Feed Additives For Growth Promotion Research Articles

Investigating antibiotic free feed additives for growth promotion in poultry: effects on performance and microbiota

The poultry industry is evolving towards antibiotic-free production to meet market demands and decelerate the increasing spread of the antimicrobial resistance. The growing need for antibiotic free products has challenged producers to decrease or completely stop using antimicrobials as feed supplements in broiler diet to improve feed efficiency, growth rate, and intestinal health. Natural feed additives (e.g., probiotics and phytobiotics) are promising alternatives to substitute antimicrobial growth promoters. The goal of our study was to characterize the effects of a Probiotic and an Essential Oils blend on broilers' performance and perform a time-series analysis to describe their excreta microbiome. A total of 320 Cobb 500 (1-day-old) chicks were raised for 21 d in 32 randomly allocated cages. Treatments consisted of 4 experimental diets: a basal diet, and a basal diet mixed with an Antibiotic (bacitracin methylene disalicylate), an essential oils blend (oregano oil, rosemary, and red pepper), or a Probiotic (Bacillus subtilis). Body weight (on 1, 10, and 21d), and feed intake (10d and 21d) were recorded and feed conversion ratio was calculated. Droppings were collected daily (1-21d) to characterize broilers' excreta microbiota by targeted sequencing of the bacterial 16S rRNA gene. The Probiotic significantly improved feed conversion ratio for starter phase 1 to 10d (P = 0.03), grower phase 10 to 21d (P = 0.05), and total period 1 to 21d (P = 0.01) compared to the Antibiotic. Feed supplements did not affect alpha diversity but did impact microbial beta diversity (P < 0.01). Age also impacted microbiome turnover as differences in alpha and beta diversity were detected. Furthermore, when compared to the basal diet, the probiotic and antibiotic significantly impacted relative abundance of Bifidobacterium (log2 fold change -1.44, P = 0.03), Intestinimonas (log2 fold change 0.560, P < 0.01) and Ligilactobacillus (log2 fold change -1.600, P < 0.01). Overall, Probiotic supplementation but not essential oils supplementation positively impacted broilers' growth performance by directly causing directional shifts in broilers' excreta microbiota structure.

Core-Satellite Nanoassemblies as SPR/SERS Dual-Mode Plasmonic Sensors for Sensitively Detecting Ractopamine in Complex Media.

Highly sensitive and reliable detection of β-adrenergic agonists is especially necessary due to the illegal abuse of growth-promoting feed additives. Here, we develop a novel surface plasmon resonance/surface-enhanced Raman scattering (SPR/SERS) dual-mode plasmonic sensor based on core-satellite nanoassemblies for the highly sensitive and reliable detection of ractopamine (RAC). The addition of RAC results in the decomposition of core-satellite nanoassemblies and consequently changes the Rayleigh scattering color of dark-field microscopy (DFM) images and the Raman scattering intensity of SERS spectra. The excellent sensitivity, specificity, and uniformity of this strategy were confirmed by detecting RAC in various complex media in the farm-to-table chain, and the limit of detection (LOD) was 0.03 ng/mL in an aqueous solution. In particular, the convenient access to livestock sewage not only ensures animal welfare but also provides great convenience for the market regulation of β-agonists. The success of our on-site strategy only with a portable Raman device promises great application prospects for β-agonist detection.

Effect of Dietary Gelsemium elegans Benth. Extract on the Growth, Slaughter Performance, Meat Quality, Intestinal Morphology, and Microflora of Yellow-Feathered Chickens.

