Apparent Amino Acid Digestibility Research Articles

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

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

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

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

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

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

Corn fermented protein, an alternative protein to soybean meal to support growth in young turkey poults

Abstract A new distiller’s high protein product (corn fermented protein – CFP) from the dry grind bioethanol process was evaluated as an alternative to soybean meal (SBM) protein in starter and grower diets for turkey poults. One-day- old male BUT6 poults (250) were distributed randomly into 50 pens. Each pen was allocated to one of the following treatments (10 pens each), control (high protein with soybean meal as primary protein source), CFP4% (4% CFP in replacement of SBM); CFP8% (8% CFP in replacement of SBM); HF-CFP4% (4% CFP with lower protein, higher fibre SBM, as primary protein source) and Premium (5% soy protein isolate (SPI) in place of high protein SBM). All diets were isonitrogenous and isoenergetic. Growth performance was measured weekly. At day 42, three poults per pen were sampled to obtain the ileal digesta. Apparent amino acid digestibility (AAAD), nitrogen retention (ANR) and apparent metabolisable energy corrected for nitrogen (AMEn) were measured. At day 42 poult weight and day 0–d42 weight gain for birds fed CFP8% were significantly better than the control. From day 0–42 feed intake nor feed conversion ratio were affected by dietary treatment (P > 0.05). Poults receiving CFP 8% had higher AMEn and ANR compared to the control (P < 0.05). The CFP8%-fed poults had significantly higher valine, isoleucine and proline digestibility compared to the control. Feeding the CFP8% diet significantly lowered growth carbon footprint (P < 0.05). In conclusion, CFP8% can increase ANR and growth performance of turkeys. This would decrease the dependency on SBM, reducing both economic and the environmental cost of turkey production.

Endogenous Enzyme Activities, Digestibility of Nutrients and Digestive Physiology as Affected by High Inclusion of Cottonseed Meal in Broiler Chicken Diets

A 3 × 3 factorial study examined the performance, endogenous enzyme activities and apparent ileal digestibility of nutrients, including energy, protein, starch, dry matter, amino acids and minerals of birds fed diets containing graded levels of cottonseed meal (CSM) with or without microbial enzymes. Nine iso-caloric and iso-nitrogenous diets were formulated mainly from wheat/sorghum/soybean meal. Three levels of CSM none (0%), low (5%, 10%, and 15%) or high (6%, 12%, and 18%) in the starter, grower, and finisher diets, respectively, were included. The diets were supplemented with three levels of a composite xylanase and beta-glucanase product at 0, 100 or 150 mg/kg diet. Each of the nine dietary treatments was randomly assigned to 6 replicates, with 10 birds per replicate. Feed intake (FI) and weight gain (WG) were recorded on day 10, 24 and 35, and feed conversion ratio (FCR) was obtained from the data, while enzyme activities and nutrient digestibility were measured on samples collected on day 10 and 24, and day 24 only, respectively. Feed intake up to day 35 decreased (P < 0.05) significantly with increasing enzyme supplementation. On the CSM-containing diets, enzyme supplementation at 100 or 150 mg/kg improved WG up to day 24, with the heaviest birds (1514 g/b) observed in the low CSM with 100 mg/kg enzyme group. Enzyme supplementation improved (P < 0.01) FCR all through the growth phases and also improved (P < 0.05) ileal crude protein and starch digestibility. High levels of CSM decreased the digestibility of starch, but this was improved (P < 0.05) by enzyme supplementation, showing an interaction between CSM and microbial enzyme on starch digestibility. The digestibility of arginine, glutamic acid and threonine improved with increased CSM inclusion, and that of methionine improved with increased enzyme supplementation. There was an interaction effect (P < 0.01) between CSM and enzyme on magnesium digestibility. Cottonseed meal inclusion improved the digestibility of copper and potassium and reduced the digestibility of phosphorus, while that of calcium and manganese was increased (P < 0.01) with enzyme supplementation. At day 10, lipase activity was increased (P < 0.05) by higher CSM levels, while on day 24, general proteolytic activity was highest (P < 0.05) when 100 mg enzyme was supplemented in the diet. These results indicate that relatively high levels of CSM in diet have no negative effects on the growth and digestive physiology of broiler chickens when supplemented with xylanase and β–glucanase.

