The Dynamics of Probiotics on Growth Performance and Immune Response in Broilers

Overcrowding Stress in Livestock Production Alters Gut Microbiota Composition and Neuronal Nitric Oxide Synthase (nNOS) Expression in nNOS-HiBiT Knock-in Mouse Model

Overcrowding stress in livestock farming is a significant concern for animal health and livestock products such as meats, milk, and eggs. It affects gut health by altering microbiota and regulating neuronal nitric oxide synthase (nNOS). This study aimed to investigate the effects of overcrowding stress on the gut microbiota composition and nNOS expression. We generated an nNOS-HiBiT knock-in mouse model using the HiBiT system, a highly sensitive tool for accurately quantifying gene expression. Overcrowding stress was induced by housing twenty mice per cage (MPC20) and compared with a control group of two mice per cage (MPC2). Overcrowding stress increases nNOS levels in the hypothalamus and ileum and serum corticosterone levels. Gut microbial composition differed between the control and overcrowding stress-induced groups in the ileum, cecum, and colon. Specifically, Bifidobacterium and Akkermansia decreased in all three regions of MPC20, whereas Helicobacter in the ileum and colon and Parasuterella in the cecum increased in MPC20. Notably, Bifidobacterium consistently decreased when nNOS and corticosterone expression were used as covariates under overcrowding stress. These regional variations reflect the differential impact of overcrowding stress on the intestinal tract, indicating complex interactions through nNOS expression within the brain-gut-microbiome axis. Importantly, the addition of probiotic feed, particularly those containing Bifidobacterium, may counteract these decreases, leading to enhanced gut health and improved quality of livestock food products. This study enhances our understanding of the correlation between overcrowding stress and the gut microbiota, providing valuable data for improving the management environment in livestock farming.

Effects of a novel synbiotics-enzyme complex as a replacement for antibiotics on growth performance, slaughter and meat characteristics, immune organ index, and intestinal morphology of broilers

Introduction

Antibiotic use in broilers is being discouraged globally due to the challenges it poses. This study was conducted to assess the effects of supplementing broilers with a Symbiotic-Enzyme complex (SEC) containing prebiotics (mannose oligosaccharides), probiotics (Clostridium butyricum and Bacillus subtilis), and enzymes (glucose oxidase, and α-galactosidase) as an alternative to antibiotics on growth performance, carcass and meat quality traits, mortality, linear body measurements, intestinal morphology and immune organ indexes.

Method

A total of 864 mixed-sex 1-day-old arbor acres (AA+) broilers were allocated to 8 experimental groups replicated 9 times with 12 chickens per replicate. These included 6 treatment groups with SEC inclusion levels of 0.025, 0.04, 0.05, 0.06, 0.08, and 0.10%, respectively, and two control groups: a negative control group containing a basal diet only and the positive control group (Antibiotics group) containing a basal diet and antibiotic oxytetracycline added at 0.2%. Growth performance was measured on day 21 and 42, and the mortality, carcass, meat quality traits, linear body measurements, intestinal morphology, and organ size indexes were measured on day 42.

Results

The results indicated that supplementing broilers with 0.1% SEC resulted in insignificant (P > 0.05) increases in average daily feed intake (ADFI), significant (P < 0.05) increases in the average daily gains (ADG), and significant (P < 0.05) reduction in a feed-to-gain ratio (F/G) in all the phases compared to the control and antibiotics groups. Supplementation of broilers with 0.1% SEC inclusion levels also significantly (P < 0.05) increased the body slope length, chest width, chest depth, keel length, and shank circumference. Furthermore, broilers on diets containing 0.1% SEC inclusion level also had significantly (P < 0.05) higher dressed, semi-evisceration, evisceration, and breast muscle percentages. Including SEC at 0.1% also significantly (P < 0.05) increased villus height and villus-to-crypt ratio (V/C) but reduced crypt depth in the duodenum, jejunum, and ileum compared to the control groups. SEC inclusion at 0.1% significantly (P < 0.05) increased the spleen, bursal, and thymus indexes, respectively.

Conclusion

Supplementation of broilers with 0.1% SEC can be used as an antibiotic alternative because it increases the F/G, improves the carcass and meat quality, increases the body conformation, improves the small intestines' functions, and immune organ size.

Precision Glycan Supplementation Improves Gut Microbiota Diversity, Performance, and Disease Outbreak Resistance in Broiler Chickens

The poultry industry contributes significantly to the global meat industry but faces many production challenges like high-density housing, welfare issues, and pathogenic infections. While antibiotics have commonly been used to treat many of these issues, they are being removed from poultry production globally due to increased microbial resistance. Precision glycans offer a viable alternative to antibiotics by modulating microbial metabolic pathways. In this study, we investigated the effects of precision glycan supplementation on productivity and gut microbiota in broilers. The experiment was conducted in a commercial setting using 32,400 male Ross chickens randomly divided into three sheds with 10,800 birds each. One shed with 12 pen replicates of 900 birds was used as control, while the other two with an equal number of replicates and birds were assigned to precision glycan supplementation. The treatment significantly improved the average daily weight gain and feed conversion ratio, with a significant modification in the abundance of several bacterial taxa in the caecum, ileum, and ileum mucosa microbial communities. There was increased richness and diversity in the caecum, with a reduction in Proteobacteria and an increase in Firmicutes. Richness remained unchanged in the ileum, with an increase in diversity and reduction in pathogenic genera like Clostridium and Escherichia-Shigella. Ileum mucosa showed a lower abundance of mucin degraders and an increased presence of next-generation probiotics. Supplemented birds showed a high level of disease resistance when the farm experienced an outbreak of infectious bronchitis, evidenced by lower mortality. Histological analysis confirmed improvements in the ileum and liver health, where the precision glycan supplementation reduced the area of congested sinusoids compared to the control group in the liver and significantly improved ileum intestinal morphology by increasing crypt depth and surface area. These results collectively suggest that precision glycans offer substantial benefits in poultry production by improving productivity, gut health, and disease resistance.

Salmonella Infection in Poultry: A Review on the Pathogen and Control Strategies

Salmonella is the leading cause of food-borne zoonotic disease worldwide. Non-typhoidal Salmonella serotypes are the primary etiological agents associated with salmonellosis in poultry. Contaminated poultry eggs and meat products are the major sources of human Salmonella infection. Horizontal and vertical transmission are the primary routes of infection in chickens. The principal virulence genes linked to Salmonella pathogenesis in poultry are located in Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2). Cell-mediated and humoral immune responses are involved in the defense against Salmonella invasion in poultry. Vaccination of chickens and supplementation of feed additives like prebiotics, probiotics, postbiotics, synbiotics, and bacteriophages are currently being used to mitigate the Salmonella load in poultry. Despite the existence of various control measures, there is still a need for a broad, safe, and well-defined strategy that can confer long-term protection from Salmonella in poultry flocks. This review examines the current knowledge on the etiology, transmission, cell wall structure, nomenclature, pathogenesis, immune response, and efficacy of preventative approaches to Salmonella.

