Apparent Amino Acid Digestibility Research Articles

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.

The Contribution of Phytate-Degrading Enzymes to Chicken-Meat Production.

The contribution that exogenous phytases have made towards sustainable chicken-meat production over the past two decades has been unequivocally immense. Initially, their acceptance by the global industry was negligible, but today, exogenous phytases are routine additions to broiler diets, very often at elevated inclusion levels. The genesis of this remarkable development is based on the capacity of phytases to enhance phosphorus (P) utilization, thereby reducing P excretion. This was amplified by an expanding appreciation of the powerful anti-nutritive properties of the substrate, phytate (myo-inositol hexaphosphate; IP6), which is invariably present in all plant-sourced feedstuffs and practical broiler diets. The surprisingly broad spectra of anti-nutritive properties harbored by dietary phytate are counteracted by exogenous phytases via the hydrolysis of phytate and the positive consequences of phytate degradation. Phytases enhance the utilization of minerals, including phosphorus, sodium, and calcium, the protein digestion, and the intestinal uptakes of amino acids and glucose to varying extents. The liberation of phytate-bound phosphorus (P) by phytase is fundamental; however, the impacts of phytase on protein digestion, the intestinal uptakes of amino acids, and the apparent amino acid digestibility coefficients are intriguing and important. Numerous factors are involved, but it appears that phytases have positive impacts on the initiation of protein digestion by pepsin. This extends to promoting the intestinal uptakes of amino acids stemming from the enhanced uptakes of monomeric amino acids via Na+-dependent transporters and, arguably more importantly, from the enhanced uptakes of oligopeptides via PepT-1, which is functionally dependent on the Na+/H+ exchanger, NHE. Our comprehension of the phytate-phytase axis in poultry nutrition has expanded over the past 30 years; this has promoted the extraordinary surge in acceptance of exogenous phytases, coupled with the development of more efficacious preparations in combination with the deflating inclusion costs for exogenous phytases. The purpose of this paper is to review the progress that has been made with phytate-degrading enzymes since their introduction in 1991 and the underlying mechanisms driving their positive contribution to chicken-meat production now and into the future.

Impact of dietary glutamate and glycine on growth and nutrient utilization in rainbow trout (Oncorhynchus mykiss)

A feeding trial was conducted to test the effect of dietary glutamate and glycine supplementation on growth potential, nutritional utilization and digestion, and energy metabolism of rainbow trout (Oncorhynchus mykiss). Four isonitrogenous and isolipidic diets (2 × 2 factorial design) were formulated with glutamate (Glu) and glycine (Gly) as the main factors. The protein source consisted mainly of black soldier fly larvae meal (40% inclusion in all diets) for its low-level content of glutamate and glycine. Triplicate groups of rainbow trout (30 fish/tank with mean initial body weight of 87.5 g ± 0.9) were restrictively fed by hand twice a day for 6 weeks. Dietary Glu and Gly supplementation did not affect feed intake, specific growth rate, or the feed conversion ratio. Whole body protein, lipid, amino acid and fatty acid composition were also unaffected by the supplementation of Glu and Gly in the diets. Dietary Gly supplementation increased the apparent digestibility of amino acids. Furthermore, supplementation with Gly, increased the concentration of serine, glycine, tryptophane, tyrosine and citrulline, while supplementation with Glu in the diets increased the concentration of hydroxy-proline and β-alanine in the serum of rainbow trout. Both dietary Glu and Gly supplementation improved the digestibility of the fatty acids. The expression of genes involved in the hepatic bile acid synthesis (e.g., apical sodium dependent bile acid transporter and organic solute transporter) were affected by supplementation of Gly in the diets. In general, this study showed that dietary supplementation with Gly and Glu improved the nutrient digestibility in rainbow trout.

Determining the apparent ileal digestibility of amino acids for soybean meal from select soybean varieties with varying levels of crude protein

Determining the apparent ileal digestibility of amino acids for soybean meal from select soybean varieties with varying levels of crude protein

Nutrient digestibility in broiler chickens fed diets containing high levels of soybean oil is affected by the source of fiber

