Effects of sodium butyrate and salinomycin upon intestinal microbiota, mucosal morphology and performance of broiler chickens

Efficacy of supplementing Aspergillus awamori in enhancing growth performance, gut microbiota, digestibility, immunity, and antioxidant activity of heat-stressed broiler chickens fed diets containing olive pulp

BACKGROUND

Gut microbes play a significant role in digestion, developing immunity, and intestinal health. Therefore, direct-fed microbials are used to modify gut microbiota, maintain a healthy digestive system, enhance immunity, and promote the broilers' performance. In addition, it has a role in improving the utilization of unconventional feed ingredients (olive pulp, OP). This study provides the potential role of Aspergillus awamori in enhancing gut microbial content, nutrient utilization, growth performance, and antioxidative status in heat-stressed broiler chickens fed diets containing olive pulp.

METHODS

Three hundred chicks (Ross 308; one day old) were divided into four treatment groups (75 chick/ group) randomly, as follows; CON: chicks fed a basal diet based on corn and soybean meal, OP10: chicks fed a diet containing 10% OP, OA1: chicks fed a diet containing OP with A. awamori at 100 mg per kg, OA2: chicks fed a diet containing OP with A. awamori at 200 mg per kg.

RESULTS

Adding A. awamori to the broiler diet that contains OP had a positive effect on productive performance via enhancing nutrition digestibility, body weight gain, feed conversion ratio, and carcass characteristics. A. awamori supplementation had a positive impact on immune responses by increasing serum immunoglobulin G and the relative weight of bursa of Fabricius (P < 0.05) compared to the other groups. Chickens fed A. awamori showed a noticeable improvement in the oxidative status through the increase in the level of serum superoxide dismutase, and glutathione peroxidase, and the decrease in the level of malondialdehyde. Feeding A. awamori also modified the intestinal microbial content by increasing the population of Lactobacillus (P < 0.05).

CONCLUSIONS

Our study indicated that adding 200 mg A. awamori reduced the negative effect of heat stress by modifying the microbial content of the intestine, immune response, and enhancing feed utilization, thus improving broiler performance, as well as, improving the nutritional value of the olive pulp. Therefore, adding A. awamori to the OP diet can be effectively used in heat-stressed broiler diets.

Canaries' Microbiota: The Gut Bacterial Communities along One Female Reproductive Cycle

Investigations of bacterial communities are on the rise both in human and veterinary medicine. Their role in health maintenance and pathogenic mechanisms is in the limelight of infectious, metabolic, and cancer research. Among the most considered, gut bacterial communities take the cake. Their part in animals was assessed mainly to improve animal production, public health, and pet management. In this regard, canaries deserve attention, being a popular pet and source of economic income for bird-keepers, for whom breeding represents a pivotal point. Thus, the present work aimed to follow gut bacterial communities' evolution along on whole reproductive cycle of 12 healthy female canaries. Feces were collected during parental care, molting, and resting phase, and submitted for 16S rRNA sequencing. Data were analyzed and a substantial presence of Lactobacillus aviarius along all the phases, and a relevant shift of microbiota during molting and rest due to an abrupt decrease of the Vermiphilaceae family were detected. Although the meaning of such change is not clear, future research may highlight unforeseen scenarios. Moreover, Lactobacillus aviarius may be deemed for normal bacteria flora restoration in debilitated birds, perhaps improving their health and productivity.

Effects of Major Families of Modulators on Performances and Gastrointestinal Microbiota of Poultry, Pigs and Ruminants: A Systematic Approach

Considering the ban on the use of antibiotics as growth stimulators in the livestock industry, the use of microbiota modulators appears to be an alternative solution to improve animal performance. This review aims to describe the effect of different families of modulators on the gastrointestinal microbiota of poultry, pigs and ruminants and their consequences on host physiology. To this end, 65, 32 and 4 controlled trials or systematic reviews were selected from PubMed for poultry, pigs and ruminants, respectively. Microorganisms and their derivatives were the most studied modulator family in poultry, while in pigs, the micronutrient family was the most investigated. With only four controlled trials selected for ruminants, it was difficult to conclude on the modulators of interest for this species. For some modulators, most studies showed a beneficial effect on both the phenotype and the microbiota. This was the case for probiotics and plants in poultry and minerals and probiotics in pigs. These modulators seem to be a good way for improving animal performance.

Butyrate's role in human health and the current progress towards its clinical application to treat gastrointestinal disease

Butyrate is a key energy source for colonocytes and is produced by the gut microbiota through fermentation of dietary fiber. Butyrate is a histone deacetylase inhibitor and also signals through three G-protein coupled receptors. It is clear that butyrate has an important role in gastrointestinal health and that butyrate levels can impact both host and microbial functions that are intimately coupled with each other. Maintaining optimal butyrate levels improves gastrointestinal health in animal models by supporting colonocyte function, decreasing inflammation, maintaining the gut barrier, and promoting a healthy microbiome. Butyrate has also shown protective actions in the context of intestinal diseases such as inflammatory bowel disease, graft-versus-host disease of the gastrointestinal tract, and colon cancer, whereas lower levels of butyrate and/or the microbes which are responsible for producing this metabolite are associated with disease and poorer health outcomes. However, clinical efforts to increase butyrate levels in humans and reverse these negative outcomes have generated mixed results. This article discusses our current understanding of the molecular mechanisms of butyrate action with a focus on the gastrointestinal system, the links between host and microbial factors, and the efforts that are currently underway to apply the knowledge gained from the bench to bedside.

Growth performance, nutrient digestibility, antioxidant state, ileal histomorphometry, and cecal ecology of broilers fed on fermented canola meal with and without exogenous enzymes

This study was conducted to evaluate the effects of supplementation of exogenous enzymes in broiler diets that includes fermented canola meal on performance, nutrient digestibility, biochemical indication, antioxidative capacity, digestive enzyme activity, immune responses, and gut health. Five hundred 1-day-old Ross 308 broiler chicks were randomly allocated into five experimental groups (5 replicate/group), the first group: a control (CON) contained a basal diet, and the second to the fifth groups were fed diets as follows: containing 20% canola meal (CM), contains 20% fermented canola meal (FCM), contains 20% canola meal and exogenous enzymes at 0.02%/kg feed (ECM), and contains 20% fermented canola meal and exogenous enzymes at 0.02%/kg feed (EFC), respectively. At the finisher phase, the best body weight gain, feed conversion ratio, and nutrient utilization were associated with chickens fed EFC compared to other groups (P < 0.05). Total protein, albumin, alanine aminotransferase, and superoxide dismutase levels increased (P < 0.05), while cholesterol and malondialdehyde levels decreased in chickens fed on EFC. Likewise, there was a significant increase in the relative weight of the bursa of Fabricius and antibody titer against Newcastle disease, whereas the weight of abdominal fat decreased in the EFC group compared to other groups. Furthermore, there was a significant improvement in the activity of lipase and amylase enzymes (P < 0.05) in the EFC group. Fermented canola meal addition improved gut health (decreased Escherichia coli, increased Lactobacillus, and the highest values of villus height). Overall, these results confirmed that supplementing a fermented canola meal diet with exogenous enzymes improved growth performance through enhancing nutrient digestibility, immunity, antioxidant capacity, and gut health. Thus, adding enzymes to a diet containing fermented canola meal can be recommended as an alternative protein source that could be safely used to replace up to 20% soybean meal in broiler diets.

Impact of Dietary Supplementation with Sodium Butyrate Protected by Medium-Chain Fatty Acid Salts on Gut Health of Broiler Chickens

Nutritional strategies to improve gut health of broilers are under research. This study investigated the effect of dietary supplementation with sodium butyrate protected by sodium salts of medium-chain fatty acids as a feed additive on broiler gut health. The first experiment was conducted to evaluate the effect of supplementing at 0.5, 1, and 2 kg/t in broilers housed under optimal conditions. Supplementation at 0.5 and 1 kg/t maintained goblet cell counts at 10 days of age (p ≤ 0.05), and supplementation at 1 kg/t decreased intraepithelial lymphocyte counts compared to 2 kg/t at 39 days (p ≤ 0.10). Abdominal fat pad levels of lauric and myristic acids were gradually increased by supplement dose (p ≤ 0.05). In the second experiment, the feed additive at 1 kg/t was evaluated in coccidiosis-challenged broilers. Experimental treatments were as follows: non-challenged, control-challenged, and supplemented-challenged treatments. Coccidiosis negatively impact performance and modify histomorphometry and microbiota (p ≤ 0.05). The feed additive increased crypt depth at 7 days post-inoculation and goblet cell count at 14 days post-inoculation (p ≤ 0.05). Further, supplementation interacted with the microbiota modification led by the coccidiosis (p ≤ 0.05). These results suggest that this feed additive could be a useful strategy to reinforce the gut barrier, especially for birds under coccidiosis-challenge treatments.

