Effects of feed supplementation with 3 different probiotic Bacillus strains and their combination on the performance of broiler chickens challenged with Clostridium perfringens

Effect of arginine supplementation on the growth performance, intestinal health, and immune responses of broilers during necrotic enteritis challenge

The objective of this study was to evaluate the effect of 25% arginine supplementation as a functional amino acid in partially alleviating the detrimental effects of necrotic enteritis (NE) on the growth performance, serum biochemistry, gut integrity, and the relative gene expression of tight junction proteins and inflammatory cytokines in broilers during NE. Three hundred and sixty 1-day-old chicks were randomly allocated to 4 treatments in a 2 × 2 factorial arrangement -basal diet and 125% arginine diet, with or without NE challenge. NE was induced by inoculating 1 × 104Eimeria maxima sporulated oocysts on d 14 and 1 × 108 CFU/bird C. perfringens on d 19, 20, and 21. The NE challenge had a significant effect on the BWG (p < 0.05), FCR (p < 0.05), serum AST (p < 0.05), GLU (p < 0.05), and K+ (p < 0.05) levels, and intestinal permeability (p < 0.05) and jejunal lesion score (p < 0.05). A significant challenge × diet interaction effect was observed in the cecal tonsil CD8+: CD4+ T-cell ratio on d 21 (p < 0.05) and 28 (p < 0.05) and spleen CD8+: CD4+ T-cell ratio on d 21 (p < 0.05) and 35 (p < 0.05). Arginine supplementation significantly increased the CD8+: CD4+ T-cell ratio in uninfected birds but decreased the CD8+: CD4+ T-cell ratio in infected birds. On d 21, a significant interaction effect was observed on the relative expression of the iNOS gene (p < 0.05). Arginine supplementation significantly downregulated the expression of the iNOS gene in infected birds. A significant effect of the challenge (p < 0.05) was observed on the relative gene expression of the ZO-1 gene in the jejunum. NE challenge significantly downregulated the expression of the ZO-1 gene on d 21. In conclusion, arginine supplementation did not alleviate the depression in growth performance and disease severity during the NE challenge. However, arginine downregulated the expression of inflammatory cytokines and enzymes, preventing inflammatory injury to the tissues during NE. Hence, arginine might be supplemented with other alternatives to downregulate inflammatory response during NE in poultry.

Growth performance, organs weight, intestinal histomorphology, and oocyst shedding in broiler chickens offered novel single strain Bacillus subtilis isolated from camel dung and challenged with Eimeria

We evaluated a single strain Bacillus subtilis BS-9 direct-fed microbial (BSDFM) isolated from camel dung in Eimeria challenged broiler chickens. Seven-hundred d-old Ross 708 male chicks were placed in pens (25 birds/pen) and allocated to 2 treatments (n = 14). From d 0 to 13, control pens received untreated water (-BSDFM), and 2 treated pens received water and 2 mL x 108 colony forming unit/bird/d (+BSDFM); daily water intake (WI) was recorded. On d 9, birds in half (+Eimeria) of pens per treatment received of 1 mL of Eimeria maxima and Eimeria acervulina oocysts orally, and the other half (-Eimeria) sterile saline solution. Birds had ad libitum access to feed and a water line from d 14. Feed intake (FI), body weight (BW) and mortality were recorded for calculating BW gain (BWG) and feed conversion ratio (FCR). On d 14 and 35, samples of birds were necropsied for organ weight and intestinal measurements. Excreta samples were collected from d 14 to 19 for oocyst count. There was no treatment effect (P > 0.05) on growth performance or WI on d 0 to 9. There were interactions between BSDFM and Eimeria on d 19 (P = 0.014) and 29 (P = 0.036) BW with unchallenged +BSDFM birds being heavier than birds in the other treatments. The main effects (P < 0.05) on d 10 to 35 FI, BW, and BWG were such that +BSDFM increased and Eimeria decreased (P < 0.01) these parameters. There was interaction (P = 0.022) between BSDFM and Eimeria on d 10 to 35 FCR such that the FCR of challenged -BSDFM birds was poor than that of unchallenged counterparts, but none differed with +BSDFM birds. There was an interaction (P = 0.039) between BSDFM and Eimeria on d 14 bursa weight with challenged birds exhibiting heavier bursa than unchallenged +BSDFM birds. Eimeria reduced (P = 0.01) and BSDFM (P = 0.002) increased the villi height to crypt depth ratio. Results showed that BSDFM supplementation via water can support the growth performance of broiler chickens challenged with Eimeria and may be a strategy to reduce adverse effects of coccidiosis.