This study evaluated the effects of including soluble and insoluble dietary fiber sources in soybean oil-containing diet for broiler chickens on coefficient of apparent ileal digestibility (AID) of amino acids, coefficient of apparent retention (AR) of nutrients, and nitrogen-corrected apparent metabolizable energy (AMEn). A total of 180 broilers were divided into 30 groups and fed 3 diets from day 14 to 21 of age. The diets were corn–soybean meal containing 6.8% soybean oil without or with soybean hulls (SBH) or sugar beet pulp (SBP) at 8.0% as sources of insoluble and soluble fiber, respectively. The SBH and SBP contained 6.0% and 14.7% of soluble dietary fiber and 60.5% and 37.0% of insoluble dietary fiber, respectively. The AID of indispensable amino acids was decreased ( P &lt; 0.05) due to dietary inclusion of SBH, but not of SBP. Dietary SBH and SBP reduced the AR of gross energy (by 14% and 8%, respectively) and AMEn (by 20% and 14%, respectively). Overall, inclusion of SBH or SBP at 8.0% in a corn–soybean meal-based diet for broilers that contains high level of soybean oil might not improve nutrient digestibility. However, SBP has less detrimental effects on nutrient digestibility than SBH.

Comparison of methods for the effective evaluation of the energy content of poultry byproduct meal for beagles.

The objectives of this study were to compare the energy values of poultry byproduct meal (PBM) as feed for adult beagle dogs using the direct, difference, and regression methods to examine dogs' nitrogen metabolism, energy utilization, gaseous metabolism, and body health. Five groups of six 12 mo old female beagles with an average body weight of 9.67 ± 0.52 kg were tested in a 5 × 6 incomplete Latin square design, with six repetitions in each group. Five experimental diets were tested consisting of 100% PBM; three substitution diets containing either 15%, 30%, or 45% PBM (termed 15PBM, 30PBM, and 45PBM, respectively); and a basal diet (included 6.90% PBM). Each experimental period lasted for 10 d, comprising 4 d of dietary acclimation followed by 6 d of testing (including 3 d feeding period and 3 d fasting period), during which the heat production (HP) was determined and feces and urine were collected. Results showed that, in the feeding state, the nitrogen intake, urinary nitrogen, apparent nitrogen digestibility, retained nitrogen, andHP increased significantly (P < 0.05) as the PBM level increased. The net protein utilization, biological value of protein, and total apparent digestibility of amino acids did not differ between the 30PBM and 45PBM diets (P > 0.05). The O2 consumption and CO2 production of beagles during the fasting period were not influenced by the PBM level (P > 0.05). The digestible energy and metabolizable energy values of the PBM estimated by the regression method were 20.16 and 18.18 MJ/kg dry matter (DM), respectively, and did not differ from those determined by the direct method (P > 0.05). The fecal DM percentages and fecal PBM scores were significantly higher in the PBM diet than in the difference method groups (P < 0.05). The direct method group had a significantly higher fecal score (4.63) than the other groups (P < 0.05), The fecal score of the 45PBM diet (3.50) was significantly higher than the 30PBM diet (2.90; P < 0.05). In summary, the direct and difference methods of determining the effective energy value of PBM for beagles, produce significantly different results. Under the conditions of this test, the best proportion of PBM in beagle feed for optimum energy provision is 30%.

Feeding thermally processed spray-dried egg whites, singly or in combination with 15-acetyldeoxynivalenol or peroxidized soybean oil on growth performance, digestibility, intestinal morphology, and oxidative status in nursery pigs.

Two experiments (EXP) determined the susceptibility of spray-dried egg white (SDEW) to oxidation (heating at 100 °C for 72 h; thermally processed, TP) and whether feeding TP-SDEW, 15-acetyldeoxynivalenol (15-ADON), or peroxidized soybean oil (PSO), singularly or in combination, would affect pig performance, intestinal morphology, digestibility, and markers of oxidative stress in nursery pigs. In EXP 1, 32 pigs (7.14 kg body weight, BW) were placed individually into pens and fed diets containing either 12% SDEW, 6% TP-SDEW plus 6% SDEW, or 12% TP-SDEW. Performance was measured at the end of the 24-d feeding period with biological samples harvested following euthanasia. In EXP 2, 64 pigs (10.6 kg BW) were placed individually into pens and fed diets containing 7.5% soybean oil or PSO, 10% SDEW or TP-SDEW, and diets without or with 3 mg 15-ADON/kg diet in a 2 × 2 × 2 factorial arrangement. Performance was measured at the end of the 28-d feeding period with biological samples harvested following euthanasia. In EXP 1, dietary treatment did not affect pig performance, apparent ileal digestibility of amino acids (AAs), apparent total tract digestibility (ATTD) of gross energy (GE) or nitrogen (N), ileal crypt depth, or villi height:crypt depth ratio (P > 0.05). The effects of feeding TP-SDEW on protein damage in the plasma and liver (P < 0.05) were variable. In EXP 2, there were no three-way interactions and only one two-way interactions among dietary treatments on parameters evaluated. There was no effect of feeding TP-SDEW on ATTD of GE or N, intestinal morphology, or on oxidative markers in the plasma, liver, or ileum (P > 0.05). There was no effect of feeding diets containing added 15-ADON on ATTD of GE, ileal AA digestibility, intestinal morphology, oxidative markers in the plasma, liver, or ileum, or pig performance (P > 0.05). Feeding pigs diets containing PSO resulted in reduced ATTD of GE and N, plasma vitamin E concentration, and pig performance (P < 0.01) but did not affect intestinal morphology or oxidative markers in the liver or ileum (P > 0.05). In conclusion, it was difficult to induce protein oxidation in SDEW and when achieved there were limited effects on performance, digestibility, intestinal morphology, and oxidative status. Furthermore, singly adding 15-A-DON to a diet had no effect on the animal. At last, adding PSO reduces animal performance, but has limited effect on digestibility, intestinal morphology, and oxidative status in nursery pigs.

