Study of Bacillus subtilis on growth performance, nutrition metabolism and intestinal microflora of 1 to 42 d broiler chickens

Creating Single-Cell Protein-Producing Bacillus subtilis Mutants Using Chemical Mutagen and Amino Acid Inhibitors

Due to population growth and climate changes, there is a rising need for alternative food and protein sources to reduce protein scarcity and the environmental impact of food industries. Single-cell proteins (SCPs) have the potential to partially or fully substitute plant- and animal-derived dietary proteins. Bacillus subtilis is an appealing bacterium for SCP production because of its fast growth and ability to obtain high protein and essential amino acid (AA) content in its biomass. It is also capable of utilizing a wide range of substrates. B. subtilis attractiveness and efficiency can be further enhanced using mutagenesis. In this study, a novel approach to creating mutant strains with enhanced protein and AA content was experimentally validated. The method is based on the application of AA inhibitors for selective pressure to ensure the growth of mutants with enhanced protein and/or AA synthesis capacity. For AA inhibitors, three herbicides were used: glufosinate-ammonium (GA), L-methionine sulfoximine (MSO), and S-(2-aminoethyl)-L-cysteine (AEC). Initially, AA inhibitor doses for the complete inhibition of wild-type (WT) B. subtilis strain were determined. Then, B. subtilis was treated with EMS chemical mutagen and created mutants were cultivated on a medium containing inhibitory dose of AA inhibitors. Growing samples were selected, analyzed, and compared. The optimal inhibitory concentrations of herbicides for mutant selection were 0.05-0.4 M for GA, 0.01-0.05 M for MSO, and 0.2 M for AEC. The best-performing mutants were selected when using GA-improvement of 7.1 times higher biomass content, 1.5 times higher protein concentration, 1.2 times higher AA content, and 1.2 times higher essential AA index was achieved in comparison with WT B. subtilis. Enhanced mutants were also successfully selected when using MSO and AEC. This study demonstrates the potential of using AA inhibitors for the selection of mutants with improved protein and AA profiles.

Effects of compatibility of Clostridium butyricum and Bacillus subtilis on growth performance, lipid metabolism, antioxidant status and cecal microflora of broilers during the starter phase

OBJECTIVE

This study aimed to determine the effects of compatibility of Clostridium butyricum and Bacillus subtilis on growth performance, lipid metabolism, antioxidant status and cecal microflora of broilers during the starter phase.

METHODS

A total of 600 1-day-old Ross 308 broilers were randomly divided into two groups with six replicates in each group. Chickens in the control group were fed a basal diet, while chickens in the experimental group were fed a diet supplemented with 2×108 colony forming units (CFU)/kg of C. butyricum and 1×109 CFU/kg of B. subtilis. The experimental period was 21 days.

RESULTS

Addition of C. butyricum and B. subtilis significantly increased (p<0.05) the body weight and liver nicotinamide adenine dinucleotide phosphate-malic enzyme (NADP-ME) activity of broilers, enhanced (p<0.05) the average daily gain and average daily feed intake of broilers. However, the addition of C. butyricum and B. subtilis did not significantly affect the concentrations of triglyceride and total cholesterol in the serum, the activities of fatty acid synthase and acetyl-CoA carboxylase in the liver, the total antioxidant capacity, glutathione peroxidase activity and malondialdehyde content in the serum and liver. Besides, microbial analysis revealed that supplementation of C. butyricum and B. subtilis increased (p<0.05) the abundance of Firmicutes such as CHKCI001 and Faecalibacterium, decreased (p<0.05) the abundance of Bacteroidota such as Bacteroides and Alistipes. Spearman correlation analysis confirmed that the above cecal microbiota were closely related to the growth performance of broilers (p<0.05). In addition, simultaneous supplementation of C. butyricum and B. subtilis significant affected (p<0.05) 33 different functional pathways such as lipid metabolism and carbohydrate metabolism. This explains the phenomenon of increased growth performance and liver NADP-ME activity in the probiotics group.

CONCLUSION

The compatibility of C. butyricum and B. subtilis could improve the growth of broilers during the starter phase by changing the cecal microflora.

Oregano essential oil and Bacillus subtilis role in enhancing broiler's growth, stress indicators, intestinal integrity, and gene expression under high stocking density

This study investigates the role of dietary Bacillus subtilis and oregano essential oil in mitigating the effects of high stocking density on growth performance, carcass traits, physiological stress indicators, gene expression, and intestinal integrity in broiler chickens. A total of, 1250 one-day-old Ross 308 male broiler chicks were randomly allocated to five experimental groups, where each group had five replicates of 50 chicks. Group 1 (control, LSD): 15 chicks/m2 fed a basal diet without feed additive, group 2 (HSD): 20 chicks/m2 fed a basal diet without feed additive, group 3 (BHSD): 20 chicks/m2 fed a basal diet supplemented with B. subtilis (500 mg/kg diet), group 4 (OHSD): 20 chicks/m2 fed a basal diet supplemented with oregano essential oil (300 mg/kg diet), group 5 (CHSD): 20 chicks/m2 fed a basal diet supplemented with oregano essential oil and B. subtilis. At 35 days of age, there was a noticeable improvement in the growth performance of broilers fed CHSD under high stocking density through the increase in body weight gain, dressing percentage, and crude protein digestibility with a decrease in feed conversion rate compared to other groups. Adding CHSD enhanced the state of oxidation and immunity through increasing superoxide dismutase, glutathione peroxidase, and the relative weight of bursa of Fabricius, while decreasing malondialdehyde, in addition to increasing plasma triiodothyronine levels. The microbial structure and morphometric parameters improved in the group that received the CHSD compared to the other groups, where villus height and Lactobacillus population increased, whereas Escherichia coli and Clostridium perfringens population decreased. Glucose transporter 2 (GLUT2), fatty acid transporter 1 (FABP1), and amino acid transferase 1 (CAT1) gene expression levels significantly increased when feeding on oregano essential oil with B. subtilis. In conclusion, combining oregano essential oil and B. subtilis supplements mitigated the effects of high stocking density by enhancing growth performance, antioxidative status, and intestinal integrity, in addition to modifying the genetic expression of genes related to nutrient absorption.

Dietary supplementation with Bacillus subtilis KC1 alleviates the negative effects of Mycoplasma gallisepticum on growth performance and amino acid metabolism of broiler chickens

The aim of this study was to explore whether and how Bacillus subtilis KC1 can enhance the growth performance of Mycoplasma gallisepticum (MG)-infected broilers. Broilers were randomly divided into 4 groups: the control group (basal diet), the MG group (basal diet + MG challenge), the KC group (basal diet + B. subtilis KC1 supplementation), the KC + MG group (basal diet + B. subtilis KC1 supplementation + MG challenge). The results showed that, compared to the control group, MG group exhibited significantly reduced body weight and average daily gain, and increased feed conversion ratio of broilers. However, compared to the MG group, the B. subtilis KC1 + MG group exhibited significantly improved above indicators of growth performance. In addition, compared to the MG group, B. subtilis KC1 + MG group exhibited increased superoxide dismutase levels and reduced levels of malondialdehyde, interleukin-1β, and tumor necrosis factor-α of broilers. Furthermore, metabolomics and transcriptomics analyses indicated that MG infection disrupted amino acid metabolism in broilers, whereas B. subtilis KC1 supplementation alleviated the abnormal amino acid metabolism caused by MG. These results suggested that B. subtilis KC1 may alleviate the poor growth performance caused by MG infection in broilers by improving amino acid metabolism.

Dietary Bacillus velezensis KNF-209 supplementation improves growth performance, enhances immunity, and promotes gut health in broilers

This study aimed to investigate the effects of dietary Bacillus velezensis KNF-209 (BV-KNF-209) on the growth performance, immunity, and gut health of broilers. A total of 540 one-day-old male Cobb-500 broilers were randomly divided into 5 groups of 6 replicates with 18 broilers per replicate. Dietary treatments were corn-soybean meal basal diets supplemented with 0, 50, 100, 200, and 400 mg/kg BV-KNF-209 (CON, BV 50, BV 100, BV 200, and BV 400 groups, respectively) for 42 d. Compared with the CON group, the average daily gains (ADG) at 0 to 42 d in the BV 100 and BV 200 groups were significantly increased (P < 0.01), and the feed-to-gain (F:G) ratios were significantly decreased at 0 to 21 d (P < 0.01) and 0 to 42 d (P < 0.05). The BV 200 and BV 400 groups had higher serum immunoglobulin M (IgM) levels at d 21 and 42 (P < 0.05). The serum levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were significantly decreased in the BV 50, BV 100, and BV 200 groups at d 21 (P < 0.05), and serum IL-1β and IL-6 levels were also reduced in the BV 100 and BV 200 groups at d 42 (P < 0.05). Meanwhile, increased interleukin-10 (IL-10) levels in the jejunal and ileal mucosa at d 42 were observed in the BV 100, BV 200, and BV 400 groups (P < 0.05), while the IL-1β and IL-6 levels (P < 0.01) were decreased. The BV 200 and BV 400 groups showed significantly higher activities of lipase and trypsin (P < 0.05) in jejunal digesta as well as higher activities of amylase and trypsin (P < 0.01) in ileal digesta at d 42. The cecal acetic acid and propionic acid levels in the BV groups and lactic acid levels in the BV 50, BV 100, and BV 200 groups (P < 0.05) were significantly higher compared to those in the CON group. Overall, dietary BV-KNF-209 supplementation significantly improved broiler growth performance, an effect that may have been achieved by heightening immunity, increasing digestive enzyme activity, and raising intestinal short-chain fatty acids and lactic acid levels.