Different levels of single-strain probiotic (Bacillus subtilis) with proteolytic enzyme (serratiopeptidase) can be used as an alternative to antibiotic growth promoters in broiler

In the current study, the proteolytic enzyme (serratiopeptidase) was used to enhance the efficacy of Bacillus subtilis (B. subtilis) probiotic as a growth promotor in broiler chicken. The effects of serratiopeptidase on the efficacy of different levels of B. subtilis as a growth promotor in broiler chicks were evaluated regarding growth performance traits, villus histomorphometric characterization, and intestinal microbiota count. Day-old broiler chicks (n = 120) were allocated into 4 groups having 3 replicates/group. In the control group (C), the basal diet was kept without supplementation. In treatment groups (P100, P150, and P200), the basal diet was supplemented with 100, 150, and 200 mg probiotics, respectively besides 30 mg proteolytic enzyme in the 3 treated groups for 4 wk. The performance parameters were significantly affected by the supplementation of serratiopeptidase to the B. subtilis treatment groups. Feed intake (FI), body weight gain (WG), feed conversion ratio (FCR), and dressing percent were significantly improved in the treatment groups as compared to the control group. Significantly, the lowest feed intake was recorded for the P200 group. The highest body weight gain and dressing percentage were recorded for the P200 group. An improved FCR was recorded in the P200 group (1.7) as compared to the control group. The different levels of B. subtilis supplemented with serratiopeptidase revealed significant improvements (P<0.05) in the morphology of the intestine by showing increases in villus height and width and crypt depth of the small intestine. The microbial count revealed that E. coli and salmonella colonies were significantly reduced in the P200 group as compared to the control and other treatment groups. In conclusion, the supplementation of B. subtilis with serratiopeptidase as a growth promoter in broiler chicks significantly improved the overall performance, and intestinal health and reduced microbial load contributing to optimizing the performance of broiler chickens. The greatest improvement was observed in the P200 group fed with B. subtilis as a probiotic and serratiopeptidase enzyme (200 mg:30 mg).

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.

The protective effects of Bacillus licheniformis against inflammatory responses and intestinal barrier damage in broilers with necrotic enteritis induced by Clostridium perfringens

BACKGROUND

Bacillus licheniformis is a gram-positive bacterium that has strong environmental adaptability and can improve the growth performance, immunity, and antioxidant function of broilers. The current study aimed to elucidate the protective capability of B. licheniformis against inflammatory responses and intestinal barrier damage in broilers with necrotic enteritis (NE) induced by Clostridium perfringens (CP).

RESULTS

The results showed that B. licheniformis enhanced the final body weight in broilers compared with that of broilers in the CP group after the stress of infection (P < 0.05). Bacillus licheniformis reversed the decreased levels of serum and jejunum mucosa immunoglobulins and anti-inflammatory cytokines, reduced the values of villus height and the ratio of villus height to crypt depth, and mitigated the increased levels of serum d-lactic acid and diamine oxidase in CP-challenged broilers (P < 0.05). Moreover, B. licheniformis modulated the expression levels of genes involved in the TLR4/NF-κB signalling pathway, the NLRP3 inflammasome activation pathway, and the sirt 1/Parkin signalling pathway in CP-challenged broilers. Compared with the CP challenge group, the B. licheniformis-treated group exhibited reduced abundance values of Shuttleworthia and Alistipes and enhanced abundance values of Parabacteroides in the caecal contents (P < 0.05).

CONCLUSION

Bacillus licheniformis improved the final body weight and alleviated the inflammatory response and intestinal barrier function damage in birds with NE induced by CP by maintaining intestinal physiological function, enhancing immunity, regulating inflammatory cytokine secretion, modulating the mitophagy response, and increasing the abundance of beneficial intestinal flora. © 2023 Society of Chemical Industry.

