ATTD.

Co-fermentation with multiple-strains and cellulase enhances the nutritional quality of hot-pressed rapeseed meal by modifying its physicochemical properties

The thermal damage of proteins and the presence of anti-nutritional factors seriously affect the quality of hot-pressed rapeseed meal (RSM), thereby limiting its utilization in the feed and food industry. Previously, we developed a co-fermentation method with multi-strains and cellulase that can simultaneously degrade the protein and anti-nutrient components in hot-pressed RSM. This study aimed to evaluate the impact of fermentation on the physicochemical properties and nutritional value of hot-pressed RSM. After fermentation, the levels of neutral detergent fiber (NDF) and glucosinolate (GLS) in hot pressed RSM decreased by 41.47% and 77.30%, respectively, and the trichloroacetic acid-soluble protein (TASP) and lysine contents increased by 1007.62% and 65.25%, respectively. During the fermentation process, the extensive hydrolysis of rapeseed protein resulted in a 49.11% yield of peptides < 3K Da, and intensified the umami, saltiness, sweetness, and bitterness of fermented rapeseed meal (FRSM). Animal experiments demonstrated that co-fermentation effectively enhances the ileal digestibility of most amino acids in hot-pressed RSM, as well as the deposition of nitrogen and energy, thereby improving the growth of growing pigs. Overall, the co-fermentation with microbes and cellulase is an effective strategy for enhancing the quality of hot-pressed RSM.

Interactive effects of dietary energy levels with amino acid density on growth performance and optimal digestible Lys to energy ratio of male broiler chickens

A total of 2,400 day-old off-sex male Ross 308 chicks were used in a 4 × 3 factorial array (8 replicates with 25 birds per replicate) to determine the interactive effects of dietary metabolizable energy (ME) and amino acid (AA) densities on productive traits of broiler chickens reared to 42 d of age. The experimental factors were 4 ME levels (control, -50, -100, -150 kcal) and 3 digestible AA levels (control, +3.0 and +6.0%). Diets were fed for starter (0-10 d), grower (11-24 d), finisher (25-35 d), and withdrawal (36-42 d) phases, with consistent reduction of ME and increase in AA density for each phase. Overall, ME reduction did not compromise final body weight (BW; d 42). However, when ME was reduced by 50 kcal, only the diets with +6% AA density improved BW, resulting in an interaction between ME and AA levels (P < 0.05). Reducing ME and increasing AA densities independently increased total feed intake (P < 0.01). An interaction between ME and AA density on feed conversion ratio (FCR) was observed where increasing AA density at both +3.0 and +6.0% levels at control ME reduced FCR, but with reduced ME diets, FCR was reduced only at +6% AA density (P < 0.01). Quadratic broken line models estimated a digestible Lys to ME ratio (mg Lys/1,000 kcal ME) of 474 and 407 in starter and grower diets, respectively, to optimize both BW and FCR. However, in finisher phase a ratio of 363 could only be predicted for optimal FCR and in withdrawal a ratio of 349 to optimize BW. In summary, these results indicate that the interaction between ME and AA densities affects the productive traits of broiler chickens. Increasing AA density at control ME density improves FCR, while reduced ME diets require higher AA density to improve FCR. Quadratic broken line models suggest specific digestible Lys to ME ratios for optimizing BW and FCR across different phases of the production cycle.

Determination and Prediction of Amino Acid Digestibility in Rapeseed Cake for Growing-Finishing Pigs.

The experiment was conducted to determine the apparent or standardized ileal digestibility (AID or SID) of crude protein (CP) and amino acids (AA) in 10 rapeseed cake samples fed to pigs, and to construct predictive models for the SID of CP and AA based on the chemical composition of rapeseed cakes. Twenty-two cannulated pigs (initial body weight: 39.8 ± 1.2 kg) were assigned to two 11 × 3 incomplete Latin square designs, including an N-free diet and 10 diets containing rapeseed cake. Each experimental period included 5 days of adaptation and 2 days of ileal digesta collection. Titanium dioxide (TiO2) was added at 0.3% to all the diets as an indigestible marker for calculating the ileal CP and AA digestibility. The coefficients of variation (CV) of the content of crude fat (EE), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), and total glucosinolates (TGS) in 10 samples of rapeseed cake were greater than 10%. The standardized ileal digestibility (SID) of crude protein (CP), lysine (Lys), methionine (Met), threonine (Thr), and tryptophan (Trp) in rapeseed cake was 73.34% (61.49 to 81.12%), 63.01% (41.41 to 73.10%), 69.47% (50.55 to 88.16%), 79.61% (74.41 to 87.58%), and 94.43% (91.34 to 97.20%), respectively. The best prediction equations for SIDCP, SIDLys, and SIDVal were as follows: SIDCP = 90.124 - 0.54NDF (R2 = 0.58), SIDLys = 100.107 - 1.229NDF (R2 = 0.94), and SIDVal = 151.012 - 2.990TGS (R2 = 0.57). Overall, great variation exists among the 10 rapeseed cakes, and the NDF, TGS, and heating temperature can be used as the key predictors for the SID of CP and AA.

Effect of increasing supplementation of dietary glycine on growth performance, meat quality, liver characteristics, and intestinal health in broiler chickens raised under heat stress conditions

The current study aimed to investigate the effect of increasing supplementation of dietary glycine (Gly) on growth performance, meat quality, liver characteristics, and intestinal health in broiler chickens raised under heat stress (HS) conditions. A total of one thousand six hundred 25-d-old broiler chickens were randomly allotted to 1 of 5 dietary treatments with 8 replicates. Each replicate comprised 20 male and 20 female birds. A negative control (NC) diet was prepared to meet or exceed energy and nutrient requirement estimates, whereas a positive control (PC) diet was formulated to contain increasing concentrations of AMEn by 50 kcal/kg as well as those of digestible amino acids, total Ca, and available P by 10% compared with the respective concentrations in the NC diet. Three additional diets were prepared by supplementing the NC diet with 0.4, 0.8, or 1.6% Gly. All chickens were raised under cyclic HS conditions at 29°C ± 0.89°C for 10 h/d and 23°C ± 1.45°C for the remaining time over an 18-d feeding trial. Results indicated that broiler chickens fed the NC diet had a greater (P < 0.05) FCR than those fed the PC diet under HS conditions. Increasing supplementation of up to 1.6% Gly in diets decreased (linear, P < 0.001) FCR in broiler chickens. Increasing supplementation of dietary Gly tended to increase (linear, P = 0.070) water holding capacity in the breast meat. Increasing supplementation of dietary Gly decreased (linear, P < 0.05) serum aspartate aminotransferase concentrations and tended to decrease blood heterophil:lymphocyte (linear, P = 0.083) and liver malondialdehyde concentrations (quadratic, P = 0.084). A tendency for increased villus height (linear, P = 0.086) and a significant increase in villus height:crypt depth ratio and goblet cell numbers (linear, P < 0.05) were identified following increasing Gly supplementation. In conclusion, increasing supplementation of dietary Gly improved feed efficiency, meat quality, liver health, and intestinal morphology possibly by mitigating oxidative stress and stress response in broiler chickens raised under HS conditions.

Influence of varying branched-chain amino acid ratio in diets containing corn gluten meal, L-isoleucine, and L-valine on 0–21 d turkey poult performance, relative mTOR activation, and apparent ileal amino acid digestibility

Influence of varying branched-chain amino acid ratio in diets containing corn gluten meal, L-isoleucine, and L-valine on 0–21 d turkey poult performance, relative mTOR activation, and apparent ileal amino acid digestibility

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.