A Screen of Natural Product Extracts Identifies Moenomycin as a Potent Antigonococcal Agent.

Increasing multidrug resistance in Neisseria gonorrheae is a growing public health crisis. Resistance to the last line therapies, cephalosporins and azithromycin, are of particular concern, fueling the need to discover new treatments. Here, we identified the phosphoglycolipid moenomycin from a screen of microbial natural products against drug-resistant N. gonorrheae as a potent antigonococcal agent. Moenomycin demonstrates excellent activity (MIC = 0.004-0.03 µg/mL) against a variety of multidrug-resistant N. gonorrheae. Importantly, moenomycin, thought to be a Gram-positive specific antibiotic, penetrates the Gram-negative gonococcal outer membrane. Moenomycin causes intracellular accumulation of peptidoglycan precursors, cell blebbing, and rupture of the cell envelope, all consistent with cell wall biosynthesis inhibition. Serial bacterial exposure to moenomycin for 14 days revealed slow development of resistance (MICDay14 = 0.03-0.06 µg/mL), unlike the clinically used drug azithromycin. Our results offer the potential utility of moenomycin as a lead for antigonococcal therapeutic candidates and warrant further investigation.

Effects of supplementation with narasin, salinomycin, or flavomycin on performance and ruminal fermentation characteristics of Bos indicus Nellore cattle fed with forage-based diets.

The aim of the present study was to evaluate the inclusion of narasin, salinomycin, or flavomycin for 140 d on ruminal fermentation parameters, apparent nutrient digestibility, and performance of Nellore cattle offered a forage-based diet. In experiment 1, 32 rumen-cannulated Bos indicus Nellore steers [initial body weight (BW) = 220 ± 12.6 kg] were assigned to individual pens in a randomized complete block design according to their initial shrunk BW. Within block, animals were randomly assigned to 1 of 4 treatments: (1) forage-based diet without feed additives (CON; n = 8), (2) CON diet plus 13 ppm of narasin (NAR; n = 8), (3) CON diet plus 20 ppm of salinomycin (SAL; n = 8), or (4) CON diet plus 3 ppm of flavomycin (FLA; n = 8). The experimental period lasted 140 d and was divided into 5 periods of 28 d each. The inclusion of feed additives did not impact (P ≥ 0.17) dry matter intake (DMI), nutrient intake, and apparent total tract digestibility of nutrients. Nonetheless, steers fed NAR had lower (P < 0.01) molar proportion of acetate compared with CON, SAL, and FLA steers, whereas ruminal acetate tended to be greater (P < 0.09) for SAL vs. CON and FLA, but did not differ (P = 0.68) between CON vs. FLA steers. Ruminal propionate was the highest (P < 0.01) for steers fed NAR and did not differ (P > 0.20) between CON, SAL, and FLA. Consequently, NAR steers had the lowest (P < 0.01) Ac:Pr ratio, whereas Ac:Pr did not differ (P > 0.18) among CON, SAL, and FLA. Total volatile fatty acids were greater (P < 0.04) for NAR and CON vs. SAL and FLA, but did not differ (P > 0.67) among NAR vs. CON and SAL vs. FLA. In experiment 2, 164 Nellore bulls (initial shrunk BW = 299 ± 2.5 kg) were assigned to feedlot pens for 140 d in a randomized complete block design. Within block (n = 10), animals were randomly assigned to the same treatments used in experiment 1. Average daily gain was greater (P < 0.01) in NAR vs. CON, SAL, and FLA bulls, and did not differ (P > 0.12) between CON, SAL, and FLA bulls. Bulls fed NAR had greater (P < 0.02) DMI (as kg/d or % BW) and final shrunk BW compared with CON, SAL, and FLA bulls, whereas DMI and final shrunk BW did not differ (P > 0.26) between CON, SAL, and FLA bulls. Feed efficiency, however, was not impacted (P = 0.51) by any feed additives used herein. Collectively, narasin was the only feed additive that benefited performance and ruminal fermentation of Nellore animals fed a forage-based diet.