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.

Effect of extrusion on energy and nutrient digestibility of lentil-based diets containing either supplemental plant or animal protein fed to growing pigs.

Non-food grade and excess lentil grain production may be included in swine feeds to provide starch and protein and reduce feed cost. Extrusion processing may increase energy and nutrient digestibility of lentil-based diets containing either supplemental plant or animal protein sources. Therefore, the apparent ileal digestibility (AID) of crude protein (CP) and amino acids (AA), apparent total tract digestibility (ATTD) of gross energy (GE), and digestible energy (DE) value of lentil-based diets were assessed in growing pigs. Two diets were formulated to provide 2.4 Mcal net energy (NE)/kg and 4.35g standardized ileal digestible lysine/Mcal NE: (1) soybean meal (SBM) diet, containing 50% lentil, 31% wheat, and 12.8% SBM; and (2) fish meal (FM) diet, containing 40% lentil, 45% wheat, and 10% FM. Following mixing, each diet batch was divided into two parts: one part remained as mash, whereas the other part was extruded using a single-screw extruder (400rpm, 250kg/h). Eight ileal-cannulated barrows (32.3 ± 1.5kg) were fed the four diets at 2.8 times maintenance DE requirement (110 kcal per kg of body weight0.75) for four 9-d periods in a double 4 × 4 Latin square to achieve 8 observations per diet. Data were analyzed as a 2 × 2 factorial arrangement including protein source, post-mixing processing, and their interaction as fixed effects. The lentil sample contained 32.3% starch, 24.4% CP, 9.3% total dietary fiber, and 1.7mg/g of trypsin inhibitor activity on as is-basis. Interactions between dietary protein source and post-mixing processing were not observed. Feeding FM diets resulted in greater (P < 0.05) AID of dry matter (DM), GE, and most AA, and ATTD of CP, but lower apparent hindgut fermentation of DM and GE than SBM diets. Extrusion increased (P < 0.05) the ATTD of GE and DE value of diets. The AID of CP and AA was 3.2 and 4.7%-units greater (P < 0.05), respectively, for the extruded than mash diets. In conclusion, feeding FM diets resulted in greater ileal digestibility of DM, GE, and AA than SBM diets. Extrusion increased the AID of CP and most AA, and DE value of lentil-based diets containing either supplemental plant protein or animal-protein, indicating that extrusion can increase the energy and protein value of plant-based diets fed to pigs.

Effects of Protease in Soybean Meal-Reduced Diets on Growth Performance, Nutrient Digestibility, and Intestinal Health of Weaned Piglets.

This experiment was conducted in weaned piglets to determine the effects of exogenous protease to low soybean meal (SBM) diets on growth performance, diarrhea rate, nutrient digestibility, and intestinal morphology. Seventy-two Duroc × Landrace × Yorkshire weaned barrows (21-day-old, 5.88 ± 0.95 kg) were randomly divided into four treatments with six replicates in each following a 2 × 2 factorial arrangement of SBM levels (0 to 14 d, 9%, 7.5%; 15 to 42 d, 20%, 18.5%) and protease (0 or 150 mg/kg) for a 42-day trial. Fecal samples were collected on days 11 to 14 and 38 to 42 of the experiment, and serum, intestinal tissue, and chyme samples were taken at the end of the experiments. Adding protease in low SBM diets had a significant increase in ADG (p < 0.05) and a decrease in F/G (p < 0.05). Protease significantly reduced the diarrhea rate (p < 0.05). Low SBM level decreased the apparent total tract digestibility (ATTD) of crude protein (CP) and ash (p < 0.05) but increased the ATTD of dry matter (DM), ash, organic matter (OM), and CP after the addition of protease (p < 0.05). The apparent ileal digestibility (AID) of aspartic acid (Asp), threonine (Thr), serine (Ser), alanine (Ala), lysine (Lys), and total amino acids (AAs) were significantly increased by protease supplementation (p < 0.05). Both the SBM-reduced and protease-added diets lead to lower albumin (ALB), albumin/globulin (A/G), and urea nitrogen (UREA) (p < 0.05), but greater globulin (GLOB) with low SBM diets (p < 0.05). The SBM-reduced and protease-added diets decreased the duodenum pH, respectively (p < 0.05). The protease increased the villus:crypt (V:C) in the duodenum and ileum, and ileal villus length (p < 0.05). In conclusion, the dietary supplementation of 150 mg/kg protease improved the intestinal health and performance of the weaned piglets and reversed the negative effect of a 1.5% SBM reduction in nutrient utilization, intestinal pH, and intestinal morphological parameters of weaned piglets.

