Effect of Bacillus velezensis to substitute in-feed antibiotics on the production, blood biochemistry and egg quality indices of laying hens.

BACKGROUND: The excessive use of antibiotics in the livestock feed industry caused inevitable side effects of microbial resistance. Besides this residual antibiotics in animal-derived foodstuff imposed serious health problems for humans. So this study aimed to investigate the potential use of Bacillus velezensis to substitute antibiotics for poultry production. A total of 468, 49-week-old Hy-Line Brown chickens, were randomly divided into four groups the control group (regular diet), experiment group I (0.1% B. veleznesis), experiment group II (0.2% B. veleznesis), and antibiotic group (50 mg/kg flavomycin), with three replicates per group and trial period consisted on 42 days. RESULTS: The results showed that, compared with the control group, the average egg production rate and daily feed intake of experimental groups I and II increased significantly (P < 0.05), while the average egg weight was increased in experimental group II as compared to (I) (P < 0.01). The feed conversion ratio was decreased (P > 0.05) in group (II) Egg quality parameters such as yolk weight of the experimental group II was increased, but that of the antibiotic group and experiment group I was decreased, neither significant (P > 0.05). Moreover, the eggshell strength, yolk color, albumen height, and Haugh unit were significantly increased (P < 0.05). Compared with the control group, probiotic groups can increase the progesterone and motilin (P > 0.05) but decrease the secretin and cholecystokinin in the blood plasma (P > 0.05). CONCLUSIONS: This study suggested that B. velezensis can substitute in-feed-antibiotics and improved most of the study parameters significantly. Which suggested that B. velezensis has potential future application value to replace the feed antibiotics.

A comparison of the effects of antibiotics, probiotics, synbiotics and prebiotics on the performance and carcass characteristics of broilers.

Routine use of the antibiotic flavomycin in broiler production may lead to resistance, and alternative growth promoters are used to enhance performance. Two hundred day-old male Ross 308 broiler chicks were allocated to five dietary supplements included from d 1-42: flavomycin, three possible alternatives, a probiotic, prebiotic and a synbiotic, as well as a control treatment. There were four replicate cages of 10 birds each in each treatment. Compared with the control and antibiotics treatments, the probiotic, prebiotic and synbiotic treatments increased (p = 0.001) weight gain (64, 66, 73, 70 and 74 g/d, respectively). The synbiotic treatment reduced (p = 0.004) the feed conversion ratio, compared with the control and antibiotic treatments (1.70, 1.84, 1.83, respectively). Compared with the control and antibiotic treatments, the birds fed the synbiotic treatment had greater relative gizzard (+47%) and spleen weights (+115%), and lighter kidneys (-47%). The birds fed the symbiotic treatment also had thinner walls of the caudal gut segments. The prebiotic had the most beneficial effect on cecal microbiota, stimulating aerobic and lactic acid producing bacteria and reducing Escherichia coli bacteria. Enterococci were increased in the antibiotic treatment. We conclude that there were significant performance and health benefits of using prebiotics, probiotics and synbiotics for broilers, rather than antibiotics.

Effects of rotating antibiotic and ionophore feed additives on volatile fatty acid production, potential for methane production, and microbial populations of steers consuming a moderate-forage diet.

Ionophores and antibiotics have been shown to decrease ruminal methanogenesis both in vitro and in vivo but have shown little evidence toward a sustainable means of mitigation. Feed additive rotation was proposed and investigated for methane, VFA, and microbial population response. In the present study, cannulated steers ( = 12) were fed a moderate-forage basal diet in a Calan gate facility for 13 wk. In addition to the basal diet, steers were randomly assigned to 1 of 6 treatments: 1) control, no additive; 2) bambermycin, 20 mg bambermycin/d; 3) monensin, 200 mg monensin/d; 4) the basal diet + weekly rotation of bambermycin and monensin treatments (B7M); 5) the basal diet + rotation of bambermycin and monensin treatments every 14 d (B14M); and 6) the basal diet + rotation of bambermycin and monensin treatments every 21 d (B21M). Steers were blocked by weight in a randomized complete block design where the week was the repeated measure. Rumen fluid was collected weekly for analysis ( = 13), and results were normalized according to individual OM intake (OMI; kg/d). Potential activity of methane production was not significantly different among treatments ( > 0.05). However, treatment tended to affect the CH-to-propionate ratio ( = 0.0565), which was highest in the control and lowest in the monensin, B21M, and B14M treatments (0.42 vs. 0.36, 0.36, and 0.33, respectively). The CH:propionate ratio was lowest in wk 2 and 3 ( < 0.05) but the ratio in wk 4 to 12 was not different from the ratio in wk 0. Week also affected total VFA, with total VFA peaking at wk 3 and plummeting at wk 4 (4.02 vs. 2.86 m/kg OMI; < 0.05). A significant treatment × week interaction was observed for the acetate-to-propionate (A:P) ratio, where bambermycin- and rotationally fed steers did not have a reduced A:P ratio compared with monensin-fed steers throughout the feeding period ( < 0.0001). Microbial analysis revealed significant shifts, but several predominant classes showed adaptation between 4 and 6 wk after additive initiation. There was no significant evidence to suggest that rotations of monensin and bambermycin provided additional benefits to steers consuming a moderate-forage diet at the microbial/animal and environmental level versus those continuously fed.