The plant species Gelsemium elegans Benth. (GEB) promotes pig and sheep growth; however, little is known about its effects in chickens. In this study, a GEB extract (GEBE) was prepared, and its effects on the growth, slaughter, antioxidant performance, meat quality, serum biochemical indices, intestinal morphology, and microflora of yellow-feathered chickens were evaluated. In total, 600 chickens aged 15 days were randomly divided into four groups with five replicates each and fed a basal diet containing 0% (control), 0.25% (0.25 GEBE), 0.75% (0.75 GEBE), or 1.25% (1.25 GEBE) GEBE until 49 days of age. Chickens were then killed, and their meat, organs, and serum and cecal contents were collected. GEBE reduced the feed conversion ratio, particularly in the 0.75 and 1.25 GEBE groups. Furthermore, the GEBE diet improved meat tenderness and reduced the meat expressible moisture content and liver malondialdehyde content, indicating high meat quality. Whereas the 0.25 GEBE diet increased the level of Lactobacillus acidophilus in the cecum, the 0.75 GEBE diet decreased the Escherichia coli level therein. These findings demonstrate that GEBE may improve the meat quality and cecal microbiota of yellow-feathered chickens, providing a basis for identifying candidate alternatives to conventional antibiotics as growth promoting feed additives.

Effect of Dietary Compound Acidifiers Supplementation on Growth Performance, Serum Biochemical Parameters, and Body Composition of Juvenile American Eel (Anguilla rostrata)

As growth-promoting feed additives, compound acidifiers (CAs) have been widely reported in many farmed fish species, whereas there is little information on the application of CAs in the eel diet. The present trial was conducted to evaluate the supplementation effects of CAs on growth performance, serum biochemical parameters, and body composition of the juvenile American eel (Anguilla rostrata). The CAs supplementation levels in the diet of American eel were 0, 2.0, 3.0, 4.0, and 5.0 g/kg, respectively. The trial lasted for 12 weeks. The most beneficial effects of CAs on promoting growth performance, decreasing levels of serum lipid, modifying parameters of the liver function and immune function in the serum, and increasing the utilization of calcium and phosphorus in the diet were observed in the fish fed with 4.0 g/kg CAs. Dietary CAs supplementation had no significant effects on the body composition of whole fish, whereas 5.0 g/kg of dietary CAs supplementation exerted negative effects on growth performance, serum biochemical parameters, and utilization of calcium and phosphorus. The recommended level of CAs in the diet was 3.5–3.7 g/kg to achieve the optimal weight gain and feed conversion ratio for the juvenile American eel.

Growth indices, intestinal histomorphology, and blood profile of rabbits fed probiotics- and prebiotics-supplemented diets.

In a 12-week feeding trial, 32 rabbits (Chinchilla × New Zealand White; 56 days old; 691 ± 1 g body weight) were used to investigate the effect of pro- and prebiotics as growth enhancer on the growth performance, intestinal mucosal development, hematological and serum biochemical responses of rabbits. The dietary Biotronic® prebiotics and Biovet®-YC probiotics were added at 400 mg/kg and 50 mg/kg, respectively. The rabbits were housed individually and randomly assigned to four dietary treatments (n = 8/group; 50:50 bucks to does) including a control diet (diet 1), diet 2 (control + Biotronic® prebiotics), diet 3 (control + Biovet®-YC probiotics) and diet 4 (control + symbiotics [Biotronic® prebiotics and Biovet®-YC probiotics]). Body weight (BW), average daily gain (ADG), dry matter intake (DMI), and feed conversion ratio (FCR) were monitored. Five rabbits per treatment were used for organ assessment and intestinal histomorphology after feeding trial. Blood samples were collected for hematological and serum biochemical analysis. Results showed that supplementation of Biotronic® prebiotics and symbiotics in rabbit diet significantly (P < 0.05) increased final BW and ADG compared to Biovet®-YC probiotic and control diets. Kidney, lung, esophagus, gastro-intestinal tract, small and large intestines were significantly (P < 0.05) influenced by dietary treatments. Ileal mucosal assessment revealed that villus height (VH), villus width, villus density, crypt depth (CD), and VH:CD ratio of rabbits fed Biotronic® prebiotic and symbiotic diets were similar and significantly (P < 0.05) higher than those rabbits fed control and Biovet®-YC probiotic diets. Packed cell volume of rabbits fed symbiotic and control diets was significantly (P < 0.05) higher than those fed Biotronic® prebiotic and Biovet®-YC probiotic diets. This study suggests that Biotronic® prebiotics and its combination with Biovet®-YC probiotics are good alternative growth promoting feed additives in rabbit nutrition. They improved performance, intestinal development and blood profiles and aid feed digestion, nutrient absorption and utilization in rabbits.

