Beneficial effects of dietary supplementation of Bacillus strains on growth performance and gut health in chickens with mixed coccidiosis infection

The present study investigated the effects of dietary supplementation with several Bacillus strains on growth performance, intestinal inflammatory and anti-inflammatory cytokines, anti-oxidants and tight junction (TJ) protein mRNA expression in broiler chickens challenged with mixed coccidia infection (oocysts of Eimeria tenella, Eimeria maxima and Eimeria acervulina). Ten different Bacillus strains were screened for their beneficial effects on coccidiosis challenge by measuring relative body weight gain (RBWG), lesion score, and total oocyst count. Three out of ten Bacillus strains were evaluated in depth by measuring RBWG, lesion score, total oocyst count, and the gene expression of proinflammatory (IL-6 and IL-8), anti-inflammatory (IL-10 and TGF-β), anti-oxidant (SOD1 and HMOX1), and TJ (JAM2 and occludin) proteins. Our results showed that out of the ten different Bacillus strains, chickens fed with three strains, one Bacillus licheniformis and two Bacillus amyloliquefaciens, showed significantly higher RBWG, lower lesion scores (ceca, jejunum, and duodenum), and lower total fecal oocyst counts compared to non-Bacillus-fed control chickens. Post-coccidia challenge, the RBWG for the Bacillus-fed groups were 95-100 % as opposed to the control birds (70 %) at 6 days post infection (dpi) and 10 dpi. Similarly, the lesion scores for three organs were around 0.8-0.9 for the Bacillus-fed groups as opposed to control birds (lesion score range ∼1.4-2). The total oocyst counts were much lower in the Bacillus-fed group (10-20 folds lesser) than the control group. Furthermore, the Bacillus-fed groups showed differential gene expression at 3 dpi in different tissues, such as caecum, jejunum, and duodenum. Bacillus-fed chickens showed significant pro- and anti-inflammatory responses and higher expression of anti-oxidants and TJ proteins in the ceca, duodenum, and jejunum. Overall, our results demonstrated that dietary supplementation with Bacillus strains as direct-fed microbials (DFM) significantly improved the body weight gain after mixed coccidia challenge compared to non-Bacillus-fed and coccidia challenged control group. In conclusion, the results of this study are promising and indicate the many beneficial effects of DFM-supplementation in poultry diets to reduce the negative consequences of enteric diseases and to decrease economic losses imposed by coccidia infection in chickens.

Comparative effects of direct-fed microbials alone or with a trace minerals supplements on the productive performance, blood metabolites, and antioxidant status in grazing Awassi lambs

Twenty Awassi lambs were used to find the effects of direct-fed microbials (DFM) and long-acting trace minerals rumen bolus (TMB) supplements on performance, blood biochemical variables, and antioxidant status of the lambs under grazing conditions. The lambs were randomly distributed into four groups as follows: (1) untreated, (2) oral dose of 5 mL DFM, (3) TMB, or (4) oral dose of 5 mL DFM and TMB. The treatments were carried out for 90 days. Supplementation with TMB significantly increased (P < 0.05) average daily gain (ADG) and feed efficiency compared with the control. A significant (P < 0.05) increase in blood albumin in the DFM and a significant (P < 0.05) decrease in aspartate aminotrasferase were found in the lambs supplemented with TMB alone or in combination with DFM. Supplementing lambs with TMB resulted in higher glutathione peroxidase, total antioxidant capacity (P < 0.001) and activity of superoxide dismutase (P < 0.05) compared with no supplementation and supplementation with DFM only. In conclusion, TMB supplementation had a positive impact on performance traits and the antioxidant system of the lambs under grazing condition.

Effect of feeding Azolla pinnata in combination with direct-fed microbial on broiler performance

A study was conducted on broiler birds for 42 days to determine the effect of feeding azolla along with direct-fed microbial (DFM) on growth performance, nutrient utilization, biochemical parameters and carcass characteristics. A total of 360-day-old male broiler chicks were divided into 3 groups and 12 replicates with 10 chicks per replicate, according to complete randomized block design. One group was fed a diet containing 2.5% azolla (A) and another was fed a diet containing 2.5% azolla, with direct-fed microbial (A + DFM), viz. L. plantarum and L. rhamnosus, at the concentration of 13.4 × 10⁸ and 1.52 × 10⁸ CFU per mL, respectively, mixed in the daily quota of feed. The control group (CON) was fed a basal diet without azolla and DFM. Azolla fed alone and with DFM did not affect growth performance and feed conversion ratio (FCR) of birds during pre-starter and starter phase; however, significantly (P < 0.05) lower weight gain and higher FCR were observed during finisher period, resulting in an impaired overall FCR. Decreased (P < 0.05) plasma cholesterol and increased (P < 0.05) tibial calcium content were observed in birds fed azolla with DFM. The highest value (P < 0.05) of carcass characteristics like gizzard weight, breast muscle yield and lower meat pH were recorded in the birds fed azolla in combination with DFM, followed by birds fed azolla alone. In conclusion, azolla feeding at 2.5% level shows positive effect on breast muscle yield and gizzard weight of broiler which can be enhanced upon adding DFM to azolla-based diet.