Effect of Sunflower Kernel Peptides Produced by Dual-Degradation on the Growth Performance, Nutrient Digestibility, and Health Status of Broilers

The purpose of this study was to investigate the effect of sunflower kernel peptides produced by enzymatic digestion, fermentation, or both on the growth performance, nutrient digestibility, and health status of broilers. Four diets contained 20% of sunflower kernel meal as its raw form (CON) or degraded by protease (ESM), Bacillus pumilus (FSM), or both (DSM). A total of 480 yellow broilers at one day old were randomly distributed to 4 groups with 6 replicates of 20 chicks each. The feeding trial lasted for 63 d. Results showed that peptide content was increased (p<0.001) from 3.97% (CON) to 32.5% (ESM), 24.2% (FSM), and 39.1% (DSM). The three sunflower peptide groups improved (p≤0.001) feed intake and body weight gain. The peptide groups increased (p≤0.015) ileal apparent digestibility of dry matter, energy, crude protein, and amino acids (methionine, lysine, tryptophan, and threonine). Furthermore, the peptide groups improved (p≤0.029) the health status by increasing serum immunoglobulins (IgA, IgG) and glutathione peroxidase. Additionally, among the peptide groups, DSM showed more pronounced effects (p<0.05) on these parameters than ESM or FSM. It is concluded that dual-degradation by enzymolysis and fermentation has a better improvement in the nutrition and application of sunflower kernel meal in broilers.

The Effect of Dietary Fumonisin Exposure on Apparent Ileal Digestibility of Amino Acids in Fattening Pigs

The cellular toxicity of the Fusarium mycotoxin fumonisins (FUMs) has been widely accounted for. However, the ability of FUMs to destroy intestinal functions is an emergence of growing concern. Thus, this experiment ascertained whether dietary FUMs obstruct the apparent ileal digestibility (AID) of crude protein (CP) and amino acids (AAs) in fattening pigs during either short (7 d)- or long (21 d)-term exposure. Ten Danbred fattening pigs (initial body weight (BW) of 67.5 ± 4.1) inserted with a post-valve T-cecum cannula in the terminal ileum were enrolled in the trial. The pigs were randomly divided into a control group fed a basal commercial diet and a group fed in vitro-produced FUMs to provide a 40 mg FUMs/kg-contaminated diet. Titanium dioxide was added at an inclusion rate of 0.5% as an indigestible marker to diets. During two separate periods, ileal digesta were collected for 3 consecutive days for the determination of the AID of CP and the various dispensable and indispensable AAs. Data were subjected to two-way ANOVA of SPSS version 20.0 software using FUMs dose (i = 2; 0 or 40 mg FUMs/ kg feed) and duration (j = 2; short- vs. long-term exposure) as fixed factors. According to our findings, a dietary intake of 40 mg/kg FUMs substantially interfered with the AID of arginine, histidine, and tyrosine (p = 0.003, 0.047, and 0.047, respectively) in terms of the dose and duration interaction effect. In addition, the main duration effect of the AID of histidine was significant (p &lt; 0.001). It is, therefore, conceivable that a dietary dose of a 40 mg/kg FUMs-contaminated diet does not drastically affect CP and AAs digestibility in fattening pigs over a period of 7 or 21 days.

Effects of Protein Source, Whole Wheat and Butyric Acid on Live Performance, Gut Health and Amino Acid Digestibility in Broiler Chickens.

