The incidence of milk leakage (ML) after dry-off (DO) and related risk factors was studied in 1,175 dairy cows from 41 commercial herds in 8 European countries: Belgium, Czech Republic, Denmark, France, Germany, Italy, the Netherlands, and Spain. Milk leakage was assessed twice for 30 s each during 3 visits at 20 to 24 h, 30 to 34 h, and 48 to 52 h after DO. Information related to dry-cow management and udder health was collected at herd and cow level, including individual somatic cell count (ISCC) from test-day controls and occurrence of clinical mastitis cases from DO until 30 d in lactation. Mixed-effect logistic regression analyses were used to identify possible risk factors for ML and to study the association between ML and new intramammary infections. Intramammary infections were defined as clinical mastitis cases during the dry period and in the first 30 d in lactation or a rise in ISCC from before to after the dry period (threshold: 200,000 cells/mL) or both. Milk leakage was observed in 24.5% of the cows between 20 and 52 h after DO, where the herd incidence varied between 0.0 and 77.8%. The reduction in number of milkings in the weeks before DO had statistically significant effect on the ML incidence. When the milking frequency was reduced from 3 times/d to 2 or maintained at twice a day, cows had 11 (95% CI = 3.43-35.46) or 9 (95% CI = 1.85-48.22) times higher odds of leaking milk, respectively, compared with cows where the milking frequency was reduced from twice to once a day. Also, the milk production 24 h before DO was associated with ML incidence. Hence, cows with a milk production between 13 and 21 L or above 21 L had 2.3 (95% CI = 1.48-3.53) and 3.1 (95% CI = 1.79-5.3) times higher odds of leaking milk, respectively, compared with cows with a milk production below 13 L. A higher ML incidence was present in the group of cows with an average ISCC in the last 3 mo before DO ≥200,000 cells/mL (odds ratio = 1.7; 95% CI = 1.13-2.41) compared with cows with an average ISCC <100,000 cells/mL. Quarters with ML tended to have 2.0 times higher odds of developing clinical mastitis compared with quarters not leaking milk. Cows with ML tended to have 1.5 times higher odds of intramammary infections (i.e., an increase of ISCC or clinical mastitis) compared with cows without ML.

• Klíčová slova
• clinical mastitis, dry-off, intramammary infection, milk leakage, risk factor,
• MeSH
• incidence MeSH
• laktace MeSH
• mastitida skotu epidemiologie   patofyziologie   MeSH
• mléčné žlázy zvířat patofyziologie   MeSH
• mlékárenství * MeSH
• mléko cytologie   MeSH
• nemoci skotu epidemiologie   patofyziologie   MeSH
• počet buněk veterinární   MeSH
• rizikové faktory MeSH
• skot MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa MeSH

The reaction of ethyl linoleate with collagen proceeded at 60 degrees C following the first order kinetics but during the hydroperoxide decomposition the rate constant of the first order decomposition was substantially lower than that of the second order decomposition. Contrary to cellulose, collagen catalyzed the hydroperoxide decomposition. The amount of total oxidation products rose rapidly at the stage of rapid hydroperoxide formation, and slowly afterwards. The browning reaction was fasted in the stage of maximum hydroperoxide content, and both ether-insoluble and ether-soluble pigments were formed, the latter low in nitrogen. The amount of lipid oligomers increased mainly in the reaction stage following the hydroperoxide maximum. Soluble collagen was converted into insoluble forms by the reaction with oxidized lipids. Basic amino acids were blocked by reaction with oxidized lipids but the bonds formed became resistant to acid hydrolysis only in the stage following the hydroperoxide maximum. Changes of sensory profiles could be explained by reactions of flavour-active carbonylic oxidation products with protein.

