Improved Nutrient Digestibility Research Articles

Diets Fermented with Bacteria and Enzymes in China Improve Growth Performance and Health of Weaned Piglets

Microbial fermentation has been widely used to preserve or improve the nutritional properties of food. Liquid feeding can increase feed intake and reduce the morbidity of piglets. The objective of this study was to evaluate the effects of a diet fermented with bacteria and enzymes and liquid feeding on growth performance, nutrient digestibility, digestive enzyme activity, microflora, and expressions of intestinal development-related genes in weaning pigs. A total of 198 piglets (Duroc × Landrace × Yorkshire) with body weights of 8.70 ± 0.45 kg were assigned to three groups with six replicates per treatment, and 11 weaned piglets per replicate according to the initial body weight and sex. The three dietary treatments (all nonpelleted diets) were a standard dry feed as the control (CON), a control diet supplemented with antibiotics (AB), and a liquid feeding with a fermented diet (LFD). The liquid feeding diet, having the same composition and proportion of each ingredient as the control diet, was prepared by storing the dietary cereals (corn, soybeans, etc.) and water (1:0.5, wt/wt) in a closed tank at 26–30 °C with enzymes and bacteria, and then adding the remaining dietary ingredients immediately before feeding. The whole trial lasted 42 days. On days 11 to 14 and 39 to 42, fresh faecal samples were collected to evaluate the apparent total tract digestibility of nutrients. Performance, digestibility, serum physiochemical parameters, intestinal barrier function, microbiota, and microbial metabolites were measured. The experimental data were subjected to analysis of variance using the GLM procedure of SAS for a complete randomized block design, with a “pen” as the experimental unit. The results showed that the AB increased (p < 0.05) average daily gain and reduced (p < 0.05) feed conversion (F/G) over the course of 1–14 days compared to the control. The liquid feeding group significantly increased (p < 0.05) average daily gain, average daily feed intake, and final body weight compared to the other two dietary groups. The digestibility of crude protein, ether extract, ash, gross energy, Ca, and P also improved in the liquid feeding group. Moreover, the liquid feeding group significantly decreased (p < 0.05) serum urea nitrogen and D-lactate concentrations, as well as the activity of diamine oxidase, and increased (p < 0.05) serum total protein and glucose concentrations on day 14. Furthermore, the liquid feeding group significantly increased (p < 0.05) mRNA expressions of zonula occludens-2 (ZO-2) in the jejunum and zonula occludens-1 (ZO-1), ZO-2, occludin, and claudin-1 in the ileum. In addition, microbiota measurement suggested an increase in Lactobacillus content and a decrease in Escherichia coli with higher (p < 0.05) concentrations of acetic acid, propionic acid, butyric acid, and total volatile fatty acids in the caecal and colonic digesta of piglets in the liquid feeding group. In conclusion, the diet in the liquid feeding group was able to increase palatability, improve nutrient digestibility, and modulate metabolism, which resulted in higher feed efficiency and better growth performance in the piglets.

Antifungal and carboxylesterase-producing bacteria applied into corn silage still affected the fermented total mixed ration.

This study investigated the effects of corn silage as a source of microbial inoculant containing antifungal and carboxylesterase-producing bacteria on fermentation, aerobic stability, and nutrient digestibility of fermented total mixed ration (FTMR) with different energy levels. Corn silage was used as a bacterial source by ensiling for 72 d with an inoculant mixture of Lactobacillus brevis 5M2 and L. buchneri 6M1 at a 1:1 ratio. The corn silage without or with inoculant (CON vs MIX) was mixed with the other ingredients to formulate for low and high energy diets (LOW vs HIGH) for Hanwoo steers. All diets were ensiled into 20 L mini silo (5 kg) for 40 d in quadruplicate. The MIX diets had lower (p<0.05) acid detergent fiber with higher (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber compared to the CON diets. In terms of fermentation characteristics, the MIX diets had higher (p<0.05) acetate than the CON diets. The MIX diets had extended (p<0.05) lactic acid bacteria growth at 4 to 7 d of aerobic exposure and showed lower (p<0.05) yeast growth at 7 d of aerobic exposure than the CON diets. In terms of rumen fermentation, the MIX diets had higher (p<0.05) total fermentable fraction and total volatile fatty acid, with lower (p<0.05) pH than those of CON diets. The interaction (p = 0.036) between inoculant and diet level was only found in the immediately fermentable fraction, which inoculant was only effective on LOW diets. Application of corn silage with inoculant on FTMR presented an antifungal effect by inhibiting yeast at aerobic exposure and a carboxylesterase effect by improving nutrient digestibility. It also indicated that fermented feedstuffs could be used as microbial source for FTMR. Generally, the interaction between inoculant and diet level had less effect on this FTMR study.

Xylanase Impact beyond Performance: Effects on Gut Structure, Faecal Volatile Fatty Acid Content and Ammonia Emissions in Weaned Piglets Fed Diets Containing Fibrous Ingredients.

