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

Probiotics Strains Modulate Gut Microbiota and Lipid Metabolism in Mule Ducks

Background:

Livestock production should respond to societal, environmental and economic changes. Since 2006 and the ban on antibiotics as growth factors in European Union, the use of probiotics has become widespread and has demonstrated the effect of intestinal microbiota on the performance of farm animals.

Objective:

The aim of this study was to investigate the effect of supplementation with Lactobacillus salivarius (as a probiotics strain or combined with other strains) on zootechnical performance, metabolic and immune gene expression and intestinal microbiota diversity in mule ducks using high-throughput sequencing and real-time PCR.

Method:

The mule ducks were reared for 79 days and overfed for 12 days with or without probiotics. Samples were collected at 14 (starting period) and 91 days (end of overfeeding period), 3 hours post feeding.

Results:

Irrespective of digestive content, age, level of feed intake or supplementation with probiotics, Firmicutes, Proteobacteria and Bacteroidetes were the dominant phyla in the bacterial community in mule ducks. At 14 days, both the ileal and cecal samples were dominated by Firmicutes (in particular the Clostridiales order). Overfeeding induced a shift between Clostridiales and Lactobacillales in the ileal samples whereas in the cecal samples, the relative abundance of Firmicutes decreased. Overfeeding also induced hepatic over-expression of Fatty Acid Synthase (FAS) and of the lipid transporter gene Fatty Acid Binding Protein 4 (FABP4). This increase in lipid metabolism genes is associated with a decrease in inflammatory response.

Conclusion:

Finally, probiotic supplementation had only a slight impact on gene expression and microbiota diversity, both at 14 days and after overfeeding.

Eucalyptus leaves powder, antibiotic and probiotic addition to broiler diets: effect on growth performance, immune response, blood components and carcass traits

The study was conducted to investigate the effects of different levels of eucalyptus powder (EP), virginiamycin and probiotic on performance, immunity, blood components and carcass traits of broiler chickens. A total of 250, 1-day-old male broiler chickens (Ross 308) were randomly allocated to five treatments with five replicates and 10 chicks each, as a completely randomized design. The dietary treatments consisted of: basal diet (BD), BD+0.25% EP, BD+0.5% EP, BD+0.01% of diet probiotic (Protexin), BD+0.02% of diet antibiotic (virginiamycin). Dietary supplementation did not affect feed intake, BW gain (BWG) and feed conversion ratio (FCR) during starter and grower phases, but BWG and FCR were affected during the finisher and whole periods (P<0.05).The highest BWG and lowest FCR were obtained in birds fed with virginiamycin and 0.5% EP. Dietary supplementation significantly increased the relative weight of carcass and breast (P<0.05). Treatments had no effect on relative weights of internal organs and small intestine except for bursa that increased by treatments. Relative length of jejunum also increased by treatments (P<0.05). Antibody production against sheep red blood cells did not changed in primary titer (day 35), but it significantly increased in secondary titer (day 42) by 0.5% EP. White blood cell counts were increased and cholesterol decreased by dietary supplementation (P<0.05). In conclusion, the results of this study showed that 0.5% EP served as a useful replacement for antibiotic and would improve performance and immune response of broiler chickens.

Safety assessment of antibiotic and probiotic feed additives for Gallus gallus domesticus

Antibiotics in feed select for resistant strains and is thus a threat to human health. In this study, the effect of a multi-strain probiotic and antibiotics on the growth and health of broilers was studied. Equal numbers of broilers received on a daily basis either a multi-strain probiotic or a combination of sulphadiazine, colistin and trimethoprim, whereas the control group received standard feed. The villi of immature broilers (19 days old) administered antibiotics had a larger surface area and their lymphocyte and basophil counts were higher compared to broilers from the probiotic and control groups. The cecal microbiomes of mature broilers (29 days old) that received probiotics had higher levels of Enterobacteriaceae, but lower numbers of Clostridiales, Brucellaceae, Synergistaceae, Erysipelotrichaceae and Coriobacteriaceae compared to the antibiotic-treated group. A decline in the bioluminescence of Listeria monocytogenes observed for broilers on probiotics suggested that the probiotic may be used to control bacterial infections. No significant differences in total red blood cell, haemoglobin and haematocrit content, and mean values for corpuscular volume, corpuscular haemoglobin and corpuscular haemoglobin numbers were recorded amongst broilers from the different treatment groups. This study provides valuable information on the health and performance of broilers when administered probiotics and antibiotics as additives.

Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: a review

With the increase in regulations regarding the use of antibiotic growth promoters and the rise in consumer demand for poultry products from ‘Raised Without Antibiotics’ or ‘No Antibiotics Ever’ flocks, the quest for alternative products or approaches has intensified in recent years. A great deal of research has focused on the development of antibiotic alternatives to maintain or improve poultry health and performance. This review describes the potential for the various alternatives available to increase animal productivity and help poultry perform to their genetic potential under existing commercial conditions. The classes of alternatives described include probiotics, prebiotics, synbiotics, organic acids, enzymes, phytogenics, antimicrobial peptides, hyperimmune egg antibodies, bacteriophages, clay, and metals. A brief description of the mechanism of action, efficacy, and advantages and disadvantages of their uses are also presented. Though the beneficial effects of many of the alternatives developed have been well demonstrated, the general consensus is that these products lack consistency and the results vary greatly from farm to farm. Furthermore, their mode of action needs to be better defined. Optimal combinations of various alternatives coupled with good management and husbandry practices will be the key to maximize performance and maintain animal productivity, while we move forward with the ultimate goal of reducing antibiotic use in the animal industry.

Effects of dietary inclusion level of a mixture of probiotic cultures and enzymes on broiler chickens immunity response

The current study was conducted to analyse the effect of a mixture of probiotic cultures and enzymes (Probio Enzyme, XVET GmbH, Germany) on the immune response and weight of central lymphoid organs and liver in broilers. A total of 270 male chickens were randomly divided into nine groups, with three replicates of 10 birds each. Treatment groups were fed for either 22 or 42 days with different levels of Probio Enzyme 250, 500, 750 and 1000 g/ton, whereas the control group fed a basal diet without Probio Enzyme. To analyse the effects of dietary supplementation on broilers humoral immune response, the antibodies titres for avian influenza (AI) and Newcastle disease virus (NDV) and to the sheep red blood cells (SRBC) challenge were assayed in birds from each experimental unit, along with the assessment of the weight of the main lymphoid organs and liver. The addition of the Probio Enzyme mixture did not significantly affect the titres of the antibodies against AI and NDV at day 42, despite the wide individual variation observed specially on the antibody titres at day 33. Treatments affected the production of IgG after the second challenge with SRBC (P = 0.003), which was transposed to the correspondent total Ig titres (P = 0.044). Conversely, a lower birds' body weight (BW) was found in the majority of treated groups compared to control (P = 0.031). The spleen was the only lymphoid organ showing differences in the absolute and relative weight (P = 0.003 and P = 0.001, respectively). No differences were found in thymus and Bursa of Fabricius weights. In conclusion, broilers treated with Probio Enzyme showed a satisfactory immune response compared with control, despite the wide variation found after the first vaccine challenge against AI. Moreover, the probiotic mixture dose and duration modulated differently the immune response and the spleen weight, unaffecting the central lymphoid organs weight.

Effect of laboratory-isolated Lactobacillus plantarum LGFCP4 from gastrointestinal tract of guinea fowl on growth performance, carcass traits, intestinal histomorphometry and gastrointestinal microflora population in broiler chicken

The study aimed to investigate the effect of feed supplements, viz Lactobacillus plantarum LGFCP4 (laboratory isolate from GIT of Guinea fowl), Lactobacillus acidophilus (NCDC, Karnal) and in-feed antibiotic bacitracin methylene disalicylate (BMD) on growth performance, FCR, carcass traits and immune organs weight, intestinal histomorphometry and gastrointestinal microflora population in broiler chickens. In a completely randomized design, CARIBRO-Dhanraja broiler chicks (n = 160) were used with four treatment groups. During the entire experimental duration of 35 days, treatment groups were provided with different dietary treatments (T1 - basal diet (negative control), T2 - antibiotic growth promoter BMD 20 g/100 kg feed (positive control), T3 - 1 × 10⁸  cfu of L. acidophilus/gm-fermented feed +MOS 1 g/kg feed and T4 - 1 × 10⁸  cfu of laboratory-isolated L. plantarum LGFCP4/gm-fermented feed+ MOS 1 g/kg feed. After 35 days of experimental period, no significant results have been observed in different growth performance traits among treatment groups. Cut-up parts and edible organs' weight remained unaffected by dietary supplementation, whereas weight of immune organs were significantly higher (p < 0.05) in L. plantarum LGFCP4-supplemented group. At the end of feeding trial, significantly (p < 0.05) lower E. coli count was observed in crop of T4 birds, while in ileum, T2 and T3 showed lower count. In caeca, T2 group showed lowest E. coli count. Salmonella count in crop and ileum was significantly (p < 0.05) low in T3 and T4, while in caeca, T2 group showed lowest count. In terms of histomorphometry, duodenal villous height (VH), crypt depth (CD) and VH:CD ratio were higher for T3 and T4 and lowest values were obtained for T2 group. The results of the study showed that L. plantarum LGFCP4 isolated from GIT of guinea fowl can effectively replace in-feed antibiotic growth promoters in broiler diets by altering intestinal villi morphology and improving the gut health by reducing the pathogenic microbial load.