Influence of antimicrobial feed additives on broiler commensal posthatch gut microbiota development and performance.

The effects of avilamycin, zinc bacitracin, and flavophospholipol on broiler gut microbial community colonization and bird performance in the first 17 days posthatch were investigated. Significant differences in gut microbiota associated with gut section, dietary treatment, and age were identified by terminal restriction fragment length polymorphism (T-RFLP), although no performance-related differences between dietary treatments were detected. Similar age-related shifts in the gut microbiota were identified regardless of diet but varied between the ilea and ceca. Interbird variabilities in ileal bacterial communities were reduced (3 to 7 days posthatch) in chicks fed with feed containing antimicrobial agents. Avilamycin and flavophospholipol had the most consistent effect on gut microbial communities. Operational taxonomic units (OTU) linked to changes in gut microbiota in birds on antimicrobial-supplemented diets were characterized and identified. Some OTUs could be identified to the species level; however, the majority could be only tentatively classified to the genus, family, order, or domain level. OTUs 140 to 146 (Lachnospiraceae), OTU 186/188 (Lactobacillus johnsonii), OTU 220 (Lachnospiraceae), OTUs 284 to 288 (unclassified bacterial spp. or Ruminococcaceae), OTU 296/298 (unclassified bacterium or Clostridiales), and OTU 480/482 (Oxalobacteraceae) were less prevalent in the guts of chicks fed antimicrobial-supplemented diets. OTU 178/180 (Lactobacillus crispatus), OTU 152 (Lactobacillus reuteri or unclassified Clostridiales), OTU 198/200 (Subdoligranulum spp.), and OTU 490/492 (unclassified bacterium or Enterobacteriaceae) were less prevalent in the gut of chicks raised on the antimicrobial-free diet. The identification of key bacterial species influenced by antimicrobial-supplemented feed immediately posthatch may assist in the formulation of diets that facilitate beneficial gut microbial colonization and, hence, the development of alternatives to current antimicrobial agents in feed for sustainable poultry production.

Effect of lactoferrin on the growth performance, intestinal morphology, and expression of PR-39 and protegrin-1 genes in weaned piglets.

A total of 90 weaned female pigs (Duroc x Landrace x Yorkshire) were used in a 15-d growth experiment to investigate the effect of lactoferrin on growth performance, intestinal morphology, and expression of PR-39 and protegrin-1 genes. The pigs were allocated on the basis of BW and litter to 3 dietary treatments in a randomized complete block design. There were 3 replicate pens per treatment, and the pigs were grouped with 10 pigs per pen. The dietary treatments were (1) basal diet; (2) basal diet + 20 mg of flavomycin/kg + 110 mg of aureomycin/kg; (3) basal diet + 1.0 g of lactoferrin/kg. Six pigs, randomly selected from each treatment (2 piglets/pen) were slaughtered for intestinal morphology and expression of PR-39 and protegrin-1 genes at the end of the experiment. Supplementation with lactoferrin improved growth performance; it increased ADG by 41.80% (P < 0.01) and efficiency of gain (G:F) by 17.20% (P < 0.05). Intestinal villus height was increased by 15.30% (P < 0.05), and crypt depth was decreased by 9.60% (P < 0.05). Supplemental lactoferrin increased the relative abundance of mRNA for PR-39 and protegrin-1 by 143% (P < 0.01) and 217% (P < 0.01), respectively. The use of lactoferrin as an additive to improve nonspecific immunity and strengthen host defenses would be good a method of defending weaned pigs from infections and weanling stress.

