Effect of pelleting temperature and probiotic supplementation on growth performance and immune function of broilers fed maize/soy-based diets

Unraveling the benefits of Bacillus subtilis DSM 29784 poultry probiotic through its secreted metabolites: an in vitro approach

The probiotic Bacillus subtilis 29784 (Bs29784) sustains chicken's intestinal health, enhancing animal resilience and performance through the production of the bioactive metabolites hypoxanthine (HPX), niacin (NIA), and pantothenate (PTH). Here, using enterocyte in vitro models, we determine the functional link between these metabolites and the three pillars of intestinal resilience: immune response, intestinal barrier, and microbiota. We evaluated in vitro the capacity of Bs29784 vegetative cells, spores, and metabolites to modulate global immune regulators (using HT-29-NF-κB and HT-29-AP-1 reporter cells), intestinal integrity (HT-29-MUC2 reporter cells and Caco-2 cells), and cytokine production (Caco-2 cells). Finally, we simulated intestinal fermentations using chicken's intestinal contents as inocula to determine the effect of Bs29784 metabolites on the microbiota and their fermentation profile. Bs29784 vegetative cells reduced the inflammatory response more effectively than spores, indicating that their benefit is linked to metabolic activity. To assess this hypothesis, we studied Bs29784 metabolites individually. The results showed that each metabolite had different beneficial effects. PTH and NIA reduced the activation of the pro-inflammatory pathways AP-1 and NF-κB. HPX upregulated mucin production by enhancing MUC2 expression. HPX, NIA, and PTH increased cell proliferation. PTH and HPX increased epithelial resilience to an inflammatory challenge by limiting permeability increase. In cecal fermentations, NIA increased acetate, HPX increased butyrate, whereas PTH increased acetate, butyrate, and propionate. In ileal fermentations, PTH increased butyrate. All molecules modulated microbiota, explaining the different fermentation patterns. Altogether, we show that Bs29784 influences intestinal health by acting on the three lines of resilience via its secreted metabolites.

IMPORTANCE

Probiotics provide beneficial metabolites to its host. Here, we describe the mode of action of a commonly used probiotic in poultry, Bs29784. By using in vitro cellular techniques and simulated chickens' intestinal model, we show the functional link between Bs29784 metabolites and the three lines of animal resilience. Indeed, both Bs29784 vegetative cells and its metabolites stimulate cellular anti-inflammatory responses, strengthen intestinal barrier, and positively modulate microbiota composition and fermentative profile. Taken together, these results strengthen our understanding of the effect of Bs29784 on its host and explain, at least partly, its positive effects on animal health, resilience, and performance.

Meta-analysis to predict the effects of probiotics on meat quality of broiler

The demand for chicken meat has surged globally due to its status as a primary protein source in human diets. However, ensuring high-quality meat products has become an increasingly important subject to consumers. In this study, 21 articles from PubMed and Web of Science databases published between 2005 and 2023 were examined to assess the influence of probiotic supplementation on broiler meat quality. The meta-analysis revealed significant findings across various meat quality parameters. Specifically, probiotics were found to significantly affect meat colour parameters, including redness, yellowness, and lightness, in both breast and thigh meat samples. Moreover, significant differences were observed in parameters such as water-holding capacity (p < 0.001), cook loss (p = 0.047), and shear force (p = 0.025) between control and probiotic groups. However, it's essential to note the considerable heterogeneity among the studies, emphasising the need for a cautious interpretation of the results. Despite this variability, the study underscores the potential of probiotics to positively influence broiler meat quality, highlighting avenues for further research and standardisation in poultry production practices. These findings also contribute to a better understanding of probiotics' role in improving meat quality and meeting consumer preferences for nutritious and high-quality poultry products.

Microbiota but not immune modulation by a pro- and postbiotic was associated with the diet-additive interaction in broilers

This study investigated the diet-additive interactions of a Lactobacilli-based probiotic (Pro) and postbiotic (Post) on immune parameters and cecal microbiota composition, with subsequent effects on the metabolome in broilers. A completely randomized block design was employed with 2 diets [standard (SD), and challenge (CD)] and 3 additive conditions (Control, Pro, Post) involving 1,368 one-day-old male Ross 308 broilers equally distributed among 36 pens in a 42 d study. Diets were formulated to contain identical nutrient levels, with CD higher than SD in non-starch polysaccharide content by including rye and barley. Total non-specific serum Ig A, M and G concentrations were determined weekly from d14 to 35. Following vaccination, titres of specific antibodies binding Newcastle disease virus (NDV) and infectious bursal disease virus (IBDV) were measured. Microbiota composition was analyzed by 16S rRNA gene sequencing at d14 and 35, and α- and β-diversity indexes (Observed, Chao1, Bray, Jaccard) were calculated. Cecal short-chain fatty acids and the semi-polar metabolome were determined in the Control SD and all CD groups at d35. At d35, a diet-additive interaction was observed on cecal microbiota composition. Within SD, Pro and Post did not affect operational taxonomic units (OTU) abundance (adjusted-P > 0.05) and diversity indexes (P > 0.05). Within CD, Pro and Post affected the relative abundances of 37 and 44 OTUs, respectively (adjusted-P < 0.05), with Post but not Pro affecting β-diversity indexes (P = 0.041 and 0.064 for Bray and Jaccard, respectively). Within CD, Post increased cecal acetate (21%; P = 0.007) and butyrate (41%; P = 0.002) concentration and affected the concentration of 2 metabolites (adjusted-P < 0.05), while Pro affected 240 metabolites (adjusted-P < 0.05). No diet-additive interactions were observed on serum Ig (P > 0.05), except for IgM at d14 (P = 0.004). Diet composition, but not the additives, affected immune status parameters. The Pro and Post affected cecal microbiota composition only under dietary challenging conditions as previously reported for growth.