The addition of xylanase to piglet diets is known to improve performance and nutrient digestibility. The present study aimed to assess the impact of new xylanase on the growth performance, nutrient digestibility, and gut function of weaned piglets. A total of 144 pigs, weaned at 28 days (7.48 kg initial body weight, IBW), were assigned to 36 pens and 9 pens per treatment. Dietary treatments were a basal complex control diet, and the basal diet supplemented with 45,000, 90,000 and 135,000 U/kg xylanase. Performance was measured at days 0, 14 and 35. At day 35, samples were collected for assessment of intestinal histology, and volatile fatty acid and ammonia concentrations. After two weeks post-weaning, additional 12 piglets (11.34 kg IBW) were placed in metabolic crates for assessment of apparent total tract nutrient digestibility using a dietary marker. The addition of xylanase at 90,000 and 135,000 U/kg significantly improved average daily gain (333.6 g/day control, 364.86 g/day, 90,000 U/kg, 405.89 g/day, 135,000 U/kg, p < 0.05), G:F (0.557 control, 0.612 90,000 U/kg, 0.692 135,000 U/kg, p < 0.05), and reduced diarrhoea. This was driven improved nutrient digestibility and villus height in the jejunum (372.87 µm control, 432.53 µm 45,000 U/kg, 465.80 µm 90,000 U/kg, 491.28 µm 135,000 U/kg, p < 0.05). Xylanase supplementation also linearly increased faecal butyrate levels and had a quadratic relationship with propionate concentrations. 135,000 U/kg xylanase also reduced ammonia emissions. In conclusion, dietary supplementation with xylanase improved growth performance and feed efficiency in weaning piglets, likely driven by improvements to gut structure and function.

Effects of Allium mongolicum regel essential oil supplementation on growth performance, nutrient digestibility, rumen fermentation, and bacterial communities in sheep.

The objectives of this research were to investigate the effects of Allium mongolicum Regel essential oil on growth performance, nutrient digestibility, rumen fermentation, and bacterial communities in sheep Twenty sheep were randomly divided into two dietary groups with 10 replicates each: (1) a basal diet without AMO as the control group (n = 10) and (2) a basal diet supplemented with 40 mg/kg AMO as the AMO group (n = 10). The average daily gain (ADG) was increased (P < 0.05), and the feed conversion ratio (FCR) was reduced (P < 0.05) in the AMO group compared with the control. The ruminal acetate, propionate, total volatile fatty acids (TVFA), and microbial protein (MCP) were higher (P < 0.05) in the AMO group than in the control. Moreover, ruminal pH and ammonia nitrogen (NH3-N) were lower (P < 0.05) in the AMO group than in the control. The relative abundances of the phylum levels of Firmicutes, Actinobacteriota, and Verrucomicrobiota were higher (P < 0.05) in the AMO group than in the control, and the relative abundances of Bacteroidetes and Spirochaetota were lower (P < 0.05) in the AMO group than in the control. The relative abundance of Prevotella and Prevotellaceae_UCG-003 at the genus level was increased (P < 0.05) in the AMO group compared with the control; however, the relative abundance of Succiniclasticum, Norank_f__F082, Christensenellaceae_R-7_group, and Norank_f__Muribaculaceae was decreased (P < 0.05) in the AMO group compared with the control. The activities of cellulase, α-amylase, and proteinase were higher (P < 0.05) in the AMO group than in the control. The apparent digestibility of dry matter (DM) and crude protein (CP) was increased (P < 0.05) in the AMO group compared with the control. In conclusion, AMO supplementation has the potential to improve growth performance. Moreover, supplementation with AMO improved nutrient digestibility, rumen fermentation, and bacterial communities in the rumen of sheep.

Impacts of particle size and multienzyme supplementation on growth, cost-benefit, carcass characteristics, and nutrient digestibility of broilers

Feed intake in poultry is affected by particle sizes, with coarse particles being more favoured. However, the threshold of coarseness is yet to be established. Feeding mash diets of varying particle sizes supplemented with multienzymes to broiler chickens at both starter and finisher phases could thus help establish this threshold. The study evaluated the response of broiler chickens to diets of varying particle sizes supplemented with graded levels of multienzyme. Three sieves (3, 4, and 5 mm) were fabricated to obtain three (3) diets of different particle sizes supplemented with multienzyme at three (3) levels (0, 1, and 2 g/kg) to have nine (9) dietary treatments. A total of 450-day-old Cobb500 unsexed broiler chicks were randomly allotted to nine (9) dietary treatments with five (5) replicates of ten (10) birds each, arranged in a 3 × 3 factorial experimental layout using a Completely Randomized Design. Growth parameters, cost-benefit, nutrient digestibility, and carcass characteristics of the chickens were evaluated. Data obtained in the study were subjected to Analysis of Variance, and means were separated using Duncan Multiple Range Test. The average feed particle size ranged from 886.52 to 1329.13 µm with a geometric standard deviation of 1.00. At the starter phase, birds fed 5 mm particles had the highest total feed intake (916.58 g/bird) and the poorest feed conversion ratio (2.65), while birds fed 3 mm particles had the lowest total feed intake (852.62 g/b) and the best feed conversion ratio (2.20). Birds fed 2 g/kg multienzyme had the highest feed costs at the starter (N 130.81) and finisher (N 331.33) phases. During the starter phase, birds offered 3 mm feed particles showed the highest (p<0.05) ether extract digestibility (0.82), while in the finisher phase, multienzyme supplementation decreased ash digestibility in birds fed diets with 3- and 4-mm feed particles. The combination of multienzyme and feed particle size impacted relative breast and back weights, but not the gizzard. The study concluded that broiler chickens can be fed diets of 3 mm particle size at the starter phase and 4 mm particle size at the finisher phase, with or without multienzyme supplementation, for a better feed conversion ratio, and diets of 5 mm particles with 1 g/kg multienzyme supplementation can be fed to broiler chickens at finisher phase for improved nutrient digestibility.