Size-dependent modulation of CoOOH nanoflakes light scattering for rapid and selective detection of tetracycline in milk

As an antibiotic, tetracycline has been widely used against bacterial infection or as feed additives for growth promotion, which may lead to the enrichment of antibiotic residues in animals or their products. Therefore, the detection of tetracycline is closely related to human health. The morphological transformation of CoOOH nanoflakes induced by tetracycline was monitored by scanning electron microscope images, dark-field light scattering images and optical spectra, which found that tetracycline could decompose CoOOH nanoflakes into small nanoparticles with low light scattering signal. As a result, the reduced light scattering of CoOOH nanoflakes was proportional to the increased concentration of tetracycline in the range of 1.0–250 μmol/L, and the limit of determination (LOD) was 0.23 μmol/L (3σ/k). Most foreign substances did not interfere in the analysis of tetracycline. Furthermore, the concentration of tetracycline in different milk samples detected with the standard addition method was so low that it accorded with the safety regulation, which was similar to the detection result with high-performance liquid chromatography (HPLC).

Subchronic toxicity and hepatocyte apoptosis of dietary olaquindox in common carp (Cyprinus carpio)

Olaquindox as one of the effective antimicrobial agents and growth-promoting feed additives, had been widely used in animal and fish production. However, few studies have been done to unveil its possible toxic effect and tissue injury on aquatic animal. In this study, the toxic effect and underlying mechanisms of olaquindox toxicity were investigated in common carp when feed with different doses of olaquindox for 90 days. The morbidity and mortality, pathological changes, hematology parameters, residue concentration in the tissues of common carp were assessed, hepatocyte apoptosis was detected through ultrastructural observation and flow cytometry methods. The results showed that the morbidity and mortality increased with the increasing dosages of dietary olaquindox, subchronic exposure to olaquindox caused remarkably pathological changes, including congestion and bleeding, intramuscular edema, vacuolar degeneration, degeneration and deformation in renal tubules architecture, respiratory epithelium fusion and intestinal epithelial microvilli disintegration. Besides, dietary olaquindox led to significant changes in blood biochemical parameters including red blood cell, hemoglobin, alanine aminotransferase and aspartate aminotransferase, an elevated residue concentration of olaquindox was detected in liver and kidney after exposure, hepatocyte apoptosis and necrosis were observed. Moreover, insulin-like growth factor I (IGF-I) mRNA level in liver was higher than normal level with the dose below 25 mg/kg olaquindox and was lower than normal level with the dose above 50 mg/kg. Our results demonstrated that dietary olaquindox may pose subchronic toxicity and residue in fish organs and provided scientific data for the safe application of olaquindox in fish.

Effects of dietary supplementation of cinnamaldehyde and formic acid on growth performance, intestinal microbiota and immune response in broiler chickens

