A multi-microbe probiotic formulation processed at low and high drying temperatures: effects on growth performance, nutrient retention and caecal microbiology of broilers

Multifaceted Role of Probiotics in Enhancing Health and Growth of Aquatic Animals: Mechanisms, Benefits, and Applications in Sustainable Aquaculture-A Review and Bibliometric Analysis

Probiotics play a pivotal role in enhancing the health and growth of aquatic animals in aquaculture. These beneficial microorganisms contribute to improved digestion and nutrient absorption by producing digestive enzymes such as amylases, proteases, and lipases, besides providing essential nutrients. By creating a favorable microbial balance in the gastrointestinal tract (GIT), probiotics reduce harmful microorganisms and promote the proliferation of beneficial bacteria like Lactobacillus spp. and Bifidobacterium spp. This modification of gut microflora leads to more efficient digestion and significantly enhances overall health and growth performance in fish. Additionally, probiotics produce antimicrobial substances, such as bacteriocins and organic acids, which inhibit pathogenic bacteria and bolster disease resistance. They also play a crucial role in improving water quality in aquaculture systems by aiding in the turnover of organic nutrients and reducing toxic substances. Incorporating probiotics into aquaculture practices has demonstrated considerable potential in boosting the productivity and health of aquatic animals, making them an essential component of sustainable aquaculture. This review delves into the multifaceted benefits of probiotics, including enhanced feed utilization, immune responses, and pathogen resistance, and elucidates the mechanisms underlying these effects. Furthermore, it includes a bibliometric analysis of the past 30 years, providing a comprehensive overview of research trends and advancements in this field.

Nutritional supplements for the control of avian coccidiosis

Coccidiosis is acclaimed as the most prevalent enteric parasitic ailment of poultry. It is caused by an apicomplexan protozoon of the genus Eimeria, which resides in chicken intestinal epithelium leading to intestinal damage. As a result, bloody droppings are there, feed efficiency is reduced, the growth rate is impaired, and egg production is temporarily decreased. Treatment and prevention of coccidiosis are primarily accomplished by inoculating live vaccines and administering anticoccidial drugs. Due to anticoccidials’ continuous and excessive use, the mounting issue is drug resistant Eimeria strains. The poultry industry has managed resistance-related issues by suggesting shuttle and rotation schemes. Furthermore, new drugs have also been developed and introduced, but it takes a long time and causes cost inflation in the poultry industry. Moreover, government disallows growth promoters and drugs at sub-therapeutic doses in poultry due to increased concerns about the drug residues in poultry products. These constraints have motivated scientists to work on alternative ways to control coccidiosis effectively, safely, and sustainably. Using nutritional supplements is a novel way to solve the constraints mentioned above. The intriguing aspects of using dietary supplements against coccidiosis are that they reduce the risk of drug-resistant pathogen strains, ensure healthy, nutritious poultry products, have less reliance on synthetic drugs, and are typically considered environmentally safe. Furthermore, they improve productivity, enhance nonspecific immunity, preventing oxidation of fats (acting as antioxidants) and inflammation (acting as an anti-inflammatory). The present manuscript focuses on the efficacy, possible mechanism of action, applications, and different facets of nutrition supplements (such as organic acids, minerals, vitamins, probiotics, essential oils, amino acids, dietary nucleotides, feed enzymes, and yeast derivatives) as feed additive for treating poultry coccidiosis.

Probiotics in Poultry Nutrition as a Natural Alternative for Antibiotics

Since the early 1950s, antibiotics have been used in poultry for improving feed efficiency and growth performance. Nevertheless, various side effects have appeared, such as antibiotic resistance, antibiotic residues in eggs and meat, and imbalance of beneficial intestinal bacteria. Consequently, it is essential to find other alternatives that include probiotics that improve poultry production. Probiotics are live microorganisms administered in adequate doses and improve host health. Probiotics are available to be used as feed additives, increasing the availability of the nutrients for enhanced growth by digesting the feed properly. Immunity and meat and egg quality can be improved by supplementation of probiotics in poultry feed. Furthermore, the major reason for using probiotics as feed additives is that they can compete with various infectious diseases causing pathogens in poultry's gastrointestinal tract. Hence, this chapter focuses on the types and mechanisms of action of probiotics and their benefits, by feed supplementation, for poultry health and production.