Deconstruction of a multi-strain Bacillus-based probiotic used for poultry: an in vitro assessment of its individual components against C. perfringens

OBJECTIVE

Probiotics have been used in poultry production to improve the performance and health of chickens raised without antibiotics. The combination of different probiotic strains has been used with the hope of conferring multiple benefits to the host. However, the inclusion of several strains does not necessarily boost benefits. There is a lack of studies that compare the efficacy of multi-strain probiotics to their individual components. In this study, the effects of a Bacillus-based probiotic product mix containing B. coagulans, B. licheniformis, B. pumilus, and B. subtilis against Clostridium perfringens were tested in vitro using a co-culture method. The individual strains and different combinations of the strains used in the product were also tested against C. perfringens.

RESULTS

The probiotic product mix tested in this study did not show effects against C. perfringens (P = 0.499). When tested individually, the strain of B. subtilis was the most efficient strain to decrease C. perfringens concentrations (P ≤ 0.01), and the addition of other Bacillus species strains significantly decreased its efficacy against C. perfringens. We concluded that the probiotic mix of Bacillus strains used in this study (B. coagulans, B. licheniformis, B. pumilus and B subtilis) was not effective in decreasing C. perfringens concentrations in vitro. However, when deconstructing the probiotic, the strain of B. subtilis alone or combined with the strain of B. licheniformis were effective against C. perfringens. This suggests that the anticlostridial properties of the particular strains of Bacillus used in this study were negatively affected when combined with other Bacillus spp. strains.

Recent Trends on Mitigative Effect of Probiotics on Oxidative-Stress-Induced Gut Dysfunction in Broilers under Necrotic Enteritis Challenge: A Review

Gut health includes normal intestinal physiology, complete intestinal epithelial barrier, efficient immune response, sustained inflammatory balance, healthy microbiota, high nutrient absorption efficiency, nutrient metabolism, and energy balance. One of the diseases that causes severe economic losses to farmers is necrotic enteritis, which occurs primarily in the gut and is associated with high mortality rate. Necrotic enteritis (NE) primarily damages the intestinal mucosa, thereby inducing intestinal inflammation and high immune response which diverts nutrients and energy needed for growth to response mediated effects. In the era of antibiotic ban, dietary interventions like microbial therapy (probiotics) to reduce inflammation, paracellular permeability, and promote gut homeostasis may be the best way to reduce broiler production losses. The current review highlights the severity effects of NE; intestinal inflammation, gut lesions, alteration of gut microbiota balance, cell apoptosis, reduced growth performance, and death. These negative effects are consequences of; disrupted intestinal barrier function and villi development, altered expression of tight junction proteins and protein structure, increased translocation of endotoxins and excessive stimulation of proinflammatory cytokines. We further explored the mechanisms by which probiotics mitigate NE challenge and restore the gut integrity of birds under disease stress; synthesis of metabolites and bacteriocins, competitive exclusion of pathogens, upregulation of tight junction proteins and adhesion molecules, increased secretion of intestinal secretory immunoglobulins and enzymes, reduction in pro-inflammatory cytokines and immune response and the increased production of anti-inflammatory cytokines and immune boost via the modulation of the TLR/NF-ĸ pathway. Furthermore, increased beneficial microbes in the gut microbiome improve nutrient utilization, host immunity, and energy metabolism. Probiotics along with biosecurity measures could mitigate the adverse effects of NE in broiler production.

Dietary yeast cell wall enhanced intestinal health of broiler chickens by modulating intestinal integrity, immune responses, and microbiota

This study was conducted to determine the effects of dietary yeast cell wall (YCW) on growth performance, intestinal health, and immune responses of broiler chickens. In a randomized completely block design (block: initial body weight), a total of 800 broilers (Ross 308; 45.18 ± 3.13 g of initial body weight) were assigned to 2 dietary treatments (40 birds/pen; 10 replicates/treatment) and fed for 5 wk: 1) a basal broiler diet based on corn-soybean meal (CON) and 2) CON + 0.05% dietary YCW. Growth performance was measured at intervals in 3 phase feed program. On the final day of the study, one bird per pen was randomly selected and euthanized for sample collection. Broilers fed YCW had decreased (P < 0.05) feed conversion ratio during the grower phase compared with those fed CON. The YCW increased (P < 0.05) villus height to crypt depth ratio in the duodenum, jejunum, and ileum compared with the CON. In addition, the YCW tended to higher (P < 0.10) number of goblet cells in the duodenum than in the CON. Broilers fed YCW had increased (P < 0.05) serum TGF- β1, ileal gene expression of the claudin family, and relative abundance of Lactobacillus, Prevotella, and Enterococcus compared with the CON, but decreased serum TNF-α (P < 0.05), IL-1β (P < 0.05), and IL-6 (P < 0.10), ileal gene expression of IL-6 (P < 0.05), and relative abundance of Clostridium (P < 0.05). The present study demonstrated that the addition of dietary YCW in broiler diets enhanced the intestinal health of broiler chickens and may be associated with modulated intestinal morphology and integrity by upregulating tight junction-related protein gene expression and modifying the ileal microbiota. In addition, dietary YCW modulated immune responses and inflammatory cytokine gene expression in the ileum.