A total of 896 1-day-old straight-run (Ross-308) broilers were used to investigate the interactive effects of protein source (PS), diet structure (DS) and butyric acid (BA) on live performance and carcass characteristics, gut development and its morphology and apparent ileal digestibility (AID) of protein and amino acids (AA). Eight experimental diets comprising 8 replicates with 14 birds each were tested in a 2 × 2 × 2 factorial arrangement with complete randomized design by two levels of BA (0 and 0.1%), two forms of DS (whole vs. ground wheat) and two PS, i.e., soybean meal and canola meal (SBM vs. CM). Throughout the entire experimental period (0 to 35 d), broilers fed SBM-based diets exhibited better (p < 0.05) growth performance (feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR)), carcass parameters (p < 0.05), gut health (p < 0.05), and nutrient digestibility (p < 0.05) than CM-fed broilers. Dietary whole wheat (WW) positively affected FI (p = 0.001), BWG (p = 0.004) and FCR (p = 0.035) during the overall experimental period. Broilers fed WW had 6, 5, 8, 11 and 10% lower empty relative weights of crop, proventriculus, jejunum, ileum and colon and 25 and 15% heavier gizzard and pancreas, respectively, with longer villus height (p < 0.001), reduced crypt depth (p = 0.031) and longer villus height-to-crypt depth ratio (p < 0.001) than those fed ground-wheat-based diets. Broilers fed WW had greater (p < 0.05) AID of CP and most of the AA. Butyric acid supplementation resulted in improved (p < 0.05) growth performance and digestibility of threonine, valine, leucine, isoleucine, phenylalanine, serine and aspartate. The broilers consuming SBM had 28% lower abdominal fat than those fed CM-based diets. In conclusion, harmful consequences of a less digestible PS can partially be compensated by the inclusion of WW, and supplementation of BA further reduces these detrimental effects.

Effects of a Novel Protease on Growth Performance, Nutrient Digestibility and Intestinal Health in Weaned Piglets.

Simple SummaryA novel type of protease with high stability, high resistance to acid and a wider range of enzyme cutting sites has been developed recently. This experiment was conducted to investigate the effects of the novel protease in weaned piglets. Our results indicate that dietary protease supplementation promotes nutrient absorption, improves small intestine morphology and enhances digestive enzyme activities of weaned piglets.This experiment was conducted to evaluate the effects of different protease levels on performance, diarrhea rate, nutrient digestibility, blood metabolites, digestive enzyme activities, and intestinal health of weaned piglets. A total of 96 weaned piglets (Duroc × Landrace × Yorkshire, 28 d of age, initial average BW = 6.55 ± 0.17 kg) were divided into four groups (4 pigs/pen and 6 replicates/group) according to a completely random block design. Piglets were fed different levels of protease (0, 150, 300 or 600 mg/kg of diet) for 28 d. The results showed that the addition of protease had no significant effect on the growth performance of weaned piglets (p > 0.05), and the addition of 300 mg/kg protease significantly increased the apparent total intestinal digestibility (ATTD) of nutrients and the apparent ileal digestibility (AID) of amino acids in weaned piglets (p < 0.05), while the addition of 150 mg/kg and 600 mg/kg protease had no significant effect on the digestibility (p > 0.05). The nutrient digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and total energy (GE) showed a trend of increasing and then decreasing with increasing protease concentration (p < 0.05). Adding 300 and 600 mg/kg protease significantly decreased serum ALB/GLO levels (p < 0.05) and duodenal pH (p < 0.05) and increased duodenal villus height (p < 0.05). The addition of protease significantly increased jejunal trypsin and chymotrypsin activities (p < 0.01) and duodenal and jejunal mucosal tight junction proteins in piglets. The mRNA expression levels of ZO-1 and CLAUDIN-1 in the duodenum together with ZO-1 and OCCLUDIN in the jejunum of piglets in the 300 and 600 mg/kg protease supplementation groups were significantly higher than those in the control group (p < 0.05). The results showed that, compared with the control group, protease could promote nutrient absorption, improve small intestine morphology and enhance digestive enzyme activity in weaned piglets. The suitable addition amount was 150–300 mg/kg in the present study.

Enhancing egg production and quality by the supplementation of probiotic strains (Clostridium and Brevibacillus) via improved amino acid digestibility, intestinal health, immune response, and antioxidant activity.

