Probiotics as an alternative to antibiotics in modulating the intestinal microbiota and performance of broiler chickens.

AIMS: Gut bacteria play an important role in poultry nutrition and the immune defense system. Changes in the intestinal microbiome affect the physiological state, metabolism, and innate immunity of poultry. The present study aimed to characterize age-related changes in the gastrointestinal tract microflora in broiler chickens, depending on supplementation of the diet with the in-feed antibiotic Stafac® 110 and a Bacillus subtilis strain-based probiotic. METHODS AND RESULTS: In this regard, a comprehensive analysis of the taxonomic structure of the microbial community in the gastrointestinal tract (GIT) of broiler chickens was carried out using a molecular genetic technique of the terminal-restriction fragment length polymorphism analysis and taking into account age dynamics and feeding treatment. A beneficial effect on the microbiological composition and body weight of broilers was observed when using the antibiotic and probiotic in compound feeds. Different bacterial communities were revealed in the duodenum and cecum, and their positive impact on broiler growth was established. The results obtained shed light on the formation of GIT microflora of broiler chickens during the growing period and its changes in response to the use of the antibiotic and the probiotic. CONCLUSIONS: We suggest that the implementation of the tested in-feed antibiotic and probiotic can be beneficial in regulating the intestinal microflora microbiological processes in the GIT and improving the feeding efficiency and productivity of broiler chickens.

Investigating adverse effects of chronic dietary exposure to herbicide glyphosate on zootechnical characteristics and clinical, biochemical and immunological blood parameters in broiler chickens.

Although the herbicide glyphosate is widely used globally and considered safe, more evidence of its adverse effects on animals and humans is accumulating. The present investigation was aimed at evaluating the impact of different glyphosate concentrations on zootechnical characteristics and clinical, biochemical and immunological blood parameters in Ross 308 broiler chickens. Four groups were employed, including untreated control and three experimental groups fed diets enriched with glyphosate at doses of 10, 20 and 100 ppm that conformed to 0.5, 1 and 5 maximum residue limits, respectively. The results showed that glyphosate is a stress factor triggering a multifaceted effect on important blood parameters (e.g., white blood cell and phagocytic counts), which was shown for the first time in the experiments involving productive meat-type poultry. It was first revealed that glyphosate-induced changes in blood parameters may be related to a negative impact on the zootechnical characteristics including the digestive tract organ development and body weight gain. The study findings suggested that exposure to glyphosate in the feedstuffs can adversely affect the physiological condition and productivity of broilers.

An Investigation on the Effects of Partial Replacement of Rapeseed Cake in Ayrshire Dairy Heifers' Diets with By-Product Source of Animal Protein on Body Weight Dynamics, Nutrient Balancing, and Blood Biochemical Markers.

Recently, the secondary use of by-products of the processing industry resulting from the production of poultry meat, which can be included in animal diets, has become a popular topic in the feed industry. For studying the effects of partial replacement of rapeseed cake (RC) with the by-product source of animal protein concentrate Agro-Matic (PCAM) on growth dynamics, nutrient absorption and nitrogen balance, as well as blood biochemical parameters during the growing period, a total of 48 Russian Ayrshire dairy heifers were selected for this experiment and they were divided into three experimental groups (16 in each group, including the control group). The heifers of the control group were fed the basal diet which contained rapeseed cake (30%), while the second (RC + PCAM) and third groups (PCAM + RC) were fed the basal diet after replacing a part of the rapeseed cake with 2.25% and 4.5% of protein concentrate Agro-Matic respectively. The results showed that the weight of heifers treated with PCAM at 3 months of age exceeded the control by 2.3 kg (p > 0.05) in group 2 by 4.4 kg (p < 0.05). Similar results were obtained at the age of 6 months of raising. Feeding 4.50% protein concentrate Agro-Matic has a positive effect on the digestibility of nutrients; in particular, there was a significant increase in the digestibility of crude protein in the PCAM + RC group (77.23 vs. 73.42%) compared with the control group. Moreover, a similar trend was found in the digestibility of nitrogen in the diet. At the age of 3 months, heifers showed a significant decrease in the concentration of ketone bodies in the second group (1.82 vs. 2.20 mmol/L) relative to the control group. Urea was significantly lower in the RC + PCAM group (5.05 vs. 6.62 mmol/L) relative to the PCAM + RC group, while acid capacity (alkaline reserve) was higher by 2.41% (p < 0.05) relative to the control. In the 10th month of age, a positive effect on the blood of heifers was observed, as in the second and the third experimental groups, ß-globulin and phosphorus increased (p < 0.05), while in the second group aspartate aminotransferase decreased (p < 0.05). Consequently, replacing the rapeseed cake with the protein concentrate Agro-Matic revealed an improvement in the dynamics of growth, nutrient digestibility and nitrogen balance, and it has an effect on improving some biochemical parameters of the blood.