An experiment was conducted to investigate the effects of replacing antibiotic growth promoter (AGP) with a combination of essential oil and organic acids (EO + OA) on growth performance, gut microbiota and immune response in broiler chickens. In Experiment 1, 320 day-old broiler chicks were randomly distributed to 32 pens with 10 birds in each pen and the pens were equally allotted to four treatment groups. In Experiment 2, 120 day-old chicks were divided into the same four treatment groups, each group containing three replicated pens with 10 birds in each pen. The groups were (1) Negative Control (NC) without AGP or other growth-promoting feed additives; (2) AGP (NC + enramycin; 125 mg/kg feed; (3) OA (NC + OA; 500 mg/kg feed); and (4) EO + OA (NC + a combination of cinnamaldehyde and calcium formate; 500 mg/kg feed). Experiment 1 lasted for 40 days, whereas Experiment 2 continued for 28 days. In Experiment 2, all birds were orally challenged with Escherichia coli (108 bacteria/bird) on Day 14. Overall intake, growth and feed conversion ratio (FCR) on Day 40 had no difference (P &gt; 0.05) among the groups in Experiment 1. In Experiment 2, growth, feed intake and FCR were not affected by any dietary treatments until Day 14, but after being challenged with E. coli, bodyweight gain and FCR improved (P &lt; 0.05) for AGP and EO + OA compared with NC. Mortality rate was also lower (P &lt; 0.05) for AGP and EO + OA than NC in Experiment 2. Villi height was higher (P &lt; 0.001) in OA and EO + OA groups compared with NC and AGP groups. Any treatment did not affect (P &gt; 0.05) the counts of total bacteria, E. coli and Lactobacillus in the contents of ileum and caecum. However, Salmonella counts in the ileal and caecal contents decreased (P &lt; 0.001) for AGP, OA and EO + OA compared with NC group. Clostridium counts were lower for EO + OA group than for NC and AGP groups in the ileum, and for AGP, OA and EO + OA groups than for NC in the caeca (P &lt; 0.05). Antibody titer on Day 35 against Newcastle disease vaccine was higher in EO + OA group than in NC, AGP and OA groups (P &lt; 0.001). In conclusion, EO + OA did not affect growth and FCR in broilers. However, AGP and EO + AO improved growth performance and FCR after being challenged with E. coli. Moreover, EO + OA was effective in reducing the Clostridium count in the small intestine and caecum and increasing the villus height and antibody titer against Newcastle disease vaccine.

Development of a highly sensitive and specific monoclonal antibody based enzyme-linked immunosorbent assay for the detection of a new β-agonist, phenylethanolamine A, in food samples.

All β-agonists are banned as feed additives for growth promotion in animals due to toxic effects on humans after consuming the β-agonist contaminated meats. Phenylethanolamine A (PA) is a newly emerged β-agonist. Thus there is a need to develop highly sensitive and specific analytical methods for the detection of PA in food samples. In this study, the monoclonal antibody (mAb) against PA was produced by hybridoma technology and used for the development of enzyme-linked immunosorbent assay (ELISA). The IC50 values and limits of detection (LODs) of the ELISA using homogeneous combination of coating antigen/antibody for PA were 0.16 ng mL-1 and 0.011 ng mL-1 , respectively. The cross-reactive (CR) values of the assay with 14 structurally related β-agonists were lower than 0.59%. Swine liver and meat samples were spiked with PA at different content and analysed by ELISA. Acceptable recovery rates of 91.40-105.51% and intra-assay coefficients of variation of 1.56-9.92% (n = 3) were obtained. The ELISA for seven spiked samples was confirmed by LC-MS/MS with a high correlation coefficient of 0.9881. The proposed mAb-based ELISA was highly sensitive and specific for PA and could be used as a quantitative/screening method for PA analysis in food samples. © 2016 Society of Chemical Industry.

Extensive Literature Search on the ‘Effects of Copper intake levels in the gut microbiota profile of target animals, in particular piglets’

Extensive Literature Search on the ‘Effects of Copper intake levels in the gut microbiota profile of target animals, in particular piglets’

Livestock-associated Staphylococcus aureus: the United States experience.