Effects of selenium-enriched Bacillus sp. compounds on growth performance, antioxidant status, and lipid parameters breast meat quality of Chinese Huainan partridge chicks in winter cold stress.

BACKGROUND: Both selenium (Se) and probiotic Bacillus regulate the metabolism to help defense clod stress and improve the meat quality in breeding chicks. The purpose of this study was to evaluate the effect of supplemental Se and Bacillus in the form of Se-enriched Bacillus (SECB) on the growth performance, lipid parameters, breast Se and antibiotic levels, and breast meat quality of chicken in winter cold stress. METHODS: Five hundred 1-d-old chickens were divided into five groups randomly: Control, inorganic Se, compound Bacillus, SECB, and antibiotic. The feed duration was 56 d. RESULTS: After 28 d of treatment, chicks feed SECB or compound Bacillus had higher body weights than the control, and after 56 d, chicks given either SECB or compound Bacillus had higher body weights than the control chicks or those given inorganic Se. Adding SECB to feed significantly increased the lightness, redness, and yellowness of breast meat, improved the water-holding capacity, and reduced the shear force and cooking loss. The concentration of Se in the breast muscle very significantly increased after SECB and inorganic Se supplementation, which was opposite to the concentration of flavomycin in antibiotic supplemented chicks. The antioxidative status of plasma and breast meat was significantly improved with added compound Bacillus and SECB: the total antioxidant capacity, total superoxide dismutase, and glutathione peroxidase ability in the breast muscle significantly improved, and the malondialdehyde concentration in plasma decreased. The levels of total cholesterol plasma triglyceride and very-low-density lipoprotein cholesterol in the plasma and breast muscle was decreased compared to that of the control, while the plasma high-density lipoprotein cholesterol concentration increased. CONCLUSIONS: In conclusion, SECB supplementation promoted the body growth, antioxidative status, and Se concentrations in the plasma and breast meat, and also improved the breast meat quality.

Effects of dietary coated-oleum cinnamomi supplementation on the immunity and intestinal integrity of broiler chickens.

Oleum cinnamomi (OCM) is increasingly used as a feed additive in animal diets. The aim of this study was to investigate the effects of dietary supplementation with coated-OCM (cOCM) on the immunity and intestinal integrity of broiler chickens. A total of 396 one-day-old chicks were randomly assigned into six groups. The basal diets were supplemented with 50 mg/kg of flavomycin (positive control) as well as 0 (control), 50, 100, 200, and 300 mg/kg of cOCM. Compared with the control, both positive control and cOCM treatments did not improve the growth performance. Serum immunoglobulin (Ig) Y levels were decreased by flavomycin and 50 mg/kg of cOCM treatments (p < 0.05). Dietary cOCM decreased ileal secretory IgA contents at d 21 and commonly down-regulated duodenal and ileal mRNA expression of interleukin (IL)-1ß and IL-8 at d 42 (p < 0.05). The 300 mg/kg of cOCM increased jejunal ratio of villus height to crypt depth and upregulated intestinal claudin-1 expression (p < 0.05). Jejunal (at d 21) and duodenal (at d 42) mucin-2 expression was up and downregulated by both 50 and 300 mg/kg of cOCM, respectively (p < 0.05). In conclusion, dietary cOCM addition helped to maintain noninflammatory states of humoral and mucosal immunity, and improved the intestinal integrity of broiler chickens.

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.

In-feed bambermycin medication induces anti-inflammatory effects and prevents parietal cell loss without influencing Helicobacter suis colonization in the stomach of mice.