Effectiveness of probiotics and clove essential oils in improving growth performance, immuno-antioxidant status, ileum morphometric, and microbial community structure for heat-stressed broilers

Recently, interest has increased in using bio-additives, herbs, and their extracts as feed additives because of their potential role in improving chick's health and productivity, especially during stress. Thus, our aim in this study is to examine whether nutritional supplementation (probiotics and clove essential oils) will help mitigate the negative effect of heat stress on the bird by modifying the microbial content, boosting immunity, oxidative status, metabolic, and growth. In this study, three hundred one-day-old broiler chicks (Ross 308) were fed the following experimental diet: (CON) basal diet (control diet); (CEO) CON with clove essential oils (300 mg/kg); (PRO) CON with probiotics (2 g/kg); (PC) CON with probiotics and clove essential oils. Our results showed a significant improvement (P < 0.05) in body weight gain, feed conversion ratio, nutrient digestibility, and digestive enzymes activities in broilers fed on PC, CEO, and PRO compared to the control group. Moreover, a significant decrease was recorded in the abdominal fat content and an increase in the relative weight of bursa of Fabricius, and higher antibody levels against Newcastle disease virus, as well as, there was an increase (P < 0.05) in interleukin 10 (IL-10) in all treated groups. Meanwhile, there was a decrease in tumor necrosis factor-α (TNF-α) in all supplemented groups compared with the control group. Serum triglycerides, cholesterol, low-density lipoprotein concentrations, and alanine aminotransferase activities were significantly lower in the treated groups. Superoxide dismutase and glutathione peroxidase levels were elevated (P < 0.05) and the malondialdehyde level value significantly decreased in all supplemented groups. The treated groups enhanced the ileum structure by increasing Lactobacillus, decreasing E. coli, and improving the morphometrically (P < 0.05). This study strongly suggests that clove essential oil and probiotic mixture can be used as a feed supplement to reduce the effects of heat stress by improving the growth performance and enhancing immuno-antioxidant status, ileum morphometric, as well as modifying the microbial community structure of the ileum of broilers.

Preventing bacterial disease in poultry in the post-antibiotic era: a case for innate immunity modulation as an alternative to antibiotic use

The widespread use of antibiotics in the poultry industry has led to the emergence of antibiotic-resistant bacteria, which pose a significant health risk to humans and animals. These public health concerns, which have led to legislation limiting antibiotic use in animals, drive the need to find alternative strategies for controlling and treating bacterial infections. Modulation of the avian innate immune system using immunostimulatory compounds provides a promising solution to enhance poultry immune responses to a broad range of bacterial infections without the risk of generating antibiotic resistance. An array of immunomodulatory compounds have been investigated for their impact on poultry performance and immune responses. However, further research is required to identify compounds capable of controlling bacterial infections without detrimentally affecting bird performance. It is also crucial to determine the safety and effectiveness of these compounds in conjunction with poultry vaccines. This review provides an overview of the various immune modulators known to enhance innate immunity against avian bacterial pathogens in chickens, and describes the mechanisms involved.

The effect of Bacillus subtilis and its delivery route on hatch and growth performance, blood biochemistry, immune status, gut morphology, and microbiota of broiler chickens

This study evaluated the effect of probiotics (Bacillus subtilis fermentation extract) and its delivery route (in-feed or in ovo) on hatch and growth performance, blood biochemistry, immune status, gut morphology, and microbiota of broiler chickens. Hatching eggs were incubated for 21 d. On d 12, viable eggs were randomly allotted to 4 groups: the noninjected, in ovo saline (S), in ovo Bacillus subtilis 1 (P1), and in ovo Bacillus subtilis 2 (P2). On d 18, S, P1, and P2 groups received 0.2 mL saline diluent, 10 × 10⁶, and 20 × 10⁶ CFU of the bacterium via the amnion, respectively. At hatch, chicks were re-allotted to 5 new treatment groups: P1, P2, 0.005% in-feed Bacillus subtilis extract (P3), 0.05% in-feed bacitracin methylene disalicylate (BMD,), and corn-wheat-soybean diet negative control (NC) in 9 replicate pens (22 birds/pen) and raised for 35 d. Hatch parameters were assessed on d 0, and growth performance indices measured weekly. On d 25, 1 bird/cage was euthanized, and samples collected for further analysis. Data were analyzed by generalized linear model. Treatments S and P2 recorded higher (P = 0.01) chick BW/ Egg Weight values compared to the non-injected eggs. P3 and P2 reduced (P = 0.02) FI at week 5 compared to the NC treatment. However, no change in average body weight gain (ABG) and feed conversion ratio (FCR) were observed during the same period. At d 35, while BMD treatment showed a tendency (P = 0.09) to increase FI compared to the NC treatment, ABG and FCR were similar for all treatments. Blood sodium and chloride levels were increased (P < 0.05) by the BMD treatment compared to the NC treatment. Compared to other treatments, BMD and P3 treatments increased (P < 0.001) jejunal and ileal villus height to crypt depth ratios, respectively. However, P1 and P2 increased (P < 0.001) villus height to crypt depth ratio in the duodenum compared to NC treatment. Treatments did not affect gut microbial diversity; however, BMD treatment increased (P < 0.05) the proportion of bacteria in the genus Enterococcus in the ileum and reduced (P < 0.05) the proportion of bacteria in the genus Streptococcus in the ceca. All probiotics treatments (irrespective of route and dose) reduced (P < 0.001) the levels of serum IgG compared to the NC treatment. However, P1 and P2 had the lowest numerical decrease in serum IgG concentrations, suggesting that Bacillus subtilis (especially in ovo delivered) might provide broiler chickens with better immunological protection by neutralizing pathogenic organisms that could result in the production of natural antibodies.

An updated review on probiotics as an alternative of antibiotics in poultry - A review

Antibiotics used to be supplemented to animal feeds as growth promoter and as an effective strategy to reduce the burden of pathogenic bacteria present in the gastro-intestinal tract. However, in-feed antibiotics also kill bacteria that may be beneficial to the animal. Secondly, unrestricted use of antibiotics enhanced the antibiotic resistance in pathogenic bacteria. To overcome above problems, scientists are taking a great deal of measures to develop alternatives of antibiotics. There is convincing evidence that probiotics could replace in-feed antibiotics in poultry production. Because they have beneficial effects on growth performance, meat quality, bone health and eggshell quality in poultry. Better immune responses, healthier intestinal microflora and morphology which help the birds to resist against disease attack were also identified with the supplementation of probiotics. Probiotics establish cross-feeding between different bacterial strains of gut ecosystem and reduce the blood cholesterol level via bile salt hydrolase activity. The action mode of probiotics was also updated according to recently published literatures, i.e antimicrobial substances generation or toxin reduction. This comprehensive review of probiotics is aimed to highlight the beneficial effects of probiotics as a potential alternative strategy to replace the antibiotics in poultry.

Influence of fermented feed additive on gut morphology, immune status, and microbiota in broilers

BACKGROUND

This study examined the effects of a solid-state fermented feed additive (FFA) on the small intestine histology/morphology, immunity and microbiota of broilers. Two hundred eighty-eight day-old Arbor Acre chicks, were randomly assigned to one of four groups (each group has 6 replicates, with each replicate containing 12 chickens). The negative control (NC; basal diet), the positive control (PC; basal diet +antibiotic 15 ppm), the fermented feed additive low dose (FFL; basal diet + 0.3 kg/t FFA), and the fermented feed additive high dose (FFH; 3 kg/t FFA) with Lactobacillus casei (L.casei).

RESULTS

The study found that the FFH and FFL groups gained more weight (1-21d) and the FFL and PC diets had better feed conversion ratio (P < 0.05) than the NC from 0-42d. The FFH group had higher villus height (P < 0.05) in the duodenum than the PC and villus height to crypt depth ratio VH/CD compared to PC and FFL groups. The FFL chickens had greater (P < 0.05) jejunal and ileal villus height than PC and NC groups respectively. The FFL group had a higher ileal VH/CD ratio (P < 0.05). Jejunum VH/CD was higher in FFL and FFH (P < 0.05) than PC (P < 0.05). FFH had a smaller thymus than NC (P < 0.05). FFA diets also increased IL-10 expression (P < 0.05). While IL-1 and TLR4 mRNA expression decreased (P < 0.05) compared to NC. The microbiota analysis showed that the microorganisms that have pathogenic properties such as phylum Delsulfobacterota and class Desulfovibriona and Negativicutes was also significantly reduced in the group treated with FFH and PC while microorganisms having beneficial properties like Lactobacillaceae family, Lactobacillus aviarus genus and Lactobacillus spp were also tended to increase in the FFH and FFL fermented feed groups compared to the PC and NC groups.