Heat-Killed Lactobacillus acidophilus Promotes Growth by Modulating the Gut Microbiota Composition and Fecal Metabolites of Piglets

Probiotics can improve animal growth performance and intestinal health. However, understanding the effects of paraprobiotics on the growth performance and gut microbiota of piglets and how the paraprobiotics exert their impact are still limited. The present study was conducted to investigate the effects of heat-killed Lactobacillus acidophilus IFFI 6005 supplementation on the growth performance, intestinal microbiota, and fecal metabolites of piglets. First, a feed-additive sample of heat-killed Lactobacillus acidophilus IFFI 6005 was prepared by culture. Second, 96 (initial BW = 14.38 ± 0.67 kg, weaning age of 40 days) healthy piglets were selected and randomized into four treatment groups. Each treatment group consisted of three replicates (n = 8). Pigs were fed a basal diet (NC), basal diet plus antibiotics (PC), basal diet plus Lactobacillus acidophilus IFFI 6005 at 600 g/t (LA, 1.0 × 1010 cfu/g), and basal diet plus heat-killed Lactobacillus acidophilus IFFI 6005 at 600 g/t (HKLA), respectively; the trial lasted for 30 days. The results showed that the ratios of feed to gain (F:G) and diarrhea rate of both the HKLA and PC groups were significantly lower compared with the NC and LA groups (p < 0.05); however, there was no significant difference between the HKLA and PC group (p > 0.05). In addition, the average daily weight gain (ADG) of the HKLA group was significantly higher (p < 0.05) than that of the other three groups in terms of growth performance. Finally, 16S rRNA sequencing and metabolome analysis based on fecal samples further elaborated that the addition of heat-killed Lactobacillus acidophilus IFFI 6005 to the feed improved the intestinal microbial diversity and abundance (p < 0.05) and reduced the abundance of pathogenic bacteria (p < 0.05), but it did not affect the abundance of Lactobacillus (p > 0.05). Through the comparison of microbial abundance and metabolite content between the two groups (NC_vs_HKLA), the largest differences were found in six microorganisms and 10 metabolites in the intestine (p < 0.05). These differential metabolites were involved in the digestion, absorption and utilization of protein and starch, as well as in oxidative stress. In summary, addition of heat-killed Lactobacillus acidophilus IFFI 6005 as a new feed additive in piglets has beneficial effects on the growth performance, intestinal bacteria and metabolites, and can be used as an alternative to antibiotics.

Bacillus spp. as potential probiotics: promoting piglet growth by improving intestinal health

The application of Bacillus spp. as probiotics in the swine industry, particularly for piglet production, has garnered significant attention in recent years. This review aimed to summarized the role and mechanisms of Bacillus spp. in promoting growth and maintaining gut health in piglets. Bacillus spp. can enhance intestinal barrier function by promoting the proliferation and repair of intestinal epithelial cells and increasing mucosal barrier integrity, thereby reducing the risk of pathogenic microbial invasion. Additionally, Bacillus spp. can activate the intestinal immune system of piglets, thereby enhancing the body's resistance to diseases. Moreover, Bacillus spp. can optimize the gut microbial community structure, enhance the activity of beneficial bacteria such as Lactobacillus, and inhibit the growth of harmful bacteria such as Escherichia coli, ultimately promoting piglet growth performance and improving feed efficiency. Bacillus spp. has advantages as well as challenges as an animal probiotic, and safety evaluation should be conducted when using the newly isolated Bacillus spp. This review provides a scientific basis for the application of Bacillus spp. in modern piglet production, highlighting their potential in improving the efficiency of livestock production and animal welfare.

Stability of Bacillus and Enterococcus faecium 669 Probiotic Strains When Added to Different Feed Matrices Used in Dairy Production

Few data are available evaluating the stability of direct-fed microbials (DFM) following their inclusion in different feed matrices. Therefore, six Exp. evaluated the recovery of bacilli spores (BOVACILLUS^TM; Exp. 1 to 3) and an Enterococcus faecium DFM (LACTIFERM^®; Exp. 4 to 6) when included in different feed preparations. The Bacillus-based DFM was included into pelleted feed prepared in different temperatures (75 to 95 °C), whereas both DFM were assessed in premix and milk replacer preparations. Bacillus spores and E. faecium recovery was evaluated through standard methodologies and data were reported as log10 colony forming units/gram of feed. The recovery of Bacillus spores was within the expected range and was not impacted by the temperature of pellet preparation (Exp. 1). Bacilli recovery was also stable up to 12 months in the premix and was not impacted by the temperature of milk replacer preparation. Regarding the Exp. with E. faecium (Exp. 4 to 6), its recoveries in the mineral premix and milk powder did not differ from T0 and were not impacted by the conditions of milk replacer preparation. These data are novel and demonstrate the stability of a Bacillus-based and an E. faecium-based DFM when included in different feed matrices often used in dairy production.

Effects of a multi-strain Bacillus subtilis-based direct-fed microbial on immunity markers and intestinal morphology in diets fed to weanling pigs

The objective of this experiment was to evaluate the effects of a multi-strain Bacillus subtilis-based direct-fed microbial (DFM) on nursery pig health as indicated by intestinal mucosal and blood plasma immunological markers and intestinal morphology. Eighty pigs, of equal number of barrows and gilts (initial BW: 7.0 ± 0.60 kg), weaned at 21 ± 1 d of age were randomly allotted to sixteen pens, with five pigs per pen. Two dietary treatments were implemented, a basal control (CON) and a basal control plus DFM (CDFM). Both diets were corn, soybean meal, and distillers dried grains based and were formulated to meet or exceed all nutritional requirements (NRC, 2012) and manufactured on site. Diets were fed for 42 d. On d 21 and 42 of the experiment, one pig per pen was randomly selected and euthanized, with equal number of males and females represented. Blood samples were collected prior to euthanasia for assessment of plasma concentrations of immunoglobulin A (IgA) and intestinal fatty acid binding protein. Segments of the gastrointestinal tract including duodenum, jejunum, ileum, ascending and distal colon were removed for analysis of intestinal morphology, and levels of interleukin 6, interleukin 10 (IL-10), and tumor necrosis factor alpha. Jejunal villus height was greater in the CDFM pigs as compared with CON pigs (P = 0.02) and ascending colon crypt depth tended to be greater on d 21 (P = 0.10). Compared to CON, CDFM significantly increased overall plasma IgA (P = 0.03) (0.58 vs. 0.73 0.05 mg/mL, respectively), while it tended to increase plasma IgA (P = 0.06) on d 21 (0.34 vs. 0.54 ± 0.07 mg/mL, respectively) and tended to increase overall IL-10 (P = 0.10) in the jejunum (113 vs. 195 ± 35 pg/mL, respectively). Addition of a multi-strain Bacillus subtilis-based DFM may have an early benefit to nursery pig health status, observed through specific changes in morphology and both systemic and localized immunological markers.

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.