Influence of Using Various Levels of Protein Concentrate in Rations of Ayrshire Dairy Cows on Rumen Microbiome, Reproductive Traits and Economic Efficiency.

Animal feeding research has revealed a close relationship between the chemical composition and nutritional value of cow rations, the number of rumen bacterial communities and animal productivity. Our present research aimed to investigate the outcome of inclusion of different levels of protein concentrate in rations of Ayrshire dairy cows in relation to the rumen microbiome, reproductive traits and economic value. Forty-five Ayrshire cows were divided into three groups (15 in each). The first control group 0 AM was fed the basal ration, while the second 1 AM and third 2 AM groups were fed the basic ration with the sunflower cake replaced by different levels of protein concentrate Agro-Matic (1 and 1.5 kg/head/day, respectively). Ruminal fluid samples, reproductive parameters and economic value were studied. During the early lactation period, 120 days in milk (DIM), the number of pathogenic microorganisms decreased in both the 1 AM and 2 AM groups when compared with the control group 0 AM; moreover, a significant decrease in Peptococcus bacteria was recorded in the 1 AM group, while Fusobacterium decreased in the 2 AM group. At the end of lactation, the total number of cellulolytic bacteria increased with the use of protein concentrate in animals of the 1 AM group when compared with the control group. Regarding undesirable bacteria, the 2 AM group recorded the highest value for Lactobacilli and Actinobacteria when compared with the 0 AM group (0.18 and 8.90 vs. 0.04 and 4.24), and the differences were significant (p < 0.05). The insemination index and the duration of the days open period decreased in the 2 AM group, while the differences were p > 0.05. The profitability of milk production increased by 2.76% and 6.28% in both supplemented groups, and the differences compared to the 0 AM group were significant. We conclude that the supplementation of Agro-Matic caused no deviations from the normal standards of cellulolytic, amylolytic, transit and pathogenic bacteria, no impact on reproductive functions and significantly improved the profitability of the milk production process of Ayrshire dairy cows.

The Comparative Analysis of the Ruminal Bacterial Population in Reindeer (Rangifer tarandus L.) from the Russian Arctic Zone: Regional and Seasonal Effects.

