In-house validation method for quantification of formaldehyde in silage and feedingstuffs with the use HPLC-DAD technique

An HPLC-DAD method was developed for the determination of formaldehyde in animal feed and silage. The method is based on the determination of the product of chemical reaction between formaldehyde and 2,4-dinitrophenylhydrazine. A 3 g of feed or silage were extracted with Milli-Q water with phosphoric acid and next formaldehyde was derivative with the use 2,4-dinitrophenyl- hydrazine in acetronitrile solution. The extract was purified with 0.45 µm syringe filters and separeted on Zorbax Eclipse XDB C18 column and detection was carried out at 360 nm. Formal- dehyde was eluted with a mobile phase consisting of acetonitrile/water in isocratic elution. This method provided average recoveries of 90.6% to 102.2%, with CVs of 2.6% to 6.4% for feed and from 91.3% to 108.7% with CVs of 1.1% to 4.1% for silage in the ranged of 50 to 1000 mg/kg feeds and silage. The LOD and LOQ for formaldehyde in feed and silage ranged from 1.6 to 2.6 and 2.7 to 5.7 mg/kg, respectively. The methodology was applied for the analysis of feed and silage samples collected from poultry, pigs and cows farms.

Circadian blood pressure profiles and ambulatory arterial stiffness index in children and adolescents with congenital adrenal hyperplasia due to 21-hydroxylase deficiency in relation to their genotypes

OBJECTIVE

Lifelong steroid therapy and exposure to adrenal androgen excess in 21-hydroxylase deficient (21-OHD) congenital adrenal hyperplasia (CAH) children and adolescents may modify circadian blood pressure profile and result in vascular complications. The objective of the study was to evaluate vascular abnormalities in 21-OHD children and adolescents in relation to their genotypes.

DESIGN

A cross-sectional study conducted at a tertiary referral center.

PATIENTS

Seventy patients with 21-OHD CAH (27 boys), aged from 3 to 17.9 years: 9 with nonclassic CAH, 61 with classic CAH: 10 with simple virilising (SV) and 51 with salt wasting CAH (13-Del/Del, 8-Del/I2G, 7-I2G/I2G and 23-other genotypes).

MAIN OUTCOMES MEASURES

The assessment of systolic and diastolic BP (SBP, DBP) loads, night dip% and arterial ambulatory stiffness index (AASI) in 21-OHD CAH patients.

Molecular diversity of Clostridium botulinum and phenotypically similar strains

This study was undertaken to examine phenotypic and genetic features of strains preliminary classified as Clostridium botulinum species. The phenotypic characteristics were assessed with different culture media and biochemical tests. The genetic characterization included detection of botulinum toxin genes by PCR and macrorestriction analysis with SmaI, XhoI and SacII by PFGE (Pulsed-field Gel Electrophoresis). Despite similar biochemical properties of all analysed strains, only 47% of them contained genes determining toxicity specific to C. botulinum species. The most valuable differentiation of C. botulinum and C. botulinum-like strains was obtained after SmaI digestion. The highest affinity was observed among C. botulinum type B profiles which was even up to 100%. It was found 100% of affinity between C. botulinum and C. botulinum-like strains, however, the similarity among C. botulinum and C. botulinum-like was generally lower than 80%.

Development and Validation of an Analytical Method for Determination of Ergot Alkaloids in Animal Feedingstuffs with High Performance Liquid Chromatography-fluorescence Detection

A high performance liquid chromatography combined with fluorescence detection (HPLC-FLD) method was developed for determination of five ergot alkaloids (EA): ergometrine, ergotamine, ergocornine, ergocrypine and ergocristine in animal feedingstuffs. The method was based on the application of QuEChERS salts for extraction and modified QuEChERS dispersive SPE for the cleanup step. Alkaloids separation was performed on a C18, 250 mm x 4.6 mm, 5 μm column with the mobile phase containing ammonium carbonate and acetonitrile. The excitation and emission wavelengths were 330 and 420 nm respectively. The method was validated according to the Commission Decision 2002/657/EC and all parameters are in agreement with the requirements of the Decision. Linearity was determined for the concentration range of 25-400 μg/kg. The coefficient of determination (R2) for all curves was from 0.985 to 0.996. The limit of detection (LOD) was in the range 3.23 to 6.53 μg/kg and the limit of quantification (LOQ) from 11.78 to 13.06 μg/kg. The decision limit (CCα) ranged from 29.56 to 43.08 μg/kg and detection capability (CCβ) from 40.65 to 51.01 μg/kg. The highest coefficient of variation (CV) for repeatability was 14.3% and for reproducibility 15.4%.