This study focused on evaluating the influence of Clostridium butyricum and Brevibacillus strains on egg production, egg quality, immune response and antioxidant function, apparent fecal amino acid digestibility, and jejunal morphology when supplemented as probiotics in the diets of laying hens in the peak phase. A total of 288 healthy 30-week-old Hy-Line Brown laying hens were arbitrarily assigned to four dietary groups, which included control diet and control diet supplemented with 0.02% C. butyricum zlc-17, C. butyricum lwc-13, or Brevibacillus zlb-z1, for 84 days. The results showed that dietary C. butyricum and Brevibacillus sp. exerted a positively significant influence (P ≤ 0.05) compared to the control group on the performance, egg quality, and physiological response of the birds. The diets could reduce mortality rate and enhance (P ≤ 0.05) egg weight and egg mass, egg production rate, and feed efficiency. Further analysis suggested that the probiotic strains can enhance (P ≤ 0.05) eggshell quality, Haugh unit, thick albumen content, and albumen height. Also, probiotics enhanced (P ≤ 0.05) the antioxidant status via increased antioxidant enzymes and jejunal morphology as evidenced by increased villi surface area (VSA), the ratio of villi height to crypt depth, villi width, and villi height, and a significant reduction in crypt depth. Besides, nutrient absorption and retention were enhanced, as apparent fecal amino acid digestibility of key essential amino acids was substantially improved in the diet-based group. The concentrations of immunoglobulin M and A (IgM and IgA) increased significantly (P ≤ 0.05) in the probiotics group and the same effect was notable for complement proteins (C3) and immune organ (Spleen). Conclusively, the supplementation of Clostridium butyricum zlc-17 in comparison to Clostridium butyricum lwc-13 and Brevibacillus zlb-z1 strains significantly (P ≤ 0.05) promoted the antioxidant status, modulated the intestinal structure, enhanced amino acid digestibility, and regulated the immunity index of the laying hens, which finally improves the laying performance and egg quality of the laying hens.

Apparent ileal digestibility of amino acids by pigs is not affected by increasing dietary calcium from deficient to excess concentrations, but phosphorus digestibility is reduced

The objective was to test the hypothesis that the concentration of calcium (Ca) in diets affects apparent ileal digestibility (AID) of amino acids (AA) by pigs due to interactions between Ca, phosphorus (P), and AA. Six corn-soybean meal-based diets with Ca included at 50–175 % of the requirement were formulated. Dietary Ca was increased by increasing inclusion levels of calcium carbonate, whereas the concentration of P was constant among diets. Six growing barrows (initial body weight: 81.43 ± 1.14 kg) were equipped with a T-cannula in the distal ileum and allotted to a 6 × 6 Latin square design with 6 diets. Ileal digesta were collected and analyzed for Ca, P, crude protein, and AA. The statistical model included diet as fixed variable and period and animal as random effects. Contrast coefficients were used to test linear and quadratic effects of increasing dietary Ca. The AID of dry matter was not affected by the level of Ca in the diets. The AID of Ca linearly (P < 0.001) increased, but the AID of P decreased in a quadratic manner (P = 0.022) with increasing Ca in diets. The AID of crude protein and all indispensable and dispensable AA was not affected by dietary Ca levels.

Comparative ileal digestibility of gross energy and amino acids in low and high tannin sorghum fed to growing pigs

Low tannin sorghum cultivars (LTS) have been previously proved to contain greater available energy and apparent total tract digestibility (ATTD) of gross energy (GE) and crude protein (CP) than high tannin sorghum cultivars (HTS); however, their comparative ileal digestibility of energy and nitrogen excluding microbial interference in pigs remains mostly unknown. This study was designed to compare apparent (AID) and standardized ileal digestibility (SID) of amino acids (AA) associated with the AID and hindgut disappearance (HGD) of GE and CP in 4 LTS and 4 HTS fed to growing pigs. Eighteen barrows (27.6 ± 3.5 kg) fitted with a distal ileum T-cannula were allotted to a replicated 9 × 3 Youden square design with 9 diets and 3 periods to give a total of 6 replicate pigs per diet. Each period lasted 10 days, with 5 days adaption to the diets followed by 3 days collection of faeces and then 2 days collection of ileal digesta. Eight sorghum diets contained 966 g/kg sorghum grain as the only source of dietary energy and nitrogen, and one nitrogen-free diet was used to determine basal ileal endogenous nitrogen loss. Mean AID, ATTD, and HGD of GE and CP were higher in LTS than in HTS (P < 0.05). Mean SID of 8 out of 15 AA were decreased in HTS (P < 0.05). The AID, ATTD, and HGD of GE or CP had a negative correlation with condensed tannins and total phenolics in sorghum grain (P < 0.05). The SID of essential AA, including lysine, threonine, valine, histidine, and arginine, were highly or moderately negatively correlated with condensed tannins and total phenolics content in sorghum grains (P < 0.05). Overall, HTS provided less ileal digestibility and hindgut disappearance of energy and nitrogen, implying that condensed tannins in sorghum grain may impede nutrient digestibility, not only in the foregut but also in the hindgut segements of pigs.