• MeSH
• aminokyseliny metabolismus   MeSH
• celulosa metabolismus   MeSH
• chromatografie na tenké vrstvě MeSH
• hydrolýza MeSH
• kinetika MeSH
• kolagen metabolismus   MeSH
• kyseliny linolové metabolismus   MeSH
• magnetická rezonanční spektroskopie MeSH
• Maillardova reakce MeSH
• oxidace-redukce MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aminokyseliny MeSH
• celulosa MeSH
• ethyl linoleate MeSH Prohlížeč
• kolagen MeSH
• kyseliny linolové MeSH

A reproducible and sensitive gas chromatographic method has been developed for the trace analysis of fluazifop-butyl, haloxyfop-ethoxyethyl and quizalofop-ethyl as well as their main metabolites (corresponding acids analysed after conversion to methyl esters) in some fruits and vegetables treated with herbicidal sprays. Comparable detection limits (0.01 mg/kg) were achieved when mass fragmentography and/or the electron capture detector were employed. However, in the latter case, bromination of fluazifop esters had to be carried out prior to GC analysis. By means of the nitrogen-phosphorus detector, determination of residues at a level of 0.05 mg/kg was possible. The residue values found in strawberries, cabbages, cauliflower and carrots were used to discuss the degree of metabolic hydrolysis of parent esters, i.e. active ingredients of herbicides.

• MeSH
• chinoxaliny analýza   MeSH
• chromatografie plynová MeSH
• herbicidy analýza   MeSH
• hydrolýza MeSH
• ovoce analýza   MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• propionáty analýza   MeSH
• pyridiny analýza   MeSH
• rezidua pesticidů analýza   MeSH
• zelenina analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chinoxaliny MeSH
• fluazifop-butyl MeSH Prohlížeč
• haloxyfop MeSH Prohlížeč
• herbicidy MeSH
• propionáty MeSH
• pyridiny MeSH
• quizalofop-ethyl MeSH Prohlížeč
• rezidua pesticidů MeSH

A sensitive and reproducible gas chromatographic procedure for the determination of diquat and paraquat in potatoes and rapeseed was developed. The volatilization of analytes was carried out via their hydrogenation with sodium borohydride-nickel(II) chloride. After their isolation from the reaction mixture, the derivatives of bipiperidine were separated on a column packed with Apiezon L plus potassium hydroxide. Comparable detection limits (0.005 mg/kg) were achieved with a nitrogen-phosphorus detector and by mass fragmentography, however, the latter method was preferred for analyses of rapeseed extracts owing to its higher selectivity.

• MeSH
• Brassica analýza   MeSH
• chemické jevy MeSH
• chemie MeSH
• chromatografie plynová MeSH
• diquat analýza   MeSH
• kontaminace potravin analýza   MeSH
• paraquat analýza   MeSH
• pyridinové sloučeniny MeSH
• Solanum tuberosum analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• diquat MeSH
• paraquat MeSH
• pyridinové sloučeniny MeSH

During the reaction of oxidized ethyl linoleate with egg albumin in dry medium at 60 degrees C, hydroperoxides were rapidly decomposed almost completely, while carbonylic anisidine-active and thiobarbituric-acid-active substances were decomposed rapidly in the beginning and only slowly afterwards. Both hydroperoxides and carbonylic oxidation products were substantially more stable in mixtures with cellulose than with albumin. Hydrogen-bonded lipoproteins were rapidly formed, passed through a maximum, and remained nearly constant in the last reaction stage. Covalently bonded lipids in lipoproteins were mainly formed in the stage following the rapid decomposition of hydroperoxides and carbonylic compounds, and immediately following the decrease of hydrogen-bonded lipoproteins. The binding of oxidized lipids into lipoproteins was accompanied by the formation of protein oligomers and by the loss of available lysine.