The minimum inhibitory concentration of bambermycin on three porcine Helicobacter suis strains was shown to be 8 µg/mL. The effect of in-feed medication with this antibiotic on the course of a gastric infection with one of these strains, the host response and the gastric microbiota was determined in mice, as all of these parameters may be involved in gastric pathology. In H. suis infected mice which were not treated with bambermycin, an increased number of infiltrating B-cells, T-cells and macrophages in combination with a Th2 response was demonstrated, as well as a decreased parietal cell mass. Compared to this non-treated, infected group, in H. suis infected mice medicated with bambermycin, gastric H. suis colonization was not altered, but a decreased number of infiltrating T-cells, B-cells and macrophages as well as downregulated expressions of IL-1ß, IL-8M, IL-10 and IFN-γ were demonstrated and the parietal cell mass was not affected. In bambermycin treated mice that were not infected with H. suis, the number of infiltrating T-cells and expression of IL-1ß were lower than in non-infected mice that did not receive bambermycin. Gastric microbiota analysis indicated that the relative abundance of bacteria that might exert unfavorable effects on the host was decreased during bambermycin supplementation. In conclusion, bambermycin did not affect H. suis colonization, but decreased gastric inflammation and inhibited the effects of a H. suis infection on parietal cell loss. Not only direct interaction of H. suis with parietal cells, but also inflammation may play a role in death of these gastric acid producing cells.

Affinity-Based Screen for Inhibitors of Bacterial Transglycosylase.

The rise of antibiotic resistance has created a mounting crisis across the globe and an unmet medical need for new antibiotics. As part of our efforts to develop new antibiotics to target the uncharted surface bacterial transglycosylase, we report an affinity-based ligand screen method using penicillin-binding proteins immobilized on beads to selectively isolate the binders from complex natural products. In combination with mass spectrometry and assays with moenomycin A and salicylanilide analogues (1-10) as reference inhibitors, we isolated four potent antibacterials confirmed to be benastatin derivatives (11-13) and albofungin (14). Compounds 11 and 14 were effective antibiotics against a broad-spectrum of Gram-positive and Gram-negative bacteria, including Acinetobacter baumannii, Clostridium difficile, Staphylococcus aureus, and drug-resistant strains with minimum inhibitory concentrations in the submicromolar to nanomolar range.

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.

Development of bacterial transglycosylase inhibitors as new antibiotics: moenomycin A treatment for drug-resistant Helicobacter pylori.

The problem of multidrug-resistant Helicobacter pylori requires new antibiotics development. We have evaluated a potential antibiotics, moenomycin A, which is classified as a phosphoglycolipid antibiotics that targets transglycosylase and is previously thought to be limited in Gram-positive bacteria. Herein, we report the activity of moenomycin A against multidrug-resistant H. pylori and the isolates from patients with different gastrointestinal diseases.

Effects of flavomycin and probiotic supplementation to diets containing different sources of fat on growth performance, intestinal morphology, apparent metabolizable energy, and fat digestibility in broiler chickens.

This study was conducted with broilers to evaluate the effects of growth-promoting antibiotic (flavomycin) and probiotic (7 bacterial species) supplementation in diets containing soybean oil or free fatty acids (FFA) on performance, morphological parameters of the small intestine, apparent digestibility of gross energy (GE) in the ileum, and apparent digestibility of fat in the ileum and total intestinal tract. Eight-hundred and sixty 4-d-old Ross 308 broiler chicks were used in a 3 × 3 factorial arrangement of dietary treatments that comprised 3 additives (without additive, flavomycin, and probiotic) and 3 fat sources (without fat, 30 g/kg of FFA, and 30 g/kg of soybean oil) with 4 pen replicates per treatment. All diets contained chromic oxide (3 g/kg) as an indigestible marker. Body weight and feed intake were recorded weekly over 40 d. Flavomycin interacted positively with soybean oil and FFA causing improvements (P < 0.05) in BW gain. Among the different fat sources, soybean oil significantly increased (P < 0.05) BW gain and jejunal villi height, whereas flavomycin improved (P < 0.05) BW gain and feed conversion when compared with the remaining dietary additives. However, the probiotic negatively affected (P < 0.05) BW gain and feed conversion despite increased (P < 0.05) villi heights of the duodenum, jejunum, and ileum. At 21 and 38 d of age, fat and GE digestibility were higher (P < 0.05) in the ileum and total intestinal tract of birds fed diets containing soybean oil than those of birds fed FFA. Fat and GE digestibility were highest (P < 0.05) among birds fed flavomycin but lowest (P < 0.05) among probiotic-fed birds. Flavomycin addition to soybean oil or FFA diets significantly increased (P < 0.05) fat and GE digestibility when compared with the same diets containing the probiotic. Therefore, soybean oil is a better energy source than FFA, as indicated by increased growth, nutrient digestibility, and jejunal villi height. However, probiotic supplementation to fat-rich diets caused detrimental effects on nutrient digestibility and growth.