Lignocellulose and probiotic supplementation in broiler chicken diet: effect on growth performance, digestive health, litter quality, and genes expression

Three hundred one-day-old Avian 48 broiler chicks were used to investigate the effect of lignocellulose (LC) and probiotic supplementation in broiler chicken diet on growth performance, digestive health, litter quality, and some gene expression. Experimental treatments consisted of 3 × 2 factorial arrangements with 3 levels of LC without or with probiotics to formulate 6 experimental groups. Groups 1, 2, and 3 were fed on the basal diet with dietary LC inclusion at 0, 0.5, and 1.0%, respectively, while groups 4, 5, and 6 were fed on the previously mentioned design with Bacillus subtilis at 100 gm/ton. The results revealed that Dietary LC inclusion nonsignificantly (P ≥ 0.05) reduced body weight (BW), body weight gain (BWG), and feed intake. Meanwhile, B. subtilis supplementation improved BW and BWG and enhanced the effect of LC on the broilers' weight. The group fed a 0.5% LC and B. subtilis-supplemented diet recorded the best (P ≥ 0.05) BW, BWG, FCR, PER, EEU, and PI. LC and or B. subtilis supplementation improved carcass traits of broiler (higher dressing% with lower abdominal fat% compared with a control group), intestinal health, and absorptive capacity. LC potentiates the effect of B. subtilis supplementation in broilers' diet in modulating intestinal microflora (lowered (P ≥ 0.05) cecal Coliform and increased Lactobacillus counts), the highest Coliform counts were recorded in group fed 0.5 or 1.0% LC plus B. subtilis. LC at 0.5 or 1.0% and or B. subtilis supplementation reduced (P ≥ 0.05) litter moisture% at the 2nd, 4th, and 6th wk compared to the control group. Dietary inclusion of LC and or B. subtilis supplementation significantly (P < 0.001) up-regulated hepatic growth-related genes (growth hormone receptor (GHR) and insulin growth factor1 (IGF-1)) and antioxidant-related genes (superoxide dismutase 1 (SOD1), glutathione peroxidase (GPX1) and uncoupling protein (UCP) and down-regulated (P < 0.001) splenic toll-like receptor 4 (TLRP) gene expression while had no significant effect on splenic interleukin 8 (IL8) and tumor necrosis factor (TNF) with the best-obtained results with 1.0% followed by 0.5% LC with B. subtilis supplementation. We concluded that dietary LC and/or B. subtilis supplementation positively affected the growth performance, feed efficiency, carcass quality, intestinal absorptive capacity and health, litter quality and growth, and antioxidant and immune-related gene expression.

Bacillus subtilis HW2 enhances growth performance and alleviates gut injury via attenuation of endoplasmic reticulum stress and regulation of gut microbiota in broilers under necrotic enteritis challenge

This study investigated the effects of Bacillus subtilis HW2 on the growth performance, immune response, endoplasmic reticulum (ER) stress, and intestinal health in broilers with necrotic enteritis. Three hundred 1-day-old male Cobb 500 broilers (33.88 ± 2.34 g) were randomly allocated to 5 groups including non-infected control (NC group), basal diet + necrotic enteritis challenge (NE group), basal diet + 1 × 106 CFU/g B. subtilis HW2 + necrotic enteritis challenge (L-Pro group), basal diet + 5 × 106 CFU/g B. subtilis HW2 + necrotic enteritis challenge (M-Pro group), and basal diet + 1 × 107 CFU/g B. subtilis HW2 + necrotic enteritis challenge (H-Pro group), with 6 replicates per group. All broilers except NC group were orally given with sporulated coccidian oocysts at day 14 and Clostridium perfringens from days 19 to 21. Results showed that L-Pro and M-Pro groups improved growth performance and intestinal morphology in necrotic enteritis-challenged broilers, and L-Pro, M-Pro, and H-Pro groups improved intestinal barrier function and immune response and decreased ER stress in necrotic enteritis-challenged broilers. Analysis of the gut microbiota revealed that L-Pro group increased the abundances of Alistipes, Coprobacter, Barnesiella, and Limosilactobacillus, decreased Erysipelatoclostridium abundance on day 42 in necrotic enteritis-challenged broilers. M-Pro group increased Turicibacter abundance on day 28 and the abundances of Alistipes, Barnesiella, and Limosilactobacillus on day 42 in necrotic enteritis-challenged broilers. H-Pro group decreased Romboutsia abundance on day 28 and unidentified_Clostridia abundance on day 42 in necrotic enteritis-challenged broilers. Analysis of short-chain fatty acids (SCFAs) revealed higher isobutyric acid and isovaleric acid levels in L-Pro and M-Pro groups than NE group. Correlation analysis revealed the correlations between the biochemical parameters and gut microbiota as well as SCFAs, especially Romboutsia, Barnesiella, Coprobacter, isobutyric acid, and isovaleric acid. Overall, our results indicated that B. subtilis HW2 supplementation could ameliorate necrotic enteritis infection-induced gut injury. The optimal dietary supplementation dosage of Bacillus subtilis HW2 was 5 × 106 CFU/g.

Association of Bacillus subtilis and Bacillus amyloliquefaciens: minimizes the adverse effects of necrotic enteritis in the gastrointestinal tract and improves zootechnical performance in broiler chickens

This study aimed to evaluate the efficiency and capacity of the probiotic composed of Bacillus subtilis and Bacillus amyloliquefaciens, in improving the zootechnical performance of broiler chickens challenged with Eimeria spp. and Clostridium perfringens. The broilers were distributed in a completely randomized design in poultry isolators (12 birds each), resulting in 3 treatments: T1 (control, no challenge and no Bacillus in diet), T2 (challenged with Eimeria spp., followed by Clostridium perfringens infection and no Bacillus in the diet), and T3 (challenged with Eimeria spp., Clostridium perfringens and treated with Bacillus subtilis and Bacillus amyloliquefaciens). They were evaluated for a period of 29 d, divided into preinitial (1-7 d of age), initial (8-21 d), and growth (22-29 d) phases. Assessments of body weight, weight gain, feed consumption, and feed conversion were conducted, along with the classification of the scores and optical microscopy of the tract gastrointestinal. The animals challenged and treated with the probiotic containing Bacillus spp. showed improved indicators of zootechnical performance. Additionally, the animals challenged and treated (T3) had a better score for intestinal lesions compared to the other treatment groups. Therefore, the probiotic consisting of Bacillus subtilis and Bacillus amyloliquefaciens could be considered an effective option for disease prevention and improving the zootechnical performance of broiler chickens.

Lactobacillus acidophilus and Bacillus subtilis significantly change the growth performance, serum immunity and cecal microbiota of Cherry Valley ducks during the fattening period

This study explored the effects of a Bacillus subtilis and Lactobacillus acidophilus mixture containing the co-fermented products of the two probiotics on growth performance, serum immunity and cecal microbiota of Cherry Valley ducks. This study included 480 one-day-old Cherry Valley ducks divided into four feeding groups: basal diet (control group) and basal diet supplemented with 300, 500, or 700 mg/kg of the probiotic powder; the ducks were raised for 42 days. Compared with the control group, body weight on day 42 and the average daily gain on days 15-42 significantly increased (p < 0.05), and the feed conversion rate significantly decreased (p < 0.05) in the experimental groups. Furthermore, the serum immunoglobulin (Ig) A, IgG, IgM, and interleukin (IL)-4 levels increased significantly (p < 0.05), and IL-1β, IL-2, and tumor necrosis factor-α decreased significantly (p < 0.05) in the experimental groups. Finally, Sellimonas, Prevotellaceae NK3B31 group, Lachnospiraceae NK4A136 group and Butyricoccus played an important role in the cecal microbiota of the experimental group. Thus, the probiotic powder has impacts on the growth performance, serum immunity and cecal microbiota of Cherry Valley Ducks.

Effects of antibiotic, acidifier, and probiotic supplementation on mortality rates, lipoprotein profile, and carcass traits of broiler chickens

Antimicrobial resistance is a significant issue, therefore it's relevant to assess the effects of antibiotics, acidifiers, and probiotic supplementation finding a good alternative to reduce the use of antibiotics in broiler production in rural areas of Bangladesh. Using randomized control trial, this 28-day study evaluated 360 Hubbard Classic broiler chicks divided into four groups: oxytetracycline-treated, acidifier-treated, Lactobacillus-based probiotic-treated, and control (no antibiotics, acidifiers, or probiotics). Each group was replicated three times with 30 birds each with adlibitum feeding. Body weight and feed intake were recorded weekly, and on 28th day, carcass traits and blood lipoprotein levels were evaluated. Results showed that in first and fourth weeks, the body weight gain significantly varied in probiotics and acidifier-treated birds than the control group (P < 0.001). The probiotic group had gained considerable increase in body weight (185.0 g vs 161.7 g and 1745.0 g vs 1592.7 g) than the control group. Notably, in the first week, the feed conversion ratio for the probiotic group was 0.76, but the antibiotic group's was 0.96 (P < 0.001). The weights of the drumstick (88.33 g) and liver (61.0 g) having probiotic supplements were substantially higher than those in the control group (77.0 g and 51.33 g, respectively) (P < 0.001). According to serum lipoprotein analysis, the probiotic and acidifier groups exhibited lower LDL levels (71.1 mg/dl and 69.8 mg/dl, respectively) and higher triglyceride levels (122.9 mg/dl and 135.4 mg/dl). These findings highlight the potential of probiotics and acidifiers as effective antibiotic alternatives, promoting carcass traits and lowering LDL levels in broilers in Bangladesh.