Riboflavin and Bacillus subtilis effects on growth performance and woody-breast of Ross 708 broilers with or without Eimeria spp. challenge

This study was conducted to assess the effects of the dietary supplementation of riboflavin (as a bile salt hydrolase [BSH] inhibitor) and Bacillus subtilis on growth performance and woody breast of male broilers challenged with Eimeria spp. Intestinal bacteria, including supplemented probiotics, can produce BSH enzymes that deconjugate conjugated bile salts and reduce fat digestion. A 3 × 2 × 2 (riboflavin × Bacillus subtilis × Eimeria spp. challenge) factorial arrangement of treatments in randomized complete block design was used. On d 14, birds were gavaged with 20× doses of commercial cocci vaccine (Coccivac^R-B52, Merck Animal Health, Omaha, NE). Dietary treatment of riboflavin and B. subtilis did not affect body weight (BW), body weight gain (BWG), and feed conversion (FCR) d 0 to 14 and overall d 0 to 41. Eimeria spp challenge reduced BWG, feed intake (FI), and increased FCR between d 14 to 28, but increased BWG and lowered FCR between d 28 to 35. There were no effects of the Eimeria spp. challenge on the overall d 0 to 41 FCR and FI, but BWG was reduced. Eimeria spp. challenge increased the abdominal fat pad weight and slight woody breast incidences on processed birds on d 42. Dietary inclusion of B. subtilis and riboflavin at tested levels did not help birds to mitigate the negative impact of Eimeria spp. challenge to enhance the growth performance.

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.

Efficacy of dietary supplementary probiotics as substitutes for antibiotic growth promoters during the starter period on growth performances, carcass traits, and immune organs of male layer chicken

Background and Aim

With the increased concerns about global protein supply, chicken meat, especially from male layer chicken, constitutes an alternative in terms of quality and carcass traits. Probiotics have been proposed for replacing antibiotic growth promoters (AGPs), which have been prohibited as poultry supplement feeds. The present study aimed to determine the efficacy of dietary supplementary probiotics during the starter period on growth performances, carcass traits, and immune organs of male layer chicken.

Materials and Methods

In this study, one hundred and eighty 1-day-old male chicks from the strain ISA brown were used. They were divided into six groups according to the feed: 100% basal feed (T0), basal feed+2.5 g AGP/kg feed (T1), basal feed+probiotics 1 mL/kg feed (T2), basal feed+probiotics 3 mL/kg feed (T3), basal feed+probiotics 4 mL/kg feed (T4), and basal feed+probiotics 5 mL/kg feed (T5). Probiotics (Lactobacillus acidophilus, Lactobacillus plantarum, and Bifidobacterium spp.) were given at a concentration of 1.2×109 colony-forming unit/mL. Virginiamycin was used as AGP. ISA brown layer chicken was treated for 21 days. Growth performances (body weight, feed consumption, and feed conversion ratio [FCR]), carcass traits (weight at slaughter, weight of the carcass, breast muscles, liver, lungs, kidneys, and heart), immune organs (spleen, thymus, and bursa of Fabricius), and non-edible organs (head, legs, and wings) were analyzed.

Results

Probiotic supplementation at 4 and 5 mL/kg feed (T4 and T5) during the starter phase improved the body weight, FCR, and feed consumption. The weight at slaughter, weight of the carcass, breast muscles, and liver from the T4 and T5 groups were significantly greater than those in the other treatment groups. In addition, the weight of the heart, lungs, and kidneys was increased in the T1, T2, T3, T4, and T5 groups compared with that measured in the T0 group. Furthermore, there were significant differences regarding the immune organs between the T0 and the other treatment groups. The weight of the head, legs, and wings was also greater in the probiotic and AGP supplementation groups (T1, T2, T3, T4, and T5) than that in the basal feed group (T0).

Conclusion

Probiotic (L. acidophilus, L. plantarum, and Bifidobacterium spp.) supplementation at 4 and 5 mL/kg feed during the starter period can be used to improve the growth, carcass traits, and weight of immune organs in male layer chicken.

Bacillus spore-forming probiotics: benefits with concerns?

Representatives of the genus Bacillus are multifunctional microorganisms with a broad range of applications in both traditional fermentation and modern biotechnological processes. Bacillus spp. has several beneficial properties. They serve as starter cultures for various traditional fermented foods and are important biotechnological producers of enzymes, antibiotics, and bioactive peptides. They are also used as probiotics for humans, in veterinary medicine, and as feed additives for animals of agricultural importance. The beneficial effects of bacilli are well-reported and broadly acknowledged. However, with a better understanding of their positive role, many questions have been raised regarding their safety and the relevance of spore formation in the practical application of this group of microorganisms. What is the role of Bacillus spp. in the human microbial consortium? When and why did they start colonizing the gastrointestinal tract (GIT) of humans and other animals? Can spore-forming probiotics be considered as truly beneficial organisms, or should they still be approached with caution and regarded as "benefits with concerns"? In this review, we not only hope to answer the above questions but to expand the scope of the conversation surrounding bacilli probiotics.

Probiotics-Live Biotherapeutics: a Story of Success, Limitations, and Future Prospects-Not Only for Humans

In livestock production, lactic acid bacteria (LAB) represent the most widespread microorganisms used as probiotics. For such critical use, these bacteria must be correctly identified and characterized to ensure their safety and efficiency. Recently, probiotics have become highly recognized as supplements for humans and in particular for animals because of their beneficial outcome on health improvement and well-being maintenance. Various factors, encompassing dietary and management constraints, have been demonstrated to tremendously influence the structure, composition, and activities of gut microbial communities in farm animals. Previous investigations reported the potential of probiotics in animal diets and nutrition. But a high rate of inconsistency in the efficiency of probiotics has been reported. This may be due, in a major part, to the dynamics of the gastrointestinal microbial communities. Under stressing surroundings, the direct-fed microbials may play a key role as the salient limiting factor of the severity of the dysbiosis caused by disruption of the normal intestinal balance. Probiotics are live microorganisms, which confer health benefits on the host by positively modifying the intestinal microflora. Thus, the aim of this review is to summarize and to highlight the positive influence of probiotics and potential probiotic microbe supplementation in animal feed with mention of several limitations.

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.

Bacillus subtilis natto as a potential probiotic in animal nutrition

The growing global demand for animal products and processed meat has created a challenge for the livestock sector to enhance animal productivity without compromising product quality. The restriction of antibiotics in animal feeds as growth promoters makes the use of probiotics a natural and safe alternative to obtain functional foods that provide animal health and quality and to maintain food safety for consumers. To incorporate these additives into the diet, detailed studies are required, in which in vitro and in vivo assays are used to prove the efficacy and to ensure the safety of probiotic candidate strains. Studies on the use of Bacillus subtilis natto as a spore-forming probiotic bacterium in animal nutrition have shown no hazardous effects and have demonstrated the effectiveness of its use as a probiotic, mainly due to its proven antimicrobial, anti-inflammatory, antioxidant, enzymatic, and immunomodulatory activity. This review summarizes the recent scientific background on the probiotic effects of B. subtilis natto in animal nutrition. It focuses on its safety assessment, host-associated efficacy, and industrial requirements.