Influence of dietary Bacillus coagulans and/or Bacillus licheniformis-based probiotics on performance, gut health, gene expression, and litter quality of broiler chickens

Probiotics are non-pathogenic microorganisms that are potentially important non-antibiotic alternatives. This study aimed to compare novel multi-strain and single-strain Bacillus probiotics and their respective influences on broiler chickens' performance, gut health, litter quality, immune response, and NBN and TLR gene expression. A total of 1200 Arbor-Acres 1-day-old broiler chicks were randomly allocated into three treatments (T1 was a control, T2 was supplemented with a combined Bacillus coagulans (2 × 10⁹ cfu/g) and Bacillus licheniformis (8 × 10⁹ cfu/g) probiotic strains (0.2 kg/ton of feed), and T3 was supplemented with Bacillus licheniformis (3.2 × 10⁹ cfu/g) probiotic (0.5 kg/ton of feed) with eight replicas of each. Supplementing the broiler diet with either the single-strain (T3) or the multi-strain (T2) Bacillus-based probiotic raised the overall birds' body weight, body weight gain, feed conversion ratio, and European production efficiency factor compared to the control (T1), with a significant enhancement achieved by the multi-strain Bacillus product (P = 0.005). T2 and T3 exhibited significantly improved cholesterol, Alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and alkaline phosphatase levels than the control (P ≤ 0.05). The transcript levels of both NBN and TLR genes were upregulated in the liver in the T2 and T3 groups. The T2 group experienced significant reductions in gut bacterial counts, especially for Clostridia, and recorded the lowest litter moisture and nitrogen. In conclusion, supplementing broiler diets with probiotics of multiple Bacillus strains increased production profitability by promoting bird growth, improving feed intake, enhancing gut mucosa and immune organs, and upregulating genes responsible for immunity. All these inhibit the overgrowth of enteric pathogens and sustain litter quality.

Bacillus Species as Direct-Fed Microbial Antibiotic Alternatives for Monogastric Production

Antibiotic growth promoters have been utilized for long time at subtherapeutic levels as feed supplements in monogastric animal rations. Because of their side-effects such as antibiotic resistance, reduction of beneficial bacteria in the gut, and dysbiosis, it is necessary to look for non-therapeutic alternatives. Probiotics play an important role as the key substitutes to antibacterial agents due to their many beneficial effects on the monogastric animal host. For instance, enhancement of the gut microbiota balance can contribute to improvement of feed utilization efficiency, nutrients absorption, growth rate, and economic profitability of livestock. Probiotics are defined as "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host." They are available in diverse forms for use as feed supplements. Their utilization as feed additives assists in good digestion of feed ingredients and hence, making the nutrients available for promoting growth. Immunity can also be enhanced by supplementing probiotics to monogastrics diets. Moreover, probiotics can help in improving major meat quality traits and countering a variety of monogastric animals infectious diseases. A proper selection of the probiotic strains is required in order to confer optimal beneficial effects. The present review focuses on the general functional, safety, and technological screening criteria for selection of ideal Bacillus probiotics as feed supplements as well as their mechanism of action and beneficial effects on monogastric animals for improving production performance and health status.