The fermented product of high-yield surfactin strain Bacillus subtilis LYS1 improves the growth performance and intestinal villi morphology in broilers

This study aimed to select Bacillus spp. for surfactin production by solid-state fermentation and to investigate the physiochemical characterizations of the fermented product (FP) and its effect on growth performance, carcass trait, intestinal morphology, and clinical blood biochemistry of broilers. Accordingly, the correlations between the functional components of FP and the growth performance of broilers are elucidated. Four hundred eighty 1-day-old Ross 308 broiler chicks were randomly assigned to dietary supplementation of 2.5% fish meal, 2.5% unfermented product, or 2.5% FP produced by Bacillus subtilis LYS1 (LYS1), Bacillus amyloliquefaciens Da16, B. subtilis Lo6 (Lo6), B. subtilis NSN7, B. subtilis subsp. natto N21, or B. subtilis N12. Each treatment had 6 replicates. The experimental period was 5 wk. Results showed that the Lo6 showed the highest protease activity among all fermented groups. The LYS1 showed the highest surfactin yields (10.69 mg/g) among all fermented groups (P < 0.05). The weight gain (WG), feed conversion ratio (FCR), and production efficiency factor (PEF) of LYS1 group were significantly better than unfermented group at 0 to 3 and 0 to 5-wk-old (P < 0.05). The Bacillus-like counts and surfactin content of FP were moderately correlated to WG (0.7 > r > 0.3), FCR (-0.3 > r > -0.7), and PEF (0.7 > r > 0.3) at 0 to 3 and 0 to 5-wk-old (P < 0.05). The protease activity of FP was moderately correlated to WG (0.7 > r > 0.3), FCR (-0.3 > r > -0.7), and PEF (0.7 > r > 0.3) at 0 to 3-wk-old (P < 0.05). The villus height to crypt depth ratio in duodenum and jejunum of fish meal group and LYS1 group were higher than unfermented group (P < 0.05). In conclusion, LYS1 shows the highest surfactin yields. Diets supplemented with 2.5% LYS1 FP can improve the growth performance and the development of intestinal villi in broilers. Moreover, this study proves that the surfactin content, Bacillus-like counts, and protease activity of FP show a correlation to the growth performance of broilers.

Effect of Bacillus subtilis and Oregano Oil on Performance, Gut Microbiome, and Intestinal Morphology in Pullets

This study aimed to examine the effect of probiotics containing Bacillus subtilis and oregano essential oil on the growth performance, intestinal morphology, and cecal microbial composition in pullets aged 0-18 weeks. A total of 324 day-old Hy-Line Brown chicks were randomly assigned to three treatment groups, with six replicates per group and 18 birds per pen. The experimental treatments consisted of the following: a control group receiving a basal diet (Con), a group receiving a basal diet supplemented with 1 g/kg (3 × 108 cfu/kg) of Bacillus subtilis (BS), and a group receiving a basal diet supplemented with 0.3 g/kg of oregano essential oil (ORO). The groups supplemented with BS and ORO demonstrated significantly higher villus height/crypt depth ratios than the Con group. Microbial richness was significantly higher in groups supplemented with BS (p = 0.0317) and ORO (p = 0.00794) than in the Con group. These findings revealed a distinct separation between gut microbial communities of the Con group and those supplemented with ORO, based on unweighted and weighted UniFrac indices. Therefore, supplementation with Bacillus subtilis and oregano oil improved the composition of the microbiota, suggesting their positive effects on the gut health of pullets.

Bacillus subtilis KC1 prevents Mycoplasma gallisepticum-induced lung injury by enhancing intestinal Bifidobacterium animalis and regulating indole metabolism in chickens

It has been reported that dietary administration of Bacillus subtilis KC1 is effective in alleviating lung injury induced by Mycoplasma gallisepticum (MG) infection in chickens. However, the underlying molecular mechanism of B. subtilis KC1 against MG infection is still unclear. The purpose of this study was to determine whether B. subtilis KC1 could alleviate MG infection-induced lung injury in chickens by regulating their gut microbiota. The results of this study indicate that B. subtilis KC1 supplementation has the potential to alleviate MG infection-induced lung injury as reflected by reduced MG colonization, reduced pathologic changes, and decreased production of pro-inflammatory cytokines. In addition, B. subtilis KC1 supplementation was partially effective in alleviating the gut microbiota disorder caused by MG infection. Importantly, B. subtilis KC1 enriched the beneficial Bifidobacterium animalis in gut and thus reversed indole metabolic dysfunction caused by MG infection. B. subtilis KC1 supplementation increased levels of indole, which enhanced aryl hydrocarbon receptor activation, improving barrier function and alleviating lung inflammation caused by MG. Overall, this study indicates that B. subtilis KC1 has a "gut-lung axis" mechanism that can reduce the severity of MG infection by enriching intestinal B. animalis and regulating indole metabolism.

Soybean Oil Regulates the Fatty Acid Synthesis II System of Bacillus amyloliquefaciens LFB112 by Activating Acetyl-CoA Levels

[Background] Bacillus LFB112 is a strain of Bacillus amyloliquefaciens screened in our laboratory. Previous studies found that it has a strong ability for fatty acid metabolism and can improve the lipid metabolism of broilers when used as feed additives. [Methods] This study aimed to confirm the fatty acid metabolism of Bacillus LFB112. Sterilized soybean oil (SSO) was added to the Beef Peptone Yeast (BPY) medium, and its effect on fatty acid content in the supernatant and bacteria, as well as expression levels of genes related to fatty acid metabolism, were studied. The control group was the original culture medium without oil. [Results] Acetic acid produced by the SSO group of Bacillus LFB112 decreased, but the content of unsaturated fatty acids increased. The 1.6% SSO group significantly increased the contents of pyruvate and acetyl-CoA in the pellets. Furthermore, the mRNA levels of enzymes involved in the type II fatty acid synthesis pathway of FabD, FabH, FabG, FabZ, FabI, and FabF were up-regulated. [Conclusions] Soybean oil increased the content of acetyl-CoA in Bacillus LFB112, activated its type II fatty acid synthesis pathway, and improved the fatty acid metabolism level of Bacillus LFB112. These intriguing results pave the way for further investigations into the intricate interplay between Bacillus LFB112 and fatty acid metabolism, with potential applications in animal nutrition and feed additive development.

Advances in enteropathogen control throughout the meat chicken production chain

Enteropathogens, namely Salmonella and Campylobacter, are a concern in global public health and have been attributed in numerous risk assessments to a poultry source. During the last decade, a large body of research addressing this problem has been published. The literature reviewed contains review articles on certain aspects of poultry production chain; however, in the past decade there has not been a review on the entire chain-farm to fork-of poultry production. For this review, a pool of 514 articles were selected for relevance via a systematic screening process (from >7500 original search articles). These studies identified a diversity of management and intervention strategies for the elimination or reduction of enteropathogens in poultry production. Many studies were laboratory or limited field trials with implementation in true commercial operations being problematic. Entities considering using commercial antienteropathogen products and interventions are advised to perform an internal validation and fit-for-purpose trial as Salmonella and Campylobacter serovars and biovars may have regional diversity. Future research should focus on nonchemical application within the processing plant and how a combination of synergisticinterventions through the production chain may contribute to reducing the overall carcass burden of enteropathogens, coupled with increased consumer education on safe handling and cooking of poultry.

Metabolic profiling of bacterial co-cultures reveals intermicrobiome interactions and dominant species

In animal production, the use of probiotic microorganisms has increased since the ban on antibiotic growth promoters in 2006. The added microorganisms interact with the microbiome of the animals, whereby the probiotic activity is not fully understood. Several microorganisms of the genus Bacillus are already known for their probiotic activity and are applied as feed supplements to increase the health status of the animals. They are thought to interact with Escherichia coli, one of the most abundant bacteria in the animal gut. In biotechnological applications, co-culturing enables the regulation of bacterial interaction or the production of target metabolites. The basic principles of multi-imaging high-performance thin-layer chromatography (HPTLC) with upstream cultivation were further developed to analyze the metabolic profiles of three axenic bacilli cultures compared to their co-cultures with E. coli DSM 18039 (K12). The comparative profiling visualized bacteria's metabolic interactions and showed how the presence of E. coli affects the metabolite formation of bacilli. The characteristic metabolic profile images showed not only the influence of microbiomes but also of inoculation, cultivation and nutrients on the commercial probiotic. The formation of antimicrobially active metabolites, detected via three different planar bioassays, was influenced by the presence of other microorganisms, especially in the probiotic. This first application of multi-imaging HPTLC in the field of co-culturing enabled visualization of metabolic interactions of bacteria via their produced chemical as well as bioactive metabolite profiles. The metabolic profiling provided evidence of bacterial interactions, intermicrobiome influences and dominant species in the co-culture.