A new monocomponent xylanase improves performance, ileal digestibility of energy and nutrients, intestinal morphology, and intestinal microbiota in young broilers

Supplementation of feed enzymes such as xylanases has been shown to lower intestinal digesta viscosity and improve nutrient digestion thereby resulting in better gut health due to the reduced availability of undigested nutrients for the growth of harmful bacteria. Oligosaccharides produced by xylanase in situ from dietary non-starch polysaccharides with potential prebiotic effects could modulate the gut microbiome. This paper reports the positive effects of a new monocomponent xylanase in improving performance and nutrient digestion and modulating the intestinal microbiota of broilers. A corn-wheat-soybean meal-based diet was formulated and used to develop three dietary treatments using different doses (0, 45,000 U/kg and 90,000 U/kg) of the xylanase. A total of 288, one-day-old male broiler (Ross 308) chicks were allocated to 36 cages (12 replicates per treatment and 8 chicks per cage) and offered the experimental diets from d 0 to 21 post-hatch. The data were subjected to ANOVA using the General Linear Models procedure of SAS. The results confirm that supplemental xylanase at both dose levels improved (P < 0.05) broiler performance and nutrient digestibility. Xylanase supplementation had significant (P < 0.05) effects in modulating the intestinal microbiota with a higher relative abundance of commensal bacteria such as Lactobacillus and a lower abundance of potentially non-beneficial bacteria such as E. shigella indicating a prebiotic mode of action.

PSVII-3 Effects of Feeding Direct-fed Microbials on Digestibility and Rumen Fermentation Characteristics of Finishing Bos Indicus Cattle

Abstract Direct feed microbials (DFM) are probiotics often fed to feedlot to cattle offered to improve rumen fermentation and/or intestinal health, thus benefiting animal health and performance. We hypothesized that DFM supplementation would improve nutrient digestibility and rumen fermentation in finishing Bos indicus cattle. On day -1, 30 rumen-cannulated Nellore bulls were blocked based on initial body weight (BW; 350 ± 35.0 kg) in 1 of 30 pens and, within each block, animals were randomly assigned to: (1) Control: corn-based diet without DFM (n = 10), (2) EFSC: CONT + 1 gram/head per day of a DFM based on Enterococcus faecium and Saccharomyces cerevisiae (Probios Precise, Chr. Hansen A/S, Horsholm, Denmark; n = 10), and (3) BLBS: CONT + 2 grams/head per day of a DFM based on Bacillus licheniformis and Bacillus subtilis (Bovacillus, Chr. Hansen A/S; n = 10). The experimental period lasted 35 days, while between days 30 to 33, total fecal collection was performed and on days 34 and 35, feces and rumen fluid were collected at 0, 3, 6, 9, 12, 15, 18, and 21 h post-feeding for ammonia, VFA, and pH determination. All data were analyzed as orthogonal contrasts using SAS: (1) DFM vs. CONT and (2) EFSC vs. BLBS. Inclusion or type of DFM did not affect either nutrient digestibility or ruminal fermentation parameters (P ≥ 0.40). In contrast, DFM supplementation, regardless of type, yielded a reduced mean ammonia concentration (14.7 vs. 15.7 mg/L; P = 0.05). Moreover, ammonia concentrations were decreased in EFSC at 3 and 6 h post-feeding vs. CONT (P ≤ 0.04), but also less for BSBL vs. CONT at 6 h (P &amp;lt; 0.01). In summary, DFM supplementation, regardless of type, reduced proteolysis, with no effect on other parameters of rumen fermentation in Bos indicus bulls fed a finishing diet.

Effect of Dietary Lactose Supplementation on Growth Performance and Intestinal Epithelium Functions in Weaned Pigs Challenged by Rotavirus.