306 Nutrient Digestibility and Dietary Energy Values in Growing Pigs Fed a Corn Distillers Dried Grains with Soluble (Cddgs)-Based Diet with Multi-Enzyme Supplementation

Abstract Dietary enzyme supplementation may enhance the digestibility and utilization of non-starch components of the diet by pigs. This study was conducted to evaluate the efficacy of a multi-carbohydrase enzyme (ENZ) in growing pigs for apparent ileal digestibility (AID) of amino acids (AA), apparent total tract digestibility (ATTD) of nutrients and energy values in a corn distillers dried grains with solubles (cDDGS)-based diet. A total of 12 ileal-cannulated pigs [initial body weight (BW) = 31.7 kg ± 3.04] were housed in individual metabolic crates for 21 days (Period 1) and subsequently transferred to individual floor pens for additional 28 days (Period 2). These animals were assigned to 2 diets (n = 6) in a completely randomized design (CRD). The diets were formulated on corn, soybean meal and cDDGS (30%) without (CON) or with ENZ supplementation. The ENZ (Proprietary xylanase/cellulase product, Kerry Inc.) was included in the diets at 200 g/tonne. Feeds were formulated to 1.15% SID lysine and met or exceeded nutrient requirements for growing pigs (NRC, 2012). Pigs were fed diets at three times maintenance energy requirement based on BW, which was assessed at every 2 weeks intervals throughout the study, Titanium dioxide was added to the diets as an indigestible marker. In period 1, pigs had 14 d of adaptation, followed by 4 d fecal and urine using the total collection method and 2 d ileal digesta collection. In period 2, pigs had 23 days adaptation, followed by 2 d fecal collection and 2 d illeal digesta collection. The AID of AA and gross energy (GE) and ATTD of nutrients and GE were calculated by an index method. Data were analyzed as a CRD, using pig as the experimental unit and enzyme supplementation as the main effect. Overall, average daily gain and gain:feed ratio of pigs were 857 and 918 g/d and 0.52 and 0.54 for CON and ENZ, respectively (P &amp;gt; 0.05). In period 1, ENZ supplementation improved (P &amp;lt; 0.05) the ATTD of dry matter (DM), ash, organic matter (OM), neutral detergent fiber (NDF), and GE by 4.4%, 26.8%, 2.8%, 11.3%, and 3.6%, respectively. Also, ENZ tended to improve (P &amp;lt; 0.10) the ATTD of crude protein (CP) by 7.4% and AID of threonine, CP, and GE by 6.6%, 7.6%, and 13.7%, respectively. In period 2, ENZ improved (P &amp;lt; 0.05) the ATTD of DM, ash, OM, CP, NDF, and GE by 5%, 30.1%, 3.4%, 4.1%, 19.6%, and 4.2%, respectively. similarly, EMZ improved (P &amp;lt; 0.05) the AID of threonine, CP, and GE by 4.2%, 6.0%, and 6.4%, respectively. In conclusion, multi-carbohydrase supplementation in a corn-SBM diet with 30% cDDGS increased the digestibility of nutrients and energy in growing pigs and may represent a useful strategy to optimize the utilization of such raw material.