Compound probiotics can improve intestinal health by affecting the gut microbiota of broilers

Probiotics, as a widely used additive, have played a unique advantage in replacing antibiotic products. As a result, the probiotic effects on broiler development, intestinal flora, intestinal barrier, and immunity were assessed by this investigation. Four hundred and eighty 1-day-old Arbor Acres broilers were randomly allotted to 4 groups of 5 replicates with 24 broilers each. The control was fed only a basal corn-soybean meal diet. Probiotics I, probiotics II, and probiotics III were fed basal diet and 1, 5, and 10 g/kg compound probiotics (Lactobacillus casei: Lactobacillus acidophilus: Bifidobacterium = 1:1:2), respectively. We found that broilers in the compound probiotic group exhibited better growth performance and carcass characteristics compared with control, especially among probiotics III group. The intestinal barrier-related genes relative expression of Claudin, Occludin, MUC2, and ZO-1 mRNA in the probiotic group increased at 21 and 42 d compared with control, especially among probiotics III group (P < 0.05). The early gut immune-related genes (TLR2, TLR4, IL-1β, and IL-2) mRNA increased compared with control, while the trend at 42 d was completely opposite to that in the earlier stage (P < 0.05). Among them, probiotics III group showed the most significant changes compared to probiotics II group and probiotics I group. Select probiotics III group and control group for 16S rDNA amplicon sequencing analysis. The 16S rDNA amplicon sequencing results demonstrated that probiotics increased the relative abundance of beneficial microbes such as o_Bacteroidales, f_Rikenellaceae, and g_Alistipes and improved the cecum's gut microbiota of 42-day-old broilers. Additionally, adding the probiotics decreased the relative abundance of harmful microbes such as Proteobacteria. PICRUSt2 functional analysis revealed that most proteins were enriched in DNA replication, transcription, and glycolysis processes. Therefore, this study can provide theoretical reference value for probiotics to improve production performance, improve intestinal barrier, immunity, intestinal flora of broilers, and the application of probiotics.

Effect of multi-strain probiotics on the performance of AA+ male broilers

The aim of the experiment was to investigate the effects of a probiotic complex (PC) consisting of Bacillus subtilis, Clostridium butyricum and Enterococcus faecalis on productive performance, carcass traits, immune organ indices, fecal microbiota counts and noxious gas emissions in AA+ male broilers. Three hundred and sixty 1-day-old AA+ male broilers with similar body weight (44.77 ± 0.25) were randomly divided into 3 treatment groups of 6 replicates each, with 20 broilers in each replicate. The experimental groups consisted of a group fed a basal diet and groups fed basal diet supplemented with 0.1 and 0.2% PC. The results showed that the addition of PC had no significant effect (P > 0.05) on growth performance, and carcass traits of AA+ broilers during the experimental period (1-42 days of age). Dietary addition of PC significantly increased the thymus index of AA+ broilers (P < 0.05), reduced the number of E. coli and Salmonella in feces (P < 0.01) and reduced the concentrations of fecal NH₃ and H₂S emissions (P < 0.01). Furthermore, birds fed 0.2% PC diet had the highest number of fecal Lactobacillus counts. Results indicate that probiotic complex consisting of Bacillus subtilis, Clostridium butyricum and Enterococcus faecalis enhances immune organ development, reduces the number of E. coli and Salmonella in feces, increases the number of Lactobacillus and reduces NH₃ and H₂S emissions in feces. This trial provides a theoretical basis for the use of probiotic complexes in broiler production.

Host-derived bacillus spp. as probiotic additives for improved growth performance in broilers

In recent years, the utilization of antibiotics in animal feed has been restricted, probiotics have been increasingly used to replace antibiotics in maintaining animal health. The aim of this study was to screen and evaluate probiotics with excellent probiotic potential from the gut of healthy goslings for clinical application. Thirteen strains of Bacillus (named AH-G201 to AH-G2013), including 2 strains of Bacillus subtilis (B. subtilis), 6 strains of Bacillus licheniformis (B. licheniformis) and 5 strains of Bacillus amyloliquefaciens (B. amyloliquefaciens), were isolated and identified. Then, acid and bile salts tolerance tests were performed to screen probiotics strains that could survive under different environments. The effects of screened probiotics on the growth of pathogenic Escherichia coli (E. coli) and Salmonella were assessed. Furthermore, we performed the drug resistance tests and safety tests in animals. The results showed that B. Subtilis AH-G201, B. licheniformis AH-G202 and AH-G204 exhibited higher gastrointestinal resistance under in vitro conditions, and showed a moderate level of resistance to the tested antibiotics. Importantly, AH-G201 and AH-G202 showed 24 to 60% inhibition rate against pathogenic E. coli and Salmonella. Moreover, the safety analysis of AH-G201 and AH-G202 suggested that the 2 probiotics strains have no adverse effects on body weight gain and feed intake in the broilers, and in addition, they have significantly improved growth performance. Finally, we analyzed effects of B. Subtilis AH-G201and B. licheniformis AH-G202 on growth performance, immune organ index and the feces microbes of broilers. The results showed that broilers fed with high doses (5 × 10⁹ CFU/mL, for single strain) of a mixture of AH-G201 and AH-G202 exhibited good growth performance, and exhibited the greatest gain in spleen weight and the highest lactic acid bacteria counts. These findings indicate that the combined addition of B. Subtilis AH-G201 and B. licheniformis AH-G202 has the potential to replace antibiotics and to improve the growth performance of broilers.

Evaluation of in ovo feeding of low or high mixtures of cysteine and lysine on performance, intestinal morphology and physiological responses of thermal-challenged broiler embryos

The objective of this study was to evaluate the effect of in ovo feeding cysteine, lysine or their combinations on the perinatal and post-hatch physiological responses of broiler embryos exposed to heat stress during incubation. A total of two thousand fertile eggs of broiler breeders (Ross 308) flock (at 38 weeks of age) were used for this study. In the first 10 days, the eggs were incubated using the conventional protocol of relative humidity and temperature of 55% and 37.8°C respectively. From day ten onward, the temperature was increased to 39.6°C for 6 h per day. On day 17.5, 1,500 eggs with the evidence of living embryos were randomly selected and assigned to 6 treatments having five replicates of 50 eggs each. The treatments were: un-injected eggs (UI), eggs injected with only 0.5 ml distilled water (DW), 3.5 mg/egg cysteine (CY), 2mg/egg lysine (LY), 3.4 mg cysteine+2 mg lysine (CLH) and 1.7 mg cysteine+1 mg lysine (CLL). On day 21, the hatchability, anatomical characteristics, chick quality and the antioxidant status of the chicks were evaluated. During the post-hatch phase, data were collected on the haematology, biochemical parameters, growth performance and intestinal morphology of the birds. The results revealed that the hatchability of CY chicks was higher (p &lt; 0.05) than in the other treatments, while the lowest values were recorded in CLH. The hatching muscle of the chicks of CLL was similar to those of CY but higher (p &lt; 0.05) than the others. The MDA of DW and UI chickens was similar and higher than birds in the other treatment groups. The serum SOD of CLL birds was comparable to that of CY but higher than the values recorded in the other treatments. The final weights of CLL chickens were similar to those of LY but significantly higher (p &lt; 0.05) than those of the other treatments. The duodenal villus heights of the birds of CLL were higher than those of the other treatment groups, whereas the villus height of the birds of CLH was higher than those of UI, DW and CY. Overall, in ovo feeding of cysteine alone improved the hatchability of thermally-challenged broiler embryos. In contrast, a low-dose mixture of cysteine plus lysine improved the post-hatch growth performance.

Impact of Bacillus subtilis Antibiotic Bacilysin and Campylobacter jejuni Efflux Pumps on Pathogen Survival in Mixed Biofilms

The foodborne pathogen Campylobacter jejuni is typically found in an agricultural environment; in animals, such as birds, as an intestinal commensal; and also in food products, especially fresh poultry meat. Campylobacter interactions within mixed species biofilms are poorly understood, especially at the microscale. We have recently shown that the beneficial bacterium Bacillus subtilis reduces C. jejuni survival and biofilm formation in coculture by secreting the antibiotic bacillaene. We extend these studies here by providing evidence that besides bacillaene, the antagonistic effect of B. subtilis involves a nonribosomal peptide bacilysin and that the fully functional antagonism depends on the quorum-sensing transcriptional regulator ComA. Using confocal laser scanning microscopy, we also show that secreted antibiotics influence the distribution of C. jejuni and B. subtilis cells in the submerged biofilm and decrease the thickness of the pathogen's biofilm. Furthermore, we demonstrate that genes encoding structural or regulatory proteins of the efflux apparatus system (cmeF and cmeR), respectively, contribute to the survival of C. jejuni during interaction with B. subtilis PS-216. In conclusion, this study demonstrates a strong potential of B. subtilis PS-216 to reduce C. jejuni biofilm growth, which supports the application of the PS-216 strain to pathogen biofilm control. IMPORTANCE Campylobacter jejuni is a prevalent cause of foodborne infections worldwide, while Bacillus subtilis as a potential probiotic represents an alternative strategy to control this alimentary infection. However, only limited literature exists on the specific mechanisms that shape interactions between B. subtilis and C. jejuni in biofilms. This study shows that in the two species biofilms, B. subtilis produces two antibiotics, bacillaene and bacilysin, that inhibit C. jejuni growth. In addition, we provide the first evidence that specific pathogen efflux pumps contribute to the defense against B. subtilis attack. Specifically, the CmeDEF pump acts during the defense against bacilysin, while CmeR-dependent overexpression of CmeABC nullifies the bacillaene attack. The role of specific B. subtilis antibiotics and these polyspecific pumps, known for providing resistance against medically relevant antibiotics, has not been studied during bacterial competition in biofilms before. Hence, this work broadens our understanding of mechanisms that shape antagonisms and defense during probiotic-pathogen interactions.