CONCLUSION

These findings suggested that the FFA diet may modulate cecal microbiota by reducing pathogenic microorganisms such as phylum Delsulfobacterota and class Desulfovibriona and Negativicutes improve beneficial microorganisms like Lactobacillaceae family, Lactobacillus aviarus genus and Lactobacillus spp. While FFA diet also affect immunity, and gene expression related to immunity.

Gastrointestinal Microbiota and Their Manipulation for Improved Growth and Performance in Chickens

The gut of warm-blooded animals is colonized by microbes possibly constituting at least 100 times more genetic material of microbial cells than that of the somatic cells of the host. These microbes have a profound effect on several physiological functions ranging from energy metabolism to the immune response of the host, particularly those associated with the gut immune system. The gut of a newly hatched chick is typically sterile but is rapidly colonized by microbes in the environment, undergoing cycles of development. Several factors such as diet, region of the gastrointestinal tract, housing, environment, and genetics can influence the microbial composition of an individual bird and can confer a distinctive microbiome signature to the individual bird. The microbial composition can be modified by the supplementation of probiotics, prebiotics, or synbiotics. Supplementing these additives can prevent dysbiosis caused by stress factors such as infection, heat stress, and toxins that cause dysbiosis. The mechanism of action and beneficial effects of probiotics vary depending on the strains used. However, it is difficult to establish a relationship between the gut microbiome and host health and productivity due to high variability between flocks due to environmental, nutritional, and host factors. This review compiles information on the gut microbiota, dysbiosis, and additives such as probiotics, postbiotics, prebiotics, and synbiotics, which are capable of modifying gut microbiota and elaborates on the interaction of these additives with chicken gut commensals, immune system, and their consequent effects on health and productivity. Factors to be considered and the unexplored potential of genetic engineering of poultry probiotics in addressing public health concerns and zoonosis associated with the poultry industry are discussed.

Effects of phenylpyruvate on the growth performance and intestinal microbiota in broiler chicken

1. The purpose of this study was to see how dietary supplementation with phenylpyruvate affected broiler growth, slaughter performance, gut health microbiota and immunity. This information can be used to develop alternative approaches to antibiotic replacement in modern poultry production and health.2. A total of 288, one-day-old broiler chickens were randomly assigned to one of four groups (six replicates each replicate has 12 chickens). A control basal diet (NC), basal diet plus antibiotic virginiamycin 15ppm (PC), basal diet plus phenylpyruvate 1 kg/t or 2 kg/t, respectively (LCP and HCP).3. Results showed that the birds in the PC group had higher ADFI during the first 21 d, and better FCR than the NC group. Feeding LCP and HCP improved broilers' FCR by 0.001 and 0.037% compared to the NC group respectively. The HCP-fed group has a higher all-eviscerated ratio than the NC group and less abdominal fat than the birds fed LCP. The birds fed HCP has increased villus length and crypt depth in the ileum compared to the NC group.4. The bursa index was lower in the HCP group whereas the thymus index was lower in LCP and PC groups. In contrast, birds fed HCP has lower pro-inflammatory cytokine IL-1, as well as lower TLR4. Phenylpyruvate improved number in the Selenomonadaceae, genus Megamonas bacteroides spp., which are known for their beneficial effects on the maintenance of the cell surface structure, regulating aromatic amino acids and Clostridia jejuni-suppressive treatment respectively.5. It was concluded that phenylpyruvate can be utilised in feed to improve growth performance and positively modulate gut microbiota. However, this was less efficient than antibiotics in improving growth performance, although more efficient in improving productive performance and gut morphology. Moreover, a high dose of phenylpyruvate is more effective than a low dose.

Molasses, Antox® and EN-FLORAX® decreased antibody decay rate and enhanced response to a very virulent infectious bursal disease virus and Newcastle disease vaccine La Sota in ISA Brown chicks

This study evaluated the effects of molasses, Antox® and EN-FLORAX® on antibody (Ab) decay and response to a very virulent IBD virus (vvIBDV) and ND vaccine La Sota (NDVLS) in ISA Brown chicks. Five groups, (A, B, C, D and E) of 50 chicks each were used for the study. Groups A, B and C were supplemented with molasses, Antox® and EN-FLORAX®, respectively, orally from 1 to 49 days, and inoculated with a vvIBDV at 28 days of age. Groups D, and E were positive, and negative controls, respectively. At 35 days of age, all groups were vaccinated with NDVLS. Antibody (Ab) titers to vvIBDV, and NDV, were determined by indirect enzyme linked immunosorbent assay (I-ELISA), and hemagglutination-inhibition (HI) tests, respectively. Results revealed significantly (P < .05) decreased Ab decay rates in supplemented groups (A, B, and C) compared to controls (D and E) up to day 28. There were significantly (P < .05) higher mean IBDV and ND HI Ab titers in supplemented groups compared to D with the highest in A up to day 49. Molasses, Antox®, and EN-FLORAX® decreased rate of Ab decay, elicited stronger Ab response against vvIBDV and production of protective NDVLS HI Ab titers.

Role of Different Growth Enhancers as Alternative to In-feed Antibiotics in Poultry Industry

The poultry industry has grown so fast alongside the irrational use of antibiotics to maximize profit and make the production cost-effective during the last few decades. The rising and indiscriminate use of antibiotics might result in the deposition of residues in poultry food products and in the development of resistance to these drugs by microorganisms. Therefore, many diseases are becoming difficult to treat both in humans and animals. In addition, the use of low-dose antibiotics as growth enhancer results in antibiotic residues in food products, which have detrimental effects on human health. On the other hand, many studies have shown that antibiotics administered to poultry and livestock are poorly absorbed through the gut and usually excreted without metabolism. These excreted antibiotics eventually accumulate in the environment and enter the human food chain, resulting in the bioaccumulation of drug residues in the human body. In this regard, to find out alternatives is of paramount importance for the production of safe meat and egg. Therefore, in recent years, much research attention was disarticulated toward the exploration for alternatives to antibiotic as in-feed growth enhancers after its ban by the EU. As a result, probiotics, prebiotics, phytobiotics, spirulina, symbiotic, and their combination are being used more frequently in poultry production. Feed additives therefore gained popularity in poultry production by having many advantages but without any residues in poultry products. In addition, numerous studies demonstrating that such biological supplements compete with antimicrobial resistance have been conducted. Therefore, the purpose of this review article was to highlight the advantages of using biological products instead of antibiotics as poultry in-feed growth enhancers to enhance the production performance, reduce intestinal pathogenic bacteria, and maintain gut health, potentiating the immune response, safety, and wholesomeness of meat and eggs as evidence of consumer protection, as well as to improve the safety of poultry products for human consumption.

The Efficiency of Probiotics Administrated via Different Routes and Doses in Enhancing Production Performance, Meat Quality, Gut Morphology, and Microbial Profile of Broiler Chickens

Simple Summary

Antimicrobial growth promoters (AGPs) have been used in the animal production industry around the world for decades, with the consequence of a high potential of antibiotic-resistant bacteria transfer to humans. Efficiently raising broiler chickens in an antibiotic-free production system is a challenge, and identifying an effective nutritional alternative to support growth performance, gut health, and functionality without administrating AGPs is of essence. Several antimicrobial alternative options that are commercially available include herbal essential oils, exogenous enzymes, organic acids, plant secondary metabolites, probiotics, and prebiotics. Probiotics in animal feed is projected to attain a massive global growth, reaching USD 6.24 billion by 2026. This study tested the efficiency of probiotics when supplemented via different administration routes (feed or water) and doses, or in combination with prebiotics, on growth performance, meat quality, gut morphology, and microbial profile of broiler chickens. The outcomes revealed that probiotics enhance production performance, and compared to AGPs, do not reduce the beta-diversity of the gut microbial community. Water-soluble probiotics seemed to be more effective in improving growth performance.