PSIII-12 A Preliminary Evaluation on Novel Tryptophan Additive on Apparent Total Tract and Ileal Digesta of Nutrients in Growing Pigs Using Cannulation Technique

Abstract Amino acids (AA) are the primary structure of proteins. Earlier studies proved that AA contents in the diet are closely related to efficiency of nutrient utilization in pigs. Therefore, we aimed to analyze the effect of tryptophan [(Trp), Trp-proline and calcium-Trp)] supplementation on the apparent total tract digestibility (ATTD) and apparent ileal digestibility (AID) of dry matter (DM), nitrogen (N), energy (GE), and amino acids (AAs) in eight growing pigs [(Landrace × Yorkshire) × Duroc)]. Pigs with average body weights of 25 kg were surgically inserted with post-valve T-caecum cannulation approximately 15 cm anterior to the ileo-cecal junction and randomly assigned to the following diets: CON (corn- soybean meal-distillers dried grain soluble -based basal diet), Trp Pro (CON + 20g/kg Trp Pro), Ca-Trp (CON+ 20g/kg Calcium Trp), and N-free diet using a 4× 4 Latin squares design in duplicates. The novel Trp supplements did not exhibit any significant difference in ATTD and AID of DM, GE, and N digestibility. However, the ATTD of essential AAs such as valine, isoleucine, phenylalanine, lysine, and tryptophan and some non-essential AA like serine, glutamic acid, and glycine was increased (P &amp;lt; 0.05) in novel Trp group. The inclusion of the novel Trp to the diet reduced (P &amp;gt; 0.05) ATTD of threonine but increased the AID of threonine. While other AAs showed the least response to the Trp supplementation. Also, ATTD of methionine tended to be greater in Trp group compared with the CON. In short, the inclusion of 20 g/kg modified form of novel Trp supplementations showed beneficial effects to enhance the AA deposits in the tissue of pigs without any adverse effect.

Nitrogen-corrected apparent metabolizable energy and apparent ileal digestibility of amino acids of thermally processed food waste for broilers

Nitrogen-corrected apparent metabolizable energy and apparent ileal digestibility of amino acids of thermally processed food waste for broilers

Differences in small intestinal apparent amino acid digestibility of raw bovine, caprine, and ovine milk are explained by gastric amino acid retention in piglets as an infant model.

The rate of stomach emptying of milk from different ruminant species differs, suggesting that the small intestinal digestibility of nutrients could also differ across these milk types. To determine the small intestinal amino acid (AA) digestibility of raw bovine, caprine, and ovine milk in the piglet as an animal model for the infant. Seven-day-old piglets (n = 12) consumed either bovine, caprine, or ovine milk diets for 15 days (n = 4 piglets/milk). On day 15, fasted piglets received a single meal of fresh raw milk normalized for protein content and containing the indigestible marker titanium dioxide. Entire gastrointestinal tract contents were collected at 210 min postprandially. Apparent AA digestibility (disappearance) in different regions of the small intestine was determined. On average, 35% of the dietary AAs were apparently taken up in the small intestine during the first 210 min post-feeding, with 67% of the AA digestibility occurring in the first quarter (p ≤ 0.05) and 33% in the subsequent two quarters. Overall, except for isoleucine, valine, phenylalanine, and tyrosine, the small intestinal apparent digestibility of all AAs at 210 min postprandially in piglets fed ovine milk was, on average, 29% higher (p ≤ 0.05) than for those fed bovine milk. Except for lysine, there was no difference in the apparent digestibility (p > 0.05) of any AAs between piglets fed caprine milk or ovine milk. The apparent digestibility of alanine was higher (p ≤ 0.05) in piglets fed caprine milk than those fed bovine milk. When apparent digestibility was corrected for gastric AA retention, only small differences in the small intestinal apparent digestibility of AAs were observed across milk types. Bovine, caprine and ovine milk had different apparent small intestinal AA digestibility at 210 min postprandially. When corrected for gastric AA retention, the differences in apparent digestibility across species largely disappeared. The apparent AA digestibility differed across small intestinal locations.