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.

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.

The effect of mannanoligosaccharides, bambermycins, and virginiamycin on performance of large white male market turkeys.

A study was conducted to evaluate the effects of mannanoligosaccharides (MOS), bambermycins (BAM), and virginiamycin (VIR) on the growth performance of male turkeys. Hybrid Large White male poults were assigned to six dietary treatments: control, MOS, BAM, VIR, MOS+BAM (MB), and MOS+VIR (MV). All diets were formulated to meet NRC (1994) nutrient requirements. There were eight replicate floor pens per treatment with 20 birds per pen reared from 1 to 140 d. Body weight and feed conversion (FC) were collected at 3-wk intervals and at 20 wk of age. Mortality and culled birds were recorded daily. All treatments except MV significantly (P < 0.05) increased 20 wk BW. Body weight was increased at 12 wk by BAM, whereas VIR increased BW at Weeks 12 and 15. All treatments improved FC for Weeks 0 to 3, whereas VIR, MB, and MV improved FC for Weeks 0 to 12 and 0 to 18. There were no treatment effects on cumulative mortality or cull rate. Dietary supplemental MOS, BAM, and VIR resulted in improved growth performance of Large White turkeys. These results indicate that MOS may be utilized as an alternative to antibiotic growth promotants to improve turkey performance.

A simple screen for murein transglycosylase inhibitors.

A simple assay for detection of compounds that bind to the active site in the transglycosylation domain of the essential bifunctional transglycosylase and transpeptidase penicillin-binding proteins (PBPs) is reported. The method is based on a competition with the specific transglycosylase inhibitor moenomycin. With moenomycin coupled to Affi-Gel beads, a simple filtration procedure allows the amount of labeled PBPs that bind to moenomycin beads in the presence of test substances to be determined. The PBPs can easily be labeled by the covalent binding of penicillin derivatives. Crude membrane extracts can be used as a source for the PBPs, and different kinds of labels for the penicillin-PBP complexes can be used. The assay can be adapted to high-throughput screens.

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.

Influence of Trichoderma viride enzyme complex on nutrient utilization and performance of laying hens in diets with and without antibiotic supplementation.

The experiment was designed to test possible interactions of an enzyme complex (product from Trichoderma viride) and a feed antibiotic (flavophospholipol) in a barley diet on metabolism variables and egg production performance of Warren Brown laying hens. The basal diet contained 40% winter barley (French cultivar "Express", six row). The four treatments were as follows: O, control (without supplement); E, enzyme complex, 600 ppm; A, flavophospholipol, 10 ppm; EA, enzyme complex, 600 ppm and flavophospholipol, 10 ppm. The enzyme complex contained the following main activities: cellulase (10,500 U/g), endo-beta-(1:3)(1:4)-glucanase (24,000 U/g), and xylanase (32,000 U/g). The enzyme positively influenced AME content of the feed, organic matter (OM) utilization, and neutral detergent fiber (NDF) degradability (P < or = 0.01). When supplemented alone, the antibiotic had no influence on energy and nutrient utilization. No significant differences in egg production due to dietary treatments were observed. A significant enzyme by antibiotic interaction for AME (P < or = 0.01) and OM utilization (P < or = 0.001) as well as NDF degradability (P < or = 0.01) indicated a reduced enzyme effect in the diet containing antibiotic. Negative enzyme by antibiotic interaction for energy utilization in laying hens suggested that the positive response to dietary enzyme supplementation in the mature laying hen (Treatment O vs E) was to great extent mediated by the activity of intestinal microbes.