Effects of Dietary Inclusion of β-Hydroxy-β-Methylbutyrate on Growth Performance, Fat Deposition, Bile Acid Metabolism, and Gut Microbiota Function in High-Fat and High-Cholesterol Diet-Challenged Layer Chickens

Excessive lipid deposition in layer chickens due to inappropriate feeding adversely affects egg production; however, nutritional manipulation methods to deal with this issue are still limited. β-hydroxy-β-methylbutyrate (HMB), a metabolite of L-leucine, was recently reported as a lipid-lowering nutrient in mice and pigs, although its role in layers had not been investigated. Here, we employed high-fat and high-cholesterol diet (HFHCD)-challenged growing layers as an obese model to explore HMB function in the regulation of lipid metabolism and the potential mechanisms involved. We found that dietary supplementation with (0.05% or 0.10%) HMB significantly reduced HFHCD-induced bodyweight growth in layers, mainly due to reduction in abdominal fat deposition. Mechanistically, HMB supplementation enhanced hepatic bile acid synthesis from cholesterol through elevating expression of Cyp7a1, a gene coding a key enzyme in bile acid synthesis. Furthermore, 16S rRNA gene sequencing revealed that HMB supplementation remodeled the diversity and composition of the layers' cecal microbiota, and the abundance of Bacteroidetes at the phylum level were especially affected. Correlation analysis further indicated a strong negative association between Bacteroidetes abundance and lipid metabolism-related parameters. Taken together, these data suggest that dietary HMB supplementation could improve abdominal fat deposition in layers, probably through modulating hepatic bile acid synthesis and gut microbiota function.

Effect of Dietary Supplementation of Bacillus subtilis on Growth Performance, Organ Weight, Digestive Enzyme Activities, and Serum Biochemical Indices in Broiler

This study was conducted to investigate the effects of supplementing Bacillus subtilis and an antibiotic (Zinc bacitracin) in the diet of broilers on growth performance, organ weight, blood metabolites, and digestive enzymes of broiler chickens. A total of 600 1-d Arbor Acres broilers were randomly allotted to five treatments. Each treatment consisted of six replicates with four pens, and each pen had five birds. The chicks were fed (1) the basal diet (control), (2) the basal diet with 500 mg/kg Zinc bacitracin (APZ), (3) the basal diet with B. subtilis at 1 × 108 CFU/g (B.Sut-1), (4) the basal diet with B. subtilis at 3 × 108 CFU/g (B.Sut-3), and (5) the basal diet with B. subtilis at 5 × 108 CFU/g (B.Sut-5). The experiment lasted for 42 days. In this study, the supplementation of diets with B. subtilis (B.Sut-3 and B.Sut-5 groups) increased body weight gain from 1 to 21 days compared with control (p < 0.05). Additionally, the B.Sut-3 group had a significantly heavier bursa of Fabricius than control at 21 days (p < 0.05). Serum total protein, albumin, and high-density lipoprotein concentrations were increased in B.Sut-5 and APZ groups (p < 0.05) over the whole period. Serum low-density lipoprotein, very low-density lipoprotein, triglyceride, and total cholesterol concentrations were decreased in B.Sut-5 and APZ groups at 21 and 42 days (p < 0.05). Chicks in the B.Sut-5 and APZ groups had higher serum lipase, pepsin, and amylase activities (p < 0.05) at 21 and 42 days. From the results obtained from the study, it can be concluded that Bacillus subtilis ATCC19659 at 5 × 108 CFU/g could be applied as an alternative to antibiotics in poultry diets.

Effect of Novel Lactobacillus paracaesi microcapsule on growth performance, gut health and microbiome community of broiler chickens

The beneficial action of probiotics is questioned time and again due to the loss of their survivability under gastrointestinal conditions, particularly gastric acid. In this experiment, a probiotic species was encapsulated to improve its delivery to the distal parts, and its effects on production performance, gut health, and microbial profile in broilers were investigated. A total of 240 Arbor acres (AA) broilers were randomly allotted into 3 treatments with 8 replicate pens per treatment and 10 broilers in each pen for 42 d. Dietary treatments were 1) basal feed without any additives (CON), 2) CON+15 ppm Virginiamycin (ANT), and 3) CON+500 ppm encapsulated Lactobacillus paracaesi (ELP). The result showed that the addition of ELP to the feed did not affect growth performance and carcass characteristics significantly. However, ELP increased the ratio of villus height to crypt depth (P < 0.05) and mRNA expression of ZO-1 (P < 0.05) relative to the CON or ANT group. Similarly, qPCR showed that dietary supplementation of ELP raised gene expression of the anti-inflammatory cytokine and tended to decrease proinflammatory cytokines resulting improve in immunity. Moreover, chicks fed with ELP had lower malondialdehyde (MDA) (P < 0.05) than CON and lower reactive oxygen species (ROS) (P < 0.05) level than ANT in serum. In contrast, the total antioxidant capacity (TAOC) level was tended to increase. The ammonia level of ileum and cecum chyme was decreased (P < 0.05) in the ELP group than CON while the level of propionic acid of cecal content was increased (P < 0.05). 16S rRNA sequencing revealed the dietary treatment modulated the diversity and composition of cecal microflora. At the phylum level, Bacteroidetes was enriched, and Proteobacteria was depleted in the ELP group. At the genus level, ELP increased Bacteroides (P < 0.05) compared to control. The results indicate that oral delivery of probiotics via microcapsule could impart beneficial effects on birds and be used as an alternative to antibiotics.

Feeding Bacillus subtilis ATCC19659 to Broiler Chickens Enhances Growth Performance and Immune Function by Modulating Intestinal Morphology and Cecum Microbiota

This study investigated dietary supplementation with Bacillus subtilis (BS) ATCC19659 on growth performance, biochemical indices, intestinal morphology, and cecum microflora in broiler chicks. A total of 600 Arbor 1-day Acres broilers of either sex were allotted to 5 treatments: chicks were fed a corn- and soybean-based diet (CON); chicks were fed basal diet containing 500 mg ZnB/kg (ZnB); chicks were fed basal diet containing 1 × 10⁸ CFU/g feed of BS-ATCC19659 (BS-1); chicks were fed basal diet containing 3 × 10⁸ CFU/g feed of BS-ATCC19659 (BS-3); and chicks were fed basal diet containing 5 × 10⁸ CFU/g feed of BS-ATCC19659 (BS-5). Each treatment comprised 6 replicates with 20 birds for each replicate pen. Chicks in the BS-5 and BS-3 groups had higher body weight at the 21^st and 42^nd days and average daily gain from 1 to 21 days than that in the CON group (p < 0.05). Chicks in the BS-5 and ZnB groups had higher serum antioxidant activities and immunity response than those in the CON group (p < 0.05). Compared with the CON group, the liver mRNA abundance of GHR, TGF-β, IGF-1, IFN-γ, SOD, CAT, and GPX of chicks in three BS groups and the ileum villus length (μm) of chicks in BS-3 and ZnB groups was increased (p < 0.05). Compared with the CON group, the villus height-to-crypt depth ratio of the ileum of chicks in the BS-5 and BS-3 groups and the crypt depth and villus height-to-crypt depth ratio of the jejunum in the BS-5 and ZnB groups were increased (p < 0.05). The abundance of the Cyanobacteria phyla in the cecum decreased in response to treatment with both BS-ATCC19659 and ZnB groups (p < 0.05). Compared with the CON group, the cecum abundance of genera GCA-900066575 (Lachnospiraceae), Anaerofustis, and Papillibacter (Firmicutes phylum) in three BS groups were increased (p < 0.05); The abundance of genus Escherichia–Shigella reduced in the BS-3 group (p < 0.05). Compared with the CON group, the cecum abundance of genus Clostridia_unclassified in ZnB and BS-5 groups was decreased (p < 0.05) of broilers. Generally, Bacillus subtilis ATCC19659 as feed additive positively affected growth performance, immunity response, and cecal microflora of broilers.