Effects of time of initiation of feeding after hatching and diet composition on performance, carcass characteristics, digestive tract development and immune responses of broilers

This study was conducted to evaluate the effects of time of initiation of feeding after hatching and influence of diet composition on growth performance, carcass characteristics, digestive tract development and immune responses of broilers. A total of straight-run 420 Ross 308 broiler chicks were randomly allotted to six treatments with five replicates of 14 chicks each. The dietary treatments consisted of feeding a maize-soybean meal diet immediately posthatching until 14 days of age (Control), fasting for 24 or 48 h posthatching, feeding maize for 24–48 h posthatching, and feeding a maize gluten-dextrose pre-starter diet for 5 days posthatching. The study lasted from 0 to 42 days of age. For the entire 42-day period, chicks fasted or fed maize for 48 h posthatching or those fed the maize gluten-dextrose diet for 5 days posthatching had lower (P &lt; 0.05) feed intake and lower (P &lt; 0.05) weight gain compared with the Control. However, birds fasted or those fed maize for 24 or 48 h posthatching had similar (P &gt; 0.05) feed intake and weight gain as the Control. The duodenal villus height and villus height:crypt depth ratio were lower (P &lt; 0.05) and the duodenal crypt depth was higher (P &lt; 0.05) in birds fasted for 48 h posthatching compared with the Control. Conversely, birds fasted for 48 h posthatching had higher (P &lt; 0.05) jejunal villus height and villus height:crypt depth ratio and lower (P &lt; 0.05) jejunal crypt depth compared with the Control. The antibody titres against Newcastle disease was lower (P &lt; 0.05) for the groups other than the Control, whereas the antibody titres against Avian Influenza virus was lower (P &lt; 0.05) in birds fasted for 48 h posthatching and in those fed maize for 48 h posthatching compared with the Control. Also, birds fed maize for 24 h posthatching had lower (P &lt; 0.05) antibody titres against sheep red blood cells compared with the other treatments. These results indicated that feeding a maize-soybean meal starter diet immediately after hatch has a beneficial effect on growth performance and immune response of broilers and improves morphological development of the intestine.

Effects of in ovo supplementation of probiotics on performance and immunocompetence of broiler chicks to an Eimeria challenge

Coccidiosis is regarded as the parasitic disease with the greatest economic impact on the poultry industry due to reduced performance and increased mortality. A study was conducted to investigate the effects of in ovo administration of probiotics on hatchability, performance, immune organ weights, and lesion scores in broiler chicks during a mixed Eimeria infection. At embryonic day 18, 210 eggs were injected with either sterile water or 1×106 cfu probiotic bacteria. On day 3 post-hatch, half of the chicks from each treatment group were challenged with a mixed inoculum of Eimeria acervulina, Eimeria maxima and Eimeria tenella. Measurements and tissue samples were taken on day of hatch (DOH) and days 3, 9 and 15. On day 9, 24 birds per treatment were scored for intestinal Eimeria lesions. No differences were seen among groups for hatchability as well as for body weight (BW), BW gain (BWG), or immune organ weights prior to the Eimeria challenge. On day 9, the non-challenged birds with probiotic supplementation had higher BW and BWG than the non-supplemented controls while no differences were seen among the challenged groups. On day 15, probiotic supplemented birds had improved BW compared to the non-supplemented birds as well as increased BWG from day 9 to 15. Bursa weight was not affected by treatment at any time point while spleen weight was greater in supplemented birds on day 15. Birds receiving the probiotic had significantly lower mortality than non-treated birds. Additionally, gross lesion severity was reduced due to probiotic supplementation in all intestinal segments evaluated. These results suggest that in ovo supplementation of probiotics may improve early performance and provide protection against a mixed Eimeria infection.

Combination of probiotics and coccidiosis vaccine enhances protection against an Eimeria challenge

Coccidiosis is endemic in the commercial broiler industry capable of inflicting devastating economic losses to poultry operations. Vaccines are relatively effective in controlling the disease; their efficacy could potentially be improved with concurrent use of probiotics as evaluated in this study using an Eimeria challenge. Day of hatch 400 Cobb-500 male broilers were assigned to one of four treatment groups including control (CON), vaccine-only gel application (VNC), probiotic-only gel application (NPC), and vaccine-plus-probiotic gel application (VPC). Birds were placed in floor pens (6 replicate pens/treatment, 16-17 birds/pen). NPC and VPC birds received the probiotics in the water on days 2-4, 8, 14-20, 22, 29, and 34-36. On day 15, birds were mildly challenged with 0.5 mL of a mixed oral inoculum of Eimeria sp. prepared with the coccidiosis vaccine at 10× the vaccination dose. Performance measurements were recorded on first day and weekly afterwards, and lesion scores were evaluated 6 days post-challenge. Overall, the probiotics and coccidiosis vaccine resulted in an enhanced protective effect against the challenge, with VPC birds exhibiting lower lesion scores in the duodenum than VNC or NPC birds. Birds in the VPC treatment also demonstrated higher weight gains during days 1-15, days 7-15, and days 21-28 when compared to the VNC birds. These results suggest that the combination of probiotics and coccidiosis vaccines could enhance performance and provide an additional protective effect against a mixed Eimeria challenge.