The Effects of Sodium Butyrate, Coated Sodium Butyrate, and Butyric Acid Glycerides on Nutrient Digestibility, Gastrointestinal Function, and Fecal Microbiota in Turkeys

This study aimed to determine the efficacy of sodium butyrate (SB), coated sodium butyrate (CSB), and butyric acid glycerides (BAG) in turkey nutrition based on an analysis of nutrient digestibility, gastrointestinal function, and fecal bacterial populations. A total of 400 1-day-old female BIG 6 turkeys were divided into 4 groups, with 5 replicates per group and 20 birds per replicate, to determine the effects exerted by various forms of butyric acid (SB, CSB, and BAG). The addition of CSB and BAG to turkey diets improved the feed conversion ratio (FCR, p < 0.05), increased the values of the European Efficiency Index (EEI, p < 0.01) and duodenal villus height (p < 0.05), and decreased the fecal populations of Escherichia coli and Clostridium perfringens (p < 0.05). Dietary supplementation with BAG increased protein digestibility (p < 0.05). The analyzed forms of butyrate added to turkey diets increased the butyric acid concentration in the cecal digesta (p < 0.01). The results of this study indicate that protected forms of butyric acid can be valuable feed additives in turkey nutrition.

Effects of coated sodium butyrate on performance, egg quality, nutrient digestibility, and intestinal health of laying hens

This study determined the effects of coated sodium butyrate (CSB) on production performance, egg quality, nutrient digestibility, and intestinal health of laying hens. We divided a total of 800 Lohmann laying hens, aged 51 wk, into 4 treatment groups: 0 (CON), 300 (CSB1), 500 (CSB2), and 800 (CSB3) mg/kg of CSB. Each group comprised 20 birds, with 10 replicates set. A 12-wk monitoring process was conducted for each laying hen. Compared to CON, dietary supplementation of CSB did not affect the average daily feed intake or the egg weight. The CSB3 group demonstrated a linear increase in the production performance (P < 0.05), with decreased feed conversion ratio (P < 0.05). CSB2 and CSB3 exhibited markedly elevated egg mass (P < 0.05). The CSB supplementation markedly enhanced the yolk color (P < 0.05). CSB1 improved the digestibility of dry matter (P = 0.029). No significant differences were observed among dietary treatments in the duodenal morphology (P > 0.05). The three dosages of CSB reduced the crypt depth (P < 0.05) in the jejunum, whereas CSB3 exhibited an increase in the villus height (VH; P = 0.048). The CSB3 group showed a markedly elevated ileal VH (P = 0.011). CSB supplementation significantly increased the butyric acid content in the cecum (P = 0.009). The hens fed on the 800 mg/kg CSB diet showed a significant increase (P = 0.029) in butyric acid content in the ileum. The CSB3 group showed an elevation in microbial diversity (P < 0.05). Additionally, at the phylum level, the CSB3 increased the enrichment of Bacteroidetes, the CSB2 increased Firmicutes, and the abundance of Deferribacteres was increased in CSB2 and CSB3 groups (P < 0.05). An enrichment of Muribaculaceae (family) was observed in the CSB3 group. In conclusion, dietary supplementation of CSB improved production, yolk color, intestinal morphology, butyrate content, and microbial composition in laying hens.

Effects of Coated Sodium Butyrate and Polysaccharides From Cordyceps cicadae on Intestinal Tissue Morphology and Ileal Microbiome of Squabs

This experiment was conducted to investigate the effects of dietary supplementation with different levels of coated sodium butyrate (CSB) and polysaccharides extracted from Cordyceps cicadae (CCP) on growth performance, intestinal tissue morphology and ileum microbiome in squabs. A total of 420 1-day-old squabs were randomly divided into seven groups with 5 replicates each and 12 squabs per replicate. The squabs were fed basal diet (control group) and basal diet supplemented with different levels of CSB (275, 550, and 1,100 mg/kg, groups CSB-275, CSB-550, CSB-1100) and CCP (27.5, 55, and 110 mg/kg, groups CCP-27.5, CCP-55, and CCP-110), respectively. The experiment was conducted for 28 days. The results revealed that the final BW and average daily gain concentration were higher (P < 0.05) in squabs of CSB-275 and CCP-110 groups than those in the CON group. Comparing with control group, the squabs in the groups CSB-275, CSB-550, and CCP-55 obtained higher villus height/crypt depth (VH/CD) of the duodenum and higher VH of the jejunum (P < 0.05). Operational taxonomic units in the groups CSB-550 and CCP-27.5 were also increased (P < 0.05). Regarding the relative abundance of flora, the Actinobacteria abundance in the groups CSB-550, CSB-1100, and CCP-55 were higher than in control group (P < 0.05), and the Aeriscardovia abundance of CSB-275, CSB-550, CSB-1100, and CCP-110 were elevated (P < 0.05). However, the Enterococcus abundance in CSB-275, CSB-550, CSB-1100, and CCP-27.5 decreased (P < 0.05). In summary, results obtained in the present study indicate that CSB and CCP can improve growth performance, intestinal microbial balance and gut health of squabs.

Impact of Dietary Sodium Butyrate and Salinomycin on Performance and Intestinal Microbiota in a Broiler Gut Leakage Model

Unfavorable alterations of the commensal gut microbiota and dysbacteriosis is a major health problem in the poultry industry. Understanding how dietary intervention alters the microbial ecology of broiler chickens is important for prevention strategies. A trial was conducted with 672 Ross 308 day-old male broilers fed a basic diet (no additives, control) or the basic diet supplemented with 500 mg/kg encapsulated butyrate or 68 mg/kg salinomycin. Enteric challenge was induced by inclusion of 50 g/kg rye in a grower diet and oral gavage of a 10 times overdose of a vaccine against coccidiosis. Compared to control and butyrate-supplemented birds, salinomycin supplementation alleviated growth depression. Compared to butyrate and non-supplemented control, salinomycin increased potentially beneficial Ruminococcaceae and reduced potentially pathogenic Enterobacteriaceae and counts of Lactobacillus salivarius and Clostridium perfringens. Further, salinomycin supplementation was accompanied by a pH decrease and succinic acid increase in ceca, while coated butyrate (0.5 g/kg) showed no or limited effects. Salinomycin alleviated growth depression and maintained intestinal homeostasis in the challenged broilers, while butyrate in the tested concentration showed limited effects. Thus, further investigations are required to identify optimal dietary inclusion rates for butyrate used as alternative to ionophore coccidiostats in broiler production.

Dietary sodium butyrate supplementation attenuates intestinal inflammatory response and improves gut microbiota composition in largemouth bass (Micropterus salmoides) fed with a high soybean meal diet

The study aimed to investigate the effects of dietary sodium butyrate (NaBT) supplementation on the gut health of largemouth bass (Micropterus salmoides) fed with a high soybean meal diet. Three isonitrogenous and isolipidic diets were formulated: a high fishmeal group (Control); a high soybean meal group (SBM), in which the 30% fishmeal protein in the Control diet was replaced by soy protein; and an NaBT group, in which 0.2% NaBT was added to the SBM diet. Each diet was fed to triplicate tanks (20 fish in each tank). After 8 weeks of feeding trial, the distal intestine and intestinal digesta of the fish in each treatment were sampled. The results showed that fishmeal replacement and NaBT supplementation did not affect fish growth performance. Dietary 0.2% NaBT supplementation improved intestinal morphology, increasing the villus width and villus height and reducing the width of lamina propria. The distal intestine of fish in the control and NaBT groups demonstrated lower activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GPx) and a lower malondialdehyde (MDA) content, compared with the fish in the SBM group. Moreover, the addition of 0.2% NaBT in the feed significantly decreased the expression of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) compared to the SBM diet. PCoA and UPGMA analyses based on weighted UniFrac distances demonstrated that intestinal microbial communities in the NaBT group were closer to those in the control group than to those in the SBM group. In addition, dietary 0.2% NaBT supplementation significantly increased the abundance of Firmicutes and Bacteroidetes and decreased the abundance of Tenericutes at the phylum level. Furthermore, the abundance of Bacteroides, Lachnospiraceae_unclassified, and Lachnospiraceae_uncultured was significantly increased, while that of Mycoplasma was significantly decreased in fish intestine at NaBT group at the genus level. In conclusion, dietary NaBT supplementation had beneficial roles in protecting the gut health of largemouth bass from the impairments caused by soybean meal.