Efficacy of oat hulls varying in particle size in mitigating performance deterioration in broilers fed low-density crude protein diets

Dietary fibres with increased particle size may develop foregut more efficiently in meat poultry fed diets moderately low in crude protein. The study investigated the performance of broilers fed low-density crude protein diets with the inclusion of oat hulls increasing in particle size. Ross 308 male broiler chicks (n=336) were divided into 48 pens, 12 pens per treatment (7 chicks per pen). Pens were allocated to 4 dietary treatments in mash form; positive control (PC), a standard crude protein diet, negative control (NC), around 5% lower in protein with 5% celite as an inert material, OH400: 5% lower protein diet with 5% oat hulls of geometric mean diameter (GMD) 400 µm, OH850: 5% lower protein diet with 5% oat hulls of GMD 850µm. Birds were fed ad libitum from d 1 to 35 in 3 phases; starter: d 0 to 10, grower: d 10 to 24 and finisher: d 24 to 35. Growth performance was calculated at the end of the trial. Two birds per pen were sampled on d 24 and 35 to collect data on proventriculus and gizzard weights and pooled ileal digesta. Apparent ileal digestibility of amino acids on d 24, and metabolizable energy on d 24 and 35 were recorded for each pen. Litter was sampled from each pen on d 34 to analyze litter N and moisture content. Footpad dermatitis scores of all birds per pen were recorded on d 35. Overall, no difference (P > 0.05) in body weight gain and feed intake was found between the treatments. However, NC and OH400 showed poorer FCR than PC, whereas FCR on PC and OH850 was similar (P > 0.05). Gizzard absolute weight and relative to body weight, and gizzard to proventriculus ratio were higher (P < 0.05) on OH850 compared to PC and NC on d 24 and 35. Gizzard digesta particle size was reduced (P < 0.05) on OH850 compared to all other diets on d 24 and 35. Amino acids digestibility coefficients for aspartic acid and valine increased (P < 0.05) in birds fed OH850 compared to PC, whereas coefficients for several other amino acids were improved compared to NC and OH400. The apparent ileal digestibility of metabolizable energy was similar (P > 0.05) between PC and OH850. Litter moisture and nitrogen, and footpad dermatitis scores were reduced (P < 0.05) on OH850 compared to PC. In conclusion, the inclusion of coarse oat hulls of GMD 850 µm in low-density crude protein diets can be beneficial for the broilers in developing the foregut, utilizing the nutrients efficiently and reducing litter nitrogen and moisture, and footpad scores.

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.

The effects of replacing fish meal or soy protein concentrate with wheat gluten on growth, whole-body composition, and the retention and apparent digestibility coefficient of amino acids in Japanese seabass (Lateolabrax japonicus).

The aim of this study was to evaluate the effects of replacing fish meal (FM) or soy protein concentrate (SPC) with wheat gluten on growth performance, feed utilization, and nutrient digestibility and retention in Japanese seabass (Lateolabrax japonicus). Seven isonitrogenous (441-456gkg-1 crude protein) and isocaloric (21.5-22.0MJkg-1 gross energy) diets were produced to replace 0%, 33.3%, 66.7% and 100% of FM or SPC with a mixture of wheat gluten, wheat, and taurine (GWT, 77.5% wheat gluten, 20.5% wheat and 2.0% taurine). The gradual replacement of protein in FM with GWT had no significant effects on feed intake, whole-body composition, and the hepatosomatic and viscerosomatic indices, but resulted in a linear decrease in the weight gain rate, feed efficiency, and retention of nitrogen, energy, and essential amino acids (Arg, His, Ile, Leu, Lys, Met, Phe, Thr, and Val). The apparent digestibility of most essential amino acids (Cys, His, Leu, Lys, and Phe) and total amino acids increased linearly. Replacement protein in SPC with GWT had no significant effects on feed intake, growth, the feed conversion ratio, whole-body composition, and the hepatosomatic index, but resulted in a linear decrease in nitrogen, energy, and Met retention; the digestibility of Cys and Met increased linearly. Overall, wheat gluten is a more effective alternative for replacing protein in SPC than FM.