High-throughput sequencing technology to reveal the composition and function of cecal microbiota in Dagu chicken

BACKGROUND

The chicken gut microbiota is an important and complicated ecosystem for the host. They play an important role in converting food into nutrient and energy. The coding capacity of microbiome vastly surpasses that of the host's genome, encoding biochemical pathways that the host has not developed. An optimal gut microbiota can increase agricultural productivity. This study aims to explore the composition and function of cecal microbiota in Dagu chicken under two feeding modes, free-range (outdoor, OD) and cage (indoor, ID) raising.

RESULTS

Cecal samples were collected from 24 chickens across 4 groups (12-w OD, 12-w ID, 18-w OD, and 18-w ID). We performed high-throughput sequencing of the 16S rRNA genes V4 hypervariable regions to characterize the cecal microbiota of Dagu chicken and compare the difference of cecal microbiota between free-range and cage raising chickens. It was found that 34 special operational taxonomic units (OTUs) in OD groups and 4 special OTUs in ID groups. 24 phyla were shared by the 24 samples. Bacteroidetes was the most abundant phylum with the largest proportion, followed by Firmicutes and Proteobacteria. The OD groups showed a higher proportion of Bacteroidetes (>50 %) in cecum, but a lower Firmicutes/Bacteroidetes ratio in both 12-w old (0.42, 0.62) and 18-w old groups (0.37, 0.49) compared with the ID groups. Cecal microbiota in the OD groups have higher abundance of functions involved in amino acids and glycan metabolic pathway.

CONCLUSION

The composition and function of cecal microbiota in Dagu chicken under two feeding modes, free-range and cage raising are different. The cage raising mode showed a lower proportion of Bacteroidetes in cecum, but a higher Firmicutes/Bacteroidetes ratio compared with free-range mode. Cecal microbiota in free-range mode have higher abundance of functions involved in amino acids and glycan metabolic pathway.

Effect of diet supplemented with propolis extract and probiotic additives on performance, carcass characteristics and meat composition of broiler chickens

The present research focused on the effects of propolis extract and probiotic preparation based on Lactobacillus fermentum (1 × 109 CFU per 1 g of bearing medium) on performance, carcass characteristics and meat composition of broiler chickens. The experiment was performed with 360 one day-old Ross 308 broiler chicks of mixed sex. The chicks were randomly allocated into 3 groups (n = 120 pcs chicks per group), namely, control (C) and experimental (E1, E2). Each group consisted of 3 replicated pens with 40 broiler chickens per pen. The experiment employed a randomized design, and dietary treatments were as follows: 1. basal diet with no supplementation as control (group C), 2. basal diet plus 400 mg propolis extract per 1 kg of feed mixture (group E1), 3. basal diet plus 3.3 g probiotic preparation added to drinking water (group E2). Besides, the groups were kept under the same conditions. Fattening period lasted for 42 days. Feed mixtures were produced without any antibiotic preparations and coccidiostats. As regards performance of broilers, all the investigated parameters were improved after addition of the supplements, especially after probiotic supplementation. However, neither propolis extract nor probiotic in diet of broiler chickens had any significant effect (p ≥0.05) on performance. Meat composition was evaluated as proximate composition (dry matter, crude protein, fat and ash), cholesterol content and energy value in the most valuable parts of chicken meat (breast and thigh muscles). The statistically significant results (p ≤0.05) were attained in fat, ash and cholesterol content, as well as energy value in both breast and thigh muscles after the propolis supplementation. To sum up, the present study demonstrated the promising potential of propolis extract and probiotic to enhance the performance, carcass characteristics and meat composition under conditions of the experiment with, however, statistical significance of results in a few parameters.

Steering Endogenous Butyrate Production in the Intestinal Tract of Broilers as a Tool to Improve Gut Health

The ban on antimicrobial growth promoters and efforts to reduce therapeutic antibiotic usage has led to major problems of gastrointestinal dysbiosis in livestock production in Europe. Control of dysbiosis without the use of antibiotics requires a thorough understanding of the interaction between the microbiota and the host mucosa. The gut microbiota of the healthy chicken is highly diverse, producing various metabolic end products, including gases and fermentation acids. The distal gut knows an abundance of bacteria from within the Firmicutes Clostridium clusters IV and XIVa that produce butyric acid, which is one of the metabolites that are sensed by the host as a signal. The host responds by strengthening the epithelial barrier, reducing inflammation, and increasing the production of mucins and antimicrobial peptides. Stimulating the colonization and growth of butyrate-producing bacteria thus may help optimizing gut health. Various strategies are available to stimulate butyrate production in the distal gut. These include delivery of prebiotic substrates that are broken down by bacteria into smaller molecules which are then used by butyrate producers, a concept called cross-feeding. Xylo-oligosaccharides (XOS) are such compounds as they can be converted to lactate, which is further metabolized to butyrate. Probiotic lactic acid producers can be supplied to support the cross-feeding reactions. Direct feeding of butyrate-producing Clostridium cluster IV and XIVa strains are a future tool provided that large scale production of strictly anaerobic bacteria can be optimized. Current results of strategies that promote butyrate production in the gut are promising. Nevertheless, our current understanding of the intestinal ecosystem is still insufficient, and further research efforts are needed to fully exploit the capacity of these strategies.