The Impact of Tributyrin on Performance and Intestinal Health of Broiler Chickens Post Coccidiosis Vaccination

Coccidiosis is a major intestinal disease affecting broiler chickens. Tributyrin (TB) is a valid alternative to butyrate acid, which was associated with the improvement of performance and attenuation of intestinal inflammation in animal production. However, there are few reports on TB as a prophylactic treatment against coccidiosis in broilers. The aim of the study was to investigate the effects of TB supplementation on performance and intestinal health of broiler chickens post coccidiosis vaccination with a mixed-species Eimeria. In the first experiment, 612 broiler chicks were randomly assigned to two treatments with six replicates. Treatments included no TB supplementation and coccidiosis vaccination (CV1), or TB supplementation (400 mg/kg) and coccidiosis vaccination (TBCV1). On day 5, all broilers received a single vaccine dose. Performance, intestinal histopathology, clinical severity, and fecal oocyst counts were evaluated from day 1 to day 63. TB supplementation resulted in a nonsignificant effect on body weight gain (BWG), feed intake (FI), and mortality-corrected feed conversion ratio (FCR), except in increased FI on days 22-42 (P < 0.05). The TBCV1 group had increased (P < 0.05) villi heights in the duodenum and increased (P < 0.05) villi widths in the ileum on day 63 of age and reduced oocyst shedding on days 19-26 compared to CV1(P < 0.05). The route of administration in the second experiment was different from the first experiment in which the seeder birds (half of birds from each pen) received a tenfold dose on day 5. TB supplementation in broilers resulted in increased (P < 0.05) BWG and reduced (P < 0.05) FCR on days 22-42, and increased (P < 0.05) villi heights in the duodenum and increased (P < 0.05) villi widths in the ileum on day 63 of age, as well as a lower frequency (P < 0.05) of intestinal hemorrhage on days 13-62 and reduced (P < 0.001) oocyst shedding on day 5 post-Eimeria challenge. In conclusion, the study demonstrated that TB can be considered as a feed additive for protecting broilers from coccidiosis on days 22-42.

Effects of Clostridium butyricum, Sodium Butyrate, and Butyric Acid Glycerides on the Reproductive Performance, Egg Quality, Intestinal Health, and Offspring Performance of Yellow-Feathered Breeder Hens

Butyrate has been reported to promote the performance and growth of chickens. The specific roles and efficacy of different sources of butyrate remained unclear. Thus, the present study aimed to investigate and compare the effects of Clostridium butyricum (CB), sodium butyrate (SB), and butyric acid glycerides (tributyrin, BAG) on the reproductive performance, egg quality, intestinal health, and offspring performance of yellow-feathered breeder hens. A total of 300 Lingnan yellow-feathered breeder hens were assigned to five treatment groups: control (CL), 1×10⁸CFU/kg CB (CBL), 1×10⁹CFU/kg CB (CBH), 500mg/kg SB, and 300mg/kg BAG. Results showed that the laying performance and egg quality were increased by CBL, CBH, and BAG. Both CB treatments increased the hatchability of fertilized eggs. Maternal supplementation with both levels of CB significantly elevated the growth performance of offspring. Treatment with CBL, CBH, SB, and BAG all improved the oviduct-related variables and reduced the plasmal antioxidant variables. The CBH, CBL, and BAG treatments also improved the intestinal morphology to different degrees. Jejunal contents of IL-6 were decreased by CBH and BAG, while those of IL-4, IL-6, IL-1β, and IgY were decreased by SB. Transcripts of nutrient transporters in jejunal mucosa were also upregulated by CBH, CBL, and SB treatments and expression of Bcl-2-associated X protein was decreased by CBL, CBH, and BAG. In cecal contents, CBL increased the abundance of Firmicutes and Bacillus, while CBH decreased the abundance of Proteobacteria. Also, the co-occurrence networks of intestinal microbes were regulated by CBH and BAG. In conclusion, dietary inclusion of CB and BAG improved the reproductive parameters, egg quality, and intestinal morphology of breeders. CB also influenced the hatching performance of breeders and growth performance of the offspring, while SB improved the oviduct-related variables. These beneficial effects may result from the regulation of cytokines, nutrient transporters, apoptosis, and gut microbiota; high-level CB had more obvious impact. Further study is needed to explore and understand the correlation between the altered gut microbiota induced by butyrate and the performance, egg quality, intestinal health, and also offspring performance.

Dietary tributyrin improves reproductive performance, antioxidant capacity, and ovary function of broiler breeders

The objective of this experiment was to investigate the influence of dietary tributyrin on reproduction performance and ovary function of broiler breeders with different egg laying rate. Two hundred fifty-six AA broiler breeders (48-wk-old) were allocated to 4 treatment in a 2 × 2 factorial arrangement with the main effects of tributyrin supplementation (0 and 1,000 mg/kg tributyrin [TRI]) and 2 egg laying rate levels (average [AR, 81.01 ± 0.79%] and low [LR, 70.98 ± 0.95%]). The results shown that the LR breeders presented higher egg weight, but lower egg laying rate, qualified egg rate and feed efficiency than the AR breeders (P_(laying) < 0.05). Also, the superoxidase dismutase (SOD) activity in magnum was lower while malondialdehyde (MDA) was higher in ovary and magnum of LR breeders than that in the AR breeders (P_(laying) < 0.05). Dietary supplementation with tributyrin significantly enhanced egg weight (P_(TRI) < 0.05), increased albumen height as well as Haugh unit (HU) in AR breeders (P_{(interaction)} < 0.05), and also had higher total antioxidant capacity (T-AOC) and lower MDA in ovary (P_(TRI) < 0.05). The cell apoptosis rate and proapoptosis related gene expression (caspase 8, 9 and Bax) in the ovary of LR breeders was higher, while anti-apoptosis related gene (Bcl-2) expression were lower in LR breeders when compared with the AR breeders (P_(laying) < 0.05). Dietary supplementation with tributyrin decreased the cell apoptosis rate and downregulated caspase 9 expression in LR breeders (P_{(Interaction)} < 0.05), up-regulated the Bcl-2 expression in both 2 breeders (P_(TRI) < 0.05). These findings suggest that the breeders with lower egg laying rate also characterized by deteriorate ovary function indicated by lower antioxidant capacity and higher cell apoptosis rate. Dietary supplementation with tributyrin increased egg albumen quality, decreased ovarian proapoptosis related gene expression to improve reproductive tract function; and the positive effect on egg albumen quality is more pronounced in average reproductive breeders.

The effect of different medium chain fatty acids, calcium butyrate, and salinomycin on performance, nutrient utilization and gastrointestinal tract of chicken of Polish Green Legged Partridge hen

The present study aimed to determine the effect of diets supplemented by feed additives, on the growth performance and digestive tract functioning in chicken of green-legged partridge hen (GLPH). Two types of diets were used. The both “low-digestible” (LD) diet characterized by high level of crude fibre and lard, and “high-digestible” (HD) diet characterized by low content of crude fibre and soybean oil were supplemented by different additives such as 0,34% DM (dry matter) salinomycin, 0,30 % DM medium-chain triglycerides (MCT), 1,00 % DM calcium butyrate (CB), or 0,85 % DM medium-chain fatty acids (MCFA). The experiment was conducted on 960 one-day-old male chickens of GLPH, randomly divided into 10 treatment groups. One group consisted of 12 replications (each with 8 birds). Chickens fed HD diet presented significantly higher body weight gain (BWG) in 15-56 days and also 0-56 days of experiment and lower feed conversion ratio (FCR) during whole time (0-56 days) of experiment (P < 0.05). Addition of CB and MCFA did not affect the differences in BWG (15-56; 0-56 days) and FCR (15-56 days) in comparison with the control diet. Significant interaction between the type of diet and additives (P < 0.05) was observed for feed intake (FI) throughout the experiment. The highest FI was found on LD diet with CB. On LD diet, all additives resulted in significantly worse nitrogen retention, however, on HD diet, it was observed only for salinomycin. The additives had no impact on fat digestibility when chickens were fed HD diet. There was significant (P < 0.05) lower-fat digestibility when LD diet with MCT, CB, and MCFA was used. The greatest value of nitrogen-corrected apparent metabolizable energy (AMEN) was found on HD diet (P < 0.05). The addition of MCT, CB, and MCFA increased the percentage share of ileum, and MCT also significantly increased the percentage share of the liver. The lactic acid bacteria and C. perfringens counts were lower on HD diet (P<0,05). The addition of MCT and CB increased the count of lactic acid bacteria in ceaca (P<0,05). Many interactions between experimental factors in this experiment showed that the efficacy of using different feed additives depends on the type of diet. The results suggest that MCFA may be the most beneficial feed additive for GLPH chicken as an alternative for antibiotic growth promoters (AGP).