Dietary Lactobacillus fermentum and Lactobacillus paracasei improve the intestinal health of broilers challenged with coccidia and Clostridium perfringens

Necrotic enteritis (NE) is a great threat to the intestinal health of broilers, resulting in decreased growth performance and significant economic losses. Lactobacillus fermentum (LF) and Lactobacillus paracasei (LP) exert beneficial effects on intestinal health. The aim of the present study was to investigate the effects of dietary LF and LP on the intestinal health and growth performance of broilers challenged with coccidia and Clostridium perfringens (CCP). The animal trial was carried out using 336 broilers (Ross 308) for 35 days with a completely randomized design. The broilers were divided into 4 groups based on treatment as follows: the control (CTR) group was fed the basal diet and without CCP challenge and the CCP group was fed the basal diet and with CCP challenge. The broilers in the CCP+LF and CCP+LP groups were challenged by CCP, and meanwhile, LF (1 × 10⁹ CFU/g) and LP (1 × 10⁹ CFU/g) were supplemented into the basal diets, respectively. The results showed that the growth performance and the intestinal morphology were negatively affected by the CCP challenge. In addition, the number of coccidia in the intestinal digesta and the relative abundance of Escherichia coli in the cecal digesta were increased. Besides, the mRNA level of IgA in the jejunum was downregulated, and the transcript level of IL-8 was upregulated by the CCP challenge. Dietary LF and LP failed to improve the growth performance of broilers with the CCP challenge. However, they were beneficial for intestinal barrier function. In addition, dietary LF was able to alleviate the downregulation of TGF-β mRNA level in the spleen with CCP challenge and decreased the lesion scores compared with the CCP group. Furthermore, dietary LP alleviated the upregulation of the IL-8 mRNA level in the jejunum with CCP challenge and reduced the number of coccidia in the ileal digesta. In conclusion, dietary LF and LP failed to mitigate the negative effects of CCP infection on growth performance; however, they were able to improve the intestinal health of broilers challenged with CCP by strengthening the intestinal barrier and alleviating inflammation.

Antifungal Activity and Plant Growth-Promoting Properties of Bacillus mojovensis B1302 against Rhizoctonia Cerealis

Rhizoctonia cerealis is a worldwide soil-borne pathogenic fungus that significantly infects wheat and causes sharp eyespot in China. However, the biocontrol strains used for the control of Rhizoctonia cerealis are insufficient. In the present study, antagonistic strain B1302 from the rhizosphere of wheat were isolated and identified as Bacillus mojovensis based on their morphological, physiological, and biochemical characteristics, and their 16S rDNA sequence. Culture filtrate of strain B1302 had a broad antifungal spectrum. In order to improve the antifungal activity of B1302, response surface methodology (RSM) was used to optimize the culture conditions. The final medium composition and culture conditions were 13.2 g/L of wheat bran, 14.1 g/L of soybean meal, 224 r/min of rotation speed, 7.50 of initial pH, and 1.5 × 10⁸ CFU/mL of inoculation amount at 35 °C for a culture duration of 72 h. B. mojavensis B1302 inhibited the hyphae growth of R.cerealis and produced hydrolytic enzymes (protease, chitinase, and glucanase), IAA, and had N-fixing potentiality and P-solubilisation capacity. It can also promote wheat seedling growth in potted plants. The disease incidence and index of wheat seedlings were consistent with the effect of commercial pesticides under treatment with culture filtrate. The biocontrol efficacy of culture filtrate was significant—up to 65.25%. An animal toxicological safety analysis suggested that culture filtrate was safe for use and could be developed into an effective microbial fungicide to control wheat sharp eyespot.

Potential Feed Additives as Antibiotic Alternatives in Broiler Production

This article aimed to describe the current use scenario, alternative feed additives, modes of action and ameliorative effects in broiler production. Alternative feed additives have promising importance in broiler production due to the ban on the use of certain antibiotics. The most used antibiotic alternatives in broiler production are phytogenics, organic acids, prebiotics, probiotics, enzymes, and their derivatives. Antibiotic alternatives have been reported to increase feed intake, stimulate digestion, improve feed efficiency, increase growth performance, and reduce the incidence of diseases by modulating the intestinal microbiota and immune system, inhibiting pathogens, and improving intestinal integrity. Simply, the gut microbiota is the target to raise the health benefits and growth-promoting effects of feed additives on broilers. Therefore, naturally available feed additives are promising antibiotic alternatives for broilers. Then, summarizing the category, mode of action, and ameliorative effects of potential antibiotic alternatives on broiler production may provide more informed decisions for broiler nutritionists, researchers, feed manufacturers, and producers.