Effects of Dietary Supplementation with Bacillus amyloliquefaciens US573 on Intestinal Morphology and Gut Microbiota of European Sea Bass

Probiotics or direct-fed microbials (DFM) have proven strong potential for improving aquaculture sustainability. This study aims to evaluate the effects of dietary supplementation with the DFM Bacillus amyloliquefaciens US573 on growth performance, intestinal morphology, and gut microbiota (GM) of European sea bass. For this purpose, healthy fish were divided into two feeding trials in triplicate of 25 fish in each tank. The fish were fed with a control basal diet or a DFM-supplemented diet for 42 days. Results showed that, while no significant effects on growth performance were observed, the length and abundance of villi were higher in the DFM-fed group. The benefic effects of DFM supplementation included also the absence of cysts formation and the increase in number of goblet cells playing essential role in immune response. Through DNA metabarcoding analysis of GM, 5 phyla and 14 major genera were identified. At day 42, the main microbiome changes in response to B. amyloliquefaciens US573 addition included the significant decrease in abundance of Actinobacteria phylum that perfectly correlates with a decrease in Nocardia genus representatives which represent serious threat in marine and freshwater fish. On the contrary, an obvious dominance of Betaproteobacteria associated with the abundance in Variovorax genus members, known for their ability to metabolize numerous substrates, was recorded. Interestingly, Firmicutes, particularly species affiliated to the genus Sporosarcina with recent promising probiotic potential, were identified as the most abundant. These results suggest that B. amyloliquefaciens US573 can be effectively recommended as health-promoting DFM in European sea bass farming.

A dual strain probiotic administered via the waterline beneficially modulates the ileal and cecal microbiome, sIgA and acute phase protein levels, and growth performance of broilers during a dysbacteriosis challenge

Intestinal dysbacteriosis is increasing in broilers due to the reduced use of antibiotics in feed. This study tested the effect of daily waterline administration of a dual-strain probiotic comprising Lactobacillus acidophilus AG01 and Bifidobacterium animalis subspecies lactis AG02, on growth performance and intestinal health during a 3-step microbial challenge. In total, 900 Ross 308 males were assigned to 36 floor pens (25 birds/pen, 12 pens/treatment) in a completely randomized design. Birds were fed a corn, wheat and soybean-meal based diet. Diets were formulated in 3 phases (starter: 1 to 10; grower: 11 to 24; finisher: 25 to 42 d of age). Treatments comprised a non-challenged control (NC), challenged control (CC), and the CC supplemented with 1 × 108 colony forming units (CFU)/bird/day of the probiotic (CC+Probiotic). The challenge comprised 1 × 108 CFU/bird of Avian Pathogenic Escherichia coli on d 7, 4,000 oocysts/bird of Eimeria on d 15 and 1 × 109 CFU/bird of C. perfringens on d 18, 19 and 20. Growth performance was monitored over 42 d, blood samples, and digesta were collected and intestinal dysbacteriosis scoring was performed. Compared to NC birds, CC birds exhibited reduced BW (all phases), reduced feed intake (starter and grower phase), increased FCR (grower phase and overall; P < 0.05), reduced ileal lactic acid bacteria concentrations (d 24 and 42), and increased cecal E. coli (d 24; P < 0.05). Compared to CC birds, CC+Probiotic birds exhibited increased BW, BW gain and feed intake during grower phase (P < 0.05), increased ileal lactic acid bacteria at d 24 and 42 and reduced ileal C. perfringens at d 24, increased mucosal secretory IgA and reduced serum alpha-1-acid-glycoprotein at d 42. The overall growth performance of CC+Probiotic birds was equivalent to NC birds. These results confirm the efficacy of the dual strain probiotic for mitigating the negative effects of a multi-microbial challenge, improving gut health and growth performance in commercial broilers under dysbacteriosis challenge.