Differences in Immune Response and Biochemical Parameters of Mice Fed by Kefir Milk and Lacticaseibacillus paracasei Isolated from the Kefir Grains

The health benefits of kefir consumption have been well-known for hundreds of years. The objective of this study was to investigate the effect of kefir milk and the probiotic strain Lacticaseibacillus paracasei Ž2 isolated from kefir grains on the immune response and selected parameters of the lipid and liver enzymatic profiles of mice. Mice fed with kefir milk showed significantly increased phagocytic activity and percentages of B cells in the blood and increased gene expression for mucins and percentages of CD8+ lymphocytes in the gut. By applying kefir, we achieved a significant reduction in serum LDL cholesterol and an LDL/HDL ratio that favored an increase in HDL cholesterol. Regarding the hepatic enzymes, in particular a significant reduction in ALT activity was observed. L. paracasei Ž2 alone stimulated the immune response more markedly compared with kefir milk. Regarding the systemic level, we observed increases in the proportion of all T cells (CD3⁺), CD4⁺ lymphocytes and the ratio of CD4+:CD8+ cells, and regarding the local intestinal level we noted a significant increase in gene expression for mucins (MUC-1 and MUC-2) and IgA. Moreover, we confirmed the formation of a biofilm on the surface of the forestomach only after the application of L. paracasei Ž2 alone, but not after kefir administration. The results confirmed the hypothesis that the final effect of the probiotic does not correspond with the effect of the individual strain but is the result of mutual interactions of the microorganisms presented in a preparation, and therefore in the case of multi-strain probiotics, in vivo testing of the complex preparation is necessary.

Impact of multi-strain probiotic, citric acid, garlic powder or their combinations on performance, ileal histomorphometry, microbial enumeration and humoral immunity of broiler chickens

Heat stress, one of the critical obstacles to poultry sector in subtropical and tropical countries, reduces performance, immune response, and animal welfare. This study examined the effect of dietary inclusion of probiotic (PRO), citric acid (CIT), garlic powder (GAR) or their combinations on growth, blood constituents, ileal microflora and morphology and humoral immunity of broiler chickens subjected to cyclic heat stress. Four hundred ninety one-day-old Ross-308 broiler chicks were randomly allocated to 7 groups with 7 replicates of 10 birds each as follows: control (C) group received the basal diet without supplements, PRO, CIT and GAR groups supplemented with 0.5 g kg^-1 multi-strain probiotic mixture (MPM), citric acid and garlic powder, respectively. PRO-CIT and PRO-GAR groups treated with 0.5 g kg^-1 MPM, and 0.5 g kg^-1 citric acid and garlic powder, while CIT-GAR group fed diet with 0.5 g kg^-1 of citric acid and garlic powder. Results revealed that dietary supplements and their combinations improved (P < 0.001) growth performance and decreased abdominal fat of heat-stressed birds. Dietary supplements decreased (P < 0.01) serum concentrations of cholesterol, triglycerides and LDL, while HDL was elevated (P < 0.05). Feed additives reduced (P < 0.01) ileal enumeration of Escherichia coli and total coliform while Lactobacillus count was increased (P < 0.05) only in MPM-enriched groups. Supplementation of these natural products improved (P < 0.01) ileal architecture while humoral immune response was not significantly influenced except antibody titre against Newcastle disease virus which was increased (P < 0.05) in MPM-supplemented groups. Conclusively, addition of the dietary supplements and their combinations, particularly, probiotic and citric acid combination can improve productive performance, and intestinal flora and histomorphometry of broilers exposed to cyclic heat stress.

Changes in the ceca microbiota of broilers vaccinated for coccidiosis or supplemented with salinomycin

The objective of this study was to characterize differences in the cecal microbiota of chickens vaccinated for coccidiosis or receiving salinomycin in the diet. In this study, 140 male 1-day-old broiler chickens were divided in 2 groups: vaccine group (live vaccine) vaccinated at the first day and salinomycin group (125 ppm/kg since the first day until 35 d of age). Each treatment was composed for 7 replicates of 10 birds per pen. At 28 d, the cecal content of one bird per replicate was collected for microbiota analysis. The genetic sequencing was conducted by the Miseq Illumina platform. Vaccine group showed lower body weight, weight gain, and poorer feed conversion in the total period (P < 0.05). Bacterial 16S rRNA genes were classified as 3 major phyla (Bacteroidetes, Firmicutes, and Proteobacteria), accounting for more than 98% of the total bacterial community. The microbiota complexity in the cecal was estimated based on the α-diversity indices. The vaccine did not reduce species richness and diversity (P > 0.05). The richness distribution in the salinomycin group was larger and more uniform than the vaccinated birds. Salinomycin group was related to the enrichment of Bacteroidetes, whereas Firmicutes and Proteobacteria phyla were in greater proportions in the vaccine group. The last phylum includes a wide variety of pathogenic bacteria. The vaccine did not decrease the species richness but decreased the percentage of Bacteroidetes, a phylum composed by genera that produce short-chain fatty acids improving intestinal health. Vaccine group also had higher Proteobacteria phylum, which may help explain its poorer performance.

Effects of monobutyrin supplementation on egg production, biochemical indexes, and gut microbiota of broiler breeders

The objective of the present study was to determine the effect of monobutyrin supplementation on egg production, biochemical indexes, and gut microbiota of broiler breeders at the late stage of production. A total of 180 healthy Qingyuan partridge broilers were randomly assigned to 2 groups: 1) corn-soybean meal-based diet and 2) basal diet supplemented with 250 mg monobutyrin/kg. Each treatment group had 6 replicates/cages with 15 birds within each replicate. The experiment started at week 33 and lasted for 8 wk. Egg production rate, feed conversion rate, shell breaking strength, and shell thickness were not different between control and treatment groups. Supplementation of monobutyrin increased egg weight and tended to decrease egg breaking rate of Qingyuan partridge chickens. Supplementation of monobutyrin did not affect any of the biochemical indexes except total protein concentration. The 4 antioxidant parameters measured were not affected either. Alpha diversity indexes (Shannon, Simpson, Chao1, Ace, and Good's Coverage) and composition of cecal microbiota were not affected by monobutyrin supplementation. Overall, supplementation of monobutyrin at 250 mg/kg level improved egg quality, but its effect on cecal microbiota composition was limited.

Combination of Bacillus licheniformis and Salinomycin: Effect on the Growth Performance and GIT Microbial Populations of Broiler Chickens

Simple Summary

The beneficial effects of Bacillus spp. probiotic preparations used for poultry are well-documented and characterized by growth performance improvement and positive modulation of gastrointestinal tract (GIT) microbiota. Moreover, the favorable influence of salinomycin has been frequently studied as an ionophore coccidiostat, as well as an antimicrobial agent. However, limited data are available in terms of the parallel usage of both Bacillus licheniformis DSM 28710 and salinomycin in poultry diets. From a practical point of view, evaluating the potential interactions between this species and agent is crucial to assess their parallel usage, and the current study confirmed the positive effect of their mixture on the modulation of pH value in the crop and ceca, as well as the GIT microbiota, especially in the jejunum and ceca. Additionally, the results obtained in this study show positive effects of B. licheniformis on the growth performance, as well as the influence of both experimental factors used separately in the case of GIT microbiota modulations.

