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

Avaliação da eficácia, inocuidade e depleção residual da flavomicina em novilhos confinados

Resumo A flavomicina é um aditivo que pertence à classe dos não ionóforos, contudo, com poucos estudos realizados com bovinos confinados em fase de terminação. Diante disso, o objetivo do presente estudo foi avaliar a eficácia da flavomicina sobre o desempenho produtivo, comportamento ingestivo, características de carcaça e os parâmetros bioquímicos de novilhos terminados em confinamento. Foram avaliados 32 novilhos inteiros, ½ sangue Angus ½ sangue Nelore, provenientes do mesmo rebanho, com idade média de 11 meses ± 1,5 meses e peso corporal inicial de 337 kg ± 6 kg. O delineamento experimental foi o de blocos casualizados, composto por dois tratamentos e oito repetições, sendo: Dieta sem flavomicina (controle) e Dieta com flavomicina (0,5 g animal dia-1 do produto FLAVIMPEX®80). Não ocorrendo diferença entre os tratamentos, o consumo de matéria seca médio dos animais foi de 10,03 kg dia-1, eficiência alimentar de 0,158 kg, ganho médio diário de 1,593 kg dia-1, digestibilidade aparente da dieta de 61,69%. O uso da flavomicina não foi eficaz no desempenho animal, assim como não trouxe alterações no comportamento ingestivo e melhorias nas características de carcaça dos animais. A Proteína Plasmática Total, Aspartato amino-transferase e creatinina foram inferiores para os animais suplementados com flavomicina em relação ao grupo controle. Em relação ao período experimental houve redução nos índices de Proteína Plasmática Total, aumento na albumina, Gama-Glutamil Transferase e ureia dos bovinos, mas todos se mantiveram dentro dos valores de referência para a espécie.

On the efficacy, innocuity and residual depletion of flavomycin in confined steers

Abstract Flavomycin is a non-ionophore additive little studied in finishing confined cattle. Therefore, this study aimed to evaluate the effectiveness of flavomycin on productive performance, ingestive behavior, carcass traits and biochemical parameters of steers finished in confinement. 32 whole steers, ½ Angus e ½ Nellore blood, from the same herd, with a mean age of 11 ± 1.5 months and initial body weight of 337 ± 6 kg were evaluated. The experiment was a randomized block design, consisting of two treatments and eight replications, as follows: Diet without flavomycin (control) and Diet with flavomycin (0.5 g FLAVIMPEX®80 animal day-1). There was no difference between treatments, the average dry matter intake of the animals was 10.03 kg day-1, feed efficiency was 0.158 kg, average daily gain was 1.593 kg day-1, apparent diet digestibility was 61.69%. The use of flavomycin was not effective in animal performance, and caused no changes in ingestive behavior and carcass traits of the animals. Total Plasma Protein, Aspartate amino-transferase and creatinine were lower for animals supplemented with flavomycin compared to the control group. In relation to the experimental period, there was a reduction in the levels of Total Plasma Protein, an increase in albumin, Gamma-Glutamyl Transferase and urea in cattle, but all remained within the reference range for the species.

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.

Characterisation of the effect of day length, and associated differences in dietary intake, on the gut microbiota of Soay sheep

Differences in the rumen bacterial community have been previously reported for Soay sheep housed under different day length conditions. This study extends this previous investigation to other organs of the digestive tract, as well as the analysis of ciliated protozoa and anaerobic fungi. The detectable concentrations of ciliated protozoa and anaerobic fungi decreased with increased day length in both the rumen and large colon, unlike those of bacteria where no effect was observed. Conversely, bacterial community composition was affected by day length in both the rumen and large colon, but the community composition of the detectable ciliated protozoa and anaerobic fungi was not affected. Day length-associated differences in the bacterial community composition extended to all of the organs examined, with the exception of the duodenum and the jejunum. It is proposed that differences in rumen fill and ruminal ‘by-pass’ nutrients together with endocrinological changes cause the observed effects of day length on the different gut microbial communities.