Staphylococcus aureus is a gram-positive bacterium that colonizes a variety of animal species [1]. S. aureus infections in animals are most commonly reported as a cause of mastitis in dairyproducing animals (including cattle and goats) and “bumblefoot” in chickens [2], as well as being identified as a pathogen of farmed rabbits [3]. Most reports characterizing animalassociated S. aureus have demonstrated that strains affecting animals are distinct from those infecting humans, suggesting that there are host-specific lineages which only rarely cross species boundaries [4]. Livestock-associated strains may evolve on farms because of the use of antibiotics in animal husbandry. These may be used as feed additives for growth promotion in industrial livestock and poultry [5], for prevention of disease within a herd, or for treatment of an existing disease outbreak. Agricultural-use antibiotics include many classes that are relevant for human health, including tetracyclines, macrolides, penicillins, and sulfonamides, among others. Antimicrobial resistance generated during animal husbandry may then be spread to the general human population in a number of different manners: contact with contaminated meat products (via handling or ingestion); occupational contact (farmers, meat packers, butchers, etc.) and potential secondary spread into the larger community from those who are occupationally exposed; entry into and transmission via hospitals or other health care facilities; or spread via environmental routes including air, water, or manure in areas in proximity to live animal farms or crop farms where manure has been used as a fertilizer (Fig. 1). While methicillin resistance has been the most commonly investigated phenomenon and will be the main topic of this review, resistance to any of these antibiotics can occur and can potentially be a threat to successful treatment of S. aureus infections and therefore to human health outcomes. As such, my research group and others have begun to look more broadly at any S. aureus present on farms, including those that may be susceptible to methicillin but resistant to other antibiotics.

Development of a colloidal gold-based lateral-flow immunoassay for the rapid detection of phenylethanolamine A in swine urine

Phenylethanolamine A (PEAA) is a newly emerged phenethanolamine member of the family of β-adrenergic agonists illegally used as feed additives for growth promotion.

Mannose rich fraction of Saccharomyces cerevisiae promotes growth and enhances carcass yield in commercially housed grower–finisher pigs

An 80 day study was conducted to evaluate the growth promoting effects of a unique mannose rich fraction (MRF) derived from yeast cell walls of Saccharomyces cerevisiae, relative to copper and tylosin in commercially housed grower and finisher pigs. 1008 male grower pigs (29.7±1.99kg live weight) were randomly allocated to four treatment groups of 252 pigs. There were 12 replicates for growth rates (21 pigs per pen) and 6 replicates for feed intake and FCR (42 pigs per feeder). The dietary treatments consisted of a control (CON, containing no growth promoting feed additives), copper (COP, containing 200ppm of copper as copper sulphate in both grower and finisher pigs), MRF (containing 400ppm and 200ppm of Actigen™ (Alltech Biotechnology, Nicholasville, KY) in grower and finisher diets respectively), and tylosin (TYL, containing 40g and 20g of tylosin in grower and finisher diets respectively). Growth performance and mortality were monitored over the grower (d 0–38) and finisher (d 39–80) periods. Slaughter characteristics (carcass weight and backfat thickness at the P2 position) were recorded at d 80. Mannose rich fraction pigs grew faster (P<0.01) than CON or COP pigs during the grower phase. Mannose rich fraction and TYL pigs also tended to (P=0.08) have better FCR during the grower phase than those on the CON and COP treatments. No significant treatment effects were observed for growth performance during the finisher phase or over the entire study (d 0–80). However, MRF pigs had a significantly higher (P<0.01) dressing percentage and heavier carcass weight than pig on all other treatments. There was no influence of growth promoting feed additives on backfat thickness. Overall, MRF was as effective as tylosin and more effective than copper as a growth promoter in grower pigs. Mannose rich fraction inclusion was able to enhance the yield of saleable pork, and was the most effective growth promoting option tested.

A monoclonal antibody based enzyme-linked immunosorbent assay for detection of phenylethanolamine A in tissue of swine

Phenylethanolamine A (PEA) is a phenethanolamine member of the family of β-adrenergic agonists compounds illegally used as feed additives for growth promotion. In this study, PEA was covalently linked to carrier protein cationized bovine serum albumin (cBSA) and egg albumin (OVA). A monoclonal antibody specific for PEA was produced and characteristics of monoclonal antibody (McAb) were studied. Based on the McAb, an enzyme-linked immunosorbent assay (ELISA) for detection of PEA was developed, which showed an IC50 value of 6.25ngmL−1 and a detection limit of 0.19ngmL−1. The average recovery of PEA from spiked samples was 103.4%, which demonstrated that the matrices of meat where PEA may be found do not interfere with the assay.