Abstract

The aim of the study was to investigate the effect of Bacillus licheniformis and salinomycin supplementation in broiler diets as individual factors or in combination on the growth performance, GIT morphometry, and microbiota populations. Four hundred one-day-old Ross 308 chicks were randomly distributed to four dietary treatments (10 replicates, 10 birds each). The following treatments were applied: NC—no additives; NC + SAL—salinomycin addition (60 mg/kg diet), NC + PRO—B. licheniformis DSM 28710 preparation (1.6 × 10⁹ CFU/kg; 500 mg/kg diet), and NC + SAL + PRO—combination of salinomycin and B. licheniformis. Probiotic administration resulted in improvement (p < 0.05) of the performance parameters, including body weight gain (1–10 d, and 11–22 d) and feed conversion ratio (11–22 d, 1–36 d). An interaction (p < 0.05) between experimental factors was observed in terms of lower pH values in the crop (tendency, p = 0.053) and ceca. Both factors lowered the alpha diversity and Enterobacteriaceae and promoted Bacillaceae communities in the jejunum (p < 0.05). Interactions were also observed in terms of reducing Clostridiaceae in the ceca. In conclusion, the combined use of B. licheniformis and salinomycin in broilers’ diets had beneficial effects.

Effect of Sodium Butyrate on Intestinal Health of Poultry – A Review

Health of the intestine is one of the main reasons that affects the bird’s performance, and thus the economic yield in the poultry sector. Various studies have examined how to improve the intestinal health using dietary supplements, including organic acids such as sodium butyrate (SB). The efficacy of the dietary supplementation in poultry is often assessed using an important parameter such as intestinal integrity, which is often assessed as a measure of high villus height and the ratio of villus height to crypt depth, or count of goblet cell numbers. In broilers, the villus length and width were increased by the addition of dietary SB. Since, at day 21 and 42, the villus length was increased by 55 and 27%, and 39 and 18% for birds fed 0.5 and 1 g/kg, respectively, compared with the control diet. Furthermore, SB plays an important role in development of poultry intestinal epithelium. It can be employed by the intestinal epithelial cells as an energy source to stimulate their differentiation and proliferation, and to improve intestinal barrier function. SB is effective against acid intolerant species such as Salmonella, Clostridium perfringens and E. coli. In addition, use of butyric acid at 0.6% reduced the pH of gastrointestinal segments. For this, SB could be a potential alternative in maintaining the health of gastrointestinal tract and improving the productive performance of poultry. This review refers to the expanding horizons in the research on SB supplementation in poultry health and nutrition.

Effects of Bacillus subtilis and coccidial vaccination on cecal microbial diversity and composition of Eimeria-challenged male broilers

In a companion study, the effects of dietary antibiotic alternative and coccidial vaccination on the growth performance of male broilers have been reported. In this paper, the effects of dietary probiotics and coccidial vaccination on diversity and composition of cecal microbiota were investigated using a 3 (diets) × 2 (vaccinated or non-vaccinated) factorial setting of treatments. Three diets, including a corn and soybean-meal control diet, an antibiotic diet (a control diet supplemented with bacitracin and salinomycin), and a probiotic diet (a control diet supplemented with Bacillus subtilis) were provided to broiler chicken from day 0 to 42. To simulate an Eimeria challenge in the field, all chicks were gavaged with a 20× dose of commercial coccidial vaccine containing live Eimeria oocysts on day 14. Cecal contents were collected on day 42. High-throughput sequencing of the 16S rRNA gene was used to determine microbial diversity and composition. Coccidial vaccination to broilers reduced bacterial diversity (Shannon index) of the cecal microbiota. There was a significant interaction between the dietary additive and coccidial vaccination on the observed bacterial species number. Diets supplemented with B. subtilis increased bacterial species of non-vaccinated broilers but decreased bacterial species of vaccinated broilers. In contrast, diets supplemented with antibiotics reduced bacterial species of broilers from both groups. Interactions between dietary additive and coccidial vaccination were also observed on microbial composition. Vaccinated broilers fed the B. subtilis diet exhibited the lowest Firmicutes percentage and highest Bacteroidetes percentage within the microbial community. In addition, vaccinated broilers fed the B. subtilis diet exhibited the highest Rikenella microfusus percentage. From this study, the coccidial vaccination on the day of hatch reduced the microbial diversity of broilers at a later age. The inclusion of B. subtilis-probiotics in the feed of vaccinated broilers may reduce microbial diversity in cecal content by increasing the proportion of a predominant bacterial species, R. microfusus, in the microbial community.

Effects of Partial Replacement of Soybean Meal With Rapeseed Meal, Narrow-Leaved Lupin, DDGS, and Probiotic Supplementation, on Performance and Gut Microbiota Activity and Diversity in Broilers

This study examines the impact of soybean meal (SBM) substitutes, including solvent-extracted 00 rapeseed meal (RSM), narrow-leaved lupin (LUPIN), and distillers dried grains with solubles (DDGS) (each used at a ratio of 250 g/kg−1 in the diet), as well as administered probiotic (L. casei, L. plantarum, Rhodopseudomonas palustris, S. cerevisiae), on gut microbiota activity, diversity and performance. The experimental treatments were arranged in a 4 × 2 factorial design, with the factors being protein source in the diets (SBM only, RSM, LUPIN or DDGS) given from 8 to 35 days of age, and with or without a probiotic preparation administered in drinking water during the entire rearing period. The performance declined in birds fed with SBM substitutes (P≤0.01). The RSM diet decreased concentration of short chain fatty acids (SCFAs) (P<0.01) in ileal and caecal digesta as well as decreased bacterial enzymes activity in the caeca. The LUPIN diet increased viscosity and decreased SCFAs concentration in ileum, while the DDGS diet increased butyrate concentration in caeca. SBM substitutes and probiotic were involved in changing the Clostridiales and Lactobacillales diversity in the ileal and caecal digesta. Probiotic administration did not affect performance, but it did alleviate some negative effects of SBM substitutes on microbiota activity and diversity.

Differential Impact of Subtherapeutic Antibiotics and Ionophores on Intestinal Microbiota of Broilers

Antimicrobial growth promoters (AGPs) are commonly used in the livestock industry at subtherapeutic levels to improve production efficiency, which is achieved mainly through modulation of the intestinal microbiota. However, how different classes of AGPs, particularly ionophores, regulate the gut microbiota remains unclear. In this study, male Cobb broiler chickens were supplemented for 14 days with or without one of five commonly used AGPs including three classical antibiotics (bacitracin methylene disalicylate, tylosin, and virginiamycin) and two ionophores (monensin and salinomycin) that differ in antimicrobial spectrum and mechanisms. Deep sequencing of the V3-V4 region of the bacterial 16S rRNA gene revealed that two ionophores drastically reduced a number of rare bacteria resulting in a significant decrease in richness and a concomitant increase in evenness of the cecal microbiota, whereas three antibiotics had no obvious impact. Although each AGP modulated the gut microbiota differently, the closer the antibacterial spectrum of AGPs, the more similarly the microbiota was regulated. Importantly, all AGPs had a strong tendency to enrich butyrate- and lactic acid-producing bacteria, while reducing bile salt hydrolase-producing bacteria, suggestive of enhanced metabolism and utilization of dietary carbohydrates and lipids and improved energy harvest, which may collectively be responsible for the growth-promoting effect of AGPs.

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.

Effect of a butyrate-fortified milk replacer on gastrointestinal microbiota and products of fermentation in artificially reared dairy calves at weaning

Enrichment of calf diets with exogenous butyrate has shown promise as a promotor of calf growth and intestinal development. However, the impact of dietary derived butyrate on the gut microbiota and their potential role, in turn, as mediators of its effect on calf growth and development is not known. Here, the effects of butyrate supplementation on rumen and hindgut microbiota and fermentation profiles were assessed in 16 Holstein-Friesian bull calves randomly assigned to one of two groups: Control (CON) fed conventional milk replacer or Sodium-Butyrate (SB – added to milk replacer) from days 7 to 56 of life. In the colon, total short chain fatty acid (SCFA), propionate and acetate concentrations were increased by SB (P < 0.05). 16S rRNA gene amplicon sequencing showed cecal abundance of butyrate producers Butyrivibrio and Shuttleworthia were decreased by SB (P < 0.05), while that of the propionate producer Phascolarctobacterium was higher (P < 0.05). Mogibacterium is associated with impaired gut health and was reduced in the cecum of SB calves (P < 0.05). These data show that the beneficial effects of SB on growth and performance occur in tandem with changes in the abundance of important SCFA producing and health-associated bacteria in the hindgut in milk-fed calves.