Dietary effect of probiotics and prebiotics on broiler performance, carcass, and immunity

This experiment was carried out to evaluate the effects of dietary addition of probiotics (Protexin) and prebiotics (active MOS, mannan oligosaccharides) on growth performance, carcasses, and antibody titer in broilers. A total number of 360-day-old Ross broiler chicks were randomly divided into 9 groups in a 3 × 3 factorial arrangement. Nine broiler starter (0-21 d) and finisher (21-35 d) diets were formulated by using 3 levels of probiotics (0, 1, and 2 g/kg of feed) and 3 levels of MOS (0, 1, and 1.5 g/kg of feed) and were randomly allotted to 9 groups. Feed intake was not affected by interaction of treatments during all phases (P > 0.05). Feed intake was improved due to the main effect of probiotic (P = 0.0001) or MOS (P = 0.005). No interaction (P > 0.05) was observed for weight gain in the starter, finisher, and overall phases. While, during the starter and finisher phases, weight gain was increased by probiotics (P = 0.028 or 0.04, respectively). Dietary supplementation of MOS improved weight gain (P = 0.01) and feed conversion ratio (FCR) (P = 0.03) during the overall period, but during starter and finisher periods, weight gain and FCR were not affected by prebiotics. Apart from dressing percentage, no interaction or individual effect of probiotics and prebiotics was observed for carcass, breast, thigh, heart, liver, and gizzard weight. Antibody titer for infectious bursal disease (IBD) was improved (P = 0.026) by the interaction effect between probiotics and prebiotics, when compared with the control group. Antibody titer against Newcastle disease (ND) was not affected by probiotics or prebiotics or their interactions (P > 0.05). It could be concluded that supplementation of prebiotics or probiotics can improve the growth performance of broilers. It may also be helpful in improving the antibody titer against IBD in broilers fed antibiotic-free diets.

Probiotics in poultry feed: A comprehensive review

The use of antibiotics to maintain animal well-being, promote growth and improve efficiency has been practised for more than 50 years. However, as early as the 1950s, researchers identified concern on the development of resistant bacteria for the antibiotics streptomycin and tetracycline used in turkeys and broilers respectively. These findings laid the groundwork for agricultural officials to impose stricter regulatory parameters on the use of antibiotics in poultry feeds. Probiotics are live micro-organisms included in the diet of animals as feed additives or supplements. Commonly known as a direct-fed microbial, probiotics provide beneficial properties to the host, primarily through action in the gastrointestinal tract (GIT) of the animal. Supplementation of probiotics in the diet can improve animal health and performance, through contributions to gut health and nutrient use. For instance, supplementation of probiotics has been demonstrated to benefit farm animals in immune modulation, structural modulation and increased cytokine production, which positively affect the intestinal mucosal lining against pathogens. Bacillus subtilis has been a popular bacterium used within the industry and was shown to improve intestinal villus height. Increasing the villus height and structure of the crypts in the GIT allows for the improvement of nutrient digestion and absorption. Tight junctions maintain important defences against pathogenic bacteria and cellular homeostasis. Heat stress can be a major environmental challenge in the poultry industry. Heat stress causes the bird to fluctuate its internal core temperature beyond their comfort zone. To overcome such challenges, poultry will attempt to balance its heat production and dissipation through behavioural and physiological adaptation mechanisms.

Dietary Mannan-oligosaccharides potentiate the beneficial effects of Bifidobacterium bifidum in broiler chicken

This study investigated the effects of dietary Bifidobacterium bifidum (BFD) and mannan-oligosaccharide (MOS), as a synbiotic, on the production performance, gut microbiology, serum biochemistry, antioxidant profile and health indices of broiler chicken. Six dietary treatments were T1 (negative control), T2 (positive control-20 mg antibiotic BMD kg^-1 diet; BMD: bacitracin methylene disalicylate), T3 (0·1% MOS + 10⁶  CFU BFD per g feed), T4 (0·1% MOS + 10⁷  CFU BFD per g feed), T5 (0·2% MOS + 10⁶  CFU BFD per g feed) and T6 (0·2% MOS + 10⁷  CFU BFD per g feed). Significantly (P < 0·01) better growth performance and efficiency was observed in birds supplemented with 0·2% MOS along with 10⁶  CFU BFD per g of feed compared to BMD and control birds. Supplementation with 0·2% MOS along with either 10⁶ or 10⁷  CFU BFD per g feed reduced (P < 0·01) the gut coliform, Escherichia coli, total plate count, and Clostridium perfringens count and increased the Lactobacillus and Bifidobacterium count. Significantly (P < 0·01) higher serum and liver antioxidant enzyme pool, serum HDL cholesterol and lower serum glucose, triglyceride, total cholesterol, cardiac risk ratio, atherogenic coefficient and atherogenic index of plasma were observed in birds supplemented with 0·2% MOS along with 10⁶  CFU BFD per g of feed compared to control or BMD supplemented birds. Better production performance, gut microbial composition, serum biochemistry, antioxidant profile and health indices were depicted by broiler chicken supplemented with 0·2% MOS and 10⁶  CFU BFD per g of feed.

Dietary synbiotic supplementation improves the growth performance, body antioxidant pool, serum biochemistry, meat quality, and lipid oxidative stability in broiler chickens

The present study investigated the effects of Lactobacillus acidophilus (LBA) and mannan-oligosaccharides (MOS) supplementation on the production performance, serum biochemistry, antioxidant profile, health indices, meat quality, and lipid oxidative stability of broiler chicken. A total of 252 commercial broiler chickens at 1 d old of uniform body weight were randomly allocated to 6 maize-soybean-based dietary treatments: T₁ (control diet), T₂ ( antibiotic bacitracin methylene di-salicylate [BMD] at 20 mg/kg diet), T₃ (MOS at 0.1% + LBA at 10⁶ CFU/g feed), T₄ (MOS at 0.1% + LBA at 10⁷ CFU/g feed), T₅ (MOS at 0.2% + LBA at 10⁶ CFU/g feed), and T₆ (MOS at 0.2% + LBA at 10⁷ CFU/g feed). Each treatment was assigned to 6 replicates of 7 birds. The samples for meat quality and serum biochemistry analysis were taken from 12 birds per treatment (2 birds/replicate). The results revealed better (P < 0.01) growth performance and production efficiency of birds fed either T₅ or T₆ diet compared to control or BMD supplemented diet and BMD-supplemented birds superseded the control birds. Higher (P < 0.01) serum and liver antioxidant enzyme activities, meat antioxidant capacity (2, 2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid [ABTS] and 1, 1-diphenyl-2-picrylhydrazyl [DPPH] assays], serum total protein, high-density lipoproteins (HDL) cholesterol (P < 0.05), and globulin levels (P < 0.01) were observed in birds fed either T₅ or T₆ diet compared to control or BMD supplemented birds, whereas, lower lipid oxidation (P < 0.01), cardiac risk ratio, atherogenic coefficient, atherogenic index of plasma, serum glucose, triglyceride, total cholesterol levels (P < 0.01), and serum albumin-to-globulin ratio (P < 0.05) were observed in the chickens. The pH of meat from birds fed T₄, T₅ or T₆ diet was lower (P < 0.01) compared to control and other treatments. The extract release volume (ERV), water holding capacity (WHC), and protein content of meat were higher (P < 0.05) in birds fed either T₅ or T₆ diet compared to control or BMD supplemented birds. Thus, it was concluded that the supplementation of 0.2% MOS along with LBA at 10⁶ CFU/g is optimum for better growth performance, serum biochemistry, antioxidant profile, health indices, meat quality, and lipid oxidative stability of broiler chickens.