Development of a highly sensitive and specific enzyme-linked immunosorbent assay (ELISA) for the detection of phenylethanolamine A in tissue and feed samples and confirmed by liquid chromatography tandem mass spectrometry (LC–MS/MS)

Phenylethanolamine A (PA) is a new emerged β-adrenergic agonist illegally used as feed additives for growth promotion. In this study, a highly sensitive and specific indirect competitive enzyme-linked immunosorbent assay (ELISA) for the detection of PA in tissue and feed samples was developed and confirmed by liquid chromatography tandem mass spectrometry (LC–MS/MS). By reduction of nitryl group to amino group, the PA derivative was synthesized and coupled to carrier proteins with diazobenzidine method. The antisera obtained from four immunized rabbits were characterized in terms of sensitivity and specificity. All antisera displayed high sensitivity with IC50 values lower than 0.48ngmL−1. The most sensitive ELISA was established with IC50 and limit of detection (LOD) values of 0.049ngmL−1 and 0.003ngmL−1, respectively. The cross-reactivity (CR) values of the antisera with three frequently used β-adrenergic agonists (clenbuterol, salbutamol and ractopamine) were lesser than 0.39%; there was no CR of the antisera with other six compounds including two structurally related substances (isoproterenol, phenylephrine). To investigate the accuracy and precision of the assay, swine kidney, liver, meat and feed samples were fortified with PA at different content and analyzed by ELISA. Acceptable recovery rates of 92.2–113.7% and intra-assay coefficients of variation of 3.8–10.9% (n=3) were achieved. Seven spiked samples were simultaneously analyzed by ELISA and LC–MS/MS. There was a high correlation coefficient of 0.9956 (n=7) between the two methods. The proposed ELISA proven to be a feasible quantitative/screening method for PA analysis in tissue and feed samples with the properties of high sensitivity and specificity, high sample throughput and low expensive.

Nitrofurans residue in broiler chicken meat which analysed by an HPLC

Furazolidone (FZD), furaltadone (FTD), nitrofurantoin (NFT) and nitrofurazone (NFZ) are veterinary drugs that belong to the nitrofurans (NFs) group and employed as feed additives for growth promotion and theurapetic treatment of gastrointestinal infections caused by Eschericia coli and Salmonella spp. The occurrence of NFs in animal products will end to cause health problem in human consumed such food. This research conducted to study the analysis of NF residues in chicken meat by a high performance liquid chromatography (HPLC) and to study the occurrence of NFs residues in samples collected from traditional markets and supermarkets in Bandung, Bogor and Depok. The results of validation method on several parameters for each NF showed that the average of the relative standard deviation (RSD) from the precision study were 2.15 to 2.38%, the R 2 values of the linearity study were 0.9964 to 0.9995; recoveries were 75.90 % to 91.50 % and the detection limits were 12.01 to 37.25 ng/g. The residual level of NFs for 42 field samples showed that 2 samples positive for NFZ (9.09 and 10.74 ng/g), 1 positive for NFT (10.46 ng/g), 4 positive for FTD (16.44 up to 27.21 ng/g) and none positive for FZD. Present results showed that analysis of NFs in broiler chicken meat can be done using an HPLC and the analysis results from field samples showed that these types of drugs were being used for broiler chicken production both as single and/or combination drugs, therefore it is necessary to raise public awareness to monitor the use of NF in livestock production in Indonesia. Kata Kunci : Detection, Residue, Nitrofurans, Chicken Meat, HPLC