Incidence of virulence determinants and antibiotic resistance in lactic acid bacteria isolated from food products

Background: Lactic acid bacteria (LAB) confer beneficial health effects in humans. However, the safety of these bacteria and their potential to spread resistance in the environment must be evaluated. Materials & methods: Fifty-three LAB were isolated from different food samples and assessed for the prevalence of virulence determinants and antibiotic resistance profile. Results: Multiple resistance was reported for Lactobacillus brevis MIM04, having revealed phenotypic resistance to vancomycin (MIC >128 μg/ml), ampicillin, cefotaxime, oxacillin and gentamicin. Virulence traits (cylA, gelE, esp and agg) were detected using specific primers. Enterococcus faecium CHE32, Lactobacillus plantarum CHE37 and E. faecium MLK68 lack virulence genes, possess antimicrobial activity and survive in low pH and bile salt conditions. Conclusion: Isolated LAB revealed probiotic properties.

Isolation and probiotic potential of lactic acid bacteria from swine feces for feed additive composition

Animal microbiota is becoming an object of interest as a source of beneficial bacteria for commercial use. Moreover, the escalating problem of bacterial resistance to antibiotics is threatening animals and humans; therefore, in the last decade intensive search for alternative antimicrobials has been observed. In this study, lactic acid bacteria (LAB) were isolated from suckling and weaned pigs feces (376) and characterized to determine their functional properties and usability as pigs additives. Selection of the most promising LAB was made after each stage of research. Isolates were tested for their antimicrobial activity (376) and susceptibility to antibiotics (71). Selected LAB isolates (41) were tested for the production of organic acids, enzymatic activity, cell surface hydrophobicity and survival in gastrointestinal tract. Isolates selected for feed additive (5) were identified by MALDI-TOF mass spectrometry and partial sequence analysis of 16S rRNA gene, represented by Lentilactobacillus, Lacticaseibacillus (both previously classified as Lactobacillus) and Pediococcus genus. Feed additive prototype demonstrated high viability after lyophilization and during storage at 4 °C and − 20 °C for 30 days. Finally, feed additive was tested for survival in simulated alimentary tract of pigs, showing viability at the sufficient level to colonize the host. Studies are focused on obtaining beneficial strains of LAB with probiotic properties for pigs feed additive.

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.

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.

Performance, carcass, and organoleptic scores of broiler chickens fed diets containing wet or sun-dried fermented mixture of grated cassava roots and palm kernel cake as replacements for maize

The cost and effectiveness of drying processes have often limited the incorporation of solid-state fermented agro-industrial by-products into poultry feeding programs. In this study, the efficacy of replacing maize with wet or sun-dried solid-state fermented mixture of grated cassava root meal and palm kernel cake (FCP) was evaluated. One hundred and twenty (120), three weeks old broiler chicks were allotted to four treatment groups of 30 birds each in a completely randomized design. Each group was further replicated thrice with 10 chicks per replicate. Four broiler finisher rations were formulated such that Diet 1 contained maize as the major energy source while Diets 2, 3, and 4 contained wet FCP, sun-dried FCP, and a 1:1 mixture of Cassava root meal and Palm kernel cake (CSM-PKC) respectively as replacement of maize. Data was collected on the performance, carcass, and sensory attributes of broilers. The results show that chicks on dietary wet FCP had significantly (p<0.05) lower bodyweights, weight gains, and feed intake but similar (p>0.05) feed conversion ratio compared to those on the control (T1) diets and other treatment groups. The cost of feed per kilogram weight gain was significantly lower among chicks fed wet FCP (N244.00) compared with other treatment groups. It is therefore concluded that feeding broilers with solid-state fermented mixture of grated cassava and palm kernel cake without further processing such as sun drying would be effective in replacing maize in broilers diets.

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.