Effect of a potential probiotics Lactococcus garvieae B301 on the growth performance, immune parameters and caecum microflora of broiler chickens

In this study, a novel Lactococcus garvieae B301 was isolated from the intestinal tract of a healthy piglet. L. garvieae B301 was tolerant to acid pH, simulated gastric and small intestinal transit juices, indicating that it was capable of surviving in the gastrointestinal tract. L. garvieae B301 was safe and beneficial to broilers, as broiler chickens supplemented with L. garvieae B301 had lower diarrhoea incidence and mortality than the Control. Moreover, supplementation of broiler diets with L. garvieae B301 resulted in an increase in body weight and the number of caecum lactic acid bacteria and Bifidobacterium spp., and decrease in feed-to-gain ratio and the number of caecum coliforms. It also had a positive effect on the thymus index and bursa of Fabricius index and enhanced serum levels of immune globulins. All these results showed that L. garvieae B301 could enhance the growth performance of broiler chickens and improve their health. Thus, L. garvieae B301 could be a promising feed additive for broiler chickens.

Immunomodulatory role of probiotics in poultry and potential in ovo application

Recently, there has been an increasing debate regarding the use of sub-therapeutic antibiotics in animal feed. This stems from worries that this practice may result in microbial resistance to human antibiotics employed in treating infections, thus causing a human health concern. Due to this tension, the poultry industry is under mounting pressure to reduce the use of these agents as feed additives and alternative control methods have taken the forefront in the research community. Investigators are searching for the latest alternative that will protect flocks from disease, while not hindering performance or negatively impacting profit margins. Probiotic supplementation is one option currently being explored as a means of improving performance and reducing the amount and severity of enteric diseases in poultry, and subsequent contamination of poultry products for human consumption. Probiotics are live, nonpathogenic microorganisms known to have a positive effect on the host by beneficially modifying gut microbiota and modulating the immune system. This review will discuss the role of probiotics in poultry, including their effects on performance, immune response and host defence against disease. Also addressed will be the recent applications of supplementing probiotics in ovo as an innovative means to administer such additives to promote early colonisation of beneficial bacteria.

In ovo injection of prebiotics and synbiotics affects the digestive potency of the pancreas in growing chickens

The purpose of the study was to examine the effect of 2 prebiotics and 2 synbiotics on the digestive potency of pancreas in 1-, 3-, 7-, 14-, 21-, and 34-day-old cockerels. Prebiotics (inulin and Bi²tos) and synbiotics (inulin + Lactococcus lactis subsp. lactis and Bi²tos + Lactococcus lactis subsp. cremoris) were injected in ovo into the air cell on the 12th d embryonic development. Their application increased the activity of amylase, lipase, and trypsin in the pancreas. The most pronounced changes were observed at the end of the investigated rearing period (d 34). The strongest stimulative effects on amylase were shown by both synbiotics, on lipase synbiotic Bi²tos + Lactococcus lactis subsp. cremoris, and on trypsin all the used prebiotics and synbiotics. Simultaneously, neither the absolute nor the relative mass of the pancreas in comparison to control group were changed. Also, the injected in ovo compounds did not cause a deterioration in the posthatching condition of the chicken liver, as determined by measurement of the activity of marker enzymes in the blood (alanine aminotransferase and aspartate aminotransferase). Treatment with the prebiotics and synbiotics did not change the feed conversion ratio but Bi²tos (galacto-oligosaccharide) and inulin (fructan) + Lactococcus lactis subsp. lactis significantly increased final BW.

Immune Responses in Broiler Chicks Fed Propolis Extraction Residue-supplemented Diets