The Usefulness of Prebiotics and Probiotics in Modern Poultry Nutrition: a Review / Przydatność prebiotyków i probiotyków w nowoczesnym żywieniu drobiu – przegląd

Abstract A probiotic is a culture of live microorganisms that can manipulate and maintain a beneficial microflora in the gut. Prebiotics are nondigestible feed ingredients that can positively affect the animal organism by stimulating the activity and growth of beneficial native bacteria in the gastrointestinal tract and eliminate the pathogenic ones. Some studies have shown their beneficial effects when they have been used separately or simultaneously in the form of synbiotics, to obtain enhanced mutual effect. These supplements were proposed with success as alternatives to antibiotic growth-promoting feed additives but further studies are needed to better understand their mode of action and effects. This review article presents growing interest in using these antibiotic alternatives, the potential mechanism of their action in the live organism, and discusses some recent data on the effects of these supplements in poultry nutrition.

PREVALENCE OF SOME ANTIBIOTIC RESISTANT STRAINS OF SALMONELLAE IN COMMERCIAL TABLE EGGS IN PORT-SAID CITY.

Multi-drug resistant Salmonellastrains have emerged, presumably due to the extensive use of antimicrobial agents both in human and animals. In veterinary practice, antibiotics are used in livestock production, disease prevention and as growth-promoting feed additives. In the present study, the occurrence of Salmonellain local chicken eggs and their pattern of antibiotic resistance were determined. One hundred and forty chicken egg samples - collected from different locations of Port-Said City - were analyzed and Salmonella spp . detected in 3.6% of the samples. Among all presumptive Salmonellaisolates,theisolates were confirmed as Salmonella Typhimurium(40%),Salmonella agona (20%) and Salmonella derby (40%) on the basis of serotyping and biochemical analysis. These isolates were subjected to susceptibility test against 9 antimicrobial disks. All the isolates were sensitive (100%) to doxycycline hydrochloride, chloramphenicol and trimethoprim-sulphamethoxazole. The highest percentage of resistance (100%) was found to erythromycin. Resistance against, streptomycin (20%), and penicillin G. (40%) was also found. One isolate of theSalmonella Typhimurium serovars (50%) showed resistance for streptomycin, nalidixic acid, oxytetracycline and penicillin G., while the other Salmonella typhimurium isolate (50%) showed high susceptibility for the same 4 antimicrobial drugs. Nearly similar results were shown for the isolated Salmonella derby, were one isolate (50%) showed high susceptibility for neomycin and oxytetracycline, while it was resistant to penicillin G. The otherSalmonella derby isolate (50%) showed intermediate susceptibility for neomycin and oxytetracycline, while it was highly sensitive for penicillin G. Salmonellaisolated from egg shell surfaces had more antimicrobial resistance than that of the egg contents. The present study suggested that, poultry eggs are potential reservoir of antibiotic resistant Salmonellae. The public health hazard of this microorganism, as well as recommended measures to improve quality status of table eggs were discussed.

Effects of broccoli extract and various essential oils on intestinal and faecal microflora and on xenobiotic enzymes and the antioxidant system of piglets