Ways to minimize bacterial infections, with special reference to Escherichia coli, to cope with the first-week mortality in chicks: an updated overview

On the commercial level, the poultry industry strives to find new techniques to combat bird's infection. During the first week, mortality rate increases in birds because of several bacterial infections of about ten bacterial species, especially colisepticemia. This affects the flock production, uniformity, and suitability for slaughter because of chronic infections. Escherichia coli (E. coli) causes various disease syndromes in poultry, including yolk sac infection (omphalitis), respiratory tract infection, and septicemia. The E. coli infections in the neonatal poultry are being characterized by septicemia. The acute septicemia may cause death, while the subacute form could be characterized through pericarditis, airsacculitis, and perihepatitis. Many E. coli isolates are commonly isolated from commercial broiler chickens as serogroups O₁, O₂, and O₇₈. Although prophylactic antibiotics were used to control mortality associated with bacterial infections of neonatal poultry in the past, the commercial poultry industry is searching for alternatives. This is because of the consumer's demand for reduced antibiotic-resistant bacteria. Despite the vast and rapid development in vaccine technologies against common chicken infectious diseases, no antibiotic alternatives are commercially available to prevent bacterial infections of neonatal chicks. Recent research confirmed the utility of probiotics to improve the health of neonatal poultry. However, probiotics were not efficacious to minimize death and clinical signs associated with neonatal chicks' bacterial infections. This review focuses on the causes of the increased mortality in broiler chicks during the first week of age and the methods used to minimize death.

Metabolic activity of Bacillus coagulans R11 and the health benefits of and potential pathogen inhibition by this species in the intestines of laying hens under lead exposure

Probiotics are widely used in agricultural breeding for care and maintenance of animal health, especially Bacillus coagulans, a new and popular species that could replace Lactobacillus. However, lead contamination in feed might influence the beneficial function. In the present study, Bacillus coagulans R11 was used as a model bacterium to investigate the effect of lead on changes in metabolites and genes, which could influence the beneficial function on laying hen. At the laboratory scale, transcriptomics and metabolomics were used to screen the main metabolites and related genes under lead exposure. The results showed that 4-acetamidobutanoic acid, dodecanoic acid, L-3-phenyllactic acid, apigenin and daidzein, which are antioxidants and antibacterial agents, were the main metabolites, even in the 100 ppm lead exposure group (the levels of these metabolites were 1.17-, 1.10-, 4.80-, 1.43- and 1.67-fold higher in the 100 ppm group than in pure culture medium). Twenty-three genes associated with the syntheses of the above 5 main metabolites were identified. Further animal experiments showed that B. coagulans R11 feeding of laying hens under lead exposure could prevent oxidative damage by increasing T-AOC and T-SOD activity and reducing the MDA concentration in serum and reducing the abundances of potential pathogens (Escherichia coli, Pseudomonas aeruginosa and Salmonella). Further analysis also showed that the inhibition of pathogen growth was due to the regulation of gene expression, as observed by transcriptomics, and these genes were associated with the abovementioned 5 main metabolites. However, the laying rate decreased by 10.53% compared with that of the control group when the lead exposure concentration was 100 mg/kg. The present study suggested that Bacillus coagulans R11 could help prevent oxidative damage and inhibit pathogen growth in laying hens to maintain a healthy intestinal environment for daily breeding, but under high-lead conditions, Bacillus coagulans R11 feeding could decrease the laying rate.

On application of emulsified probiotic preparation of Bacillus subtilis

The use of a new form of the probiotic preparation of Bacillus subtilis consisting in emulsion of bacteria in palmitic acid has been studied. When evaluating the effectiveness of probiotics, it was assumed that the content of bacterial DNA in the feces is proportional to their content in the intestine. Analysis of the number of bacterial DNA was carried out by real-time PCR. The results showed a positive effect from the use of emulsified bacteria. It was observed in an increase in the amount of B. subtilis in the intestine and, as a consequence, their DNA in the feces of rats.