This study was conducted to evaluate the effect of inclusion of propolis extraction residue in the feed of broilers from 1 to 21 d of age on phagocytic activity of macrophages, cutaneous basophil hypersensitivity response to phytohemagglutinin, antibody production against Newcastle disease, lymphoid organ weight and hematological profile and to determine the optimal level of inclusion. 120 chicks, reared in metabolism cages until 21 days of age, were distributed in a completely randomized design, with five treatments (0%, 1%, 2%, 3%, and 4% of propolis residue) and six replications. The relative weight of thymus and monocyte percentage were affected by propolis residue, with a quadratic response (p<0.05) and lowest values estimated at 2.38% and 2.49%, respectively. Changes in relative weight of cloacal bursa and spleen, percentage of lymphocyte, heterophil, basophil, eosinophil, and heterophil:lymphocyte ratio, antibody production against Newcastle disease, phagocytic activity of macrophages and the average number of phagocytosed erythrocytes were not observed. The nitric oxide production with regard to positive control (macrophages+erythrocytes) decreased linearly (p<0.05) with increased doses of propolis residue. The remaining variables of nitric oxide production (negative control – macrophages, and difference between the controls) were not affected by propolis residue. The cutaneous basophil hypersensitivity response to phytohemagglutinin as determined by the increase in interdigital skin thickness exhibited a quadratic response (p<0.05), which predicted a lower reaction response at a dose of 2.60% of propolis residue and highest reaction response after 43.05 hours of phytohemagglutinin injection. The inclusion of 1% to 4% of propolis extraction residue in broiler diets from 1 to 21 days of age was not able to improve the immune parameters, despite the modest changes in the relative weight in thymus, blood monocyte percentage, nitric oxide concentration, and interdigital reaction to phytohemagglutinin.

Effects of probiotics and application methods on performance and response of broiler chickens to an Eimeria challenge

Coccidiosis is an inherent risk in the commercial broiler industry and inflicts devastating economic losses to poultry operations. Probiotics may provide a potential alternative to the prophylactic use of anticoccidials in commercial production. This study evaluated the effects of probiotic applications (feed and water) on bird performance and resistance to a mixed Eimeria infection in commercial broilers. On day of hatch, 1,008 commercial male broilers (Cobb 500) were assigned to 1 of 6 treatments (8 replicate floor pens; 21 birds/pen), including noninfected negative control (NEG), Eimeria-infected positive control (POS), anticoccidial control (0.01% salinomycin, SAL), intermittent high-dose water-applied probiotic (WPI), continuous low-dose water-applied probiotic (WPC), and feed-supplemented probiotic (FSP). On d 15, all birds except those in NEG were challenged with a mixed inoculum of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Measurements were taken on d 7, 15, 21, 28, 35, and 42. Fecal samples were collected from d 20 to 24 for oocyst counts, and lesion scores were evaluated on d 21. Data were analyzed using the Fit Model platform in JMP Pro 10.0 (SAS Institute Inc.). Differences in experimental treatments were tested using Tukey's honestly significant difference following ANOVA with significance reported at P ≤ 0.05. Overall, NEG birds outperformed all other groups. For performance, the probiotic groups were comparable with the SAL-treated birds, except during the 6 d immediately following the Eimeria species challenge, where the SAL birds exhibited better performance. The WPC birds had lower duodenal and jejunal lesion scores, indicating a healthier intestine and enhanced resistance to Eimeria species compared with POS. Birds in the WPI treatment shed fewer oocysts in the feces, although this was not a trend for all of the probiotic treatment groups. The results of this study suggest probiotic supplementation without anticoccidials can enhance performance and help alleviate the negative effects of a mixed Eimeria infection.

Evaluation of probiotics in diets with different nutrient densities on growth performance, blood characteristics, relative organ weight and breast meat characteristics in broilers

1. A total of 720 1-d-old broilers were used in a 28 d experiment to determine the effects of probiotic supplementation in diets with different dietary nutrient densities. 2. Birds were randomly allotted to one of the 4 treatments in a 2 × 2 factorial arrangement (12 replicateswith 15 broilers per replicate) with two levels of nutrient density [high nutrient density (metabolisable energy (ME) 12.7 MJ/kg and crude protein (CP) 230.3 g/kg for 1-7 d; ME 13.2 MJ/kg and CP 220.3 g/kg for 8-28 d) or low nutrient density (ME 12.1 MJ/kg and CP 220.2 g/kg for 0-7 d; ME 12.6 MJ/kg and CP 209.8 g/kg for 8-28 d)] and 0 or 2 g/kg probiotics (1.0 × 10(10) viable spores/g of Bacillus subtilis endospores and 1.0 × 10(9) viable spores/g of Clostridium butyricum). 3. The high-nutrient-density diet increased body weight gain (BWG), feed conversion ratio (FCR), serum cholesterol and triglyceride concentration relative to the low-nutrient-density diet. High-nutrient-density diet reduced water loss ratio of breast muscle, liver and fat relative to body weight compared to low-nutrient density-diet. The inclusion of probiotics increased BWG and feed intake throughout the experiment. Dietary probiotics increased the percentage of blood lymphocytes and relative weight of spleen and bursa of Fabricius when compared to the non-probiotic treatment. The inclusion of probiotics decreased serum cholesterol and triglyceride concentrations and lightness (L*) value of breast meat compared to the non-probiotic-supplemented diet. 4. In conclusion, high dietary nutrient density increased growth performance and serum cholesterol and triglyceride concentrations in broiler chickens. The inclusion of probiotics increased growth performance but reduced serum cholesterol and triglyceride concentrations. The positive effect of probiotic supplementation on growth performance was reduced by the high-nutrient-density diet during the first week of life.