Abstract

To study the efficiency of Bacillus spp. probiotics administered via different routes and doses, a 6-week grow-out trial was conducted using a total of 378 day-old mixed-sex ROSS308 broiler chickens in a completely randomized block design. Six experimental diets included probiotics added at two different inclusion rates into the feed (250 g/ton; PRO250, or 500 g/ton; PRO500), or in the drinking water (25 g/L; PRO-WS), or as a feed synbiotic (250 g probiotic + 250 g/ton prebiotic; SYN), compared to a negative (NC; without additives) and positive control (PC; with antibiotics) diets. The PRO-WS enhanced feed intake (p < 0.05) and tended to improve average daily gain and final body weight (p = 0.14). Broiler gut morphology in the duodenum including the villus height (p = 0.04), villus width (p = 0.05) and crypt depth (p = 0.02) were improved by PRO500. Firmicutes was the most abundant phylum, followed by Bacteroidetes. Streptococcaceae, Lachnoospiraceae, Peptostreptococcaceae, Ruminococcaceae, and Erysipe-lotrichaceae were the top five most abundant families. Antibiotic inclusion in PC reduced microbial beta-diversity and increased similarity compared to probiotic inclusion (p = 0.05). Probiotic inclusion reduced the relative abundance of Bacteroides fragilis, which is a commonly isolated pathogen and is considered as a marker for antimicrobial resistance. Overall, probiotic supplementation via feed or water may potentially improve the production performance of the broiler chickens, and water-soluble probiotics are potentially more effective. Probiotics, especially when added to water, suggest a promising feed additive to support gut microbial maturation and diversity, and may reduce resistant bacteria in broiler chickens. However, it is suggested that the best route for the administration of probiotics be further examined under commercial conditions to find the most effective and practical application method that yields the most consistent results.

Effect of in Ovo Inoculation of Bifidobacterium spp. on Growth Performance, Thyroid Activity, Ileum Histomorphometry, and Microbial Enumeration of Broilers

Early colonization by beneficial bacteria stimulates the function and development of the digestive tract, on which the performance and vitality of broilers rely. This experiment evaluated the effects of in ovo injection of bifidobacteria on the performance, thyroid activity, bacterial enumeration, and ileal histomorphometry of broiler chickens. A total of 360 fertile eggs were inoculated into the yolk sac, on day 17 of embryogenesis, and allocated to six experimental groups: negative control (not injected, G1), positive control (injected with sterilized distilled water, G2), and groups inoculated with 2 × 10⁸ CFU of Bifidobacterium bifidum, G3; B. animalis, G4; B. longum, G5; or B. infantis, G6. The results revealed an increase (P < 0.01) in body weight and weight gain in all treated groups increases of at least 5.38 and 8.27%, respectively, compared with the control. Feed consumption was not affected during all experimental periods, while the feed conversion ratio (FCR) was enhanced (P < 0.01) only for the overall experimental period (1-28 days of age). The G3 birds recorded the lowest FCR (1.38), while the highest was observed in G1 birds (1.57). Serum concentrations of thyroxin and triiodothyronine were elevated (P < 0.05) with probiotic inoculation. The antioxidant status and immune response of bifidobacteria injected birds were improved; the serum contents of superoxide dismutase and immunoglobulins Y, M, and A were increased (P < 0.05 and P < 0.01), while the malondialdehyde content was decreased (P < 0.01). Ileal architecture was improved in the bifidobacteria treated groups; the highest values of villus height and the villus height/crypt depth ratio were recorded in G3 (936.6 and 11.80) compared with those of G1 (537.1 and 6.93). Moreover, ileal lactic acid bacteria and Bifidobacterium spp. counts increased by at least 10.64 and 51.75%, while total coliform and bacterial counts reduced by at least 15.46 and 15.18%, respectively, compared with those of the control. In conclusion, all tested strains of bifidobacteria enhanced broiler growth performance, ileal function, and thyroid hormone metabolism without obvious differences among them.

Effects of Lactobacillus reuteri and Streptomyces coelicolor on Growth Performance of Broiler Chickens

There are well documented complications associated with the continuous use of antibiotics in the poultry industry. Over the past few decades, probiotics have emerged as viable alternatives to antibiotics; however, most of these candidate probiotic microorganisms have not been fully evaluated for their effectiveness as potential probiotics for poultry. Recent evaluation of a metagenome of broiler chickens in our laboratory revealed a prevalence of Lactobacillus reuteri (L. reuteri) and Actinobacteria class of bacteria in their gastrointestinal tract. In this study Lactobacillus reuteri and Streptomyces coelicolor (S. coelicolor) were selected as probiotic bacteria, encapsulated, and added into broiler feed at a concentration of 100 mg/kg of feed. In an 8-week study, 240 one day-old chicks were randomly assigned to four dietary treatments. Three dietary treatments contained two probiotic bacteria in three different proportions (L. reuteri and S. coelicolor individually at 100 ppm, and mixture of L. reuteri and S. coelicolor at 50 ppm each). The fourth treatment had no probiotic bacteria and it functioned as the control diet. L. reuteri and S. coelicolor were added to the feed by using wheat middlings as a carrier at a concentration of 100 ppm (100 mg/kg). Chickens fed diets containing L. reuteri and S. coelicolor mixture showed 2% improvement in body weight gain, 7% decrease in feed consumption, and 6–7% decrease in feed conversion ratios. This research suggests that L. reuteri and S. coelicolor have the potential to constitute probiotics in chickens combined or separately, depending on the desired selection of performance index.

Antox® and Bactofort® mitigated the haematological alterations induced by a very virulent infectious bursal disease virus in chicks

The study investigated the mitigating effects of two probiotics on blood parameters of ISA Brown chicks inoculated with a very virulent infectious bursal disease virus (vvIBDV). Two hundred chicks were assigned into four groups of 50 birds each. Groups A and B were administered Antox® in water and Bactofort® in feed daily from 1 to 42 days of age and inoculated with a vvIBDV at 28 days and C and D served as positive and negative controls, respectively. Blood samples were examined for changes in packed cell volume (PCV), haemoglobin concentration (Hb), red blood cell (RBC), total white blood cell (TWBC), heterophil and lymphocyte counts seven days post inoculation. The PCV between groups A and C differed (P < 0.05) and in group B it was higher (P < 0.05) than that of group C. The Hb concentration between groups A, B and C differed (P < 0.05). There was a difference (P < 0.05) in RBC counts between groups A, B, C. Differences in TWBC between group A and C were significant (P < 0.05) and TWBC in group B was higher (P < 0.05) than that of group C. There was a significant difference in heterophil (P < 0.05) and lymphocyte (P < 0.05) count between group A and C, and B and C. Heterophil/lymphocyte ratio was significantly higher in positive control compared to groups A, B, C. Antox® and Bactofort® mitigated the deleterious effects of vvIBDV on blood parameters and can assist in cases of IBD outbreak.

Effect of Lactobacillus Species Probiotics on Growth Performance of Dual-Purpose Chicken

Introduction

In-feed probiotics are becoming attractive alternatives to antibiotics in the poultry industry due to the ever-growing strict prohibitions on antibiotic growth promoters (AGP) in animal production.

Methods

The study was conducted to investigate the effects of Lactobacillus paracaseis sparacasei and Lactobacillus rhamnosus on the growth performance of 120 day-olds randomly selected Sasso dual-purpose chicken. They were divided into four groups with two replicates per group and 15 chicks per replicate. The treatments were T₁ (control), T₂ (supplement diet with 4g probiotic), T₃ (supplement diet with 2g probiotic), T₄ (supplement diet with 1g probiotic). The experimental feeding trials were conducted after two weeks adaptation period.