Dietary crude protein concentrations, feed grains, and whey protein interactively influence apparent digestibility coefficients of amino acids, protein, starch, and performance of broiler chickens

The present study was designed to investigate the impacts of dietary crude protein (CP) concentrations (220 and 180 g/kg) in either maize- or wheat-based diets, without or with 25 g/kg inclusions of whey powder (WP) concentrate on performance parameters and apparent amino acid digestibility coefficients in broiler chickens. The maize and wheat used in this study had CP levels of 84 and 119 g/kg, respectively. The 2 × 2 × 2 factorial array of 8 dietary treatments was offered to a total of 336 off-sex, male Ross 308 chicks from 7 to 35 d post-hatch with 7 replicate cages (6 birds per cage) per treatment. A treatment interaction (P = 0.016) between dietary CP and feed grains was detected for weight gains, where birds offered 180 g/kg maize-based diets displayed a weight gain advantage of 6.74% (2,628 vs. 2,462 g/bird) compared to their wheat-based counterparts. An interaction (P = 0.022) between feed grains and whey protein was observed for FCR as the addition of WP to maize-based diets improved FCR by 3.45% (1.314 vs. 1.361), but compromised FCR in wheat-based diets by 2.98% (1.415 vs. 1.374). A treatment interaction (P = 0.038) between dietary CP and feed grains was recorded for relative abdominal fat-pad weights weight gains as birds offered 180 g/kg CP maize-based diets had 43.4% (11.17 vs. 7.79 g/kg) heavier fat-pads than their wheat-based counterparts. Following the reduction in dietary-CP, apparent amino acid digestibility coefficients were depressed to greater extents in wheat-based diets. However, significant interactions between CP and feed grains were found in 14 of the 16 amino acids assessed and significant interactions between CP and WP were observed for 15 amino acids. Maize was the more suitable feed grain in terms of weight gain and FCR in 180 g/kg CP diets despite causing greater fat deposition. The inclusion of WP in reduced-CP diets did not enhance bird performance. Data generated indicate concentrations of microbial amino acids in distal ileal digesta were depressing apparent amino acid digestibility coefficients, which was more evident in wheat-based diets. Higher gut viscosities in birds offered wheat-based diets may have facilitated the proliferation of microbiota along the small intestine.

Effects of xylanase on growth performance, nutrient digestibility, serum metabolites, and fecal microbiota in growing pigs fed wheat-soybean meal-based diets.

This experiment investigated the effects of xylanase on growth performance, nutrient digestibility, serum metabolites, and fecal microbiota in growing pigs fed wheat-soybean meal-based diets. Seventy-two crossbred pigs (Duroc × [Landrace × Large White]) pigs (body weight of 23.30 ± 1.51 kg) were allotted two treatments with six pens per treatment and six pigs per pen. The diets were a wheat-soybean meal-based diet (Control group) and a wheat-soybean meal-based diet supplemented with 500 U/kg xylanases (XYL group). The experiment was divided into two periods (phase 1: days 1 to 35 and phase 2: days 36 to 70). Xylanase improved G:F during phase 1 and the entire experiment (P < 0.05) and tended to improve G:F during phase 2 (P = 0.09). Compared with the control group, pigs in the XYL group had greater apparent total tract digestibility of dry matter, organic matter, and gross energy on days 35 and 70 (P < 0.05) and had greater apparent ileal digestibility of amino acids (histidine, lysine, methionine, and serine) on day 70 (P < 0.05). The fecal microbiota in the XYL group contained greater abundances of g_Terrisporobacter, g_Lactobacillus, g_Clostridium_sensu_stricto_1, and g_Romboutsia than the Control group on day 70. Xylanase increased the fecal Lactobacillus populations on day 35 (P < 0.05). On days 35 and 70, xylanase reduced the fecal E. coli populations (P < 0.05). Supplementing xylanase to wheat-soybean meal-based diets collectively improved fecal microbiota, and nutrient digestibility, thereby improving growth performance in growing pigs.