Development and Evaluation of a Commercial Direct-Fed Microbial (Zymospore®) on the Fecal Microbiome and Growth Performance of Broiler Chickens under Experimental Challenge Conditions

Simple Summary

Probiotics are recognized for their beneficial health-promoting properties, through competitive exclusion, promoting maintenance of intestinal epithelial integrity and host immune system homeostasis. The use of some spore-forming bacteria from the genus Bacillus has earned interest as a direct-fed microbial in recent years as a potential alternative to antibiotic growth promoters and growth enhancers. The present study evaluates the use of a Bacillus subtilis spore-based direct-fed microbial (Zymospore^®, Vetanco, Villa Martelli, Argentina) compared to an antibiotic growth promoter on the performance of broiler chickens under experimental intestinal challenge conditions. The results suggest that Zymospore^® increases the diversity of the broiler fecal microbiota and is an acceptable substitute for commonly used antibiotic growth promoters under defined and non-defined intestinal dysbiosis conditions.

Abstract

Direct-fed microbials (DFM) are added to broiler chicken diets in order to promote the proliferation of beneficial intestinal bacterial populations, which may lead to gains in performance efficiency and, potentially, reduce the level of enteric pathogens in the broiler chickens. The selection and laboratory evaluation of Bacillus subtilis strains as well as the experimental trial results of a novel Bacillus-based commercial DFM product are described. Fifteen wild-type Bacillus subtilis strains were characterized and assayed for their enzyme production capability, spore resistance to pH, salinity, and temperature, and ability to inhibit the growth of E. coli and Salmonella spp. The final DFM formulation was evaluated and compared to an antibiotic growth promoter (AGPs) in two experimental trials. In Experiment 1, broilers were given a defined challenge of Eimeria spp. and Clostridium perfringens to induce intestinal dysbiosis. The optimal dose of the DFM was determined to be 0.3 kg/ton of feed. At this dose, the broilers fed the DFM performed as well as the Flavomycin^®-fed broilers. Further, intestinal microbiome analysis indicates that the use of the DFM enhances bacterial diversity of the gut flora by day 5 of age, increasing levels of lactic acid bacteria (LAB) and Clostridiales by 25 days of age, which may enhance the digestion of feed and promote growth of the birds. In Experiment 2, the broilers were raised on recycled litter and given an undefined challenge orally to mimic commercial growth conditions. In this trial, the DFM performed as well as the bacitracin methylene disalicylate (BMD)-11%-fed birds. The results of the present studies suggest that this novel DFM, Zymospore^®, improves the performance of broiler chickens under experimental challenge conditions as effective as an AGP, providing a safe and effective substitute to the poultry industry.

Whole-Genome Sequence and Interaction Analysis in the Production of Six Enzymes From the Three Bacillus Strains Present in a Commercial Direct-Fed Microbial (Norum™) Using a Bliss Independence Test

The three Bacillus strains present in Norum™ were initially selected by their excellent to good relative enzyme activity (REA) production score for amylase, protease, lipase, phytase, cellulase, β-glucanase, and xylanase. Further studies confirmed that the three isolates also showed an antibacterial activity, Gram-positive and Gram-negative poultry pathogens. Norum™ (Eco-Bio/Euxxis Bioscience LLC) is a Bacillus spore direct-fed microbial (DFM). The Bacillus isolates were screened and selected based on in vitro enzyme production profiles. Moreover, in chickens fed high non-starch polysaccharides, this DFM demonstrated to reduce digesta viscosity, bacterial translocation, increase performance, bone mineralization, and balance the intestinal microbiota. In the present study, we present the whole-genome sequence of each of the three isolates in Norum™, as well as the synergistic, additive, or antagonistic effects on the enzyme production behavior of the three Bacillus strains and their combinations when grown together vs. when grown individually. The whole-genome sequence identified isolate AM1002 as Bacillus subtilis (isolate 1), isolate AM0938 as Bacillus amyloliquefaciens (isolate 2), and isolate JD17 as Bacillus licheniformis (isolate 3). The three Bacillus isolates used in the present study produce different enzymes (xylanase, cellulase, phytase, lipase, protease, and β-glucanase). However, this production was modified when two or more Bacillus strains were combined, suggesting possible synergistic, antagonistic, or additive interactions. The Bliss analysis suggested (p < 0.05) that the combination of Bacillus strains 1–2 and 1–2–3 had intermediate effects and predicted that the combination of Bacillus strains 2–3 could have better effects than the combination of all the three Bacillus strains. In summary, the current study demonstrated the need of selecting Bacillus strains based on quantitative enzyme determination and data analysis to assess the impacts of combinations to avoid antagonistic interactions that could limit treatment efficacy. These results suggest that using Bacillus strains 2–3 together could lead to a new generation of DFMs with effects superior to those already examined in Bacillus strains 1–2–3 and, therefore, a potential alternative to growth-promoting antibiotics. More research utilizing poultry models is being considered to confirm and expand the existing findings.