Screening method for the determination of tetracyclines and fluoroquinolones in animal drinking water by liquid chromatography with diode array detector

A liquid chromatography - diode array detector (HPLC-DAD) procedure has been developed for the determination of oxytetracycline (OTC), tetracycline (TC), chlorotetracycline (CTC), doxycycline (DC), enrofloxacin (ENR), ciprofloxacin (CIP), sarafloxacin (SAR) and flumequine (FLU) residues in animal drinking water. This method was applied to animal drinking water. Solid-phase extraction (SPE) clean-up on an Oasis HLB cartridge allowed an extract suitable for liquid chromatographic analysis to be obtained. Chromatographic separation was carried out on a C18 analytical column, using gradient elution with 0.1% trifluoroacetic acid - acetonitrile - methanol at 30°C. The flow-rate was 0.7 mL/min and the eluate was analysed at 330 nm. The whole procedure was evaluated according to the requirements of the Commission Decision 2002/657/EC, determining specificity, decision limit (CCα), detection capacity (CCβ), limit of detection (LOD), limit of quantification (LOQ), precision and accuracy during validation of the method. The recoveries of TCs and FQs from spiked samples at the levels of 10, 100 and 1000 μg/L were higher than 82%. The developed method based on HPLC-DAD has been applied for the determination of four tetracyclines and four fluoroquinolones in animal drinking water samples.

Assessing the possibility of genetically modified DNA transfer from GM feed to broiler, laying hen, pig and calf tissues

The aim of this study was to assess the possibility of genetically modified DNA transfer from feed containing RR soybean or/and MON810 maize to animal tissues, gut bacterial flora, food of animal origin, and the fate of GM DNA in the animal digestive tract. The experiment was carried out on broilers, laying hens, pigs and calves. All animals were divided into four groups: I--control group (non-modified feed), II--GM soybean group (non-modified maize, RR soybean), III--GM maize group (MON810 maize, non-modified soybean), and IV--GM maize and soybean group (MON810 maize, RR soybean). Samples of blood, organs, tissues, digesta from the gastrointestinal tract, and eggs were analysed for the presence of plant species specific genes, and transgenic sequences of CaMV 35S promoter and NOS terminator. PCR amplifications of these GM sequences were conducted to investigate the GM DNA transfer from feed to animal tissues and bacterial gut flora. In none of the analysed samples of blood, organs, tissues, eggs, excreta and bacterial DNA were plant reference genes or GM DNA found. A GM crop diet did not affect bacterial gut flora as regards diversity of bacteria species, quantity of particular bacteria species in the animal gut, or incorporation of transgenic DNA to the bacteria genome. It can be concluded that MON810 maize and RR soybean used for animal feeding are substantially equivalent to their conventional counterparts. Genetically modified DNA from MON810 maize and RR soybean is digested in the same way as plant DNA, with no probability of its transfer to animal tissues or gut bacterial flora.

Current issues connected with usage of genetically modified crops in production of feed and livestock feeding

Progress, which is brought by new advances in modern molecular biology, allowed interference in the genome of live organisms and gene manipulation. Introducing new genes to the recipient organism enables to give them new features, absent before. Continuous increase in the area of the biotech crops triggers continuous discussion about safety of genetically modified (GM) crops, including food and feed derived from them. Important issue connected with cultivation of genetically modified crops is a horizontal gene transfer and a bacterial antibiotic resistance. Discussion about safety of GM crops concerns also food allergies caused by eating genetically modified food. The problem of genetic modifications of GM crops used for livestock feeding is widely discussed, taking into account Polish feed law.

Microbiological quality of petfood in Poland

From epidemiological and safety point of view, petfoods produced from edible and non-edible animal by-products should be safe for slaughter animals, owners of these pets and environment. Domestic animals are recognized as highly important reservoir of pathogenic microorganisms for man. The close contact of people and especially children with pets may constitute a serious hazard for their health. Taking these aspects into account, the study was undertaken in which 2271 dried and 18 canned petfood samples were examined. Moreover, 14, 90, 23 and 22 samples of petfoods were examined for presence or number of Clostridium sp., Enterobacteriaceae, total plate count, and yeast and moulds, respectively. Salmonella was isolated from 22 (1%) out of 2271 dried petfood samples examined. Number of Enterobacteriaceae was higher than 300 cfu/g, i.e. the allowed maximum level was found in 9 (10%) samples examined. The rest of microbiological quality parameters did not exceed the allowed values.

National programme of official control of animal feedingstuffs under surveillance of veterinary inspection in Poland

Poland as a new EC country is obliged in agree with Directive 95/53/EC to drawn up one, coherent and coordinated national programme of official inspection, irrespective of the organisational structure, and the number of inspection authorities in a country. Taking these facts into account the author has worked out the Polish National Programme of an official control conducted by the Veterinary Inspection in the field of animal feedingstuffs sector in Poland. The objective of the programme is to lay down the substantive scope of official inspections and laboratory control testing of animal feedingstuffs, appropriate for the surveillance exercised by the Veterinary Inspection. The programme is under implementation process which has begun in 2004.