Effects of Paenibacillus xylanexedens on growth performance, intestinal histomorphology, intestinal microflora, and immune response in broiler chickens challenged with Escherichia coli K88

This study investigated the effects of dietary Paenibacillus xylanexedens ysm1 supplementation on growth performance, intestinal morphology, immune response, and cecal microbiota of broiler chickens challenged with Escherichia coli K88. A total of 320 one-day-old male broiler chicks were randomly allocated to 4 treatments (8 floor pens, 10 birds/pen) including 1) negative control (NC) birds fed a basal diet and not challenged with E. coli K88; 2) positive control (PC) birds fed a basal diet and challenged with of E. coli K88; 3) P. xylanexedens ysm1 treatment (PRO) birds fed a basal diet supplemented with 1 × 109P. xylanexedens ysm1 cfu/kg feed and challenged with E. coli K88; and 4) antibiotic treatment (ANT) birds fed a basal diet supplemented with 20 mg of colistin sulphate/kg of feed and challenged with E. coli K88. The E. coli challenge decreased (P < 0.05) BWG in PC birds compared with the ANT birds on days 21 and 28. The FCR was higher (P < 0.01) in PC birds compared with the NC, PRO, and ANT birds on days 14, 21, and 28. Compared with the NC, PRO, and ANT birds on day 28, PC birds had shorter villi and higher number of goblet cells in both jejunum and ileum (P < 0.001). Irrespective of the dietary treatments, the E. coli challenge reduced the number of PCNA-positive cells in both the jejunum and ileum on day 28. Paenibacillus xylanexedens ysm1 treatment resulted in higher concentration of mucosal sIgA in the jejunum as compared to the other treatment groups on days 14 and 28. The numbers of cecal E. coli were reduced (P = 0.017) in broilers treated with P. xylanexedens ysm1 or antibiotic in comparison with the PC group on day 28. In conclusion, the present study demonstrated that dietary supplementation of this new probiotic bacteria P. xylanexedens ysm1 improved broiler performance by modulating intestinal morphology, enhancing immune response, and reducing the number of E. coli in the cecum.

Effects of Dietary Direct Fed Microbial Supplementation on Performance, Intestinal Morphology and Immune Response of Broiler Chickens Challenged With Coccidiosis

Poultry coccidiosis is a costly intestinal disease that leads to considerable tissue damage, inefficient nutrient absorption, increased mortality, and predisposition to secondary infections. This study evaluated the effects of a direct feed microbial (DFM) dietary additive on performance, intestinal morphology, and immune response of broilers during a mixed coccidiosis challenge. In total, 840 Cobb500 male broilers were randomly allocated to 3 treatments (7 replicates, 40 birds/pen) including negative control (NC) fed basal diet; positive control (PC) fed basal diet with coccidiosis challenge; and DFM supplemented diet, with coccidiosis challenge. At 15 days of age, all birds except for the NC treatment were orally gavaged with live oocysts of a commercial vaccine. On d 21 (6 days post challenge), 4 birds/pen were randomly selected and euthanized for scoring of coccidia-caused lesions in the duodenum, jejunum, and ceca. Body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were recorded on d 7, 14, 28, and 42. Jejunal and ileal tissue samples were taken for histomorphological assessment from 2 birds/pen on d 21. Ileal samples were also taken for mRNA expression analysis on d 14 and d 21. The DFM birds had significantly greater BWG than PC birds during d 0-21 (P < 0.05). No differences were observed among the treatment groups in terms of FI and FCR. Dietary DFM supplementation significantly reduced lesion scores in the duodenum and jejunum when compared with PC group (P < 0.05). The coccidia challenge significantly reduced (P < 0.05) ileal villus height when compared to the non-challenged group on d 21. Conversely, dietary DFM supplementation alleviated the negative effects of coccidiosis by increasing ileal villus area on d 21 (P < 0.05). The challenged birds had significantly greater expression of IFN-γ and IL-1β in the ileum on d 21. Based on these findings, dietary DFM supplementation may help restore broiler performance during the starter and early grower periods during coccidiosis, likely by maintaining gut integrity via improving intestinal morphology and also by reducing disease severity as manifested by lower lesion scores.

Effects of Different Probiotics on Laying Performance, Egg Quality, Oxidative Status, and Gut Health in Laying Hens

With recent bans on the growth-promoting use of antibiotics, alternative strategies are needed to improve the performance of agricultural animals. Here, the effects of dietary supplementation with Clostridium butyricum and a combination of Saccharomyces boulardii and Pediococcus acidilactici were assessed on laying performance, egg quality, oxidative status, and gut health in laying hens. A total of 8208 Lohmann pink laying hens were divided into 3 treatment groups, with each group replicated 12 times (n = 228). Hens in the control group (CON) were provided a basic diet devoid of added antibiotics and probiotics. Treatment group 1 (T1) received the same base diet supplemented with 0.5 g/kg C. butyricum, and the diets of treatment group 2 (T2) supplemented with S. boulardii (0.05 g/kg) and P. acidilactici (0.1 g/kg) for the entirety of the 5-week trial. The data indicated that C. butyricum supplementation resulted in a significant reduction in ADFI, a significant increase in feed conversion, eggshell strength, and the CP% of albumen (dry matter, DM) relative to CON. The probiotic-treated hens exhibited decreased reactive oxygen species (ROS) levels in ileum and cecum, and reduced malondialdehyde (MDA) in serum. In conclusion, dietary supplementation with C. butyricum may be beneficial with respect to hen performance, egg quality, and gut health.