Probiotics and Postbiotics as Substitutes of Antibiotics in Farm Animals: A Review

Simple Summary

Breeders are searching for methods to protect farming animals against diseases caused by pathogenic bacteria. The easiest way to fight bacteria is to use antibiotics. Unfortunately, their abuse results in the presence of bacteria resistant to the most commonly used antibiotics in the environment. The restrictions on the use of antibiotics have forced the search for natural and safe ways to protect animals. It has been shown that the use of probiotics based on lactic acid bacteria may have a positive effect on the growth and use of feed by broilers, on the stabilization of the intestinal microbiota of chickens and pigs, and in the prevention of mastitis in dairy cows. The use of probiotics (live, nonpathogenic microorganisms) and postbiotics (inanimate bacteria, cell components or post-fermentation by-products) reduces the occurrence of pathogens in large-scale farms.

Abstract

Since 2006, the use of growth-promoting antibiotics has been banned throughout the European Union. To meet the expectations of livestock farmers, various studies have been carried out with the use of lactic acid bacteria. Scientists are trying to obtain the antimicrobial effect against the most common pathogens in large-scale farms. Supplementing the diet of broilers with probiotics (live, nonpathogenic microorganisms) stabilized the intestinal microbiota, which improved the results of body weight gain (BWG) and feed intake (FI). The positive effect of probiotics based on lactic acid bacteria has been shown to prevent the occurrence of diarrhea during piglet weaning. The antagonistic activity of postbiotics (inanimate bacteria, cell components, or post-fermentation by-products) from post-culture media after lactobacilli cultures has been proven on Staphylococcus aureus—the pathogen most often responsible for causing mastitis among dairy cows. The article aims to present the latest research examining the antagonistic effect of lactic acid bacteria on the most common pathogens in broilers, piglets, pigs, and cow farms.

Effect of the use of probiotic Bacillus subtilis (QST 713) as a growth promoter in broilers: an alternative to bacitracin methylene disalicylate

The global poultry trend toward the more responsible use of antibiotics is becoming recurrent and has demanded the need to generate new natural alternatives. Probiotics have gained importance as an option to use as growth promoters. This study aimed to evaluate Bacillus subtillis QST713 as a substitute for an antibiotic growth promoter (BMD). A total of 150 male broilers were assigned to three dietary treatments: 1) control diet (CO), 2) control diet + 500 g/t of BMD (AGP), and 3) control diet + 100 g/t of B. subtilis QST713 (PB), respectively. Each treatment was monitored for 5 wk for the productive variables: body weight, accumulated feed consumption, food conversion, and European efficiency factor. At the end of each week, fresh fecal samples were cultured and quantified for E. coli, Enterococcus spp., and Lactobacillus spp. At the end of the trial, blood samples were analyzed for hemogram and intestinal samples (anterior portion) for histomorphometry. The data were statistically analyzed with an analysis of variance and subjected to a least significant difference test (Tukey). The zootechnical yields were similar in the AGP and PB groups (P ˃ 0.05); both superior to the control group. In the hematological profiles, no difference was observed between the experimental groups. E. coli and Enterococcus counts were significantly lower (P ˂ 0.05), and Lactobacillus counts were significantly (P ˂ 0.05) higher in the PB group, relative to CO and AGP groups. No differences (P ˃ 0.05) were found in bacterial counts between the CO and AGP groups. The intestinal mucosa and villi in the PB group were significantly (P ˂ 0.05) longer and with less deeper crypts than CO and AGP groups. We conclude that B. subtillis QST713, used at the suggested commercial dose (100 g/ton), is an effective growth-promoting alternative to BMD that modulates the microbiota and intestinal architecture, thus producing zootechnical yields consistent with BMD.