Effects of probiotic, Clostridium butyricum, on growth performance, immune function, and cecal microflora in broiler chickens

Four hundred and fifty 1-d-old male Lingnan Yellow broiler chickens were used to investigate the effects of Clostridium butyricum on growth performance, immune function, and cecal microflora. The birds were randomly assigned to 5 treatments and offered the same antibiotic-free basal diets for 42 d. The treatments were as follows: no addition (control), 1 × 10(7) cfu C. butyricum/kg of diet (CB1), 2 × 10(7) cfu C. butyricum/kg of diet (CB2), 3 × 10(7) cfu C. butyricum/kg of diet (CB3), and 10 mg of colistine sulfate/kg of diet (antibiotic). Birds fed either CB2 or antibiotic had greater overall BW than those in the control group. During d 1 to 7, d 21 to 42, and d 1 to 42, birds fed either CB2 or CB3 or the antibiotic diet had greater ADG compared with those in the control group. No significant differences were observed in BW or ADG among the CB2, CB3, and antibiotic groups. Birds fed the CB2 or CB3 diet had greater concentrations of IgA and IgG in the serum from d 14 to 42 and greater IgM in the serum from d 21 to 42 than those in the control group. Birds fed the CB3 diet had a greater concentration of complement component 3 in the serum than those in the control group from d 7 to 42. Dietary C. butyricum decreased (P < 0.05) Escherichia coli in cecal contents on d 14 and 42, and both CB2 and CB3 decreased (P < 0.05) cecal Salmonella and Clostridium perfringen from d 14 to 42 compared with the control. Broilers fed either CB2 or CB3 had greater cecal Lactobacillus and Bifidobacterium counts from d 21 to 42, and birds fed C. butyricum had greater cecal C. butyricum counts during the whole period compared with those in the control group. The results indicate that C. butyricum promotes growth performance and immune function and benefits the balance of the intestinal microflora in broiler chickens.

A novel aflatoxin-binding Bacillus probiotic: Performance, serum biochemistry, and immunological parameters in Japanese quail

Two experiments were performed to screen bacilli isolated from quails for their aflatoxin removal potential and to assess the efficiency of their amelioration of experimental aflatoxicosis. Nonhemolytic bacilli were selected for in vitro aflatoxin B1 (AFB1) removal and conventional probiotic tests. The isolate with the highest scores was selected for assessment in field experiments and was identified as Berevibacillus laterosporus (Bl). In the second experiment, 125 male Japanese quails (21 d old) were divided into 5 groups with 5 replications to compare the toxin removal efficiency of Bl with that of a commercial toxin binder, improved Millbond-TX (IMTX). The experimental groups were as follows: Control (without any feed additive or AFB1); AFB1 (2.5 mg/kg); AFB1+Bl (2.5 mg/kg+10(8) cfu/mL); AFB1+IMTX (2.5 mg/kg+2.5 g/kg); and Bl (10(8) cfu/mL). The greatest BW gain and slaughter and carcass weights were found in the Bl group and the lowest values were observed in the AFB1 group (P<0.05). Feeding AFB1 alone to the chicks resulted in a significant decrease in serum albumin, total protein, and glucose and cholesterol levels but a significant increase in serum uric acid, urea, creatinin and phosphorus (P<0.05). Treatment of birds on AFB1 with Bl restored these to their original levels (P<0.05). AFB1+Bl-fed birds had serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and alkaline phosphatase enzyme activity similar to control birds (P<0.05). Antibody titer against Newcastle disease virus was found to be lowest in the AFB1 group but highest in the Bl group (P<0.05). Antibody production against sheep red blood cells was lower in the AFB1 group compared with the AFB1+Bl group (P<0.05). Berevibacillus laterosporus supplementation of the AFB1 diet restored the skin response to 2,4-dinitro 1-chlorobenzene to levels comparable with control birds (P<0.05). It can be concluded that selected indigenous Bl is a promising probiotic with AFB1 removal potential.

Effects of feeding of two potentially probiotic preparations from lactic acid bacteria on the performance and faecal microflora of broiler chickens

The aim of this study was to evaluate the potential of two probiotic preparations, containing live lactic acid bacteria (Lactococcus lactis CECT 539 and Lactobacillus casei CECT 4043) and their products of fermentation (organic acids and bacteriocins), as a replacement for antibiotics in stimulating health and growth of broiler chickens. The effects of the supplementation of both preparations (with proven probiotic effect in weaned piglets) and an antibiotic (avilamycin) on body weight gain (BWG), feed intake (FI), feed consumption efficiency (FCE), relative intestinal weight, and intestinal microbiota counts were studied in 1-day posthatch chickens. The experiments were conducted with medium-growth Sasso X44 chickens housed in cages and with nutritional stressed Ross 308 broiler distributed in pens. Consumption of the different diets did not affect significantly the final coliform counts in Sasso X44 chickens. However, counts of lactic acid bacteria and mesophilic microorganisms were higher in the animals receiving the two probiotic preparations (P < 0.05). In the second experiment, although no differences in BWG were observed between treatments, Ross 308 broilers receiving the probiotic Lactobacillus preparation exhibited the lowest FCE values and were considered the most efficient at converting feed into live weight.