Results

The present findings revealed that the chickens supplemented with Lactobacillus species probiotics during the first week of age have shown higher body weight than control (p < 0.05). The feed intake of week one of T₂ and T₃ were significantly higher (p< 0.05) than the T₁ (control). However, there was no significant difference (p> 0.05) in feed intake in the 2^nd, 3^rd, 4^th, and 5^{t h} weeks of all treatment groups. The present result showed that there was a significant body weight gain (p< 0.05) in all probiotic fed groups than the control group. The highest body weight gain was observed in chickens found in the T4 treatment group. Whereas the body weight gains significantly higher and improved the feed conversion (p<0.05) in the T₂ and T₄ than the T₁ (control). However, the feed conversion ratio was significantly influenced by probiotic inclusion in T₃ as compared to the control group.

Conclusion

Overall, the results suggest that Lactobacillus paracaseis sparacasei and Lactobacillus rhamnosus have a positive effect on the growth performance of broilers.

Potency of probiotic on broiler growth performance and economics analysis

The study was undertaken to know the economic analysis in broilers fed probiotic containing Lactobacillus casei and Lactobacillus rhamnosus supplementation in lieu of antibiotic growth promoters (AGP) to feed conversion ratio (FCR) and body weight (BW). The treatments were T0: control, T1: 0.01 g AGP/kg feed, T2: 0.05 g/ kg feed, T3: 0.1 g/ kg feed, T4: 0.025 g probiotic/litre drinking water; T5: 0.05 g probiotic/liter drinking water. Data analysis was carried out using the Analysis of Variance (ANOVA) method, business analysis was held out by XLSTAT then analyzing descriptively. The results indicated that there was a significant difference among the treatments. Probiotic administration of T2, T3, T4 and T5 could increase broiler's body weight and improve feed conversion ratio. The higher production performance and most profitable economic analysis was obtained with the addition of 0.025 g probiotic/litre (T4), which had the best results in a Break Even Point and Return Cost Ratio. It could be concluded that supplementation of 0.025 g probiotic/litre drinking water indicates the improve growth performance and profits in broiler.

Current Perspectives and Potential of Probiotics to Limit Foodborne Campylobacter in Poultry

Poultry has been one of the major contributors of Campylobacter related human foodborne illness. Numerous interventions have been applied to limit Campylobacter colonization in poultry at the farm level, but other strategies are under investigation to achieve more efficient control. Probiotics are viable microbial cultures that can establish in the gastrointestinal tract (GIT) of the host animal and elicit health and nutrition benefits. In addition, the early establishment of probiotics in the GIT can serve as a barrier to foodborne pathogen colonization. Thus, probiotics are a potential feed additive for reducing and eliminating the colonization of Campylobacter in the GIT of poultry. Screening probiotic candidates is laborious and time-consuming, requiring several tests and validations both in vitro and in vivo. The selected probiotic candidate should possess the desired physiological characteristics and anti-Campylobacter effects. Probiotics that limit Campylobacter colonization in the GIT rely on different mechanistic strategies such as competitive exclusion, antagonism, and immunomodulation. Although numerous research efforts have been made, the application of Campylobacter limiting probiotics used in poultry remains somewhat elusive. This review summarizes current research progress on identifying and developing probiotics against Campylobacter and presenting possible directions for future research efforts.

In ovo inoculation of an Enterococcus faecium-based product to enhance broiler hatchability, live performance, and intestinal morphology

Previous studies have suggested the use of probiotics, as alternative to antibiotics, to enhance broiler performance. The administration of probiotics in feed has been widely explored; however, few studies have evaluated the in ovo inoculation of probiotics. Therefore, the objective was to evaluate the impact of in ovo inoculation of different concentrations of GalliPro Hatch (GH), an Enterococcus faecium-based probiotic, on hatchability, live performance, and gastrointestinal parameters. Ross x Ross 708 fertile eggs were incubated, and on day 18, injected with the following treatments: 1) 50 μL of Marek's vaccine (MV), 2) MV and 1.4 × 105 cfu GH/50 μL, 3) MV and 1.4 × 106 cfu GH/50 μL, 4) MV and 1.4 × 107 cfu GH/50 μL. On the day of hatch, chicks were weighed, feather sexed, and hatch residue was analyzed. Male birds (640) were randomly assigned to 40 floor pens. On day 0, 7, 14, and 21 of the grow-out phase, performance data were collected. One bird from each pen was used to obtain yolk weight and intestinal segment weight and length. Hatchability was not impacted by any GH treatment (P = 0.58). On day 0, yolk weight was lower for all treatments than for MV alone. On day 0 to 7, feed intake was lower for 105 and 107 GH; the feed conversion ratio (FCR) was lower for all treatments than for MV alone (P = 0.05; P = 0.01, respectively). From day 14 to 21, the 107 GH treatment had higher BW gain (P = 0.05). For day 0 to 21, 107 GH had a lower FCR than MV alone (P = 0.03). On day 0, all GH treatments resulted in heavier tissues and longer jejunum, ileum, and ceca lengths than MV alone (P < 0.05). Spleen weight was higher for 105 and 107 GH than for MV alone. In conclusion, GH does not impact hatchability, and some concentrations improved live performance through the first 21 d of the grow-out phase. These improvements could result from the increased yolk absorption and improved intestinal and spleen morphology seen in this study.

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.

Effects of three Bacillus specious on hatchability, growth performance and serum biochemistry in Japanese quails fed diet contaminated with Aflatoxin B1

 In total, 240 one-day–old Japanese quails (Coturnix Coturnix Japonica) allocated at random to 6 treatments with 4 replicates and 10 birds in each. Treatments used were: 1) Negative control (without any additives or AFB1); 2) Positive control (basal diet + 2.5 ppm AFB1; 2); 3) TA008 (positive control + 108 cfu/ml Bacillus. megaterium TA008); 4) TA049 (positive control + 108 cfu mL-1 Bacillus. subtilis TA049); 5) TA010 (positive control+ 108 cfu mL-1 Brevibacillus brevis TA010) and 6) P (positive control + 2.5 g kg-1 Polysorb® in feed). Hatchability and embryonic mortality were significantly influenced by additives and AFB1 (p < 0.05). Birds fed TA008 improved 12 % hatchability and reduced 10 % embryonic mortality in compared to positive control (p < 0.05). Weight gain and feed conversion ratio did not affected by treatments (p > 0.05). Feed intake was significantly improved in birds feeding by TA008 at 0-21 days (p < 0.05). There were significant differences on relative weights of carcass, gizzard and proventriculus among treatments (p < 0.05). Serum total protein, albumin, cholesterol, glucose, HDL, globulin and uric acid were significantly affected by treatments (p < 0.05). These results showed that the inclusion of bacillus megaterium as potential probiotic into contaminated diets could improve the adverse effects of AFB1 in Japanese quails.

Effect of probiotic preparations (EM) on productive characteristics, carcass composition, and microbial contamination in a commercial broiler chicken farm

This experiment evaluated the effect of Pro-Biotyk (Em-15) and EMFarma™ probiotics on body weight, feed intake and conversion, carcass traits, and microbial contamination in a poultry house. The probiotic preparations caused a nonsignificant increase in body weight (42 days), feed intake, and feed conversion ratio (1-42 days) and a nonsignificant decrease in chicken mortality from 4 weeks of rearing. Chickens exposed to probiotics did not differ significantly in preslaughter body weight, carcass weight, dressing percentage, and the content of carcass components. The carcasses from experimental chickens had a lower percentage of breast muscle, leg muscle, abdominal fat, and neck, as well as a higher percentage of skin with subcutaneous fat, wings, and remainder of carcasses compared with the carcasses from control birds. The probiotic preparations used in this study were highly effective as auxiliary disinfectants.