Immunomodulation and effects on microbiota after in ovo administration of chicken cathelicidin-2

Host Defense Peptides (HDPs) such as cathelicidins are multifunctional effectors of the innate immune system with both antimicrobial and pleiotropic immunomodulatory functions. Chicken cathelicidin-2 (CATH-2) has multiple immunomodulatory effects in vitro and the D-amino acid analog of this peptide has been shown to partially protect young chicks from a bacterial infection. However, the mechanisms responsible for CATH-2 mediated in vivo protection have not been investigated so far. In this study, D-CATH-2 was administered in ovo and the immune status and microbiota of the chicks were investigated at 7 days posthatch to elucidate the in vivo mechanisms of the peptide. In three consecutive studies, no effects on numbers and functions of immune cells were found and only small changes were seen in gene expression of Peripheral Blood Mononuclear Cells (PBMCs). In two studies, intestinal microbiota composition was determined which was highly variable, suggesting that it was strongly influenced by environmental factors. In both studies, in ovo D-CATH-2 treatment caused significant reduction of Ruminococcaceae and Butyricicoccus in the cecum and Escherichia/Shigella in both ileum and cecum. In conclusion, this study shows that, in the absence of an infectious stimulus, in ovo administration of a CATH-2 analog alters the microbiota composition but does not affect the chicks' immune system posthatch.

Dietary sodium butyrate improves intestinal development and function by modulating the microbial community in broilers

This study investigated the effects of dietary sodium butyrate (SB) supplementation, provided as a specially coated product, on growth performance, intestinal development, morphological structure and function in broilers. In total, 720 one-day-old Arbor Acres male broilers were randomly allocated into six treatment groups with six replicates each and then fed basal diets (control) supplemented with 0, 200, 400, 800 or 1000 mg/kg of SB or with antibiotics (100 mg/kg aureomycin and 20 mg/kg colistin sulfate). The growth trial lasted for 42 days. No differences (P>0.05) in growth performance were detected between groups during the grower period (1–21 d) or over the total (1–42 d) trial period, whereas the addition of SB improved the intestinal structure by stimulating (P<0.05) goblet cells on jejunal and ileal villi accompanied by a trend towards increased (P_diets<0.10) ileal villus height. In addition, more inerratic leaf-shaped villi and mucus secretion and significantly fewer erosions were demonstrated by scanning electron microscopy. Apart from decreased (P<0.05) malondialdehyde (MDA) in the ileal mucosa at 21 d of age, supplemental SB at higher doses (800 mg/kg) led to greater (P<0.05) total antioxidant capacity and depressed (P<0.05) MDA concentrations in the jejunal mucosa. Birds fed with 400 mg/kg and 800 mg/kg SB had higher (P<0.05) acetic acid concentrations at 42 d and higher butyric acid at 21 d in the jejunum chyme. Morever, chicks fed SB diet were found to have higher concentrations of butyric acid (P<0.05) in the ileal chyme. SB additions at 400 mg/kg displayed higher Firmicutes and Proteobacteria levels, while a higher (P<0.05) relative abundance of Bacteroidetes was observed at 800 mg/kg. Furthermore, we found a striking decrease in Enterobacteriaceae and increases in Lachnospiraceae and Rikenellaceae in the cecal lumen of birds fed 800 mg/kg SB as well as a higher proportion of Ruminococcaceae and a noticeable reduction (P<0.05) of Lactobacillaceae in birds treated with 400 mg/kg SB. Taken together, our results support the importance of SB in improving the intestinal development, morphological structure and biological functions of broilers through modulation of the microbial community, which seems to be optimized for gut health at higher doses (800 mg/kg) of SB.

Diet supplementation with an organic acids-based formulation affects gut microbiota and expression of gut barrier genes in broilers

This study was designed to study the effect of diet supplementation with an organic acids-based formulation (OABF) on luminal- and mucosa-associated bacteria, concentration of volatile fatty acids (VFA), microbial glycolytic enzyme activity and expression of mucin 2 (MUC2), immunoglobulin A (IgA) and tight junction protein, i.e., zonula occludens-1 (ZO1), zonula occludens-2 (ZO2), claudin-1 (CLDN1), claudin-5 (CLDN5) and occludin (OCLN), genes at the ileal and cecal level. A 2 × 2 factorial design was used having OABF inclusion and avilamycin as main factors. Subsequently, 544 day-old male Cobb broilers were allocated in the following 4 treatments, each with 8 replicates: no additions (CON), 1 g OABF/kg diet (OA), 2.5 mg avilamycin/kg diet (AV) and combination of OA and AV (OAAV). The trial lasted for 42 days. In the ileum, OAAV resulted in lower mucosa-associated total bacteria levels (P_{O × A} = 0.028) compared with AV. In addition, ileal digesta levels of Clostridium perfringens subgroup were decreased by avilamycin (P_A = 0.045). Inclusion of OABF stimulated the activity of microbial glycolytic enzymes, whereas avilamycin resulted in lower acetate (P_A = 0.021) and higher butyrate (P_A = 0.010) molar ratios. Expression of ZO1 and CLDN5 was down-regulated by both OABF (P_O = 0.016 and P_O = 0.003, respectively) and avilamycin (P_A = 0.016 and P_A = 0.001, respectively). In addition, CLDN1 was down-regulated in AV compared with CON (P_{O × A} = 0.012). Furthermore, OABF down-regulated MUC2 (P_O = 0.027), whereas avilamycin down-regulated nuclear factor kappa B subunit 1 (NFKB1) (P_A = 0.024), toll-like receptor 2 family member B (TLR2B) (P_A = 0.011) and toll-like receptor 4 (TLR4) (P_A = 0.014) expression. In the ceca, OABF inclusion increased digesta levels of Clostridium coccoides (P_O = 0.018) and Clostridium leptum (P_O = 0.040) subgroups, while it up-regulated MUC2 expression (P_O = 0.014). Avilamycin (P_A = 0.044) and interaction (P_O × A < 0.001) effects for IgA expression were noted, with CON having higher IgA expression compared with AV. In conclusion, new findings regarding OABF inclusion effects on an array of relevant biomarkers for broiler gut ecology have been reported and discussed in parallel with avilamycin effects used as a positive control. This new knowledge is expected to provide a response baseline for follow up trials under various stress and challenge conditions.

Dietary butyrate glycerides modulate intestinal microbiota composition and serum metabolites in broilers

Butyrate can modulate the immune response and energy expenditure of animals and enhance intestinal health. The present study investigated changes in the intestinal microbiota composition and serum metabolites of young broilers in response to 3,000 ppm butyrate in the form of butyrate glycerides (BG) via pyrosequencing of bacterial 16S rRNA genes and nuclear magnetic resonance (NMR). The dietary treatment did not affect the alpha diversity of intestinal microbiota, but altered its composition. Thirty-nine key operational taxonomic units (OTUs) in differentiating cecal microbiota community structures between BG treated and untreated chickens were also identified. Bifidobacterium was, in particular, affected by the dietary treatment significantly, showing an increase in not only the abundance (approximately 3 fold, P ≤ 0.05) but also the species diversity. The (NMR)-based analysis revealed an increase in serum concentrations of alanine, low-density and very low-density lipoproteins, and lipids (P ≤ 0.05) by BG. More interestingly, the dietary treatment also boosted (P ≤ 0.05) serum concentrations of bacterial metabolites, including choline, glycerophosphorylcholine, dimethylamine, trimethylamine, trimethylamine-N-oxide, lactate, and succinate. In conclusion, the data suggest the modulation of intestinal microbiota and serum metabolites by BG dietary treatment and potential contribution of intestinal bacteria to lipid metabolism/energy homeostasis in broilers.

The Influence of Supplementation of Feed with Lactobacillus reuteri L2/6 Biocenol on Intestinal Microbiota of Conventional Mice

FISH (fluorescence in situ hybridization) analysis of the intestinal tract of conventional mice, following 14-day supplementation of feed with host non-specific (porcine) strain L. reuteri L2/6, showed in the presence of complex microbiota, a significant increase in the counts of representatives of the genera Lactobacillus and Bifidobacterium, and a significant decrease in the representatives of the genera Clostridium, Bacteroides and Enterobacteriaceae. At the same time, the supplemented strain stimulated the population of caecal lactobacilli of the species L. reuteri. These results demonstrated that the L. reuteri L2/6 colonised the jejunum, ileum and caecum and modulated the investigated intestinal microbiota.