Conditioning time and sodium bentonite affect pellet quality, growth performance, nutrient retention and intestinal morphology of growing broiler chickens

1. The present study was conducted to evaluate the effects of conditioning times and processed sodium bentonite (PSB)-based pellet binder (G. Bind™) on pellet quality, performance, small intestine morphology, and nutrient retention in growing broiler chickens (d 11-24).2. A total of 540, one-day-old male broiler chicks were fed a commercial starter diet (d 1-10). On day 11, birds were assigned to a 2 × 3 factorial arrangement including two conditioning times (2 and 4 min) and three levels of PSB (0, 7.5 and 15 g/kg) with six replicates of 15 chicks each. Feed intake and weight gain were recorded to calculate growth performance. The jejunal segment and excreta samples were collected to determine intestinal morphology and nutrient retention, respectively.3. Diets produced with 2 min conditioning time and containing 15 g/kg PSB increased (P < 0.05) pellet durability index and hardness. Conditioning time and PSB levels had no significant effect on growth performance. The inclusion of PSB to broilers diet increased (P < 0.05) energy usage of the pelleting machine. Chickens fed the diet conditioned for 2 min and containing 15 g/kg PSB had the lowest (P < 0.05) relative jejunal length. Two minutes conditioning of diets containing 15 g/kg PSB increased (P < 0.05) apparent metabolisable energy retention in broilers.4. It was concluded that 2 min conditioning of diet containing 15 g/kg PSB improved pellet quality and nutrient retention of broiler chickens, while the main effects of conditioning time and PSB levels were controversial in most evaluated parameters.

In vitro inhibition of avian pathogenic Enterococcus cecorum isolates by probiotic Bacillus strains

Enterococcus cecorum is a commensal bacteria and opportunistic pathogen that can cause outbreaks of Enterococcal spondylitis (“kinky back”) in poultry, with a growing concern worldwide. Numerous Bacillus-based probiotic strains are commercially available with proven effects in supporting gut health and growth performance, but efficacy against pathogenic E. cecorum is unknown. This study compared the in vitro inhibitory potential of cell-free supernatants (CFSs) of 18 Bacillus strains (14 commercial probiotic strains, 1 internal negative control and 3 type strains) on the growth of 9 clinical E. cecorum isolates. Standardized biomass cultures of live Bacillus were harvested and filtered to obtain CFSs. Inhibitory potential against E. cecorum isolates was assessed via a microdilution assay in which the final pathogen concentration was ∼ 10⁴ CFU/mL. Absorbance (OD) was measured every 15 min for 15 h and used to calculate percentage growth inhibition at an OD equivalent to 0.4 in the positive control (PC) (pathogen but no CFS), and growth delay vs. PC. Growth kinetic responses of pathogen isolate-Bacillus strain combinations ranged from total pathogen inhibition to partial inhibition, lag in growth, no effect, or increased growth vs. PC. Percentage inhibition of individual isolates varied markedly among Bacillus strains, from 100% to −100% (growth promotion as recorded for the type strain) (B. amyloliquefaciens DSM7^T). Five B. amyloliquefaciens CFSs produced higher average inhibition rates (>75%) than 2 out of 3 Bacillus licheniformis CFSs (−2.5, and −8.39% vs. PC, respectively) and 1 out of 2 Bacillus subtilis CFSs (7.3% vs. PC) (P < 0.05). Commercial strain 3AP4 exhibited the highest average percentage inhibition vs. PC (85.0% ± 7.9) and the most consistent inhibitory effect across pathogen isolates. The findings indicate that some commercially available poultry probiotic Bacillus strains are effective at inhibiting pathogenic E. cecorum in vitro, but effects are highly strain and pathogen isolate-dependent. Further work is required to confirm effects in vivo and isolate the inhibitory substances.

Effects of Different Papua New Guinea Sweetpotato Varieties on Performance and Level of Enteric Pathogens in Chickens

Simple Summary

The smallholder poultry industry in Papua New Guinea (PNG) has grown rapidly in the last decade. The cost of growing meat birds is high, as feed alone makes up to 80% of the total cost of production in PNG. Sweetpotato is currently used in a poultry feed as a cheaper alternative option compared to the more expensive commercially manufactured stockfeed in PNG. The PNG smallholder poultry production system involves many families who rear multiple batches of meat birds every year. These birds are sold mostly at the farm gate, at local provincial markets, or roadside markets. Consumption of contaminated chicken meat has been identified as one of the important food vehicles for food borne illness. This PNG-based study was conducted to understand whether the inclusion of local sweetpotato in poultry feed can influence the shedding of pathogens such as Clostridium perfringens, Salmonella and Campylobacter without causing negative effects on poultry performance. The results of this study releveled that Campylobacter and Salmonella levels in the broilers fed with the local sweetpotato diets can be influenced with inclusion of enzymes in the feed.

Abstract

In the last decade, research has targeted the evaluation of local feed ingredients for use in monogastric diets to alleviate the high cost of production of livestock at smallholder levels in Papua New Guinea (PNG). The PNG smallholder poultry production system involves many families who rear multiple batches of meat birds every year. This study was conducted to evaluate the levels of enteric pathogens in the caeca of broilers fed with sweetpotato diets with varying levels of non-starch polysaccharides (NSP). Selection of a sweetpotato variety for use in broiler diets should be based on the total NSP content. In particular, varieties with low soluble NSPs are economical to use as Apparent Metabolizable Energy (AME) values are within the desired range for poultry and there is minimal need to include enzymes to improve NSP digestibility. The use of varieties with a low total NSP is also advantageous as the numbers of Clostridium perfringens was lower in broilers fed with these sweetpotato varieties. The level of Campylobacter and Salmonella levels were high in the ceca of birds fed with the sweetpotato varieties with high total NSP. These levels can be reduced with the inclusion of enzymes. This information will assist in the efficient use of local varieties of sweetpotato in PNG by small holder poultry farmers for sustainable poultry production and the commercial industry.

Dietary effects of Bacillus subtilis fmbj on growth performance, small intestinal morphology, and its antioxidant capacity of broilers

This paper aimed to study the dietary effects of Bacillus subtilis fmbj (BS fmbj) on growth performance, small intestinal histomorphology, and its antioxidant capacity of broilers at 21 d of raising. A total of 300 1-d old male Arbor Acres broilers were randomly assigned to 5 groups: broilers fed the basal diets with 0 g/kg BS fmbj (CON), 0.2 g/kg BS fmbj (BS-1), 0.3 g/kg BS fmbj (BS-2), 0.4 g/kg BS fmbj (BS-3), and 0.5 g/kg BS fmbj (BS-4). The results showed that there were no differences in the growth performance among treatments during the trail. Dietary BS fmbj in broiler diets increased (P < 0.05) the serum immunoglobulin A (IgA) and immunoglobulin G (IgG) concentration, and enhanced the secretory immunoglobulin A (sIgA) level of small intestine (jejunum and ileum) compared with those in the CON group. The BS groups could improve (P < 0.05) the values of villus length, villus width, crypt depth, and villus area of small intestine compared with that in the CON group. Compared with the CON group, the BS group increased (P < 0.05) small intestinal antioxidant capacity and its mitochondrial antioxidant capacity, and also improved the antioxidant related-gene expression. The BS group exerted a lower (P < 0.05) level of oxidative damages in small intestine than that of the CON group. In conclusion, dietary BS fmbj in broiler diets was potential to improve the small intestinal histomorphology, small intestinal antioxidant capacity, and its mitochondrial antioxidant capacity. Thus this BS fmbj might be considered to be an important additive for the poultry industry.