Utility of Feed Enzymes and Yeast Derivatives in Ameliorating Deleterious Effects of Coccidiosis on Intestinal Health and Function in Broiler Chickens

Coccidiosis induced necrotic lesions impair digestive capacity and barrier function in concurrence with increased risks for secondary bacterial infections. The industry has been successful in controlling coccidiosis with anticoccidials and vaccination. However, concerns over Eimeria species resistant to anticoccidials, gaps in vaccination and restriction on antibiotics is stimulating research and application of alternative and/or complimentary strategies for coccidiosis control. The aim of this paper is to appraise literature on the utility of feed enzymes and yeast derivatives in modulating coccidiosis. Feed enzymes can complement endogenous enzymes (protease, amylase, and lipase) that may become insufficient in coccidiosis afflicted birds. Coccidiosis in the upper small intestine creates conditions that enhances efficacy of phytase and there are reports indicating supplemental phytase can mitigate the negative impact of coccidiosis on bone quality. Increase in intestinal short chain fatty acids due supplemental fiber degrading enzymes has been linked with reduced survivability of Eimeria. There is evidence whole yeast (live or dead) and derivatives can modulate coccidiosis. Immunomudulation properties of the yeast derivatives have been shown to enhance cellular and humoral immunity in Eimeria challenge models which is critical for effectiveness of coccidial vaccination. Moreover, yeast nucleotides have been shown to be beneficial in stimulating healing of intestinal mucosal surface. Other novel work has shown that certain yeast cells can produce derivatives with anticoccidial compounds effective in attenuating oocysts shedding. Yeast cell surface has also been shown to be an effective oral Eimeria vaccine delivery vehicle. Overall, while further refinement research is warranted to address inconsistencies in responses and commercial application, there is evidence feed enzymes and yeast derivatives could complement strategies for maintaining intestinal function to bolster growth performance in broilers compromised with coccidiosis. However, broilers receive diets containing several feed additives with distinct mode of actions and yet there is dearth of empirical data on the expected responses.Future evaluations should consider combinations of additives to document animal responses and potential synergies.

Comparative influence of dietary probiotic, yoghurt, and sodium butyrate on growth performance, intestinal microbiota, blood hematology, and immune response of meat-type chickens

This study was conducted to assess the effects of early dietary supplementation with probiotic, yoghurt, and sodium butyrate (SB) on the growth performance, intestinal microbiota, blood hematology, and immune response of broiler chickens. A total of 180 1-day-old SASSO broiler chicks, housed in 12 equal floor pen replicates each of 15 chicks, were assigned randomly to four feeding treatments (three replicates/treatment, n = 45): T1. Basal diet (BD) (control), T2. BD incorporated 1 g of a commercial probiotic per kilogram, T3. BD mixed with 5 g of fresh yoghurt per kilogram, and T4. BD incorporated 0.6 g SB/kg. The experimental birds received the dietary treatments from 1 to 21 days of age. The dietary supplementation (g/kg) with commercial probiotic, yoghurt, and SB during the first 21 days of age did not affect broiler's growth performance variables at day 42, relative weight of immunity organs, blood hematological indices, or the ileal and cecal bacterial counts at day 42, but increased the serum IgG levels and reduced the cecal aerobes at day 21. The probiotic and yoghurt treatments increased the serum content of antibody titer against Newcastle disease virus and decreased the counts of ileal aerobes and E. coli at day 21, whereas the SB treatment increased the ileal lactobacilli count at day 21. In conclusion, the tested feed additives displayed beneficial impacts on broilers' gut microbiota at day 21 and serum IgG at day 42, but did not affect the growth performance or blood hematological indices at 42 days of age.

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.

Dietary Lactobacillus acidophilus positively influences growth performance, gut morphology, and gut microbiology in rurally reared chickens

In a market undergoing constant evolution, the production of chicken meat that consumers would perceive as “natural” and “animal friendly” is crucial. The use of probiotics in rurally reared chickens could represent a major opportunity to achieve mutual benefit for both the industry and consumers. A total of 264 male Kabir chicks were randomly distributed to one of 2 dietary treatments: the L group received a commercial feed supplemented with 2.0 g/100 kg of Lactobacillus acidophilus D2/CSL, while the C group received the same basal diet without the additive. To assess the effects of probiotic supplementation in the chickens’ diet, productive performance was evaluated at d 21 and 42, whereas microbiological analyses of the intestinal content and intestinal histology and morphometry were performed at the end of the trial (d 42). At d 21 and 42, L birds showed better (P < 0.001) performance in terms of body weight, average daily gain, and feed conversion ratio. Enterococci, staphylococci, and Escherichia coli populations were not influenced by dietary treatment. On the contrary, Lactobacillus population increased (P = 0.032) in the L group. Furthermore, a tendency (P = 0.069) was observed for the coliforms to be influenced by diet, with lower values in the L group in comparison to the C group. Histological techniques revealed that the number of goblet cell containing neutral mucins was lower in the C group. Morphometric evaluations demonstrated that the probiotic supplementation increased the height of the mucosal layer by improving (P = 0.040) villus height, while crypt depth was unaffected. In conclusion, the results obtained in this study demonstrate that it is possible to use Lactobacillus acidophilus D2/CSL (CECT 4529) in rurally reared chicken breeds with positive effects on performance and gut health.