Objective: Since the ban of antibiotics as growth promoting feed additives in the EU in 2006 research in alternatives has gained importance. Phytogenic feed additives represent a heterogenous class of different plant derived substances that are discussed to improve the health of farm animals by direct and indirect antioxidant effects and by influencing microbial eubiosis in the gastrointestinal tract. Consequently our study aimed to investigate the influence of broccoli extract and the essential oils of turmeric, oregano, thyme and rosemary, as selected individual additives, on intestinal and faecal microflora, on xenobiotic enzymes, and on the antioxidant system of piglets. Methods: 48 four weeks old male weaned piglets were assigned to 6 groups of 8. The piglets were housed individually in stainless steel pens with slatted floor. The control group (Con) was fed a diet without an additive for 4 weeks. The diet of group BE contained 0.15 g/kg sulforaphane in form of a broccoli extract. 535, 282, 373 and 476 mg/kg of the essential oils of turmeric (Cuo), oregano (Oo), thyme (To) and rosemary (Ro) were added to the diets of the remaining 4 groups to standardise supplementation to 150 mg/kg of the oils’ key terpene compounds ar-turmerone, carvacrol, thymol and 1,8-cineole. The composition of bacterial microflora was examined by cultivating samples of jejeunal and colonic mucosa and of faeces under specific conditions. The mRNA expression of xenobiotic and antioxidant enzymes was determined by reversing transcriptase real time detection PCR (RT-PCR). Total antioxidant status was assayed using the Trolox Equivalent Antioxidant Capacity (TEAC), and lipid peroxidation was determined by measuring thiobarbioturic acid reactive substances (TBARS). Results: Compared to Con piglets all additives positively influenced weight gain and feed conversion in week 1. Over the whole trial period no significant differences in performance parameters existed between the experimental groups. Compared to group Con performance of Ro piglets was, however, slightly impaired. Compared to Con piglets Cuo, Oo and To increased the ratio of Lactobacilli:E. coli attached to the jejunal mucosa, whereas BE and Ro impaired this ratio slightly. In contrast in colonic mucosa Ro improved Lactobacilli:E. coli ratio. In faecal samples an improvement of Lactobacilli:E. coli ratio could be analysed for To and Ro. Ro was the only additive that reduced the incidence rate of piglets tested positive for enterotoxic E. coli (ETEC). All additives significantly increased jejunal TEAC and reduced TBA-RS. In the liver BE, Cuo, Oo and To increased TEAC in tendency and Ro significantly. Liver TBA-RS were slightly reduced by all additives compared to Con piglets. Whereas the influence of BE, To and Ro on jejunal TEAC mainly was derived from the induction of xenobiotic and antioxidant enzymes (indirect antioxidant effects), Cuo and Oo influenced TEAC by direct antioxidant effects. Discussion and Conclusions: Our results have shown: That within the labiatae oils Oo and To have the potential to improve performance slightly. That phytogenic substances have a small but not significant influence on intestinal microflora. That

High Prevalence of Antibiotic Resistance in Pathogenic Escherichia coli from Large- and Small-Scale Poultry Farms in Bangladesh

Antibiotic resistance in avian bacterial pathogens is a common problem in the Bangladesh poultry industry. The aim of the present study was to provide information on the present status of antibiotic resistance patterns in avian pathogenic Escherichia coli in Bangladesh. Of 279 dead or sick poultry of different ages, 101 pathogenic E coli strains isolated from broilers and layer hens with colibacillosis infections were screened to determine phenotypic expression of antimicrobial resistance against 13 antibiotics used in both veterinary and human medicine in Bangladesh. Of 101 pathogenic E. coli isolates, more than 55% were resistant to at least one or more of the tested compounds, and 36.6% of the isolates showed multiple-drug-resistant phenotypes. The most common resistances observed were against tetracycline (45.5%), trimethoprim-sulphamethoxazole (26.7%), nalidixic acid (25.7%), ampicillin (25.7%), and streptomycin (20.8%). Resistance to ciprofloxacin (12.9%), chlormaphenicol (8.9%), nitrofurantoin (2%), and gentamicin (2%) was also observed, and none of the isolates were resistant to tigecycline as well as extended spectrum beta-lactamase (ESBL) producers. One isolate was resistant to cefuroxime (1%), cefadroxil (1%), and mecillinam (1%) but was not an ESBL producer. Resistance rates, although significant in Bangladeshi isolates, were found to be lower than those reported for avian isolates from the Republic of Korea and clinical, avian, and environmental isolates from Bangladesh. The high level of antibiotic resistance in avian pathogens from Bangladesh is worrisome and indicates that widespread use of antibiotics as feed additives for growth promotion and disease prevention could have negative implications for human and animal health and the environment.