The reindeer (Rangifer tarandus L.) is a unique animal inhabitant of arctic regions. Low ambient temperatures and scant diets (primarily, lichens) have resulted in different evolutional adaptations, including the composition of the ruminal microbiota. In the study presented here, the effects of seasonal and regional aspects of the composition of the ruminal microbiota in reindeer (Nenets breed, 38 animals) were studied (wooded tundra from the Yamalo-Nenetski Autonomous District (YNAD) vs. from the Nenetski Autonomous District (NAD)). The ruminal content of calves (n = 12) and adult animals (n = 26, 15 males and 11 females) was sampled in the summer (n = 16) and winter seasons (n = 22). The composition of the ruminal microbial population was determined by the V3-V4 16S rRNA gene region sequencing. It was found that the population was dominated by Bacteroidetes and Firmicutes phyla, followed by Spirochaetes and Verrucomicrobia. An analysis of the community using non-metric multidimensional scaling and Bray-Curtis similarity metrics provided evidence that the most influential factors affecting the composition of ruminal microbiota are the region (p = 0.001) and season (p = 0.001); heat map analysis revealed several communities that are strongly affected by these two factors. In the summer season, the following communities were significantly larger compared to in the winter season: Coriobactriaceae, Erysipelothrihaceae, and Mycoplasmataceae. The following communities were significantly larger in the winter season compared to in summer: Paraprevotellaceae, Butyrivibrio spp., Succiniclasticum spp., Coprococcus spp., Ruminococcus spp., and Pseudobutyrivibrio spp. In NAD (tundra), the following communities were significantly larger in comparison to YNAD (wooded tundra): Verrucomicrobia (Verruco-5), Anaerolinaceae, PeHg47 Planctomycetes, cellulolytic Lachnospiraceae, and Succiniclasticum spp. The following bacterial groups were significantly larger in YNAD in comparison to NAD: cellulolytic Ruminococaceae, Dehalobacteriaceae, Veillionelaceae, and Oscilospira spp. The significant differences in the ruminal microbial population were primarily related to the ingredients of diets, affected by region and season. The summer-related increases in the communities of certain pathogens (Mycoplasmataceae, Fusobacterium spp., Porphyromonas endodentalis) were found. Regional differences were primarily related to the ratio of the species involved in ruminal cellulose degradation and ruminal fatty acids metabolism; these differences reflect the regional dissimilarities in botanical diet ingredients.

Effects of Essential Oils-Based Supplement and Salmonella Infection on Gene Expression, Blood Parameters, Cecal Microbiome, and Egg Production in Laying Hens.

One of the main roles in poultry resistance to infections caused by Salmonella is attributed to host immunity and intestinal microbiota. We conducted an experiment that involved challenging Lohmann White laying hens with Salmonella Enteritidis (SE), feeding them a diet supplemented with an EOs-based phytobiotic Intebio®. At 1 and 7 days post-inoculation, the expression profiles of eight genes related to immunity, transport of nutrients in the intestine, and metabolism were examined. Cecal microbiome composition and blood biochemical/immunological indices were also explored and egg production traits recorded. As a result, the SE challenge of laying hens and Intebio® administration had either a suppressive or activating effect on the expression level of the studied genes (e.g., IL6 and BPIFB3), the latter echoing mammalian/human tissue-specific expression. There were also effects of the pathogen challenge and phytobiotic intake on the cecal microbiome profiles and blood biochemical/immunological parameters, including those reflecting the activity of the birds' immune systems (e.g., serum bactericidal activity, ß-lysine content, and immunoglobulin levels). Significant differences between control and experimental subgroups in egg performance traits (i.e., egg weight/number/mass) were also found. The phytobiotic administration suggested a positive effect on the welfare and productivity of poultry.

Examination of the Expression of Immunity Genes and Bacterial Profiles in the Caecum of Growing Chickens Infected with Salmonella Enteritidis and Fed a Phytobiotic.

This study was performed to investigate the differential expression of eight immunity genes and the bacterial profiles in the caecum of growing chickens challenged with Salmonella enterica serovar Enteritidis (SE) at 1 and 23 days post inoculation (dpi) in response to SE infection at 19 days of age and administration of the phytobiotic Intebio. Following infection, the genes CASP6 and IRF7 were upregulated by greater than twofold. Chicks fed Intebio showed at 1 dpi upregulation of AvBD10, IL6, IL8L2, CASP6 and IRF7. At 23 dpi, expression of AvBD11, IL6, IL8L2, CASP6 and IRF7 lowered in the experiment subgroups as compared with the control. Examination of the caecal contents at 1 dpi demonstrated a significant decrease in the microbial biodiversity in the infected subgroup fed normal diet. Bacterial content of Lactobacillus and Bacillus declined, while that of Enterobacteriaceae rose. In the infected subgroup fed Intebio, a pronounced change in composition of the microflora was not observed. In the early infection stages, the phytobiotic seemed to promote response to infection. Subsequently, an earlier suppression of the inflammatory reaction took place in chickens fed Intebio. Thus, use of Intebio as a drug with phytobiotic activity in chickens, including those infected with Salmonella, proved to be promising.