Effect of dietary supplementation with Lactobacillus acidophilus D2/CSL (CECT 4529) on caecum microbioma and productive performance in broiler chickens

This study examines the effects of the dietary supplementation with Lactobacillus acidophilus D2/CSL (CECT 4529) (LA) on productive performances, incidence of foot pad dermatitis and caecum microbioma in broiler chickens. A total of 1,100 one-day old male Ross 308 chicks were divided into 2 groups of 16 replicates with 25 birds each and reared from 1–41 d. One group was fed a basal diet (CON) and the other group the same diet supplemented with LA. Caecum contents were collected from 4 selected birds at day one and 5 selected birds at the end of the rearing period. Then, they were submitted to DNA extraction and whole DNA shotgun metagenomic sequencing. Overall, the LA supplementation produced a significant beneficial effect on body weight gain between 15–28 d and improved feed conversion rate in the overall period. On the contrary, litter moisture, pH and incidence of the foot pad lesions were not affected by LA. Birds treated with LA showed a lower occurrence of pasty vent at both 14 and 28 d. At the end of the rearing period, Lachanospiraceae were significantly higher in LA birds in comparison to CON (17.07 vs 14.39%; P = 0.036). Moreover, Ruminococcus obeum, Clostridium clostridioforme, Roseburia intestinalis, Lachnospiraceae bacterium 14-2T and Coprococcus eutactus were significantly higher in LA birds in comparison to CON. The relative abundance of Lactobacillus acidophilus was comparable between LA and CON groups. However, a positive effect was observed in relation to the metabolic functions in the treated group, with particular reference to the higher abundance of β-glucosidase. In conclusion, the LA supplementation improved broiler productive performances and metabolic functions promoting animal health.

Effects of chromium-enriched Bacillus subtilis KT260179 supplementation on growth performance, caecal microbiology, tissue chromium level, insulin receptor expression and plasma biochemical profile of mice under heat stress

The aim of this study was to investigate the effect of providing supplementary Cr-enriched Bacillus subtilis (CEBS) to mice with regard to their growth performance, caecal microbiology, tissue Cr concentration, insulin receptor (IR) expression and plasma biochemical profile. A total of ninety-six Kunming strain mice were allocated to four different groups: control, CEBS, inorganic Cr and B. subtilis. After 15 d of treatment, mice that received CEBS or normal B. subtilis had higher body weights than control mice, and after 30 d mice given either CEBS or B. subtilis had greater body weights than control mice or those given inorganic Cr. The concentration of Cr in tissues (heart, liver, spleen, kidney and skeletal muscle) increased after CEBS supplementation. B. subtilis and CEBS supplementation caused a significant increase in the numbers of Lactobacillus and Bifidobacterium in the caecum, whereas the numbers of Escherichia coli and Staphylococcus decreased significantly compared with the control. The levels of IR RNA and protein in skeletal muscles increased significantly. Plasma glucose, total cholesterol, TAG and LDL-cholesterol levels declined significantly in the CEBS group compared with the control group, whereas plasma insulin and HDL-cholesterol levels increased significantly. In conclusion, CEBS supplementation enhanced the regulation of body growth, increased tissue organic Cr concentrations, altered caecal microbiota and enhanced IR expression to produce significant changes in plasma biochemistry.