Influence of flavomycin on microbial numbers, microbial metabolism and gut tissue protein turnover in the digestive tract of sheep.

Flavomycin is an antibiotic that promotes growth in ruminant and non-ruminant livestock. The aim of this study was to determine the mechanism of action of flavomycin in sheep by measuring microbial numbers, microbial metabolism and gut tissue protein turnover at different sites in the digestive tract. Two weight-matched groups (n 5) of male castrate lambs (30 kg) received 800 g grass cubes/d for 6 weeks, with one group receiving 20 mg/d flavomycin during the last 2 weeks. Samples of digesta and gut tissue segments were obtained immediately post mortem, 90 min after a flood-dose of [ring-D5]phenylalanine. Viable bacterial counts and volatile fatty acid concentrations were highest in ruminal digesta, followed by the colon and caecum, then the duodenum and ileum. The only effect of flavomycin was an increased bacterial count in the rumen (3.5 v. 1.2 x 10(9) per g; P=0.04). Acetate was proportionally greater and propionate and butyrate were lower in the caecum and colon than the rumen. Flavomycin had no effect on volatile fatty acid proportions or ammonia concentrations. Bacteria growing on peptides as sole C source were not affected by flavomycin. Proteolytic, peptidolytic and amino acid deamination activities were similar in the rumen, caecum and colon; they tended to be lower in animals receiving flavomycin. Protein turnover in ruminal wall and duodenal tissues, measured by a flood-dose technique, decreased with flavomycin (P=0.075 and 0.027, respectively). Thus, flavomycin differs from ionophores in its mode of action. It may influence protein metabolism of both digesta and tissue throughout the ruminant digestive tract.

Performance and caecal adaptation of turkeys to diets without or with antibiotic and with different levels of mannan-oligosaccharide.

A study on turkeys was conducted to evaluate the administration of different levels of mannan-oligosaccharide (MOS) (0.1, 0.25 and 0.5%) to a diet without or with an antibiotic (Flavomycin, 8 mg/kg feed). The growth performance as well as caecal development and metabolism indicators of turkeys after 8 weeks of experimental feeding were estimated. No interactions were noted between the contents of antibiotic and MOS in the diet in any of the parameters examined. During 8 weeks of experimental feeding, the feed intake as well as feed conversion ratio were similar in all experimental groups. The turkeys fed a control diet (without MOS) supplemented with antibiotic were the heaviest, but there were no statistical differences between groups. Depending on dietary dose, MOS had a different influence on caecal digesta parameters. The medium level of dietary MOS (0.25%) resulted in the highest caecal pH, dry matter and protein concentrations as well as the bacterial glycolytic activity (including beta-glucuronidase). Compared to other dietary treatments, the highest amount of MOS (0.5%) reduced ammonia concentration and enhanced volatile fatty acids concentration, especially of acetate and butyrate, in the caecal digesta. The medium level of dietary MOS caused a significant enhancement of propionate, iso-butyrate and iso-valerate concentrations in the digesta. The antibiotic addition to a diet resulted in a lack of birds' response.

Effect of feeding the ionophores monensin and laidlomycin propionate and the antimicrobial bambermycin to sheep experimentally infected with E. coli O157:H7 and Salmonella typhimurium.