Implications of butyrate and its derivatives for gut health and animal production

Butyrate is produced by microbial fermentation in the large intestine of humans and animals. It serves as not only a primary nutrient that provides energy to colonocytes, but also a cellular mediator regulating multiple functions of gut cells and beyond, including gene expression, cell differentiation, gut tissue development, immune modulation, oxidative stress reduction, and diarrhea control. Although there are a large number of studies in human medicine using butyrate to treat intestinal disease, the importance of butyrate in maintaining gut health has also attracted significant research attention to its application for animal production, particularly as an alternative to in-feed antibiotics. Due to the difficulties of using butyrate in practice (i.e., offensive odor and absorption in the upper gut), different forms of butyrate, such as sodium butyrate and butyrate glycerides, have been developed and examined for their effects on gut health and growth performance across different species. Butyrate and its derivatives generally demonstrate positive effects on animal production, including enhancement of gut development, control of enteric pathogens, reduction of inflammation, improvement of growth performance (including carcass composition), and modulation of gut microbiota. These benefits are more evident in young animals, and variations in the results have been reported. The present article has critically reviewed recent findings in animal research on butyrate and its derivatives in regard to their effects and mechanisms behind and discussed the implications of these findings for improving animal gut health and production. In addition, significant findings of medical research in humans that are relevant to animal production have been cited.

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-1β, 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-1β 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.

Monensin, virginiamycin, and flavomycin in a no-roughage finishing diet fed to zebu cattle

Two experiments were designed to evaluate the effects of monensin, virginiamycin, and flavomycin on growth performance, carcass characteristics, apparent total tract nutrient digestibility, and rumen fermentation of zebu cattle fed a no-roughage finishing diet (whole shelled corn [WSC] based). In Exp. 1, 100 crossbred bulls (; 392 kg [SD 46.8] average initial BW) were blocked by initial BW in a 101-d feedlot trial. Five treatments were evaluated using 4 pens per treatment (5 bulls/pen): monensin at 30 mg/kg DM, virginiamycin at 25 mg/kg DM, monensin at 20 mg/kg DM plus virginiamycin at 25 mg/kg DM, flavomycin at 4.4 mg/kg DM, and monensin at 20 mg/kg DM plus flavomycin at 2.2 mg/kg DM. There were no differences in growth performance (final BW, ADG, DMI, and G:F; ≥ 0.527) and carcass characteristics (HCW, dressing percent, and 12th-rib fat; ≥ 0.235) among treatments. In Exp. 2, 7 ruminally fistulated steers were used in a 7 × 7 Latin square design to evaluate the 5 treatments of Exp. 1 and 2 additional treatments: monensin at 30 mg/kg DM plus virginiamycin at 25 mg/kg DM and monensin at 20 mg/kg DM plus flavomycin at 4.4 mg/kg DM. Experimental periods were 14 d in length (9 d of adaptation and 5 d of measurements). Apparent total tract DM, OM, CP, and NDF digestibilities were similar among treatments ( ≥ 0.224). There was no treatment effect ( ≥ 0.253) in rumen fermentation responses (ruminal pH, rumen ammonia nitrogen, VFA, and number of protozoa). In conclusion, no evidence of benefits to cattle fed a no-roughage WSC-based diet was found to support the use of monensin combined with virginiamycin or flavomycin in the doses tested herein.