Efficacy of protected sodium butyrate, a protected blend of essential oils, their combination, and Bacillus amyloliquefaciens spore suspension against artificially induced necrotic enteritis in broilers

Necrotic enteritis caused by Clostridium perfringens leads to serious economical losses to the poultry industry. There is a growing need to find effective, nontoxic, antibiotic alternatives to prevent and cure the disease. In our study, the efficacy of protected sodium butyrate at 1.5 g/kg (BP70), a Bacillus amyloliquefaciens spore suspension with 10(9) cfu/g (BAL; Ecobiol), a protected blend of essential oils (1%) at 1.5 g/kg (EO), and a combination of sodium butyrate with essential oils (1%) protected with vegetable fat at 1.5 g/kg (BP70+EO; Natesse) was investigated in an artifical C. perfringens-infection model. Body weight gain, gross pathological and histopathological lesion scores, villus lengths, and villus length:crypt depth ratio was determined and compared with the control group. Broilers infected with C. perfringens and treated with essential oils or the combination of sodium butyrate and essential oils showed significantly better BW gain (P < 0.05), increased villus length and villus length:crypt depth ratio (P < 0.001), and decreased gross pathological and histopathological lesion scores (P < 0.05) compared with the control. Sodium butyrate alone and B. amyloliquefaciens spore suspension had no beneficial effects on the course of the disease in this study. According to our results, the protected combination of sodium butyrate and essential oils, as well as the protected essential oils, can be potential candidates for the prevention and treatment of necrotic enteritis in broiler chickens.

Growth Performance and Meat Quality of Broiler Chickens Supplemented with Bacillus licheniformis in Drinking Water

A feeding trial was conducted to investigate effects of Bacillus licheniformis on growth performance and meat quality of broilers. Nine hundred one-d-old broiler chicks were randomly assigned to 3 experimental groups with three replicate pens of 100 broiler chicks. Three treatments were i) control, ii) basal diets supplemented with 1 ml of B. licheniformis for each in feed water per day iii) basal diets supplemented with 2 ml of B. licheniformis per chick in feed water per day. The supplementation of B. licheniformis significantly increased body weight in grower chickens (p<0.05), and significantly improved the feed conversion in 3 to 6 and 0 to 6 wk feeding period compared with the control group (p<0.05). Additionally, the supplement also resulted in increased protein and free amino acid contents, and decreased fat content in chicken breast fillet (p<0.05). Furthermore, improvement in sensory attributes was observed in broilers fed with the probiotic. In conclusion, B. licheniformis treatments resulted in a significant increase (p<0.05) in broiler productivity based on an index taking into account daily weight gain and feed conversion rate. Meanwhile, the probiotic contributed towards an improvement of the chemical, nutritional and sensorial characteristics of breast fillet. Overall, the study indicates that B. licheniformis can be used as a growth promoter and meat quality enhancer in broiler poultry.

Evaluation of green tea by-product and green tea plus probiotics on the growth performance, meat quality and immunity of growing–finishing pigs

The present study was conducted to evaluate the effects of green tea by-product (GTB) and green tea plus probiotics (GT+P) on the growth performance, carcass characteristics, meat quality, blood parameters and immunity of growing–finishing pigs. In total, 80 crossbreed growing pigs were assigned to receive four dietary treatments for a period of 8 weeks. The dietary treatments were a basal diet (control), basal diet supplemented with 0.003% chlortetracycline (antibiotic), basal diet with 0.5% GTB (GTB) and basal diet containing 0.5% GT+P (GT+P). The results of our study indicated that bodyweight gain increased (P < 0.05) in response to the addition of GT+P to the basal diet. Crude protein and crude ash content, and shear values of loin meat were significantly (P < 0.05) increased in the GT+P group, although moisture and juiciness were decreased (P < 0.05). The GTB group had higher (P < 0.05) serum glucose concentrations, whereas the GT+P exhibited lower (P < 0.05) insulin concentrations. The values of thiobarbituric acid-reactive substances of fresh loin meat and meat that had been preserved for 1 week were lower (P < 0.05) in the GT+P group than those of the control and GTB groups. The growth of spleen cells incubated in concanavalin A (Con A) and lipopolysaccharide (LPS) medium was statistically higher (P < 0.05) for the GT+P group than for the GTB or antibiotic group. IL-6 and TNF-α production by spleen cells induced by Con A and LPS was increased in the GTB and GT+P group (P < 0.05) compared with the antibiotic group. Taken together, the results of the present study indicated that GT+P exerts positive effects on weight gain, meat composition, blood parameters and immunity in pigs, and could be used as an alternative to antibiotics for growing–finishing pig feeds.