Simple SummaryLactose is a kind of carbohydrate that exists in mammal milk. It has some physiological functions, such as providing energy, regulating gut microbiota, and affecting immunity. Rotavirus (RV) is the main pathogen that induces severe diarrhea in piglets, which impairs their growth and development. In this study, we investigated whether different levels (4% and 6%) of dietary lactose supplementation alleviates RV-induced diarrhea in weaned piglets. The results showed that lactose administration relieved the negative effect of RV on growth, which was derived from the improvement of nutrient utilization, gut barrier function, and immunity. Moreover, supplementing 6% lactose in the diets had a tendency to alleviate diarrhea in RV-infected piglets. Thus, we suggest that the diet of weaned piglets should be supplemented with more than 4% lactose (especially in the early period of weaning) if the cost of feed can be afforded.The purpose of this study was to investigate whether dietary lactose supplementation relieves rotavirus (RV)-induced diarrhea and gut dysfunction. Thirty-six crossbred weaned piglets were randomly allocated into three groups and fed diets containing 0, 4%, and 6% lactose for 20 days. On Day 15, half of the piglets in each group were orally infused with RV. RV infection impaired growth performance; induced severe diarrhea; decreased serum D-xylose concentration and morphology and sIgA level of jejunal mucosa; downregulated MUC1, MUC2, occludin, Bcl-2, IL-4, pBD3, pBD2, and pBD1 mRNA expression of jejunal mucosa and/or mesenteric lymph nodes; upregulated Bax, caspase-3, IL-2, IFN-γ, and IFN-β mRNA expression of jejunal mucosa and/or mesenteric lymph nodes; and damaged microbiota and metabolites of cecal digesta in weaned piglets (p < 0.05). Dietary lactose supplementation improved nutrient digestibility and growth performance and relieved the negative influence of RV challenge on intestinal barrier function, mRNA expression of cytokines, and host defense peptides of jejunal mucosa and/or mesenteric lymph nodes in weaned piglets (p < 0.05). Dietary administration of 6% lactose tended to relieve diarrhea (p = 0.07). These results suggest that lactose in feed increases growth performance and has a tendency to alleviate RV-induced diarrhea, derived from the improvement of nutrient utilization, gut barrier function, and immunity.

Effect of dietary peNDF levels on digestibility and rumen fermentation, and microbial community in growing goats.

Physically effective neutral detergent fiber (peNDF) is a concept that accounts for the particle length of NDF in diets, sustaining the normal chewing behavior and rumen fermentation of ruminants. Specifically, peNDF>1.18 is the commonest one that is calculated from NDF and the percentage of feed dry matter left on the 1.18, 8.00, and 19.00 mm sieves. This study aimed to investigate the effects of different levels of peNDF>1.18 on the rumen microbiome and its correlation with nutrient digestibility and rumen fermentation in goats. A total of 30 Lezhi black goats were randomized and blocked to five dietary treatments (n = 6). All the diets were identical in composition but varied in hay lengths, leading to the different peNDF>1.18 content of the diets: 32.97, 29.93, 28.14, 26.48, and 24.75%. The results revealed that the nutrient digestibility increased when dietary peNDF>1.18 levels decreased from 32.97% to 28.14%, with the highest digestibility at 28.14% peNDF>1.18 treatment, after which nutrient digestibility decreased with the decreasing of dietary peNDF levels. Ruminal NH3-N concentrations in the 29.93% and 28.14% groups were higher than that in the 24.75% group (p < 0.05). Ruminal microbial protein concentration was the highest in the 32.97% group (p < 0.05). Daily CH4 production in the 32.97% and 24.75% peNDF>1.18 treatments was lower than that in the 26.48% group (p < 0.05) and no differences were observed among other groups. The relative abundance of rumen fungi at the phylum and genus levels and archaea at the species were affected by dietary peNDF>1.18 content. In conclusion, decreasing dietary peNDF>1.18 levels within a certain range can improve nutrient digestibility and change the rumen microbial community structure of goats. Dietary peNDF>1.18 level should be 28.14% (roughage length around 1 cm) among the five levels for 4 months Lezhi black goats with the purpose of optimal nutrient digestibility.

Effect of Saccharomyces cerevisiae Supplementation on Reproductive Performance and Ruminal Digestibility of Queue Fine de l’Ouest Adult Rams Fed a Wheat Straw-Based Diet

This study aimed to investigate the effect of supplementing a wheat straw-based diet with Saccharomyces cerevisiae (S.C.) on feed intake, nutrient digestibility, nitrogen balance, body weight and reproduction performance. The experiment was conducted on 14 Queue Fine de l’Ouest rams between 3 and 4 years of age (body weight (B.W.): 54.7 ± 2.03 kg; body condition score (B.C.S.): 3.5 ± 0.5), for 80 days during the breeding season. The rams were divided into two homogenous groups (n = 7), housed individually in floor pens, and allocated to two dietary treatments. The control group was offered a basal diet of 1 kg/d of wheat straw and 700 g of concentrate. The experimental group (yeast) received the same basal diet supplemented with 10 g of S.C./head/day. The results indicated that the S.C. supplementation had no significant effect on the animal’s body weight, volume and concentration of semen, dry matter intake, crude protein digestibility and nitrogen balance. Compared to the control group, the S.C. addition improved (p &lt; 0.05) the digestibility of dry matter by 7.3%, organic matter by 11.9% and crude fiber by 24%. In addition, the mass motility score increased for the yeast group compared to the control (3.7 ± 0.24 vs. 1.9 ± 0.27, p &lt; 0.05). The total number of dead and abnormal spermatozoa decreased for the yeast group in contrast to the control group (9.28 ± 0.95 vs. 26.8 ± 3.85% and 25.5 ± 3.33 vs. 59.2 ± 2.78%, respectively; p &lt; 0.05). These results showed that adding S.C. to Queue Fine de l’Ouest ram’s diet during breeding season could improve nutrient digestibility and reproductive performance.