Escherichia coli O157:H7 and Salmonella are widely recognized as important agents of foodborne disease with worldwide distribution. The use of ionophores in feeding growing ruminants is widespread in the United States and has attracted recent interest due to the apparent temporal relationship between initial ionophore use and the increase in human E. coli O157:H7 cases. Two experiments were conducted to evaluate the effects of short-term feeding of ionophores on fecal shedding, intestinal concentrations, and antimicrobial susceptibility of E. coli O157:H7 and S. typhimurium in growing lambs. Sixteen lambs were used in each experiment, four lambs per treatment group: monensin, laidlomycin propionate, bambermycin, and a control treatment. Lambs were fed a grain and hay (50:50) diet with their respective ionophore for 12 d before experimental inoculation with E. coli O157:H7 or S. typhimurium. Animals were maintained on their respective diets an additional 12 d, and fecal shedding of inoculated pathogens was monitored daily. Lambs were killed and tissues and contents were sampled from the rumen, cecum, and rectum. No differences (P > 0.05) in fecal shedding of Salmonella or E. coli O157:H7 were observed due to treatment. Occurrence of Salmonella or E. coli in luminal contents and tissue samples from the rumen, cecum, and rectum did not differ (P > 0.05) among treatments. Feeding monensin decreased (P < 0.05) the incidence of scours in sheep infected with Salmonella compared with the other treatments. No differences in antimicrobial susceptibility were found in any of Salmonella or E. coli O157:H7 isolates. Results from these studies indicate that short-term ionophore feeding had very limited effects on E. coli and Salmonella shedding or on antimicrobial susceptibility in experimentally infected lambs.

Effects of hen age, Bio-Mos, and Flavomycin on poult susceptibility to oral Escherichia coli challenge.

The effects of hen age, Escherichia coli, and dietary Bio-Mos and Flavomycin on poult performance from 1 to 21 d were studied. Day-of-hatch BUTA (BIG-6) male poults were gavaged orally (1 mL) with approximately 10(8) cfu/mL E. coli composed of four serotypes or sterile carrier broth. A mixture of the same E. coli cultures was added to the poults' water troughs to attain a concentration of approximately 10(6) cfu/mL on a weekly basis to ensure a continuous bacterial challenge. Within each E. coli split plot treatment group, poults from hens of different ages (33 and 58 wk of age) were fed diets containing Bio-Mos (1 g/kg feed), Flavomycin (2.2 mg active ingredient/kg feed), Bio-Mos plus Flavomycin, or a control diet, in a randomized complete block design. This experiment yielded eight treatments per challenge group. At Weeks 1 and 3, eight birds from each treatment from the E. coli challenged and unchallenged groups were randomly chosen for bacterial sampling of liver and intestinal tissue for coliforms, aerobic bacteria, and Lactobacillus spp. E. coli isolates from tissue samples were O serotyped. During E. coli challenge, dietary Bio-Mos and Flavomycin improved poult BW and BW gains (P < or = 0.05). When poults were not challenged with E. coli, poults from old hens had improved BW and cumulative BW gains over poults from young hens (P < or = 0.05). Cumulative 3-wk BW gains for unchallenged poults from young hens were improved by Bio-Mos and Flavomycin (P < or = 0.05) alone and in combination when compared to the control diet. Two of the four E. coli serotypes administered were recovered. Several serotypes were recovered that were not administered. It may be concluded that dietary Bio-Mos and Flavomycin can improve the overall performance of poults, especially when they are faced with an E. coli challenge.

The effect of flavophospholipol (Flavomycin) and salinomycin sodium (Sacox) on the excretion of Clostridium perfringens, Salmonella enteritidis, and Campylobacter jejuni in broilers after experimental infection.

Intestinal colonization and shedding of pathogenic bacteria in animal feces is an important factor in both human food safety and animal health. The effect of broiler feed additives flavophospholipol (FPL; Flavomycin, bambermycins) and salinomycin sodium (SAL; Sacox) given singly on the excretion of Salmonella enteritidis, Campylobacter jejuni, and Clostridium perfringens was studied following controlled infection. The incidence of shedding (number of birds with positive fecal cultures) and the degree of shedding (cfu per gram of feces in positive birds) were measured to determine the influence of these two common feed additive antibiotics on shedding rates of potential pathogens. A total of 216 Ross broiler chickens, housed in battery cages, were fed either an unmedicated feed (controls), feed containing FPL, or feed containing SAL. Feed treatment groups were subdivided into three bacterial challenge groups of 24 chicks, each receiving only one of the pathogens. Bacterial challenge was administered orally on Days 11 and 12 for Salmonella and Campylobacter and on Days 2 and 3 for Clostridium. Fecal samples were collected weekly up to 6 wk of age and cultured for presence of the target organism. The shedding rate was determined by decimal dilutions of the fecal samples. Feeding FPL resulted in a reduced (P < or = 0.05) degree and incidence of Salmonella and Clostridium shedding at 6 wk. Feeding SAL reduced (P < or = 0.05) the incidence of Salmonella shedding at 6 wk. Neither feed additive affected the incidence nor the degree of Campylobacter shedding. The results of this study indicate that these feed additives may reduce the incidence of these potential human and animal pathogens in preslaughter broilers.