Ameliorative Effects of Antibiotic-, Probiotic- and Phytobiotic-Supplemented Diets on the Performance, Intestinal Health, Carcass Traits, and Meat Quality of Clostridium perfringens-Infected Broilers

Simple Summary

Necrotic enteritis is considered the most important economic problem for the poultry industry due to the sudden death rates of up to 50%. However, there is limited information concerning the ameliorative role of probiotic and/or phytobiotic compounds in the prevention of Clostridium perfringens infections in broilers. Hence, this trial is conducted to evaluate the influence of some antibiotic, probiotic and phytobiotic compounds (Maxus, CloStat, Sangrovit Extra, CloStat + Sangrovit Extra, and Gallipro Tect) on the growth performance, carcass traits, intestinal health, and meat quality of broiler chicks. The obtained in vivo results highlight that a probiotic- and/or phytobiotic-supplemented diet has many positive effects on the performance, organ weight, and meat quality of broilers. Besides, a notable reduction in the lesion score is observed with a combined probiotic and phytobiotic diet.

Abstract

The poultry industry needs efficient antibiotic alternatives to prevent necrotic enteritis (NE) infections. Here, we evaluate the effects of probiotic and/or prebiotic dietary supplementation on performance, meat quality and carcass traits, using only an NE coinfection model, in broiler chickens. Three hundred and twenty-four healthy Ross 308 broiler chicks are allocated into six groups. Taking a 35 d feeding trial, the chicks are fed a basal diet with 0.0, 0.1, 0.5, 0.12, 0.5 + 0.12, and 0.2 g Kg⁻¹ for the control (T₁), Avilamycin (Maxus; T₂), live probiotic (CloStat (Bacillus subtilis);T₃), natural phytobiotic compounds (Sangrovit Extra (sanguinarine and protopine); T₄), CloStat + Sangrovit Extra (T₅), and spore probiotic strain (Gallipro Tect (Bacillus subtilis spores); T₆) treatments, respectively. Occurring at 15 days-old, chicks are inoculated with Clostridium perfringens. The obtained results reveal that all feed additives improve the performance, feed efficiency, and survival rate, and reduces the intestinal lesions score compared with the control group. The T₆ followed by T₃ groups show a significant (p < 0.05) increase in some carcass traits, such as dressing, spleen, and thymus percentages compared with other treatments. Also, T₅ and T₆ have significantly recorded the lowest temperature and pHu values and the highest hardness and chewiness texture values compared to the other treated groups. To conclude, probiotics combined with prebiotic supplementation improves the growth, meat quality, carcass characterization and survival rate of NE-infected broiler chickens by modulating gut health conditions and decreasing lesion scores. Moreover, it could be useful as an ameliorated NE disease alternative to antibiotics in C. perfringens coinfected poultry.

Effect of Dietary Supplementation of Zinc and Multi-Microbe Probiotic on Growth Traits and Alteration of Intestinal Architecture in Broiler

This experiment aimed to investigate the effect of different levels of zinc (Zn) and a probiotic on the growth and intestinal health of broiler chickens. One hundred ninety-two-day-old broiler chicks were randomly assigned to 6 groups. The birds were supplemented with Zn (30 and 60 mg/kg) and a probiotic mixture alone or in combination with Zn. The results revealed that the broilers receiving a probiotic mixture alone or in combination with Zn (30 and 60 mg) increased (P < 0.05) final body weight, feed conversion ratio (FCR), and total goblet cell count in duodenum compared with the control group. Morphometry of the duodenum also revealed an increase (P < 0.05) in villus height (VH) and the ratio of VH and crypt depth in all the supplemented groups, whereas ileal VH increased (P < 0.05) only in Zn60 group when compared with control. Based on our results, we concluded that compared to the individual supplementation, the combined effect of Zn and probiotic mixture was superior in improving the growth performance and histomorphology of the intestine; however, the effect of two levels of Zn did not vary when combined with probiotic.

Effects of Different Dietary Levels of Blue Lupine (Lupinus angustifolius) Seed Meal With or Without Probiotics on the Performance, Carcass Criteria, Immune Organs, and Gut Morphology of Broiler Chickens

This study aimed to investigate the effects of different dietary levels of blue lupine (Lupinus angustifolius) seed meal with or without probiotics (Bacillus subtilis) in broiler diets on the growth performance, carcass characteristics, internal and immune organs, and gut morphology. Three experimental diets containing 0, 20, and 30% of blue lupine, with or without probiotics, were formulated and fed to 144 day (d)-old Ross 308 broiler chickens. Overall, chicks fed blue lupine meal diets, especially at the 30% rate, showed improved growth, feed performance parameters, and carcass characteristics in comparison to chicks fed a soybean meal-based diet. For example, a 30% blue lupine diet resulted in a significant increase in the duodenum length percentage of 35 d-old broilers; the addition of probiotics had no—effects on the dressing, thigh, and leg percentages of 21- and 35 d-old broilers and the drumstick and leg percentages of 35 d-old broilers. In conclusion, a 30% blue lupine seed diet with the addition of probiotics could provide a cheap source of protein without negative effects on the growth performance, carcass characteristics, immune organs and gut morphology of broilers.

Lactobacillus plantarum S27 from chicken faeces as a potential probiotic to replace antibiotics: in vivo evidence

This study reports the probiotic attributes of Lactobacillus strains isolated from chicken faeces and mainly their capabilities to prevent infectious diseases and improve chicken production performance. Thus, 22 Lactobacillus strains were isolated from 50 chickens' faeces samples and assessed for their resistance to gastric acidity (pH 0.5, 1, 1.5, 2 and 2.5), tolerance to bile salts, adherence to broiler intestinal cells and antibacterial activity. These in vitro screening analyses revealed Lactobacillus plantarum S22 and L. plantarum S27 as the only strains capable to survive at pH 2.0 in MRS broth (log₁₀ cfu/ml=5.02 and 8.46 log respectively), while the remaining strains were not resistant to pH≤2.0. Similarly, 21 strains were resistant to bile at 0.5% (log₁₀ cfu/ml=0.09-3.32 log), but only Lactobacillus fermentum S26, L. plantarum S22 and L. plantarum S27 were able to grow in the presence of 0.1% (w/v) bile (8.23±0.15; 8.39±0.17 and 8.57±0.07 respectively). Most of these isolates (19/22) were active against Escherichia coli ATCC 25922, E. coli SL2016 and Salmonella enterica CIP 81-3. Lactic acid is likely the main antibacterial compound produced since the neutralised supernatant was devoid of any antibacterial activity. In vitro characterisation of these 22 novel strains, based on the aforementioned criteria revealed L. plantarum S27 as the most suitable strain for in vivo analyses. To this end, this strain was assessed for its sensitivity to different antibiotics and adhesion to poultry intestinal cells to ascertain it probiotic attributes. The administration of L. plantarum S27 to the chicks at 10⁹ cfu/ml permitted to improve the animal food intake and weight. Taken together, data from in vitro and in vivo analyses indicated that L. plantarum S27 might be a worthy probiotic for chickens rather than adding antibiotics to animals feeding.

Effects of compound probiotics on the weight, immunity performance and fecal microbiota of forest musk deer

Probiotics are intended to provide health benefits when consumed, generally by improving or restoring the gut flora. The health problems of forest musk deer (FMD, Moschus berezovskii), a threatened species currently under conservation, restrict the development of captive musk deer. This study was conducted with the aim of analyzing the effects of forest musk deer compound probiotics (FMDPs) on weight, immunity performance and fecal microbiota in FMD by measuring average daily weight gain (ADG) and immune-related factors and by using high-throughput 16S rRNA sequencing to investigate differences in the fecal microbiota among the control group (4 samples), treatment group A (4 samples) and treatment group B (4 samples). The results showed that the ADG of treatment groups A and B was significantly higher than that of the control group (p = 0.032, p = 0.018). The increase in IgA and IgG levels in treatment group B was significantly higher than that in the control group (p = 0.02, p = 0.011). At the phylum and genus levels, the difference in bacterial community structure was significant between treatment group B and the control group. Both the alpha diversity and beta diversity results showed significant differences in the microbiota of FMD before and after FMDP feeding. In summary, the results indicated that FMDPs could promote the growth of growing FMD, improve immunity and balance the role of intestinal microbes.