Apparent amino acid digestibility of feed ingredients for juvenile shrimp (Litopenaeus vannamei): a new method of determination using soybean meal as an example

Apparent amino acid digestibility of feed ingredients for juvenile shrimp (Litopenaeus vannamei): a new method of determination using soybean meal as an example

Effects of Different Proteases on Protein Digestion In Vitro and In Vivo and Growth Performance of Broilers Fed Corn-Soybean Meal Diets.

This study was conducted to investigate the effects of different proteases alone or in combination on protein digestibility of broilers. In vitro, the properties of four proteases in broilers, including acidic protease (AcP), alkaline protease (AlP), neutral protease (NeP) and keratinase (Ker), on endogenous protease activity and their effects on protein digestibility of common ingredients in broiler diets were investigated using a gut-mimicking model. In vivo, 640 1-day-old male broilers were randomly divided into 8 groups of 10 with 8 replicates of 10 birds per replicate cage. Eight dietary treatments included a corn-soybean meal basal diet (control), and the basal diet with 1.6 U AcP/g, 0.8 U NeP/g, 0.8 U AlP/g, 0.4 U Ker/g, 1.6 U AcP/g + 0.8 U NeP/g, 1.6 U AcP/g + 0.8 U AlP/g, or 1.6 U AcP/g + 0.4 U Ker/g added. The experiment lasted for 31 days. The results showed that the optimum pH values of AcP, NeP, AlP and Ker were 3.0, 9.0, 11.0 and 11.0 in vitro, respectively. Ker recovery proportion was 37.68% at pH 3.3-6.2. AcP alone or in combination with NeP, AlP or Ker increased in vitro crude protein digestibility (IVCPD) and decreased ileal apparent digestibility of crude protein in 31-day-old broilers (p < 0.05). All protease supplementation reduced the ileal apparent digestibility of amino acids compared to the control (p < 0.05). Acidic protease had a positive effect on trypsin and chymotrypsin activities, while AlP and Ker showed a negative effect. In vivo, average daily gain and average daily feed intake were significantly (p < 0.05) increased in broiler diets supplemented with AcP compared to the control group. When adding exogenous proteases to broiler diets, their sensitivity to digestive pH and their negative effects on endogenous protease activity, dosage and combination effects should be taken into account. In addition, the properties and dosage of proteases and the protein level in the feed should be considered.

Effects of Dietary Crude Protein and Protease Levels on Performance, Immunity Capacity, and AA Digestibility of Broilers

Exogenous proteases are promising to stimulate the application of low-protein diets for broilers. A total of 540 1-day-old Arbor Acres male broilers were randomly assigned to 9 groups with 6 replicates of 10 birds. A 3 × 3 factorial, completely randomized arrangement was used to evaluate the effects of dietary crude protein (CP) and protease levels on growth and slaughter performance, immunity capacity, and apparent ileal digestibility (AID) of amino acids (AA). Dietary CP levels were 20.0%, 19.5%, or 19.0% during the starter phase, and 18.0%, 17.5%, or 17.0% during the finisher phase. Protease levels were 0, 250, or 500 mg/kg in diets throughout the trial. The trial lasted for 42 days. Weight gain and feed efficiency of broilers decreased as dietary CP lowered, but improved with protease supplementation. Dietary CP and protease levels had few effects and interactions on carcass characteristics, immune organ indexes, and immunoglobulin concentrations. The AID of most AA was improved by dietary CP decrease or protease supplementation. In conclusion, reducing dietary CP decreased the performance and immune capacity of broilers but increased the AID of AA. Almost independent of dietary CP level, dietary protease addition improved the performance of broilers, probably through the enhancement of AA digestibility, and had no effect on carcass traits.