Blend of secondary metabolites from mesquite to improve nutrient digestibility, microbial protein, efficient use of nitrogen, ruminal parameters, and blood metabolites in sheep.

Although chemical additives are able to improve the efficiency of ruminal fermentation, they can leave residues in the meat. However, a blend of secondary metabolites can improve ruminal fermentation without harming the population welfare. Five levels (0.0, 1.5, 3.0, 4.5, and 6.0g/day) of a blend of secondary metabolites from mesquite extract in sheep feed to promote increases in the nutritional value, ruminal parameters, nitrogen (N) use efficiency, microbial protein (MP) synthesis, and blood metabolites. Ten intact male Santa Inês sheep with average body weight of 55 ± 9.81kg were used in a 5 × 5 Latin square design, replicated twice. There was a quadratic response of the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), and total digestible nutrients (TDN). Microbial protein concentrations, MP synthesis efficiency, propionic acid levels, and acetic/propionic acid ratio also showed a quadratic response. The blend promoted a quadratic effect on plasma glucose and lactate levels. On the other hand, it decreased the concentrations of ammoniacal nitrogen, plasma urea, and plasma cholesterol. It is recommended to supply a blend of secondary metabolites at 3.43g/day.

Response of Phytogenic Additives on Enteric Methane Emissions and Animal Performance of Nellore Bulls Raised in Grassland

The objective of this study was to evaluate the intake and digestibility of nutrients, emission of enteric CH4, and productive performance of Nellore bulls grazing Urochloa brizantha cv. Marandu palisade grass pastures during the rainy season, receiving an energy supplement or mineral supplement, with or without the inclusion of phytogenic additives. Forty-eight Nellore bulls were treated with: (1) energy supplement without the inclusion of phytogenic additives; (2) energy supplement with the inclusion of phytogenic additives; (3) mineral supplement without the inclusion of phytogenic additives; and (4) mineral supplement with the inclusion of phytogenic additives. Consumption of total dry matter (DM), crude protein (CP), apNDF, and energy; digestibility of DM, CP, and energy; average daily gain; stocking rate; and gain per area were higher in animals consuming energy supplements than those consuming mineral supplements. Digestibility of DM, NDF, and energy levels were lower in animals that consumed phytogenic additives. Compared with mineral supplements, the supply of energy supplements provides higher nutrient intake, increases enteric CH4 emission, and improves nutrient digestibility, providing a greater productive performance. The inclusion of phytogenic additives negatively affected nutrient intake and digestibility, did not reduce enteric CH4 emission, and influenced productive performance.

Lactiplantibacillus plantarum Postbiotics: Alternative of Antibiotic Growth Promoter to Ameliorate Gut Health in Broiler Chickens.

The postbiotic produced from Lactiplantibacillus plantarum has been revealed as a potential alternative to antibiotic growth promoters (AGP). It helps to stimulate growth performance, improve nutrient digestibility, intestinal histomorphology, immune response, and improve meat quality in livestock. However, there is a paucity of information on the effects of L. plantarum postbiotic produced by formulated media on the gut health and immune response. Therefore, this study was conducted by using three strains of dietary L. plantarum postbiotics to determine the growth performance, intestinal histomorphology, intestinal mucin production, and immune status in broiler chickens. A 245 male Cobb 500-day-old birds were assigned randomly to five treatments, namely, NC: basal diet only (negative control), OTC: basal diet + 0.01% (w/w) oxytetracycline (positive control), RG11: basal diet + 0.1% (v/w) Postbiotic RG11, RI11: basal diet + 0.1% (v/w) Postbiotic RI11, and RS5: basal diet + 0.1% (v/w) Postbiotic RS5. The body weight and feed intake were taken weekly. The small intestine and its mucus, ceca digesta were collected on days 21 and 42. Fresh excreta for crude mucin production were collected 3 days before slaughter on day 42. From the findings, RS5 recorded a significant highest (p < 0.05) final body weight, body weight gain, and significant lowest (p < 0.05) feed conversion ratio. The concentrations of glutathione peroxidase, superoxide dismutase (SOD), acidic mucin, sulfated mucin, and intestinal trefoil factor were significantly higher (p < 0.05) in the birds fed with RI11 and RS5. Postbiotics RI11 and RS5 had up-regulated expression of intestinal Mucin 2, occludin, and secretory immunoglobulin A. The antibiotic-fed chickens also showed a reduced (p < 0.05) total bacteria and Bifidobacterium population but a significantly increased (p < 0.05) the population of Escherichia coli in the jejunum. In conclusion, the supplementation of L. plantarum postbiotic can be used to substitute AGP as it promoted growth performance, mucin production, ameliorated tight junction permeability, and immune status in broiler chickens due to improved gut health and beneficial bacteria colonization.

A novel Bacillus sp. with rapid growth property and high enzyme activity that allows efficient fermentation of soybean meal for improving digestibility in growing pigs.