Bioefficacy of enzyme preparations containing beta-glucanase and xylanase activities in broiler diets based on barley or wheat, in combination with flavomycin.

The objective of the study was to determine the effects of two enzyme preparations containing beta-glucanase and xylanase activities on barley- and wheat-based diets, respectively, for broilers, in combination with flavomycin. In addition, the stability of the enzyme preparations after pelleting was measured. Temperatures recorded during the pelleting process reached 75 to 80 C, and the activities recovered with respect to the amounts present in the mash feed before pelleting were 80% or higher. Two performance experiments were conducted simultaneously under the same conditions over 6 wk. In addition, intestinal viscosity and incidence of vent pasting were measured and carcasses were eviscerated to determine abdominal fat, carcass yield, and percentage weight of intestines and viscera. Twenty-four pens (12 per sex), each containing 75 chickens were used in each experiment. Wheat- or barley-based diets were supplemented with flavomycin and a xylanase or a beta-glucanase preparation, respectively, in a 2 x 2 factorial arrangement of treatments. In the wheat diets, xylanase and flavomycin improved feed efficiency, in parallel with a reduction of intestinal viscosity. Xylanase reduced the incidence of vent pasting and the percentage viscera, especially of intestines, and increased abdominal fat. In the barley diets, beta-glucanase and flavomycin improved feed conversion. beta-Glucanase also reduced intestinal viscosity and vent pasting. Both beta-glucanase and flavomycin reduced percentage intestines, but the effects were not additive. In general, the effects of the enzyme preparations and flavomycin were independent, except for percentage intestines with beta-glucanase.

Effect of probiotic supplementation on growth, nitrogen utilisation and serum cholesterol in broilers.

1. The effect of dietary probiotic supplementation on the growth, nitrogen utilisation and serum cholesterol content of broiler chickens was studied in 2 trials. 2. In experiment 1, the birds receiving the 0, 75, 100, 125 mg probiotic/kg diets had weight gains of 1204.0, 1272.0, 1268.3 and 1210.5, respectively at the end of 8 weeks of feeding. The group of birds fed on the 75 mg probiotic supplemented diet retained significantly (P < 0.01) more nitrogen than the control birds. Serum cholesterol content was lower in the probiotic-supplemented birds (93.3 mg/100 ml) compared to the control birds (132.2 mg/100 ml). 3. In the second experiment the probiotic plus antibiotic-supplemented group of birds had the maximum weight gain (1148.5 g) followed by antibiotic (1141.3 g), probiotic-supplemented (1128.4 g) and control birds (1045.6 g) after 6 weeks. Nitrogen retention was greatest in the antibiotic--(48.5%) followed by the probiotic--(46.5%), probiotic plus antibiotic-supplemented groups (46.3%) compared to 40.2% in control birds. 4. The apparent metabolisable energy was greatest in birds receiving the probiotic plus antibiotic-supplemented diet (12.37 MJ/kg) followed by antibiotic--(12.00 MJ/kg), probiotic-supplemented birds (11.92 MJ/kg) than in control birds (11.62 MJ/kg). Serum cholesterol was significantly (P < 0.01) lower in probiotic-supplemented birds (86.1 mg/dl) compared to 118.4 mg/dl in control birds.

Experimental results of the use of flavofosfolipol in dairy cattle.

In a field trial carried out on a farm with about 100 dairy cows, half of the animals were treated orally with 45 mg flavofosfolipol per animal daily for 370 days, while the other half were untreated controls. The administration of the flavofosfolipol did not produce any residues in the milk. Body functions and fertility were not affected. Milk production was increased, although not with statistical significance. The qualitative characteristics of the milk and its cheese-making properties were normal. The casein content was increased by 6.58% over that of the controls, and thus was statistically significant. There was a statistically significant decrease in the mean cell content of the milk. The high negative correlation between the casein level and the cell content of the milk suggests that an improvement in the function of the mammary parenchyma could be responsible for the higher casein content. This improvement in function could also be due to a favourable effect of the antibiotic, still to be clarified, on the ruminal microflora. In economic terms the use of flavofosfolipol in dairy cattle seems to be of considerable interest.