Effects of zinc and Bacillus subtilis on the reproductive performance, egg quality, nutrient digestion, intestinal morphology, and serum antioxidant capacity of geese breeders

The effects of zinc (Zn) and Bacillus subtilis (B. subtilis) on reproductive performance, egg quality, nutrient digestion, intestine morphology, and antioxidant capacity were explored in geese breeders. Geese breeders (n = 120, 46-wk of age) were randomly assigned into 6 groups with 4 replicates of 5 birds each (1 male and 4 female). Breeders were fed diets with 2 levels of B. subtilis (2.5 × 10⁹ and 5 × 10⁹ CFU/kg) crossed with three levels of Zn (25, 45, and 65 mg/kg) for duration of 10-wk. The results showed that the egg laying rate (P < 0.05), fertility rate (P < 0.01), hatchability rate (P < 0.05), yolk color (P < 0.05), and the retentions of crude protein (P < 0.05), ether extract (P < 0.05) and phosphorus of geese breeders were improved by dietary supplementation of 5 × 10⁹ CFU/kg B. subtilis and 25 mg or 45 mg/kg Zn. The serum T-SOD (P < 0.05) was increased by 45 mg/kg Zn supplementation. The serum T-AOC (P < 0.05) and retention of Zn (P < 0.05) were increased by 5 × 10⁹ CFU/kg B. subtilis supplementation. The birds fed with 5 × 10⁹ CFU/kg B. subtilis and 25 mg or 45 mg/kg Zn showed improved villus length (P < 0.01) and villus length/ crypt depth (P < 0.01) in both the jejunum and ileum. In conclusion, the combination of B. subtilis and Zn may have synergistic effects on these parameters, and dietary inclusion of 5 × 10⁹ CFU/kg B. subtilis and 45 mg/kg Zn is recommended for improving the reproductive performance of geese breeders.

Effect of probiotic supplementation on performance, morphology and gene expression associated with immune responses in early age of broiler chickens exposed to stress induced by corticosterone injection

Context Broiler chickens are exposed to various stressors, which can affect production performance. The use of dietary probiotics is one of the feasible methods to maintain performance, intestinal health, humeral immunity, and ameliorating physiological stress in the broiler. Aims In all, 288 1-day-old male broiler chicks were used to evaluate the effect of probiotic supplementation on performance, morphology, and gene expression associated with immune responses in the starter phase of broiler chickens exposed to stress. Methods In total, 288 1-day-old male broiler chicks (Ross 308) were assigned to evaluate the effects of Bacillus subtilis spore (BSS; Gallipro®200) supplementation at three levels (0, 0.8 × 105 colony-forming units (CFU) and 1.6 × 105 CFU/g feed) with corticosterone (CORT; 4 mg/kg BW at 7–9 days of age) or without CORT (oil) subcutaneous injection. The experiment was conducted in a completely randomised 2 × 3 factorial design. Key results CORT injection and probiotic supplementation led to an increase and decrease respectively, in food conversion ratio compared with the control group (P < 0.05). CORT injections reduced the expression of TLR4, HSP70 and IgA in all parts of the intestine. However, the TLR4 gene expression increased in jejunum by CORT injections. BSS supplementation induced the expression of TLR4 in all sections of the intestine, both in stress and non-stress conditions. In stress-exposed chickens, IgA expression in the jejunum was affected by BSS supplementation. Interaction effects between CORT injections and BSS supplementation on the gene expression were significant in different parts of the intestine. Conclusions Chicks exposed to stress conditions induced by CORT injection showed that the ileum was more susceptible than were the other parts, especially for TLR4 and HSP70 gene expression. BSS-supplemented birds showed more capability to face the stress condition, probably due to intestinal health and immunity-modulated effect of BSS. Implication Formulating a ration with a probiotic can be more effective in stress conditions, through modulating immune-responsive genes in the intestine.

Effects of the Probiotic Activity of Bacillus subtilis DSM 29784 in Cultures and Feeding Stuff

The European Union banned the usage of antibiotic growth promoters in animal production. The probiotic microorganism of the genus Bacillus appeared to be an attractive candidate to replace antibiotics. The Bacillus subtilis DSM 29784 is one of these strains. To date, the probiotic effect has not been completely understood, but it is supposed that the effect depends on metabolites of the microorganism. Imaging high-performance thin-layer chromatography (HPTLC) is a powerful tool to visualize differences in the metabolite profile of bacteria with high genetic similarity to allow a better understanding of the probiotic effect. In comparison to other bacteria, especially these bacterial cells were more robust to harsh cultivation conditions and produced a higher level of antioxidants or bioactive substances such as surfactin. HPTLC enabled the comparison of pure cell cultures to the spore cultivation in the feed, and the results explain and support the probiotic effect.

Performance, Serum Biochemical and Immunological Parameters, and Digestive Enzyme and Intestinal Barrier-Related Gene Expression of Broiler Chickens Fed Fermented Fava Bean By-Products as a Substitute for Conventional Feed

Improving the nutritional quality of unconventional feed ingredients such as fava bean by-products can enhance their utilization by broiler chickens. Hence, the quality of fermented fava bean by-products (FFB), in addition to growth, nutrient digestibility, digestive enzyme, and intestinal barrier-related gene expression, and serum biochemical and immunological parameters were evaluated in response to different levels of FFB. A total of 500 1-day-old broiler chicks (46.00 ± 0.388 g) were allocated to five groups with 10 replicates each (100 chicks per treatment). The first group was fed a corn-soybean diet (control diet), and the other four groups were fed a diet containing 5, 15, 25, and 35% FFB for 38 days. Birds fed 25% FFB exhibited maximum body weight gain (increase by 12.5%, compared with the control group) and the most improved feed conversion ratio. Additionally, birds fed FFB at 15, 25, and 35% showed improved dry matter and crude protein digestibility. Moreover, birds fed FFB at 25 and 35% exhibited a decrease in ileal pH and an increase in fiber digestibility (p < 0.05). Upregulation of digestive enzyme genes (AMY2A, PNLIP, and CCK) was observed in groups fed with FFB. The most prominent upregulation of genes encoding tight junction proteins (claudin-1, occludin, and junctional adhesion molecules) in the duodenum was observed in chicks fed 25 and 35% FFB (increase of 0.66-, 0.31-, and 1.06-fold and 0.74-, 0.44-, and 0.92-fold, respectively). Additionally, the highest expression level of enterocyte protective genes [glucagon-like peptide (GLP-2), mucin-2 (MUC-2), and fatty acid-binding protein (FABP-6)] was detected in duodenum of chicks fed high levels of FFB. Substitution of corn-soybean diet with FFB had an inhibitory effect on cecal pathogenic microbes (Escherichia coli and Clostridium perfringens) and increased beneficial microflora (Lactobacilli and Bifidobacterium), especially at high levels. Additionally, an increase was observed in IgM and lysozyme activity, with no effect on IgA in all groups fed FFB. All levels of FFB decreased cholesterol levels. Based on our results, we concluded that substitution of corn-soybean diet with FFB can improve the growth rate and nutrient digestibility of broiler chickens, enhance their intestinal barrier functions, and increase the number of beneficial microorganisms. Using FFB at 25% had a positive effect on the growth performance of broiler chickens, and it could be utilized in poultry farms.

Benefit of Dietary Supplementation with Bacillus subtilis BYS2 on Growth Performance, Immune Response, and Disease Resistance of Broilers

A strain of Bacillus subtilis (B. subtilis) BYS2 was previously isolated from Mount Tai, which is located in Tai'an City in the Shandong Province of China. The strain was then stored in the Environmental Microbiology Laboratory at Shandong Agricultural University. To evaluate the effect of the bacterium preparation in broiler production, we fed the bacterium (10⁶ CFU/g) to 1-day-old broilers and continued this feeding for 6 weeks to analyze its effect on growth and immune performance. We found that the average weight of the bacterium-fed group increased by 17.19% at weeks 5 compared to the control group (P < 0.05). The height of the villi in the duodenum and jejunum and the ratio of villi to crypt were significantly increased in the bacterium-fed group at weeks 5 (P < 0.05). Also, the IgG in the serum of broilers in the experimental group increased by 31.60% (P < 0.05) and IgM 30.52% (P < 0.05) compared with those in the control group. The expressions of the major pattern recognition receptors (PRRs), antiviral proteins, pro-inflammatory cytokines, and β-defensins were significantly higher than those in the control group (P < 0.05). Meanwhile, the bursa immune organ indices of broilers in the experimental group were significantly higher than those in the control group (P < 0.05). Also, after 5 weeks of continuous feeding, when infected with Escherichia coli (E. coli) O1K1 and Newcastle disease virus (NDV) F48E8, the content of bacteria and virus in tissues and organs of the experimental group decreased significantly, and the survival rate of infected chickens increased by 31.1% and 17.7%, respectively (P < 0.05). These results show that the anti-infective B. subtilis BYS2 could, to some extent, replace antibiotics to promote growth, improve innate immunity, and enhance disease resistance in broilers.