• MeSH
• chemické jevy MeSH
• chemie MeSH
• kyseliny linolové analýza   MeSH
• lipoproteiny analýza   MeSH
• ovalbumin analýza   MeSH
• oxidace-redukce MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ethyl linoleate MeSH Prohlížeč
• kyseliny linolové MeSH
• lipoproteiny MeSH
• ovalbumin MeSH

Residues of clopyralide in strawberries treated with herbicide preparation Lontrel 300 were determined using gas chromatographic method. The decrease of clopyralide content during the processing of contaminated fruits was observed. The rate of decomposition of this compound in model solutions (held at 75 degrees C, pH 3.6) followed first-order kinetics. 2,5-dicloropyridine was proved to originate under these conditions from parent compound.

• MeSH
• chromatografie plynová MeSH
• herbicidy analýza   MeSH
• hmotnostní spektrometrie MeSH
• kyseliny pikolinové analýza   MeSH
• ovoce analýza   MeSH
• rezidua pesticidů analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• clopyralid MeSH Prohlížeč
• herbicidy MeSH
• kyseliny pikolinové MeSH
• rezidua pesticidů MeSH

Derivatization of chlorophenols prior to gas chromatographic analysis resulted in a significant improvement of their chromatographic behaviour. Chlorophenols in the form of anisoles, acetates, and pentafluorobenzyl ethers were separated either on a HP-1 wide-bore capillary column or on a capillary column coated with a film of SE-54. Due to an enhancement of the poor electron-capture detection response of mono- and dichlorophenols, pentafluorobenzylation made it possible to determine trace amounts in spiked water. Moreover, simultaneous analysis of phenoxyalkanoic acids was accomplished under the same conditions.

• MeSH
• acetylace MeSH
• chlorfenoly analýza   MeSH
• chromatografie plynová MeSH
• metylace MeSH
• zásobování vodou analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chlorfenoly MeSH

Fluazifop-butyl, haloxyfop-ethoxyethyl and quizalofop-ethyl, active ingredients of new selective herbicidal preparations, as well as their metabolites converted in to corresponding methyl esters were separated on several gas chromatographic columns. Bromination of fluazifop esters increased significantly the response of the electron-capture detector. Electron impact mass spectra of all the compounds investigated were recorded, and characteristic ions suitable for selected ion monitoring are given.

• MeSH
• chinoxaliny analýza   MeSH
• chromatografie plynová MeSH
• dihydropyridiny analýza   MeSH
• estery analýza   MeSH
• herbicidy analýza   MeSH
• indikátory a reagencie MeSH
• kyseliny karboxylové analýza   MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• pyridiny analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chinoxaliny MeSH
• dihydropyridiny MeSH
• estery MeSH
• fluazifop MeSH Prohlížeč
• herbicidy MeSH
• indikátory a reagencie MeSH
• kyseliny karboxylové MeSH
• pyridiny MeSH

Residual s-triazines were isolated from forage and milk samples by methanol/chloroform extraction followed by column purification. The evaporated extracts were dissolved in acetone and analysed by gas chromatography with NPD detection and mass spectrometry. The detection limits for both methods were found to be about 5 approximately 10 ng of each s-triazine. The selective ions of the 10 s-triazines investigated (simazine, atrazine, propazine, terbuthylazine, cyanazine, desmetryne, ametryne, prometryne, terbutryne and methoprotryne) were chosen on the basis of an electron impact mass spectrometry study of the s-triazine standards and the whole mass spectra are given. Special attention was paid to the fragmentation of cyanazine and the general cleavage pathways of the s-triazines under investigation.

• MeSH
• chromatografie plynová MeSH
• herbicidy analýza   MeSH
• krmivo pro zvířata analýza   MeSH
• mléko analýza   MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• rezidua pesticidů analýza   MeSH
• skot MeSH
• spektrální analýza MeSH
• triaziny * MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• herbicidy MeSH
• rezidua pesticidů MeSH
• triaziny * MeSH

• MeSH
• fosfolipidy analýza   MeSH
• kovy analýza   MeSH
• oleje rostlin analýza   MeSH
• oleje analýza   MeSH
• oxidace-redukce MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fosfolipidy MeSH
• kovy MeSH
• oleje rostlin MeSH
• oleje MeSH