Effect of direct-fed microbial addition in guinea fowl (Numida meleagris) diets on performance and health responses

The present study was conducted to investigate the effect of intermittent use of direct-fed microbial addition (DFM-"RE3®") on growth performance and health status of indigenous guinea fowls in northern Ghana. One-hundred and eighty day-old guinea keets were randomly assigned to 4 direct-fed microbial (DFM) treatments that included: control, daily, 3 consecutive days per wk (3CDW), and 7 days repeated every other wk (7DREOW) at 1.5 ml/L through water from day 1 to 56 days. Feed intake, body weight gain, and blood hematological and serum biochemical properties were recorded. The treatments had no effects (P > 0.05) on the hematological or serum biochemical properties recorded. Birds on DFM treatments appeared to consume less feed (range: 1,584 to 1,824 g/d) compared to the control (1,870 g/d/head). Birds on DFM treatments daily and 3CDW gained more (P < 0.05) weight (334 to 394 g/d) compared to the control (306.1 g/head) with keets on daily DFM supplementation recording the lowest (P < 0.05) feed conversion ratio. The total blood protein, globulin, lipids, albumin concentrations, and cholesterol concentrations were not affected (P > 0.05) by DFM supplementation. Supplementing birds with 1.5 mL of RE3®/liter of water daily can improve body weight. Further research on immune competence from the spleen, thymus, and bursa fibrosis for evidence of increased immune competence in probiotic administered birds is recommended.

Bacillus probiotics: an alternative to antibiotics for livestock production

The use of probiotics as feed supplements in animal production has increased considerably over the last decade, particularly since the ban on antibiotic growth promoters in the livestock sector. Several Bacillus sp. are attractive for use as probiotic supplements in animal feed due to their ability to produce spores. Their heat stability and ability to survive the low pH of the gastric barrier represent an advantage over other probiotic micro-organisms. This review discusses important characteristics required for selection of Bacillus probiotic strains and summarizes the beneficial effect of Bacillus-based feed additives on animal production. Although the mechanism of action of Bacillus probiotics has not been fully elucidated, they are effective in improving the growth, survival and health status of terrestrial and aquatic livestock. Bacillus strains also have utility in bioremediation and can reduce nitrogenous waste, thereby improving environmental conditions and water quality. Finally, recent innovative approaches for using Bacillus spores in various applications are discussed.

Performance, gut morphology and microbiology effects of a Bacillus probiotic, avilamycin and their combination in mixed grain broiler diets

1. This study aimed to determine the effect of avilamycin (AGP) and a multi-strain Bacillus probiotic (DFM) on the performance, gut histology and microbiology of broilers fed on a mixed grain diet. 2. A total of 800 chicks were allocated to four treatments: a control diet, control+AGP, control+DFM, or control+AGP+DFM. Bodyweight, feed intake and FCR were measured at d 0, 21 and 42. Samples were taken at d42 to determine villus height (VH), crypt depth (CD) and ratio (VH:CD). Mucosal E. coli and Lactobacilli counts were measured at d42. 3. At d42, DFM and AGP+DFM significantly increased weight over the control, with AGP returning an intermediate value. FCR followed a similar pattern. DFM and AGP+DFM significantly increased VH and CD in all gut sections compared to the control. 4. DFM and AGP+DFM reduced E. coli counts compared to control, with AGP reducing caecal counts only, while Lactobacilli counts were increased. 5. Divergent histology and microbiology between treatments highlight the different modes of action of AGP and DFM for improving broiler growth and feed efficiency.

The effects of enzymes and direct fed microbial combination on performance and immune response of broilers under a coccidia challenge

This study evaluated the effect of an enzyme blend (xylanase, amylase and protease; XAP) in combination with a direct fed microbial (DFM) containing three strains of Bacillus spp. on intestinal histology, immune response and performance of broilers. Four dietary treatments were tested in a 2 × 2 factorial trial, including two levels of challenge (without or with coccidial infection), two levels of feed additive (with or without XAP and DFM). Diets were fed ad libitum to male Cobb500 broilers in mash feeds from 1–21 days of age, with eight replicate pens per treatment within brooder-batteries with raised wire floors and built up litter, housing six birds per pen. A mild challenge was introduced by oral gavage at day five to the challenged birds, using a six-fold concentration of coccidial vaccine. A high fibre basal diet formulated with rye and wheat middlings was used to further increase the challenge. Body weight and feed intake were measured and feed conversion ratio (FCR) was calculated during starter (1–12 d), grower (12–21 d) and overall 1–21 days. Intestinal morphology and immune response parameters were measured on day 12 and 21. Compared to the unchallenged groups, the coccidial challenge reduced (P < 0.05) body weight gain (BWG), increased FCR, reduced villus height and increased crypt depth. The challenged birds had increased pro-inflammatory cytokines (IL-6, IL-1β; P < 0.05) in the intestine as well as higher levels of acute phase proteins (APP, haemopexin and α−1-acid glycoprotein) in the plasma and circulating heterophils. XAP + DFM supplementation improved BWG, reduced FCR and increased energy efficiency compared to the non-supplemented groups. The combination of XAP and DFM reduced inflammatory responses such as APP compared to the challenged control group and maintained performance to a comparable level seen in the unchallenged control. The data indicate that XAP enzymes in combination with Bacillus-based DFM may reduce the damage and performance losses induced by coccidial challenge.