Impact of Fermented or Enzymatically Fermented Dried Olive Pomace on Growth, Expression of Digestive Enzyme and Glucose Transporter Genes, Oxidative Stability of Frozen Meat, and Economic Efficiency of Broiler Chickens

The use of dried olive pomace as complementary energy sources in poultry feed is still limited due to its low protein and high fiber contents. Bioconversion of olive pomace through solid-state fermentation with or without exogenous enzymes is considered as a trial for improving its nutritional value. This study aimed to evaluate the effects of fermented olive pomace with or without enzymatic treatment on the growth, modulations of genes encoding digestive enzymes and glucose transporters, meat oxidative stability, and economic efficiency of broiler chickens. A total of 1400 day-old broiler chicks (Ross 308) were randomly allocated to seven dietary treatments with 10 replicates of 20 birds/replicate. Treatments included control (basal corn-soybean diet) and other six treatments in which basal diet was replaced by three levels (7.5, 15, and 30%) of fermented olive pomace (FOPI) or enzymatically fermented olive pomace (FOPII) for 42 days. The highest body weight gain was observed in groups fed 7.5 and 15% FOPII (increased by 6.6 and 12.5%, respectively, when compared with the control group). Also, feeding on 7.5 and 15% FOPII yielded a better feed conversion ratio and improved the digestibility of crude protein, fat, and crude fiber. The expression of the SGLT-1 gene was upregulated in groups fed FOPI and FOPII when compared with the control group. Moreover, the expression of the GLUT2 gene was elevated in groups fed 7.5 and 15% FOPII. By increasing the levels of FOPI and FOPII in diets, the expression of genes encoding pancreatic AMY2A, PNLIP, and CCK was upregulated (p < 0.05) when compared with the control. Fat percentage and cholesterol content in breast meat were significantly reduced (p < 0.05) by nearly 13.7 and 16.7% in groups fed FOPI and FOPII at the levels of 15 and 30%. Total phenolic and flavonoid contents in breast meat were significantly increased in groups fed 15 and 30% FOPI and FOPII when compared with the control group and even after a long period of frozen storage. After 180 days of frozen storage, the inclusion of high levels of FOP significantly increased (p < 0.05) the levels of glutathione peroxide and total superoxide dismutase and meat ability to scavenge free radical 1,1-diphenyl-2-picrylhydrazyl. Furthermore, the highest net profit and profitability ratio and the lowest cost feed/kg body gain were achieved in groups fed 7.5 and 15% of FOPII, respectively. The results of this study indicated that dietary inclusion of 15% FOPII could enhance the growth performance and economic efficiency of broiler chickens. Moreover, a higher inclusion level of FOPI or FOPII could enhance the quality and increase the oxidative stability of frozen meat and extend the storage time.

Modulatory Effects of Bacillus subtilis on the Performance, Morphology, Cecal Microbiota and Gut Barrier Function of Laying Hens

We investigated the efficacy of a single bacterium strain, Bacillus subtilis (B. subtilis) YW1, on the performance, morphology, cecal microbiota, and intestinal barrier function of laying hens. A total of 216 28-week-old Hy-line Brown laying hens were divided into three dietary treatment groups, with six replicates of 12 birds each for 4 weeks. The control group (Ctr) was fed a basal diet and the treatment groups, T1 and T2, were fed a basal diet supplemented with B. subtilis at a dose rate of 5 × 108 CFU/kg and 2.5 × 109 CFU/kg, respectively. Dietary supplementation with B. subtilis did not significantly affect overall egg production in both groups, with no obvious changes in average egg weight and intestine morphology. B. subtilis administration also improved the physical barrier function of the intestine by inducing significantly greater expression levels of the tight junction protein occludin in T1 (p = 0.07) and T2 (p < 0.05). Further, supplementation with B. subtilis effectively modulated the cecal microbiota, increasing the relative level of beneficial bacteria at the genus level (e.g., Bifidobacterium p < 0.05, Lactobacillus p = 0.298, Bacillus p = 0.550) and decreasing the level of potential pathogens (e.g., Fusobacterium p < 0.05, Staphylococcus p < 0.05, Campylobacter p = 0.298). Overall, B. subtilis YW1 supplementation cannot significantly improve the egg production; however, it modulated the cecal microbiota towards a healthier pattern and promoted the mRNA expression of the tight junction protein occludin in laying hens, making B. subtilis YW1 a good probiotic candidate for application in the poultry industry, and further expanding the resources of strains of animal probiotics.

Supplementation of Bacillus subtilis GM5 enhances broiler body weight gain and modulates cecal microbiota

We investigated the effect of the strain Bacillus subtilis GM5 on growth, feed conversion, and the composition of cecum microbiota in broiler chickens. Half of which received a control diet, while the other half was fed a diet supplemented with GM5 spores. Cecal contents on days 1, 10, and 42 were subjected to metataxonomic analysis. Principal Component Analysis showed that the control and probiotic groups formed three separate clusters, indicating changes, which occurred gradually in microbial communities. On day 1, Firmicutes (53.87-57.61%) and Proteobacteria (43.77-38.93%) were prevalent in both groups, whereas samples of days 10 and 42 were predominantly occupied by Firmicutes (54.55-81.79%) and Bacteroidetes (26.94-30.45%). In the group of chickens treated with probiotic, the average daily gain in body weight was higher, while feed conversion decreased by 1.44%. A surge in the presence of beneficial bacteria of the Ruminococcaceae family was observed. The introduction of the probiotic led to an elevated Firmicutes/Bacteroidetes ratio, which positively correlated with chickens' bodyweight (Spearman ρ = 1.0, P < 0.05). Supplementing broiler feed with B. subtilis GM5 spores leads to improved feed intake and digestibility, which is paramount in reducing the cost of the final product. Thus, the probiotic strain GM5 modulates the cecal microbiota of broiler chickens and increases microbial diversity, which is well exhibited on the 42nd day.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-020-02634-2.

Effects of graded levels of microbial fermented or enzymatically treated dried brewer's grains on growth, digestive and nutrient transporter genes expression and cost effectiveness in broiler chickens

BACKGROUND

Poultry feed consists mainly of conventional grains and protein supplements, however, using treated unconventional agro-industrial by-products as replacements of corn soybean-based diet can minimize production costs and improve productivity. Therefore, in this study, the effects of fermented or enzymatically treated dried brewer grains (DBG) on growth, expression of digestive enzymes and nutrient transporters genes and the profitability of the rations were evaluated. A total of 1600 one-day-old Ross 308 broiler chicks were randomly distributed in 2 × 4 factorial arrangement (eight treatments with ten replicates, 20 birds/replicate). Experimental diets included two controls; negative control (basal corn-soybean diet; NC) and positive control (basal corn-soybean diet with exogenous enzymes; PC), and six diets in which basal diet was replaced by three levels of fermented DBG (FDBG; 5, 10 or 15%), or enzyme-treated DBG (DBG 5, 10 or 15%+Enz), for 38 days.

RESULTS

The results described that feeding FDBG (three levels) or DBG5%+Enz improved (P < 0.05) BW gain and feed efficiency of broilers. Also, feeding FDBG10% yielded the best improvement in weight gain (10%), compared to NC group. Increasing the inclusion levels of DBG either fermented or enzymatically treated up-regulated (p < 0.01) expression of digestive-genes in proventriculus (PGC and PGA5, range 1.4-1.8 fold), pancreas (AMY2A, PNLIP, CELA1, and CCK; range 1.2-2.3 fold) and duodenum (CAT1, CAT2, GLUT1, GLUT2, LAT1, Pep1; range 1.3-3 fold) when compared to NC group. Feeding treated DBG significantly increased (p < 0.05, range 4.5-13.6%) gizzard relative weight compared to NC and PC groups. An additional benefit was lower (p < 0.01) cholesterol content from 66.9 mg/100 mg (NC) to 62.8 mg/100 mg (FDBG5 or 10%) in thigh meat. Furthermore, the least cost feed/kg body gain was achieved in FDBG10% and DBG5%+Enz groups, with approx. 16% reduction compared to NC cost, leading to increasing the income gross margin by 47% and 40% in FDBG10% and DBG5%+Enz groups, respectively.

CONCLUSIONS

Substitution of corn-soybean based diet with 10% FDBG or 5% DBG+Enz resulted in better growth and higher economic efficiency of broilers chickens.

Effect of Heat-Inactivated Compound Probiotics on Growth Performance, Plasma Biochemical Indices, and Cecal Microbiome in Yellow-Feathered Broilers

This study was carried out to investigate the effect of heat-inactivated compound probiotics on growth performance, plasma biochemical indices, and gut microbiota composition and functions in yellow-feathered broilers. A total of 360 1-day-old broilers were randomly divided into 3 groups, including a basal diet as negative control group (PC), basal diet plus antibiotics with 250 mg/kg calcium oxytetracycline and 200 mg/kg Nosiheptide as positive control (PC), and basal diet plus 500 mg/kg compound probiotics consisting of heat-inactivated Bacillus subtilis and Lactobacillus acidophilus BFI (BFI). Each group had 6 replicates of 20 chickens. On d 21, 42, and 63, one chick from each replicate was selected for blood collection and cecal sampling. Compared to the NC group, dietary supplementation with heat-inactivated compound probiotics increased the feed efficiency during d 1–63 (P < 0.05). The plasma cholesterol content at 42 d and creatinine content at 63 d were decreased by dietary supplementation with heat-inactivated compound probiotics (P < 0.05). The dominant phyla in broiler cecal microbiota were Bacteroidetes, Firmicutes, and Proteobacteria, while the dominant genera were Bacteroides, Ruminococcaceae, and Phascolarctobacterium. The β-diversity index of cecal microbiota in BFI group was increased at d 42 (P < 0.01) and d 63 (P < 0.05). Dietary heat-inactivated compound probiotics increased the relative abundances of Barnesiellaceae (family), Barnesiella (genus), and Lactobacillus aviarius (species) at d 21, and reduced the relative abundances of genera Lachnoclostridium and Peptococcus at d 42, and unidentified Lachnospiraceae and Lachnoclostridium at d 63. The functional prediction of microbiota revealed that supplementation with heat-inactivated compound probiotics enriched the pathways related to methane metabolism, transcription machinery, purine metabolism and protein export. The Spearman's correlation analysis identified a significant correlation between cecal microbiota composition and overall feed efficiency and plasma metabolites. Collectively, dietary heat-inactivated compound probiotics with Bacillus subtilis and Lactobacillus acidophilus BFI enhanced feed efficiency, and decreased plasma cholesterol and creatinine contents, which might be associated with the modulation of community composition, diversity and functions of cecal microbiota in yellow-feathered broilers. These results indicated the potential of heat-inactivated probiotics used as alternatives to antibiotics for improvement of broiler health and productivity.