Moenomycin family antibiotics: chemical synthesis, biosynthesis, and biological activity

The review (with 214 references cited) is devoted to moenomycins, the only known group of antibiotics that directly inhibit bacterial peptidoglycan glycosytransferases. Naturally occurring moenomycins and chemical and biological approaches to their derivatives are described. The biological properties of moenomycins and plausible mechanisms of bacterial resistance to them are also covered here, portraying a complete picture of the chemistry and biology of these fascinating natural products

Correlation of particular bacterial PCR-denaturing gradient gel electrophoresis patterns with bovine ruminal fermentation parameters and feed efficiency traits

The influence of rumen microbial structure and functions on host physiology remains poorly understood. This study aimed to investigate the interaction between the ruminal microflora and the host by correlating bacterial diversity with fermentation measurements and feed efficiency traits, including dry matter intake, feed conversion ratio, average daily gain, and residual feed intake, using culture-independent methods. Universal bacterial partial 16S rRNA gene products were amplified from ruminal fluid collected from 58 steers raised under a low-energy diet and were subjected to PCR-denaturing gradient gel electrophoresis (DGGE) analysis. Multivariate statistical analysis was used to relate specific PCR-DGGE bands to various feed efficiency traits and metabolites. Analysis of volatile fatty acid profiles showed that butyrate was positively correlated with daily dry matter intake (P < 0.05) and tended to have higher concentration in inefficient animals (P = 0.10), while isovalerate was associated with residual feed intake (P < 0.05). Our results suggest that particular bacteria and their metabolism in the rumen may contribute to differences in host feed efficiency under a low-energy diet. This is the first study correlating PCR-DGGE bands representing specific bacteria to metabolites in the bovine rumen and to host feed efficiency traits.

Linkage of microbial ecology to phenotype: correlation of rumen microbial ecology to cattle's feed efficiency

Linkage of rumen microbial structure to host phenotypical traits may enhance the understanding of host-microbial interactions in livestock species. This study used culture-independent PCR-denaturing gradient gel electrophoresis (PCR-DGGE) to investigate the microbial profiles in the rumen of cattle differing in feed efficiency. The analysis of detectable bacterial PCR-DGGE profiles showed that the profiles generated from efficient steers clustered together and were clearly separated from those obtained from inefficient steers, indicating that specific bacterial groups may only inhabit in efficient steers. In addition, the bacterial profiles were more likely clustered within a certain breed, suggesting that host genetics may play an important role in rumen microbial structure. The correlations between the concentrations of volatile fatty acids and feed efficiency traits were also observed. Significantly higher concentrations of butyrate (P < 0.001) and valerate (P = 0.006) were detected in the efficient steers. Our results revealed potential associations between the detectable rumen microbiota and its fermentation parameters with the feed efficiency of cattle.

Risk assessment of ciprofloxacin, flavomycin, olaquindox and colistin sulfate based on microbiological impact on human gut biota

Trace levels of veterinary antibiotics that reside in livestock products may disturb the balance of human intestinal microbiota and impair the colonized barrier function, which is critical to protect against the invasion or overgrowth of exogenous pathogens. We investigated the colonization barrier disruption effect of ciprofloxacin, flavomycin, olaquindox and colistin sulfate by the minimum inhibitory concentration (MIC) assay in pure culture of human gut bacteria and evaluated the no-observed-effect-concentration (NOEC) and acceptable daily intake (ADI) based on the microbiological impact. MICs of the antibiotics were tested for total 100 isolates composed of 10 isolates from each of 10 predominant genera of human faeces that were freshly collected from healthy women at 1x10(5) and 1x10(9) colony-forming units (CFU)/ml. MIC assay was also conducted with 10 ATCC standard bacteria species of human fecal microbiota for the comparison with freshly isolated human fecal mirobiota. The most susceptible bacteria were Escherichia coli for ciprofloxacin and colistin sulfate, Fusobacterium spp. for flavomycin and Eubacterium spp. for olaquindox. MIC values were lower at 1x10(5) than at 1x10(9)CFU/ml. The susceptibility of feacal microbiota freshly isolated from healthy women tended to be similar with those of ATCC standard bactera. NOEC (microg/ml) and ADI (microg/kg BW/day) were evaluated as 0.008 and 0.15 for ciprofloxacin, 0.25 and 1 for flavomycin, 0.125 and 3 for olaquindox and 1.0 and 7 for colistin sulfate, respectively.