Supplemental effects of probiotic Bacillus subtilis fmbJ on growth performance, antioxidant capacity, and meat quality of broiler chickens

This study aimed to investigate the supplemental effects of probiotic Bacillus subtilis fmbJ (BS fmbJ) on growth performance, antioxidant capacity, and meat quality of broiler chickens. A total of 240 day-old male Arbor Acres (AA) broiler chickens were randomly allotted to 4 treatments and raised for 6 wk. Each treatment had 6 replicate pens with ten birds per replicate. Birds in the control group (CON) were fed diets without BS fmbJ and antibiotics. The BS groups were fed the basal diets with BS fmbJ at 2 × 10¹⁰ cfu/kg (BS-1 group), BS fmbJ at 3 × 10¹⁰ cfu/kg (BS-2 group), BS fmbJ at 4 × 10¹⁰ cfu/kg (BS-3 group) without antibiotics for 42 d. In the study, dietary supplementation with BS fmbJ significantly improved (P < 0.05) the average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) of broilers from 21 to 42 d and 1 to 42 d. At 42 d, the final body weight was increased (P < 0.05) in BS-2 group compared with that in CON. Dietary BS fmbJ significantly increased (P < 0.05) serum IgA and IgG concentrations of broilers after 42 days raising. The glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activity of serum and liver were increased (P < 0.05), and methane dicarboxylic aldehyde (MDA) contents in serum and liver were decreased (P < 0.05) by BS fmbJ added into the broiler diets. Dietary supplementation with BS fmbJ significantly decreased (P < 0.05) reactive oxygen species (ROS) contents in liver mitochondria of broilers. Additionally, the expression of antioxidant enzyme gene including nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were improved (P < 0.05) by BS fmbJ added into the broiler diets. Among measuring items of chicken breast meat quality, the drip loss, cooking loss, shear force, L*_24 h, a*_24 h, b*_45 min, and b*_24 h values were influenced (P < 0.05) by BS fmbJ provided in the diet. Based on these results, Bacillus subtilis fmbJ could be acted as a beneficial feed additive with antioxidant capacity in broiler diets.

Effect of different levels of rapeseed meal and sunflower meal and enzyme combination on the performance, digesta viscosity and carcass traits of broiler chickens fed wheat-based diets

The aim of the present experiment was to examine the effect of different levels of rapeseed meal (RSM) and sunflower meal (SFM) and enzyme combination (endoxylanase and β-glucanase) on the production performance, carcass quality, gizzard development and digesta viscosity of broiler chickens. The experimental design was a 3×2 factorial arrangement of treatments evaluating three diet types containing different levels of RSM and SFM (low (L), medium (M) and high (H)) and two levels of enzyme inclusion (0 or 100 g/tonne diet to provide 1220 U xylanase and 152 U β-glucanase per kg diet). Broiler starter and grower/finisher diets were formulated, based on wheat and soya bean meal and containing 50, 50 and 80 g/kg RSM and 0, 50 and 60 g/kg SFM for L, M and H treatments, respectively, during starter period and 80, 80 and 120 g/kg RSM and 0, 80 and 100 g/kg SFM for L, M and H, respectively, during grower/finisher period, and each diet was fed ad libitum to eight pens of 20 male broilers each. During the starter period (1 to 21 days), birds fed the H treatment had lower (P0.05) on feed conversion ratio (FCR). During the grower/finisher phase (22 to 42 day) and over the entire period (1 to 42 day) birds fed the H treatment had lower (P0.05) between RSM and SFM inclusion level and enzyme supplementation were observed for any of the measured parameters at any period. Diet type and enzyme supplementation had no effect (P>0.05) on carcass traits, abdominal fat pad, breast meat yield and jejunal digesta viscosity. Diet type influenced (P=0.05) relative empty gizzard weight, where the H treatment had higher relative empty gizzard weight compared with the L treatment. Enzyme supplementation tended (P=0.10) to increase relative empty gizzard weight. The present data suggest that high inclusion of SFM and RSM negatively influenced broiler performance. Enzyme supplementation improved FCR at all levels of RSM and SFM included in this study, but did not recover the reduction in weight gain caused by high inclusion of RSM and SFM.

A direct fed microbial containing a combination of three-strain Bacillus sp. can be used as an alternative to feed antibiotic growth promoters in broiler production

The objective of the study was to test the effect of a direct fed microbial (DFM) on the performance of broilers compared to an antibiotic growth promoter under large scale, commercial production settings. Three dietary treatments were tested in a completely randomized design including: 1) a control (C) diet containing 500 FTU/kg phytase and a mixture of xylanase, amylase, protease ; 2) C+ a specific three-strain combination of Bacillus spp. (DFM) and 3) C+ bacitracin methylene disalicylate (BMD). Six, similar commercial broiler houses (15,300 birds per house) were used to give two replicate houses per treatment. The birds (Hubbard x Cobb500) were fed pelleted and crumbled diets ad libitum throughout the 44 day trial period. Due to the large scale, commercial nature of the trial, no significant differences were observed in production parameters among treatments, except that DFM treatment resulted in significantly lower mortality numbers in the last two days (43 to 44d) compared to the control. However, the DFM treatment group showed numerically higher live bodyweight, lower feed conversion ratio (corrected for body weight and mortality) and lower total mortality weight compared to either the control or BMD groups, resulting in an improved production efficiency factor. When compared to control, using DFM resulted in a gross benefit of US$ 0.06 /bird, while using BMD was not cost effective. In conclusion, DFM containing a three-strain combination of Bacillus spp. may be used as an alternative to antibiotic growth promoters, resulting in economic benefit under commercial production settings in broilers fed commercial diets.

Effects of multistrain probiotics on growth performance, apparent ileal nutrient digestibility, blood characteristics, cecal microbial shedding, and excreta odor contents in broilers

This experiment was conducted to investigate the efficacy of Lactobacillus acidophilus, Bacillus subtilis, and Clostridium butyricum supplementation in broilers. A total of 400 one-day-old mixed sex Ross 308 broilers with an initial average BW of 46 ± 0.5 g were randomly allotted into 4 treatments with 5 replicate pens per treatment and 20 broilers in each pen for 35 d. Dietary treatments were (1) an antibiotic-free diet (CON), (2) CON + 5 mg/kg of avilamycin, (3) CON + 1 × 10(5) cfu of multistrain probiotics/kg of diet (P1), and (4) CON + 2 × 10(5) cfu of multistrain probiotics/kg of diet (P2). Broilers fed the P1 and P2 diets had greater BW gain than broilers fed the CON diet during d 22 to 35 (P = 0.01) and overall (P = 0.02). Feed conversion ratios in P1 and P2 were decreased (P = 0.03) compared with that in CON from d 22 to 35. Ileal digestibility of most essential amino acids, with the exception of His and Phe, were increased (P < 0.05) in P1 and P2 compared with CON. Serum IgA and IgM concentrations in P2 were higher (P < 0.05) than those in CON. The cecal Lactobacillus numbers were increased (P = 0.02), and the counts of Escherichia coli were decreased (P = 0.03) in P1 and P2 compared with CON. Dietary supplementation with multistrain probiotics decreased (P < 0.05) the excreta NH3 content compared with the CON. In conclusion, dietary supplementation with multistrain probiotics improved broiler growth performance, ileal amino acids digestibility, and humoral immunity. Furthermore, the probiotics decreased the cecal numbers of E. coli and decreased the NH3 content of excreta.