Soybean meal (SBM) contributes high-quality dietary protein for pigs. However, it also contains antinutritional factors such as allergenic high molecular weight proteins and non-starch polysaccharides (NSP) that limit its use. Therefore, the objective of this study was to screen and characterize a robust Bacillus sp. from camel dung for soybean meal fermentation to improve the digestibility in growing pigs. Molecular characterization revealed that isolate 9 (hereinafter referred to as "CP-9") was a Bacillus subtilis strain. It secreted cellulase (0.07Uml-1 ), xylanase (1.91Uml-1 ), and amylase (2.66Uml-1 ) into the culture supernatant.Isolate CP-9showed rapid growth on LB agar plates and grew at a wide range of pH (3.0-9.0) and temperatures (23-50°C) in LB broth. Protein profiling of SBM using SDS-PAGE showed a significant reduction of large globular proteins to small peptides after 48h of fermentation.On a dry matter basis, neutral detergent fibre (NDF) of the fermented SBM (F-SBM) was decreased by 34.25% (from 9.72 to 7.24%) with an increase in CP content by 16.54% (from 48.74 to 56.80%).Pigs fed with a semi-purified diet formulated with F-SBM as the sole source of crude protein had higher (p<0.05) apparent ileal digestibility (AID) of DM (80.0 vs. 71.7%), ash (55.6 vs. 36.1%), CP (84.2 vs. 78.3%), NDF (70.9 vs. 66.0%), and ADF (62.4 vs. 53.3%) compared with pigs fed with unfermented soybean meal (UF-SBM). A novel Bacillus subtilis strain CP-9 was isolated and characterized from camel dung for efficient fermentation of SBM. This bacterium ameliorates physico-chemical characteristics of F-SBM and improved nutrient digestibility in growing pigs. Our data suggest that a low-cost solid-state SBM fermentation was developed using this newly isolated bacterium. The resultant F-SBM improved the nutrient digestibility in growing pigs.

Fermented Soy and Fish Protein Dietary Sources Shape Ileal and Colonic Microbiota, Improving Nutrient Digestibility and Host Health in a Piglet Model.

Suitable protein sources are essential requirements for piglet growth and health. Typically, intestinal microbiota co-develops with the host and impact its physiology, which make it more plastic to dietary protein sources at early stages. However, the effects of fermented soybean meal (FSB) and fish meal (FM) on foregut and hindgut microbiota, and their relationship with nutrient digestion and host health remain unclear. In this study, we identified interactions between ileac and colonic microbiota which were reshaped by FSB and FM, and assessed host digestibility and host health in a piglet model. Eighteen weaned piglets (mean weight = 8.58 ± 0.44 kg) were divided into three dietary treatments, with six replicates/treatment. The level of dietary protein was 16%, with FSB, FM, and a mixture of fermented soybean meal and fish meal (MFSM) applied as protein sources. During days 1–14 and 1–28, diets containing MFSM generated higher piglet body weight and average daily gain, but lower feed to weight gain ratios when compared with the FM diet (P < 0.05). Piglets in MFSM and FM groups had lower apparent total tract digestibility (ATTD) of crude protein (CP) compared with the FSB group (P < 0.05). Serum immunoglobulins (IgM and IgG) in MFSM and FM groups were significantly higher on day 28, but serum cytokines (interleukin-6 and tumor necrosis factor-α) were significantly lower than the FSB group on days 14 and 28 (P < 0.05). When compared with FSB and FM groups, dietary MFSM significantly increased colonic acetic acid and butyric acid levels (P < 0.05). Compared with the FM and MFSM groups, the FSB diet increased the relative abundance of ileac Lactobacillus and f_Lactobacillaceae, which were significant positively correlated with CP ATTD (P < 0.05). Compared with the FSB group, the relative abundance of f_Peptostreptococcaceae and Romboutsia in MFSM or FM groups were increased and were significant positively correlated with total carbohydrate (TC) ATTD (P < 0.05). Piglets fed FSB had higher α-diversity in colonic microbiota when compared with other groups (P < 0.05). The relative abundance of colonic unidentified_Clostridiales and Romboutsia in MFSM and FSB groups were significantly higher than in the FM group (P < 0.05). Dietary MFSM or FM increased the relative abundance of colonic Streptococcaceae and Streptococcus, but decreased the relative abundance of Christensenellaceae when compared with the FSB group (P < 0.05). These bacteria showed a significantly positive correlation with serum cytokine and immunoglobulin levels (P < 0.05). Therefore, dietary FSB improved CP digestibility by increasing the relative abundance of ileac f_Lactobacillaceae and Lactobacillus, while dietary MFSM benefited TC digestibility by increasing f_Peptostreptococcaceae and Romboutsia. Dietary MFSM and FM enhanced immunoglobulin secretion by increasing colonic f_Streptococcaceae and Streptococcus prevalence, while dietary FSB promoted cytokine production by increasing microbiota diversity and Romboutsia and Christensenellaceae. Our data provide a theoretical dietary basis for young animals using plant and animal protein sources.