Effects of isoquinoline alkaloids on apparent ileal digestibility of amino acids, crude protein, starch, and acid hydrolyzed ether extract and apparent total tract digestibility of energy and crude protein by growing and finishing pigs fed corn-soybean meal diets

Two experiments were conducted to test the hypotheses that a preparation of isoquinoline alkaloids (IQ) obtained from Macleaya cordata included in corn-soybean meal (SBM) diets increases apparent ileal digestibility (AID) of nutrients, increases apparent total tract digestibility (ATTD) of gross energy (GE) and crude protein (CP) and increases plasma amino acids (AA) and protein when fed to growing or finishing pigs. Experiment 1 utilized 12 barrows (body weight: 27.1 ± 2.10 kg) equipped with a T-cannula in the distal ileum, which were allotted to 4 treatments and 4 periods for 12 replicates per treatment. Treatments included a corn-SBM basal diet and three diets formulated by adding 40, 80, or 160 mg/kg of IQ to the basal diet. In experiment 2, twelve T-cannulated barrows (BW: 77.2 ± 6.23 kg) were allotted to the same treatments as in experiment 1, but diets were fed for 3 periods for a total of 9 replicate pigs per treatment. Each period had a 10-day adaptation period, followed by fecal sample collection on day 11 and 12, and ileal digesta collection on day 13 and 14. Results indicated that AID of some AA increased when IQ was included at 40 or 160 mg/kg in experiment 1, but a reduction (P < 0.05) in the AID of acid-hydrolyzed ether extract (AEE) and starch was observed at 80 mg/kg IQ. Including 80 mg/kg IQ to diets in experiment 2 increased the AID of CP, whereas 40 mg/kg IQ resulted in an increased (P < 0.05) AID of His, Met, and Pro, and a tendency (P < 0.10) for an increase in AID of Ile, Leu, Lys, Cys, Gly, and Tyr. The ATTD of CP was also increased (P < 0.05) if the diet containing 80 mg/kg IQ was fed in experiment 2. Albumin was reduced (P < 0.05) in plasma of finishing pigs fed 40 mg/kg IQ in experiment 2. Including 80 mg/kg IQ in a diet for growing pigs increased (P < 0.05) plasma Lys, and adding 80 or 160 mg/kg increased (P < 0.05) plasma Asp, but a reduction (P < 0.05) in some plasma AA as 160 mg/kg IQ was added to diets for finishing pigs was observed. In conclusion, IQ may be added to diets for growing and finishing pigs to increase the AID of AA and CP, with optimal results observed at inclusion levels of between 40 and 80 mg/kg IQ.

Dietary muramidase increases ileal amino acid digestibility of wheat and corn-based broiler diets without affecting endogenous amino acid losses

The objective of these studies was to evaluate the impact of dietary muramidase (MUR) on endogenous amino acids (AA) losses and digestibility of nutrients in wheat and corn-based broiler diets. In experiment 1, the effect of dietary MUR on the flow of endogenous AA (EAA) at the jejunum and terminal ileum of broilers were assessed using either the nitrogen (N) free diet method (NFD) or the highly digestible protein diet method (HDP; 100 g casein/kg diet). Sialic acid and muramic acid concentrations were measured in the jejunal content. In experiment 2, a 2x2x2 factorial arrangement of treatments with 2 base grains (wheat or corn), with low or high metabolizable energy (ME) levels, and without or with MUR supplementation was implemented. All diets contained phytase, xylanase, and cellulase. Apparent ileal digestibility (AID) of dry matter (DM), protein (CP), amino acids (AA), crude fat, and energy, as well as the apparent total tract metabolizability (ATTM) of DM, CP, and gross energy (GE) were determined. The standardized ileal digestibility (SID) of AA was obtained by correcting AID values for basal ileal EAA obtained from chicks fed with NFD or HDP in experiment 1, jejunal EAA flow of all AA was higher (P < 0.001) compared to the ileum, but this effect was method dependent. Jejunal, but not ileal, EAA flow measured with HDP was higher compared to NFD, as well as sialic acid (P < 0.001) and muramic acid (P < 0.004) concentrations. Muramidase inclusion had no effect on basal EAA flow, independently of the segment and the method used. In experiment 2, dietary MUR supplementation increased the AID of CP (P < 0.05), all AA, and tended (P=0.07) to increase the AID of GE, independently of the cereal type used. However, ATTM of DM and GE, but not CP, increased with MUR inclusion compared with the control treatments, especially in wheat and low ME diets (P < 0.05). In conclusion, MUR supplementation improved AID of CP and AA without affecting EAA losses and increases energy utilization.