Effect of Bacillus subtilis on growth performance, bone mineralization, and bacterial population of broilers fed with different protein sources

The objective of this study was to investigate the impacts of Bacillus subtilis (BS), ATCC 6051a strain, as a probiotic bacterium in broiler diets based of 2 protein sources (soybean meal [SBM] and cowpea seeds [CWP]), on growth performance (GP), carcass traits, bone mineralization, and microflora population (0 to 42 d age). The SBM and CWP starter, grower, and finisher diets were tested in the presence or absence of BS (5.0 × 10¹¹ CFU spores g⁻¹ feed) in a 2 × 2 factorial arrangement of treatments in a completely randomized design. Broilers were randomly assigned to 4 dietary treatments with 6 replicate pens per treatment (20 chicks per pen). The results showed that broilers fed CWP had comparable GP (body weight gain, feed intake, and feed conversion ratio) to the birds fed the SBM diet. Carcass, breast and legs' yield, organ size (i.e., gizzard, liver, pancreas, small intestine, cecum), and bone development were not affected by the protein source. The addition of BS in both types of diet improved BWG (P < 0.001) and feed efficiency, especially in the grower and finisher period (P = 0.047; P = 0.043, respectively). In addition, BS significantly decreased abdominal fat (P = 0.026) and cecum weight (P = 0.034) and increased tibia bone P concentration (P = 0.015). Furthermore, BS decrease cecal pH (P = 0.010) and reduced Escherichia coli and Staphylococcus spp. from cecum and excreta broilers (P < 0.001; P < 0.0001, respectively). It is concluded that the BS significantly improved the GP of broilers and can beneficially affect the gut and excreta bacterial community in both SBM and CWP diets.

Efficacy of Bacillus methylotrophicus SY200 strain as feed additive against experimental Salmonella typhimurium infection in mice

To investigate the effects of Bacillus methylotrophicus SY200 on Salmonella typhimurium (STM) infection in mice, a total of 36 three-week-old male mice were selected and randomly divided into 3 equal groups (N = 12). Group A and group B were fed with basal diet while group C was fed the basal diet supplemented with 0.1% (w/w) B. methylotrophicus SY200 during the 21 days experimental period. On the 14th day of the experiment, mice of group A were intragastrically administered with 0.5 ml of normal saline, group B and C were orally administered with 0.5 ml of STM suspension. On the first day and seventh day after STM challenge, the number of total white blood cells (WBCs) and neutrophils, relative weight of visceral organs, the number of Salmonella spp., Escherichia coli, Lactobacillus spp. and Bifidobacterium spp. in ileum and cecum, and diversity of cecal microflora were measured. The results showed that: on the first day and seventh day after STM challenge, the number of WBCs and neutrophils in the blood of the mice was the highest in group B, then followed by group C, and group A. On the first day after STM challenge, the relative weight of spleen in group C was significantly higher than that in group B (p < 0.05), moreover, compared with group B, B. methylotrophicus SY200 significantly reduced the number of Salmonella spp. and E. coli (p < 0.05), and increased the number of Lactobacillus spp. and Bifidobacterium spp. (p < 0.05) in the intestines of mice, and improved the Shannon-Wiener diversity (H), Simpson (E) and richness (S) indices of cecal flora of mice (p < 0.05). The results indicated that B. methylotrophicus SY200 could alleviate the inflammatory reaction after STM infection and resist the adverse effects of STM infection on mice intestinal flora.

Effect of dietary supplementation of Bacillus subtilis spores on growth performance, oxidative status, and digestive enzyme activities in Japanese quail birds

The present trial investigated the feeding effect of B. subtilis spores on growth performance, blood metabolites, antioxidative status, and digestive enzyme activities in growing quails. A total of 750 1-day-old Japanese quail chicks were randomly allotted equally into five experimental groups: control (BS0) fed a maize-soybean basal diet with no additives, the others were supplemented with: B. subtilis spores with the levels of 1 × 10³ (BS3), 1 × 10⁵ (BS5), 1 × 10⁷ (BS7), and 1 × 10⁹ (BS9)/kg diet. Quails fed on B. subtilis diets exhibited linearly increasing live body weight and body weight gain and decreased feed-to-gain ratio compared with the control group. Daily feed intake was not significantly altered. Increasing levels of B. subtilis led to a linear increase in serum total protein and albumin levels, and a linear decrease in concentrations of glucose, creatinine, urea-N, aspartate aminotransferase, and alanine aminotransferase. Hypolipidemic impact of feeding B. subtilis spores was greatly observed and enhanced by increasing its dietary inclusion level. Triiodothyronine and thyroxine activities were significantly elevated in treated groups. Glutathione content and catalase activities were linearly increased in groups BS7, BS9, and BS5, while lipid peroxidation was decreased in all treatment groups. Duodenal proteolytic, lipolytic, and amylolytic activities as well as nutrient digestibility were linearly increased in treated groups. In conclusion, dietary supplementation of B. subtilis spores almost at all studied levels was able to promote the antioxidative status and digestive enzymes activities, while only the high concentrations (BS7 and BS9) could improve the nutrient digestion and growth performance of growing Japanese quail.

Engineering the microbiome for animal health and conservation

IMPACT STATEMENT

Considering the clear effects of microbiota on important aspects of animal biology and development (including in humans), this topic is timely and broadly appealing, as it compels us to consider the possibilities of altering the microbiome (without antibiotics) to positively affect animal health. In this review, we highlight three general approaches to manipulating the microbiome that have demonstrated success and promise for use in animal health. We also point out knowledge gaps where further inquiry would most benefit the field. Our paper not only provides a short and digestible overview of the current state of application, but also calls for further exploration of the microbial diversity at hand to expand our toolkit, while also leveraging the diversity and flexibility of animal systems to better understand mechanisms of efficacy.

Simultaneous Supplementation of Bacillus subtilis and Antibiotic Growth Promoters by Stages Improved Intestinal Function of Pullets by Altering Gut Microbiota

Early nutrition of pullets could determine the overall development and the performance of laying hens. With the aim to reduce the use of antibiotic growth promoters (AGPs) and to maintain the growth and development of pullets, the effect of simultaneous short-termed supplementation of AGPs (bacitracin zinc 20 mg/kg and colistin sulfate 4 mg/kg) and Bacillus subtilis (B. subtilis) DSM17299 probiotic, as well as the effect of supplementation of AGPs (bacitracin zinc 20 mg/kg and colistin sulfate 4 mg/kg) during the whole period (0~16 weeks) on the overall growth and development, intestinal health, and caecal microbiota of pullets were evaluated. In the present study, a total of 630 one-day-old Hy-Line Brown layers were randomly distributed into five equal groups: including the AGPs group (supplemented with AGPs based on basal diets for 16 weeks), the BA3 group (supplemented with AGPs and B. subtilis based on basal diets for 3 weeks), the BA6 group (for 6 weeks), the BA12 group (for 12 weeks), and the BA16 group (for 16 weeks). When compared with the AGPs group, the supplementation of AGPs + B. subtilis for the first 3 weeks could maintain overall growth performance, including the average body weight, average feed intake, average daily weight gain, and feed conversion ratio of pullets at 3, 6, 12, and 16 weeks of age (P > 0.05). Meanwhile, the characteristic growth indexes in different periods were separately measured. At 3 weeks of age, the amylase activity in ileum was elevated (P = 0.028), and the length of tibia was up to the standard in the BA3 group. At 12 weeks of age, the increased villus height (P = 0.046) of jejunum, increased villus height (P = 0.023) and ratio of villus height to crypt depth (P = 0.012) of ileum, decreased crypt depth (P = 0.002) of ileum, and elevated mRNA levels of sucrase in jejunum (P < 0.05) were all identified in the BA3 group. At 16 weeks of age, the secreted immunoglobulin A (sIgA) content in the jejunum mucosa of the BA3 group was greater than the other groups (P < 0.001). Furthermore, altered intestinal microbiota was found in the BA3 group. Specifically, decreased amounts of Alistipes, Bacteroides, Odoribacter, Dehalobacterium, and Sutterella and increased amounts of Lactobacillus, Dorea, Ruminococcus, and Oscillospira were determined (P < 0.05) in the BA3 group at week 6. Meanwhile, decreased amounts of B. fragilis and C. leptum (P < 0.05) were identified in the BA3 group at week 12, which were found to be relevant for the improvement of intestinal morphology (P < 0.05) by Pearson analysis. In conclusion, simultaneous supplementation of AGP and B. subtilis for 0~3 weeks increased the relative abundance of beneficial microbiota in caecum in 0~6 weeks, then improved the intestinal morphology by elevating populations of B. fragilis and C. leptum in 7~16 weeks, and further upregulated sucrase expression and increased sIgA content in the intestinal mucosa in 13~16 weeks.