Application of Fermented Brewer’s Spent Grain Extract in Plant-Based Diets Improves Pre- and Post-mortem Oxidative Status of European Seabass (Dicentrarchus labrax)

In a previous study, it was shown that dietary supplementation with a carbohydrases and antioxidant-enriched extract (BSG-extract) produced by solid-state fermentation of brewer’s spent grain (BSG) improved nutrients digestibility, feed, and protein utilization of European seabass juveniles. This work aims to investigate the effect of this BSG-extract on liver and intestine oxidative status and muscle lipid peroxidation (LPO) of European seabass. A plant-based diet (55.4% plant feedstuffs; PF) was used as a control. Four test diets were formulated by supplementing the control diet with the BSG-extract (0.4 or 0.8% diet), added directly to the diet (BSG4 and BSG8 diets), or used to pre-treat the PF mixture of the control diet (PreBSG4 and PreBSG8 diets). European seabass juveniles (IBW 22 ± 1 g) were fed the experimental diets for 66 days until apparent satiety. In fish fed BSG-extract diets, compared to the control diet, intestinal LPO was reduced up to 29-40% ( p &lt; 0.05 ); GPX, GR, and G6PD activities were increased compared to the control ( p &lt; 0.05 ). In the liver, LPO was similar among diets, but except for catalase and G6PD, fish fed BSG-extract diets had higher antioxidant enzyme activities than the control ( p &lt; 0.05 ). Except for the liver SOD activity, hepatic and intestinal antioxidant capacity was not affected by the dietary BSG-extract incorporation mode ( p &gt; 0.05 ). After 72 h of storage at 4°C, muscle LPO was higher than at time 0 h. Compared to the control, BSG-extract reduced muscle LPO levels up to 30% at time 0 h in fish fed diets BSG4, BSG8, and PreBSG8 ( p &lt; 0.008 ). Results indicate that dietary supplementation with BSG-extract increased the antioxidant level of diets, improved the intestine antioxidant capacity, and decreased LPO in European seabass juveniles’ muscle.

Cereal type and combined xylanase/glucanase supplementation influence the cecal microbiota composition in broilers

Dietary fiber-degrading enzyme supplementation in broilers aims at off-setting the anti-nutritive effect of non-starch polysaccharides and at promoting broiler health. Recently, we demonstrated that xylanase/glucanase addition in wheat-based diet improved nutrient digestibility, arabinoxylan fermentability and broiler growth. Conversely, maize arabinoxylan was found to be recalcitrant to xylanase action. These findings suggested that enzyme-mediated improvement of nutrient digestion and carbohydrate fermentation depended on the cereal type present in the diet, and may have contributed to broiler growth. Hence, we aimed at further investigating the link between dietary enzymes and carbohydrate fermentation in broilers, by studying the impact of enzyme supplementation in cereal-based diets, to the microbial communities in the ileum and ceca of broilers. For that purpose, 96 one-day-old male broilers were randomly reared in two pens and received either wheat-based or maize-based starter and grower diets. At d 20, the broilers were randomly assigned to one out of four dietary treatments. The broilers received for 8 d the wheat-based or maize-based finisher diet as such (Control treatments; WC, MC) or supplemented with a xylanase/glucanase combination (Enzyme treatments; WE, ME). At d 28, samples from the digestive tract were collected, and the ileal and cecal microbiota composition was determined by 16S ribosomal RNA gene amplicon sequencing. A similar phylogenetic (alpha) diversity was observed among the four treatments, both in the ileal and the cecal samples. Furthermore, a similar microbial composition in the ileum (beta diversity) was observed, with lactobacilli being the predominant community for all treatments. In contrast, both cereal type and enzyme supplementation were found to influence cecal communities. The type of cereal (i.e., wheat or maize) explained 47% of the total variation in microbial composition in the ceca. Further stratifying the analysis per cereal type revealed differences in microbiota composition between WC and WE, but not between MC and ME. Furthermore, the prevalence of beneficial genera, such as Faecalibacterium and Blautia, in the ceca of broilers fed wheat-based diets coincided with arabinoxylan accumulation. These findings indicated that fermentable arabinoxylan and arabinoxylo-oligosaccharides released by dietary xylanase may play an important role in bacterial metabolism.

Effects of a Bacillus-based direct-fed microbial on in vitro nutrient digestibility of forage and high-starch concentrate substrates.

Two experiments evaluated the effects of a Bacillus-based direct-fed microbial (DFM) on in vitro dry matter (DM) and neutral detergent fiber (NDF; experiment 1) and starch (experiment 2) digestibility of a variety of ruminant feedstuffs. In experiment 1, 10 forage sources were evaluated: ryegrass, alfalfa hay, leucaena, corn silage, spinifex, buffel grass, flinders grass, Mitchell grass, Rhodes grass hay, and Queensland bluegrass. Experimental treatments were control (forages with no probiotic inoculation; CON) and forage sources inoculated with a mixture containing Bacillus licheniformis and Bacillus subtilis (3.2 × 109 CFU per g; DFM). In vitro DM and NDF digestibility were evaluated at 24- and 48-h post-treatment inoculation. Treatment × hour interactions were noted for IVDMD (in vitro dry matter digestibility) and IVNDFD (in vitro neutral detergent fibre digestibility) (P ≤ 0.05). More specifically, DFM inoculation increased (P ≤ 0.03) IVDMD at 24 h in four forages and increased 48-h IVDMD (P ≤ 0.02) in alfalfa hay, ryegrass, leucaena, and Mitchell grass hay, but opposite results were observed for Queensland bluegrass (P < 0.01). A 24- and 48-h IVNDFD increased following DFM inoculation (P ≤ 0.02) in five forage sources, but reduced for Queensland bluegrass (P < 0.01). When the forages were classified according to their quality, main treatment effects were detected for IVDMD (P ≤ 0.02) and IVNDFD (P < 0.01). In experiment 2, five common cereal grains were evaluated—high-density barley (82 g/100 mL), low-density barley (69 g/100 mL), corn, sorghum, and wheat—under the same treatments as in experiment 1. In vitro starch digestibility (IVSD) was evaluated at 6- and 12-h following treatment inoculation. Treatment × hour interactions were observed for starch digestibility in three out of five concentrate sources (P ≤ 0.001). Inoculation of DFM yielded greater 24-h starch digestibility for high-, low-density barley, and wheat (P ≤ 0.02), but also greater at 48 h in wheat (P < 0.0001). Moreover, mean starch digestibility improved for corn and sorghum inoculated with DFM (P < 0.01). Using a Bacillus-based DFM (B. licheniformis and B. subtilis) improved the mean in vitro DM and NDF digestibility of different forage sources of varying qualities (based on crude protein content). Similarly, IVSD was also greater following DFM inoculation, highlighting the potential of this probiotic to improve nutrient digestibility and utilization in the beef and dairy cattle herd.