[The effect of different flavophospholipol levels in rabbit feed on the fattening rate of hybrid rabbits]. / Die Auswirkung unterschiedlicher Flavophospholipolgehalte im Kaninchenfutter auf die Mastleistung von Hybridkaninchen.

The present study was designed to evaluate the effects of dietary flavophospholipol ("Bambermycin") levels on the growth performance in 400 hybrid rabbits from weaning at 28 days until slaughter at 74 days of age. The fryers were randomly assigned to one of the four dietary treatments that consisted of either 0, 4, 8 or 16 ppm supplemental flavophospholipol. Each treatment was applied to 100 animals each. Dietary treatments exerted no significant effects on live weight, daily weight gain and feed consumption across the entire fattening period. However, daily weight gains in treated fryers were increased by 2.4% on the average. The only significant treatment effect was found in feed conversion (food/gain) in fryers fed 16 ppm supplementation; kilogram food intake per kilogram weight gain was reduced by 0.16 kg as compared to the control group. Mean feed conversion in treated groups was improved by 3.5% on the average. In addition of flavophospholipol a significantly decreased mortality was observed. It was remarkable, that losses caused by infection in control were exclusively due to infections by Bordetella species, while the treated groups were only caused by Pasteurella species.

[The effect of flavomycin on digestion in fattening bulls]. / Einfluss von Flavomycin auf die Verdauung bei Mastbullen.

Three friesian bulls (Genotype 31) were fitted with re-entrant cannulas at the duodenum to investigate the influence of a flavomycin supplement of the digestion in the forestomachs and the other parts of the digestive tract. The supplement of flavomycin increased the total digestibility of the organic matter. The digestibility of starch and sugar was between 97% and 98%. The balance of the nutrients in the digestive tract shows, that by flavomycin supplementation the degradation of organic matter and crude protein in the fore stomach was decreased and the amount of the organic matter and crude protein in the gut was increased. The balance of the amino acids in the gut showed that after flavomycin ca. 30 g more amino acids were found in the gut. The synthesis of bacterial protein in the forestomachs was, after flavomycin application, slightly reduced as was the degradation rate of the feed protein.

Influence of a dried Bacillus subtilis culture and antibiotics on performance and intestinal microflora in turkeys.

Two experiments, each involving a 3 x 2 factorial design, were conducted with Large White Nicholas turkeys. The first experiment involved three antibiotic treatments: an unmedicated control diet, the diet plus 44 ppm of penicillin-streptomycin (1:3), and the diet plus 44 ppm of Zn bacitracin; each diet was fed in the presence and absence of a dried Bacillus subtilis culture to females 0 to 16 wk of age. Antibiotic supplements increased body weight at 12 (P less than .05) and 16 (P less than .001) wk of age. Body weight and feed efficiency were not significantly affected by feeding the B. subtilis culture in this experiment. The dietary B. subtilis culture significantly increased B. subtilis counts in the crop and cecum but failed to influence intestinal Lactobacillus or Escherichia coli counts. The second experiment also involved three antibiotic treatments: an unmedicated control diet, 44 ppm of Zn-bacitracin, and 2.2 ppm of bambermycins, and each diet was fed in the presence and absence of the dried B. subtilis culture to male birds from 0 to 20 wk of age. Increased body weight gain was observed in birds receiving the B. subtilis culture at 12 wk (P less than .01). Feed efficiency of birds receiving the B. subtilis culture was improved (P less than .05) at 20 wk. Birds receiving bambermycins had greater body weights (P less than .05) at 12 and 16 wk of age than birds receiving Zn bacitracin or the control diet. Livability was not affected by the B. subtilis culture or the antibiotic treatments in either experiment.