Sodium butyrate mitigates in vitro ammonia generation in cecal content of laying hens

One of the environmental challenges that modern poultry industry faced is odor pollution caused by ammonia emission. The objectives of the study were to determine the effect of sodium butyrate on the production of ammonia in the cecal contents of laying hens using in vitro gas production study and to elucidate the mechanism behind it. The study consisted of a control (without sodium butyrate), and three experimental groups added with 10, 15, and 20 mg of sodium butyrate, respectively. Results showed that ammonia production in headspace of the syringe decreased by 8.2, 23, and 23 %, respectively, while ammonium production from the fermentation broth decreased by 6.3, 14.4, and 13.7 %, respectively. Sodium butyrate had no significant effect on the contents of uric acid and urea, nitrate-N, or total N in all treatments. However, sodium butyrate decreased the urease and uricase activities (P < 0.05) in the fermentation broth. Sodium butyrate also altered volatile fatty acids profile of the fermentation broth by decreasing the production of isovalerate (P < 0.05) and increasing those of acetate, butyrate, and isobutyrate (P < 0.05). The MiSeq System Sequencing results showed that sodium butyrate increased the relative abundance of Bacteroides and Faecalibacterium (P < 0.05) and decreased the relative abundance of Desulfovibrio, Helicobacter, and Campylobacter (P < 0.05).Our results concluded that sodium butyrate changes the diversity and relative abundance of the microbes which altered the fermentation characteristics leading to reduction in ammonia production.

The Role of Coated Sodium Butyrate on Performance of Broilers Fed High Protein and Reduced Energy Diets

Addition of butyrate or its salt has been reported to have a positive impact on growth performance in broilers due to its bactericidal and bacteriostatic properties. This study investigated the effect of enterically coated dietary sodium butyrate (SB) on broiler performance. In experiment 1, 408 day-old male Ross 308 chicks were used in a 2 × 2 factorial design. Factors were dietary energy (standard or minus 50 kcal/kg relative to standard diet) and coated SB level (0 and 1 g/kg). In experiment 2, 2160 day-old male Cobb 500 birds were used in a 2 × 2 × 2 factorial plus one arrangement of treatments. Factors included grain source (corn or wheat); protein level (standard or high); coated SB level (0 and 1 g/kg) plus a treatment using 2 kg SB in a high protein wheat-based diet. The results from the experiments showed no effect of coated SB on performance at 1 g/kg inclusion in feed across the ME range or across basal diet type (grain) or protein level (P > 0.05). However, birds fed the high protein wheat diet with 2 g/kg SB had higher body weights than the control birds at 10 and 24 days old. Birds fed high protein diets had lower body weight gain (WG) than those fed standard protein diets (P < 0.05), whereas birds fed corn based diets had higher WG than those fed wheat based diets (P < 0.05). Birds fed high dietary protein or wheat based diet showed decreased pH of caecal contents. The results indicated that dietary coated SB had no effect on broiler performance, the concentration of caecal and ileal short chain fatty acids (SCFA) or intestinal pH. Higher inclusion levels may play a beneficial role but this warrants further investigation.

Effect of different doses of coated butyric acid on growth performance and energy utilization in broilers

We recently applied four dietary treatments in experiments I and II to determine the effect of protected calcium butyrate (BP) on growth performance and nutrient digestibility in broiler chickens. A group of one-day-old male Ross 308 broiler chicks (total 960, 480 per trial) were used in the study. In experiment I, the basal diets were fed with protected BP inclusion (0.2, 0.3, or 0.4 g/kg of finished feed) (BP) or without (C). In experiment II, 4 different diets were tested: 1) basal diet with no supplementation (C), 2) basal diet supplemented with protected BP (0.3 g/kg) (BP), 3) basal diet supplemented with avilamycin (6 mg/kg, active substance) a common antibiotic growth promoter (AGP) (Av), and 4) basal diet supplemented with the combination of both avilaymicin and BP. In experiment I, considering the entire study period, the use of BP improved feed conversion ratio (P<0.05) irrespective of the dose. Apparent total tract crude fat digestibility and apparent metabolizable energy corrected for nitrogen (AMEN) were improved after BP supplementation (P<0.05). In experiment II, A or AB diets improved (P<0.05) body weight gain compared to the control treatment. The diets Av, BP, and AvB improved (P<0.05) feed conversion ratio compared to the control treatment. Birds from the treatment diet were characterized by having the thickest mucosa (P<0.05). On days 14, 35, and 42, the use of AB diets improved AMENcontent compared to the control treatment (P<0.05). The apparent ileal digestibility of amino acid data showed that Av or AvB treated birds were characterized by higher Asp, Glu, Cys, Gly, and Ala ileal digestibility than the control animals (P<0.05). The use of Av, BP, or AvB increased ileal digestibility of Thr, Ser, and Pro (P<0.05). There is an indication that BP, alone or in combination with avilamycin, improve the digestion and absorptive processes and consequently birds performance results.

Effects of Tributyrin on Intestinal Energy Status, Antioxidative Capacity and Immune Response to Lipopolysaccharide Challenge in Broilers

This study was carried out to investigate the effects of tributyrin (TB) on the growth performance, pro-inflammatory cytokines, intestinal morphology, energy status, disaccharidase activity, and antioxidative capacity of broilers challenged with lipopolysaccharide (LPS). A total of 160 one-day-old Cobb broilers were allocated to 1 of 4 treatments, with 4 replicated pens per treatment and 10 birds per pen. The experiment consisted of a 2×2 factorial arrangements of treatments with TB supplementation (0 or 500 mg/kg) and LPS challenge (0 or 500 μg/kg body weight [BW]). On days 22, 24, and 26 of the trial, broilers received an intraperitoneal administration of 500 μg/kg BW LPS or saline. Dietary TB showed no effect on growth performance. However, LPS challenge decreased the average daily gain of broilers from day 22 to day 26 of the trial. Dietary TB supplementation inhibited the increase of interleukin-1β (in the jejunum and ileum), interleukin-6 (in the duodenum and jejunum), and prostaglandin E₂ (in the duodenum) of LPS-challenged broilers. Similar inhibitory effects of TB in the activities of total nitric oxide synthase (in the ileum) and inducible nitric oxide synthase (in the jejunum) were also observed in birds challenged with LPS. Additionally, TB supplementation mitigated the decrease of ileal adenosine triphosphate, adenosine diphosphate and total adenine nucleotide and the reduction of jejunal catalase activity induced by LPS. Taken together, these results suggest that the TB supplementation was able to reduce the release of pro-inflammatory cytokines and improve the energy status and anti-oxidative capacity in the small intestine of LPS-challenged broilers.

Diet structure, butyric acid, and fermentable carbohydrates influence growth performance, gut morphology, and cecal fermentation characteristics in broilers

An experiment with 288 male (Ross 308) 1-d-old broilers was conducted to test the hypothesis that a coarse diet supplemented with butyric acid (BA) and fermentable carbohydrates (FC) improves performance of broilers with a poorly digestible protein source. The interaction effects of diet structure (fine or coarse), FC supplementation (with or without), and BA supplementation (with or without) in a poorly digestible diet based on rapeseed meal (RSM) were tested in a factorial arrangement of 8 (2×2×2) dietary treatments. The coarseness of the diet affected feed intake (FI) (P<0.001), BW gain (P=0.001), and the feed conversion ratio (FCR) (P=0.001) positively. Broilers fed the coarse diets had, on average, 14% heavier gizzards and 11, 7, 5, and 6% lower relative empty weights of the crop, duodenum, jejunum, and ileum, respectively, compared with those fed the fine diets. Dietary coarseness resulted in, on average, 6% greater ileal protein digestibility, 20% lower gizzard pH, 19% greater villus height, 18% lower crypt depth, and 23% reduced cecal branched chain fatty acids (BCFA) compared with chickens fed the fine diets. Broilers fed BA-supplemented diets had an improved FCR (P=0.004) and decreased crypt depth (P<0.001) compared with those fed diets without BA. Fermentable carbohydrate supplementation did not influence growth performance, gut development, or contents of total BCFA and total biogenic amines in the cecal digesta (P>0.05). Supplementation with FC, however, decreased the cecal concentration of spermine by approximately 31% compared with broilers fed diets without FC (P=0.002). In conclusion, feeding a coarse diet supplemented with BA improved performance of broilers fed a diet containing a poorly digestible protein source. The negative effects of a poorly digestible protein source can thus be partly counterbalanced by coarse grinding and BA supplementation in the diet.