Effects of dietary acidification and acid source on fish growth and feed efficiency (Review)

The human population has increased considerably worldwide, including in the Philippines. Aquaculture is one of the main food sectors that provides a cheap source of protein in the Philippines. Changes in diet composition in aquaculture have brought about concerns regarding certain negative effects at the gastrointestinal levels. The replacement of fish meal with a plant protein source in a considerable proportion in the diet of the majority of cultured fish species has led to proliferative and inflammatory responses in the intestines of various (functionally) monogastric animals. In aquaculture feed, the dietary supplementation of organic acids and their salts as growth promoters has been established. The use of acidifiers in aquafeed requires a different approach due to diversified feeding habits and the wide variation in the digestive system structure and physiological function. Dietary organic acids can increase pancreatic enzyme production, decrease stomach pH levels, inhibit pathogens, provide energy, improve mineral utilization and improve nutrient digestibility, all of which improve fish development performance. Acidifiers are currently widely used in animal feed, including aquafeed, and several manufacturers have created next‑generation acidifiers with additional benefits. The present review article discusses the acidifiers, their mechanisms of action, growth, feed efficiency, immunity and future research opportunities. The fish growth rate and feed utilization efficiency are also reviewed as regards dietary acid sources, such as acetic acid, citric acid, hydrochloric acid and control‑no acid. In addition, the attractability of the diets for the fish at different pH levels and dietary acid sources was determined. The survival rates of cultured fishes were determined based on the various dietary acids used. Any acids at an optimum pH level, e.g., pH 4.6 in the diet of tilapia fry, which increase attractability, growth and feed efficiency, warrant further attention.

Supplementation of Oilseeds to an Herbage Diet High in Condensed Tannins Affects Methane Production with Minimal Impact on Ruminal Fermentation in Continuous Culture

Condensed tannins (CT) have been observed to reduce enteric CH4 production when added to ruminant diets. However, high concentrations of CT in forages such as sericea lespedeza (SL; Lespedeza cuneata (Dum. Cours.) G. Don) may depress nutrient digestibility. Oilseed crops, high in lipid concentration, also reduce enteric CH4 via toxicity to methanogenic bacteria with less depression of nutrient digestibility. However, it is unclear whether combining these two feeds would result in even greater decreases in CH4 without impairing ruminal fermentation. This study used an in vitro continuous culture fermentor system to determine if supplementation of ground oilseeds would further reduce enteric CH4 production while improving nutrient digestibility of high-CT forages. The experimental design was a 4 × 4 Latin square, with four diets containing (dry matter basis) 45% orchardgrass (OCH; Dactylis glomerata L.), 45% sericea lespedeza (SL; Lespedeza cuneata (Dum. Cours.) G. Don), and 10% oilseed supplements, using canola (CAN; Brassica napus L.), soybean (SOY; Glycine max L.), sunflower (SUN; Helianthus annuus L.), or a mix of all three species (MIX; in equal proportions). Fermentors were fed 82 g of dry matter/d in four equal feedings over four 10 d periods. Methane was recorded every 10 min, and effluent samples were analyzed for pH, volatile fatty acids, dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber to determine apparent and true nutrient digestibilities. The CAN, SUN, and MIX diets had greater concentrations of crude fat (7–8 g/kg) than the SOY diet (5.7 g/kg), which contributed to the greater reduction in enteric CH4 production in those diets (13–27 mg/d) compared to the SOY diet (84 mg/d). Apparent and true nutrient digestibilities were not affected by the addition of ground oilseeds. While N intake increased concomitant with crude protein increases in the diets, there were no additional effects on N flows. While supplementing a high-CT diet with any of the three oilseeds (canola, soybean, sunflower, or a mixture of the three oilseeds) reduced total CH4 emission without depressing nutrient digestibility, canola and mixes containing canola were most effective. Further research is needed in vivo to evaluate whether these results translate to greater feed efficiency and animal production.