Effect of different feed supplements on selected quality indicators of chicken meat

The aim of the study was to evaluate the effect of different feed additives (bee pollen extract, propolis extract, and probiotic) on meat quality of broiler chickens. A total of 180 one day-old broiler chicks of mixed sex (Ross 308) were randomly divided into 3 groups. Dietary treatments were as follows: basal diet, free of supplements (control group; C);  basal diet  plus 400 mg bee pollen extract per 1 kg of feed mixtures and 3.3 g probiotic preparation added to drinking water (group E1); basal diet  plus 400 mg propolis extract per 1 kg of feed mixtures and 3.3 g probiotic preparation added to drinking water (group E2). In the experiment, the probiotic preparation based on Lactobacillus fermentum (1.109 CFU.g-1 of bearing medium) was used. Fattening period lasted for 42 days. Feed mixtures were produced without any antibiotic preparations and coccidiostatics. Meat quality was evaluated by following technological properties: cooling, freezing and roasting loss; colour parameters based on CIELab system; and shear force. Both dietary supplementations led to decrease in cooling (p ≤0.05) and freezing (p ≥0.05) losses compared with control. On the contrary, the supplemented diet tended to increase roasting losses (p ≤0.05) and shear force values in thigh muscle (p ≤0.05). Significantly higher L* values (p ≤0.05) in breast and thigh muscles, as well as the b* values in thigh muscle, were found when broiler chickens were fed the supplements, especially bee pollen extract and probiotics. In addition, the supplements improve redness (a*) of meat. The redness of breast muscle appeared to be the most affected (p ≥0.05) by propolis extract plus probiotics supplementation, while thigh muscle had the highest value (p ≤0.05) in bee pollen extract plus probiotics supplemented group. These findings suggested that the supplements have a beneficial effect on quality of chicken meat due to positive changes in most of quality indicators investigated in the study.

In vitro and in vivo screening of native lactic acid bacteria toward their selection as a probiotic in broiler chickens

Among 360 isolates from the gastrointestinal tract (GIT) of broilers, eleven isolates which showed in vitro probiotic properties were identified and selected for further tests. After the in vitro screening, three strains were chosen for the in vivo study of persistence of fresh cultures and then one strain was selected for the in vivo study of persistence of lyophilized culture. Lyophilized Lactobacillus salivarius DSPV 001P was capable of persisting in broilers during a complete rearing, even 28 days following cessation of administration. L. salivarius DSPV 001P administered to broilers and recovered from GIT was compared by pulsed-field gel electrophoresis (PFGE) to ensure that the same genotype was persistently identified. A combination of in vitro and in vivo screening of native lactic acid bacteria (LAB) described in this study may offer a method for selecting the most suitable strain for potential application as a broiler probiotic supplement.

Epithelial cell adhesion and gastrointestinal colonization of Lactobacillus in poultry

Administration of probiotic Lactobacillus cultures is an important alternative to the use of antibiotic growth promoters and has been demonstrated to improve animal health, growth performance, and preharvest food safety in poultry production. Whereas gastrointestinal colonization is thought to be critical to their probiotic functionality, factors important to Lactobacillus colonization in chickens are not well understood. In this study we investigate epithelial cell adhesion in vitro and colonization of Lactobacillusin vivo in broiler chickens. Adhesion of Lactobacillus cultures to epithelial cells was evaluated using the chicken LMH cell line. Lactobacillus cultures were able adhere effectively to LMH cells relative to Bacillus subtilis and Salmonella Typhimurium. Epithelial cell adhesion was similar for Lactobacillus crispatus TDCC 75, L. cristpatus TDCC 76, and Lactobacillus gallinarum TDCC 77, and all 3 were more adherent than L. gallinarum TDCC 78. However, when colonization was evaluated in the ileum and cecum of broiler chicks, L. crispatus TDCC 75 and L. gallinarum TDCC 77 were more persistent than L. crispatus TDCC 76 and L. gallinarum TDCC 78. The reduction of growth in medium supplemented with oxgal was greater for L. gallinarum TDCC 78 than L. gallinarum TDCC 77, suggesting that whereas adhesion was similar for the 2 strains, the difference in colonization between L. gallinarum strains may be due in part to their bile sensitivity. This study demonstrates that whereas adhesion to epithelial cells may be important in predicting gastrointestinal colonization, other factors including bile tolerance may also contribute to the colonization of Lactobacillus in poultry. Additionally, the chicken LMH cell line is expected to provide a platform for investigating mechanisms of Lactobacillus adhesion to epithelial tissue and evaluating the probiotic potential Lactobacillus in poultry.