Histo-FISH protocol to detect bacterial compositions and biofilms formation in vivo

The study of biofilm function in vivo in various niches of the gastrointestinal tract (GIT) is rather limited. It is more frequently used in in vitro approaches, as an alternative to the studies focused on formation mechanisms and function of biofilms, which do not represent the actual in vivo complexity of microbial structures. Additionally, in vitro tests can sometimes lead to unreliable results. The goal of this study was to develop a simple approach to detect bacterial populations, particularly Lactobacillus and Bifidobacterium in biofilms, in vivo by the fluorescent in situ hybridisation (FISH) method. We standardised a new Histo-FISH method based on specific fluorochrome labelling probes which are able to detect Lactobacillus spp. and Bifidobacterium spp. within biofilms on the mucosal surface of the GIT embedded in paraffin in histological slices. This method is also suitable for visualisation of bacterial populations in the GIT internal content. Depending on the labelling probes, the Histo-FISH method has the potential to detect other probiotic strains or pathogenic bacteria. This original approach permits us to analyse bacterial colonisation processes as well as biofilm formation in stomach and caecum of BALB/c and germ-free mice.

Analysis of biofilm formation by intestinal lactobacilli

In this study, the biofilm-forming potential of intestinal Lactobacillus reuteri strains under different culture conditions was characterized by microtiter plate biofilm assays. Moreover, the spatial organization of exogenously applied L. reuteri L2/6 (a pig isolate) at specific locations in gastrointestinal tract of monoassociated mice was investigated by fluorescence in situ hybridization. We did not detect biofilm formation by tested strains in nutrient-rich de Man–Rogosa–Sharpe (MRS) medium. On the contrary, a highly positive biofilm formation was observed in medium with lower accessibility to the carbon sources and lack of salts. The results obtained confirmed the significant role of Tween 80 and the quantity and nature of the sugars in the growth medium in biofilm formation. The omission of Tween 80 in MRS medium favored the formation of biofilm. Abundant biofilm formation was detected in the presence of lactose, galactose, and glucose. However, a gradual increase in sugar concentration triggered a significant decrease in biofilm formation. In addition, conditions related to the gastrointestinal environment, such as low pH and the presence of bile and mucins, highly modulated biofilm production. This effect seems to be dependent on the specificity and properties of the medium used for cultivation. From the evidence provided by this study we conclude that the biofilm formation capacity of L. reuteri is strongly dependent on the environmental factors and culture medium used.

Towards the control of necrotic enteritis in broiler chickens with in-feed antibiotics phasing-out worldwide

Poultry production has undergone a substantial increase compared to the livestock industries since 1970. However, the industry worldwide is now facing challenges with the removal of in-feed antibiotics completely or gradually, as the once well-controlled poultry diseases have re-emerged to cause tremendous loss of production. Necrotic enteritis (NE) is one of the most important diseases which costs the industry over two billion dollars annually. In this paper, we review the progress on the etiology of NE and its control through dietary modifications, pre- and probiotics, short chain fatty acids, and vaccination. The other likely measures resulted in the most advances in the toxin characterization are also discussed. Vaccine strategies may have greater potential for the control of NE mainly due to clearer etiology of NE having been elucidated in recent years with the identification of necrotic enteritis toxin B-like (NetB) toxin. Therefore, the use of alternatives to in-feed antibiotics with a better understanding of the relationship between nutrition and NE, and limiting exposure to infectious agents through biosecurity and vaccination, might be a tool to reduce the incidence of NE and to improve gut health in the absence of in-feed antibiotics. More importantly, the combinations of different measures may achieve greater protection of birds against the disease. Among all the alternatives investigated, prebiotics, organic acids and vaccination have shown improved gastrointestinal health and thus, have potential for the control of NE.

Succession of the turkey gastrointestinal bacterial microbiome related to weight gain

Because of concerns related to the use of antibiotics in animal agriculture, antibiotic-free alternatives are greatly needed to prevent disease and promote animal growth. One of the current challenges facing commercial turkey production in Minnesota is difficulty obtaining flock average weights typical of the industry standard, and this condition has been coined “Light Turkey Syndrome” or LTS. This condition has been identified in Minnesota turkey flocks for at least five years, and it has been observed that average flock body weights never approach their genetic potential. However, a single causative agent responsible for these weight reductions has not been identified despite numerous efforts to do so. The purpose of this study was to identify the bacterial community composition within the small intestines of heavy and light turkey flocks using 16S rRNA sequencing, and to identify possible correlations between microbiome and average flock weight. This study also sought to define the temporal succession of bacteria occurring in the turkey ileum. Based upon 2.7 million sequences across nine different turkey flocks, dominant operational taxonomic units (OTUs) were identified and compared between the flocks studied. OTUs that were associated with heavier weight flocks included those with similarity to Candidatus division Arthromitus and Clostridium bartlettii, while these flocks had decreased counts of several Lactobacillus species compared to lighter weight flocks. The core bacterial microbiome succession in commercial turkeys was also defined. Several defining markers of microbiome succession were identified, including the presence or abundance of Candidatus division Arthromitus, Lactobacillus aviarius, Lactobacillus ingluviei, Lactobacillus salivarius, and Clostridium bartlettii. Overall, the succession of the ileum bacterial microbiome in commercial turkeys proceeds in a predictable manner. Efforts to prevent disease and promote growth in the absence of antibiotics could involve target dominant bacteria identified in the turkey ileum that are associated with increased weight gain.

Gastrointestinal tract microbiota and probiotics in production animals

The gastrointestinal tract (GIT) microbiomes of production animals are now firmly established as a key feature underscoring animal health, development, and productivity. In particular, early gut colonization is critically important to the morphological and immunological development of the GIT, development of a functional fermentative environment, and neonatal resistance to pathogenic challenge. Although perturbations of an animal's GIT microbiome at any age can have profound consequences, perturbations during early GIT development can be particularly severe and result in significant and long-lasting sequelae. As the GIT microbiome matures, it exhibits significant diversity, ostensibly an important indicator of ecosystem health. Recognition of the immense importance of the GIT microbiota to the host has led to the development of probiotic and prebiotic feedstuffs with the express aim of ensuring animal health. We herein review the current collective understanding of the GIT microbiota of production animals.

Dose-dependent adverse effects of salinomycin on male reproductive organs and fertility in mice

Salinomycin is used as an antibiotic in animal husbandry. Its implication in cancer therapy has recently been proposed. Present study evaluated the toxic effects of Salinomycin on male reproductive system of mice. Doses of 1, 3 or 5 mg/kg of Salinomycin were administered daily for 28 days. Half of the mice were sacrificed after 24 h of the last treatment and other half were sacrificed 28 days after withdrawal of treatment. Effects of SAL on body and reproductive organ weights were studied. Histoarchitecture of testis and epididymis was evaluated along with ultrastructural changes in Leydig cells. Serum and testicular testosterone and luteinizing hormones were estimated. Superoxide dismutase, reduced glutathione, lipid peroxidation, catalase and lactate dehydrogenase activities were measured. Spermatozoa count, morphology, motility and fertility were evaluated. Expression patterns of steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage proteins (CYP11A1) were assessed by Western blotting. Salinomycin treatment was lethal to few mice and retarded body growth in others with decreased weight of testes and seminal vesicles in a dose dependent manner. Seminiferous tubules in testes were disrupted and the epithelium of epididymis showed frequent occurrence of vacuolization and necrosis. Leydig cells showed hypertrophied cytoplasm with shrunken nuclei, condensed mitochondria, proliferated endoplasmic reticulum and increased number of lipid droplets. Salinomycin decreased motility and spermatozoa count with increased number of abnormal spermatozoa leading to infertility. The testosterone and luteinizing hormone levels were decreased in testis but increased in serum at higher doses. Depletion of superoxide dismutase and reduced glutathione with increased lipid peroxidation in both testis and epididymis indicated generation of oxidative stress. Suppressed expression of StAR and CYP11A1 proteins indicates inhibition of steroidogenesis. Spermatogenesis was however observed in testis 28 days after Salinomycin withdrawal. The results indicate reversible dose-dependent adverse effects of Salinomycin on male reproductive system of mice.