Contrasting Strategies: Human Eukaryotic Versus Bacterial Microbiome Research

Most discussions of human microbiome research have focused on bacterial investigations and findings. Our target is to understand how human eukaryotic microbiome research is developing, its potential distinctiveness, and how problems can be addressed. We start with an overview of the entire eukaryotic microbiome literature (578 papers), show tendencies in the human‐based microbiome literature, and then compare the eukaryotic field to more developed human bacterial microbiome research. We are particularly concerned with problems of interpretation that are already apparent in human bacterial microbiome research (e.g. disease causality, probiotic interventions, evolutionary claims). We show where each field converges and diverges, and what this might mean for progress in human eukaryotic microbiome research. Our analysis then makes constructive suggestions for the future of the field.

Evaluating bacterial colonization of a developing broiler embryo after in ovo injection with a bioluminescent bacteria

In ovo injection of probiotics has been of interest for achieving early health benefits. However, there is limited research demonstrating where bacteria could migrate within the embryo after injection. The objective of this study was to evaluate bacterial colonization or migration after in ovo injection of broiler embryo with bioluminescent Escherichia coli. Injection using 106 CFU/mL nonpathogenic E. coli was applied to amniotic and air cell regions on day 18 of incubation. On days 18, 19, 20, and 21 the amnion, skin, lung, gastrointestinal tract (GIT), bursa, and spleen were collected. On day 21, the GIT was separated into crop, duodenum, jejunum, ileum, and ceca sections. All tissues were visualized using anin vivo imaging system to confirm the presence of bioluminescent E. coli. Samples were homogenized, 10-fold serially diluted, and spread onto appropriate agar to determine bacterial loads in all tissues. Results indicated that eggs injected into the amnion had significantly high numbers of E. coli cells in all tissues compared to air cell injected and control treatments 2 h post-injection (P < 0.0001). E. coli was also found on the lungs, spleen, and bursa of eggs injected either in the amnion or air cell (P < 0.05). Results indicated that in ovo injection into the amnion was more efficient than air cell injection, yielding a higher bacterial concentration in the evaluated tissues, specifically the ileum and ceca. Future research using bioluminescent probiotic bacteria may establish sites of preference for different probiotics leading to site-specific application that can maximize their overall impact when in ovo injected.

Studies on immune response to Newcastle disease virus in broiler chickens fed with Lactobacillus reuteri PIA16 isolated from the gut of indigenous chicken of Assam, India

Background and Aim:

The chicken gut harbors microflora which impacts the health, production performance and immune response against pathogens. Assam local chickens reared under natural conditions are known to possess high immunocompetence which may be attributable to its gut microbiota make-up. This study aimed to investigate the individual effect of two strains of Lactobacillus reuteri PIA16 isolated separately from cecum and jejunum of Assam indigenous chicken on the immunity of broiler chickens against Newcastle disease virus (NDV) when fed singly and in combination with a prebiotic.

Materials and Methods:

A total of 240 birds (48 per group) were vaccinated with Lasota strain of NDV on the 5^th and 21^st day of age. Blood samples were collected before and after immunization against ND for the detection of humoral antibody response by hemagglutination inhibition test. The cell-mediated immune (CMI) response was estimated through response to phytohemagglutinin-P (PHA-P) and expressed as web index.

Results:

A significant influence on the immune response to NDV was observed in all the L. reuteri PIA16 as well as mannan oligosaccharide (MOS) supplemented groups revealing higher antibody titer than the control counterpart. The CMI response revealed a better cutaneous basophilic hypersensitivity response to PHA-P in the treated groups than the control.

Conclusion:

Enhancement in immunity was perceived in the broilers fed with L. reuteri PIA16 and in combination with MOS due to the stimulation of the host’s humoral and CMI response by the probiotics and prebiotics used.

The impact of heat stress on the immune system in dairy cattle: A review

Heat stress is well documented to have a negative influence on livestock productivity and these impacts may be exacerbated by climate change. Dairy cattle can be more vulnerable to the negative effects of heat stress as these adverse impacts may be more profound during pregnancy and lactation. New emerging diseases are usually linked to a positive relationship with climate change and the survival of microrganisms and/or their vectors. These diseases may exaggerate the immune suppression associated with the immune suppressive effect of heat stress that is mediated by the hypothalamic-pituitary-adrenal (HPA) and the sympathetic-adrenal-medullary (SAM) axes. It has been established that heat stress has a negative impact on the immune system via cell mediated and humoral immune responses. Heat stress activates the HPA axis and increases peripheral levels of glucocorticoids subsequently suppressing the synthesis and release of cytokines. Heat stress has been reported to induce increased blood cortisol concentrations which have been shown to inhibit the production of cytokines such as interleukin-4 (IL-4), IL-5, IL-6, IL-12, interferon γ (IFNγ), and tumor necrosis factor-α (TNF- α). The impact of heat stress on the immune responses of dairy cows could be mediated by developing appropriate amelioration strategies through nutritional interventions and cooling management. In addition, improving current animal selection methods and the development of climate resilient breeds may support the sustainability of livestock production systems into the future.

Bacillus subtilis Strain DSM 29784 Modulates the Cecal Microbiome, Concentration of Short-Chain Fatty Acids, and Apparent Retention of Dietary Components in Shaver White Chickens during Grower, Developer, and Laying Phases

This study investigated the efficacy of a single strain of Bacillus subtilis (SSB) in modulating the composition of cecal microbiota and its link to the concentration of short-chain fatty acids (SCFA) and apparent retention (AR) of components. A total of 720, 4-week-old Shaver White chicks were allotted to control (CON), 1.1E+08 (low, LSSB), 2.2E+08 (medium, MSSB), or 1.1E+09 (high, HSSB) CFU/kg of diet groups. At grower (10-week), developer (16-week), and laying (28-week) phases, excreta and cecal digesta samples were taken for AR, microbial, and SCFA analyses. Microbial analysis involved high-throughput sequencing of the V3-V4 hypervariable regions of 16S rRNA gene. Bacterial diversity decreased (P < 0.05) at the developer phase as the SSB dose increased; however, a distinct clustering pattern (P < 0.05) of bacterial community was noted. Bacteroides and Faecalibacterium were differentially enriched in the developer for SSB-fed compared to CON-fed birds. Although no differences in microbial diversity were detected in grower and layer phases, different species of Clostridium (XVIII, XIVa, IV, and XIVb)-major butyrate producers-were identified in all phases, with stronger effect sizes for SSB-fed compared to CON-fed birds. Isobutyric acid was elevated in dose response (P = 0.034) in layer phase. In addition, the relative abundances of Alistipes, Lactobacillus, and Bifidobacterium were positively correlated (P < 0.05), with AR of most components for SSB-fed birds in the pullet phase. The results suggested that supplementing chickens' diet with B. subtilis DSM 29784 may selectively enrich beneficial bacterial communities, which in turn are critical in promoting the growth and performance of hens.IMPORTANCE In egg-laying chickens, the trend in the move away from the cage to alternative housing systems and restriction in antimicrobial use requires alternative approaches to maintain health and prevent diseases. There is increased research and commercial interest toward alternative gut health solutions while improving the performance and product safety in poultry production systems. One such approach, in recognition of the importance of the gut microbial community, is the use of microbes as feed supplements (such as probiotics). Unlike meat-type chickens, studies assessing the efficacy of such microbial supplements are limited for egg-laying chickens. Thus, by conducting a comprehensive assessment of the hen microbiota in response to various levels of B. subtilis DSM 29784 during the pullet phase (grower and developer) and the layer phase, the present study demonstrates the importance of direct-fed microbes in modulating gut microbiome, which may relate to improved performance efficiency in the pullet and layer phases.

The effects of fermented milk products (kefir and yogurt) and probiotic on performance, carcass characteristics, blood parameters, and gut microbial population in broiler chickens

This study was conducted to determine the effects of fermented milk products and probiotic on performance, carcass characteristics, blood parameters, and gut microbial population in broiler chickens. A total of 480 one-day-old Ross 308 broilers were allocated to 30 floor pens in a completely randomized design with six treatments, five replicates, and 16 chicks (eight males and eight females) in each replicate. On the first day, the male and female chicks were weighed and divided by the feather sexing method so that the average body weight of chicks was approximately equal in each pen. Treatments consisted of six groups (including control): group 1 had a basal diet and normal drinking water, group 2 had a basal diet and probiotics (PrimaLac^®) in drinking water as recommended by the manufacturer, group 3 had a basal diet and 2 % yogurt in drinking water, group 4 had a basal diet and 4 % yogurt in drinking water, group 5 had a basal diet and 2 % kefir in drinking water, and group 6 had a basal diet and 4 % kefir in drinking water. Chemical and microbiological characteristics of kefir and yogurt were measured after each production. The results showed that 4 % kefir, yogurt, and probiotic at the recommend level in water improved body weight gain, feed intake, and feed conversion ratio compared with other groups (P<0.05). The results indicated that treatment had a significant effect on the carcass yield, intestinal length, thigh yield, and abdominal fat in male and female chickens (P<0.05). There were no effects on total bacteria population but the lactobacilli and coliform bacteria populations showed increasing and decreasing trends, respectively, with 4 % kefir, yogurt, and probiotic supplementation at 28 and 42 d (P<0.05). In addition, blood glucose and total protein increased when using a high levels of kefir, yogurt, and probiotic in water, while cholesterol and LDL (low-density lipoprotein) concentrations were lower in 4 % kefir, yogurt, and probiotic at the recommended level. Consequently, the results of this study showed that the use of 4 % kefir, yogurt, and probiotic at recommended level in water had beneficial effects on the growth performance, intestinal bacteria population, and blood biochemical parameters in male and female broiler chickens.

Evaluation of Black Soldier Fly (Hermetia illucens) Larvae and Pre-Pupae Raised on Household Organic Waste, as Potential Ingredients for Poultry Feed

Black soldier fly (BSF) larvae and pre-pupae could be satisfactorily raised on household organic waste and used as poultry feed, offering a potential sustainable way to recycle untapped resources of waste. The present study was conducted to determine if whole (non-defatted) BSF larvae and pre-pupae raised on experimental household waste could substitute soybean meal and oil as ingredients for laying hen diets. While no significant differences in feed intake and the egg-laying rate of hens were observed throughout the experiment, egg weight and eggshell thickness were greater in the pre-pupae-fed group than in the other groups. Moreover, although diversity of the cecal microbiota was significantly higher in the pre-pupae-fed than in the control group, no significant differences in bacterial genera known to cause food poisoning were observed when comparing the treatment groups. Nonetheless, Lactobacillus and Bifidobacterium populations were significantly lower in the treatment than in the control group. Fat content in BSF was possibly related with the changes in the cecal microbiota. Hence, since BSF fat was deficient in essential fatty acids, special attention should be paid to the fat content and its fatty acid composition in the case of regular inclusion of BSF larvae and pre-pupae oil as an ingredient in poultry diets.

Probiotics and plant-derived compounds as eco-friendly agents to inhibit microbial toxins in poultry feed: a comprehensive review

Some of pathogenic bacteria and fungi have the ability to produce fetal toxins which may be the direct causes of cytotoxicity or cellular dysfunction in the colonization site. Biological and non-biological environmental factors, challenge and microbes influence the effect of toxins on these pathogens. Modern research mentions that many natural materials can reduce the production of toxins in pathogenic microbes. However, researches that explain the mechanical theories of their effects are meager. This review aimed to discuss the ameliorative potential role of plant-derived compounds and probiotics to reduce the toxin production of food-borne microbes either in poultry bodies or poultry feedstuff. Moreover, studies that highlight their own toxicological mechanisms have been discussed. Adding natural additives to feed has a clear positive effect on the enzymatic and microbiological appearance of the small intestine without any adverse effect on the liver. Studies in this respect were proposed to clarify the effects of these natural additives for feed. In conclusion, it could be suggested that the incorporation of probiotics, herbal extracts, and herbs in the poultry diets has some beneficial effects on productive performance, without a positive impact on economic efficiency. In addition, the use of these natural additives in feed has a useful impact on the microbiological appearance of the small intestine and do not have any adverse impacts on intestinal absorption or liver activity as evidenced by histological examination.

Chemical composition of chicken meat after application of humic acid and probiotic Lactobacillus fermentum

The aim of the present study was analysed and evaluated chemical parameters of chicken breast and thigh muscles after addition of humic acids and probiotic into diet for broiler chicken. A total of 200 pcs Ross 308 broiler chickens were divided into 4 groups (n=50). The control group of chickens was fed with complete feed mixtures without any additives. Chickens in experiment groups were fed a diet containing: P1 (1% of humic acid), P2 (1% of humic acid and probiotic supplement Lactobacillus fermentum) and P3 were fed with complete feed mixture containing combination of starter feed mixture (1. - 21. day) with coccidiostaticum Diclazuril and growth feed mixture (21. - 35. day) containing Salinomycinum sodium. Besides, the groups were kept under the same conditions. Fattening period lasted for 42 days. Chicken meat was analyzed for content of water, crude protein, fat and cholesterol. Based on the results, we can state that the application of humic acids or the combination of Humac Natur with probiotic did not affect the chemical composition of the breast muscle. In the breast muscle, the protein content in the experimental group P3 with the coccidiostat (22.98 g.100 g-1) was reduced (p ≤0.05) compared to control group (23.42 g.100 g-1). In the case of thigh muscle was significantly higher content of fat and cholesterol (p ≤0.05) in chickens feeding with addition of Humac Natur (fat - 9.08 g.100g-1; cholesterol - 0.86 mg.100g-1) and similar results were recorded in experimental group with combination of Humac Natur and probiotic (fat - 9.15 g.100g-1; cholesterol - 0.86 mg.100g-1) compared to control group (fat - 7.15 g.100g-1; cholesterol - 0.70 mg.100g-1). From a general point of view, we can recommend the application of Humac Natur, respectively combination Humac Natur with probiotics in feeding of broiler chickens Ross 308.

The impact of β-glucans on performance and response of broiler chickens during a coccidiosis challenge

Coccidiosis is a costly parasitic disease to the poultry industry with multiple prevention methods being explored to control its impact. This study evaluated the feeding effects of β-glucans on performance and responses of chickens during a coccidiosis challenge. Cobb 500 male broilers (n = 1280) were assigned to 1 of 8 treatment groups (8 replicate pens; 20 birds/pen) in a 2 × 4 factorial arrangement, including non-infected and Eimeria-infected birds fed for 28 d a control diet, control + BG (150 g/MT Algamune 50), control + BGZn (100 g/MT Algamune 50 Zn), and control + 0.01% Salinomycin (Sal). On d15, birds in the challenge groups received a mixed Eimeria inoculum. Birds and feed were weighed weekly on a per pen basis to evaluate body weight gain (BWG), feed intake (FI), and feed conversion ratios (FCR). Lesion scores were assessed 6 d post infection (d21) on 3 birds per pen. Performance data were subjected to ANOVA and differences were established using the LS-MEANS statement with significance reported at P ≤ 0.05. There were minor differences in lesion scores among the dietary treatments in the infected groups with reduced duodenal and cecal scores in the Sal group compared to the BGZn and BG groups, respectively. The coccidiosis challenge main effect resulted in a significant reduction in 0-28 d BW and FI. Dietary treatment resulted in non-significant effect on BWG, but Sal addition resulted in increased FI. A significant diet X challenge interaction resulted in higher FCR in the Eimeria-challenged birds supplemented with Sal and BGZn in comparison to the other challenged groups, likely due to reduced mortality in the challenged Sal and BGZn groups. Body composition analysis at d28 revealed that the Eimeria challenge reduced both fat and lean tissue contents, where the β-glucans and Sal birds had lower fat percent than control birds.

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.