Comparisons of recycled manure solids and wood shavings/sawdust as bedding material -implications for animal welfare, herd health, milk quality and bedding costs in Swedish dairy herds.

Increasing shortages and costs of common bedding materials have led dairy farmers in Sweden to consider using recycled manure solids (RMS), which are readily available and low-cost, as an alternative bedding material. The main risks are effects on udder health and milk quality, but RMS could also affect animal welfare and claw health. The advantages and disadvantages of using RMS bedding have not been fully investigated, and findings in other countries cannot be directly applied to Swedish conditions and climate. This observational cross-sectional study investigated the use of RMS as bedding regarding associations with certain aspects of animal welfare, herd health, milk quality, and bedding costs in Swedish dairy herds. Thirty-four dairy farms using RMS or wood shavings/sawdust (each n = 17) were compared. Each farm was visited 2 times during the housing period 2020-2021, once in October-December and once in March-May. Dairy barns were observed, animal welfare was assessed, and free-stall dimensions were measured. Farm owners were interviewed about housing system characteristics, herd performance, and herd management. Data on milk production and herd health were obtained from the Swedish official milk recording scheme for the indoor period October-March. The prevalence of claw disorders and abnormal claw conformation were collected from the national claw health database for the period, October-May. On each farm visit, composite samples of unused bedding outside the barn and used bedding material from the free stalls, respectively, were taken for total bacterial count and dry matter analysis. Samples of bulk tank milk for determination of total bacterial count were taken in connection to the visits. In addition, samples of unused and used bedding material and manure from alleys for analysis of 3 Treponema species associated with digital dermatitis (DD) were gathered and analyzed. Total bacterial count was significantly higher in unused (8.50 log10 cfu/g) and used RMS bedding (9.75 log10 cfu/g) than in wood shavings/sawdust (used 4.74; unused 8.63 log10 cfu/g), but there were no significant differences in bulk milk total bacterial count (median 4.07 versus 3.89 log10 cfu/mL) or somatic cell count (median 243,800 versus 229,200 cells /mL). The aspects of animal welfare that were assessed did not differ significantly between the 2 bedding systems, while the prevalence of total claw disorders (25.9 versus 38.0% of trimmed cows), dermatitis (6.9 versus 16.2% of trimmed cows) and sole ulcers (2.0 versus 4.0% of trimmed cows) were significantly lower in the RMS herds. Treponema spp. were not detected in unused RMS material, but all RMS herds had presence of DD recorded at foot trimming. An economic assessment based on the interview results and price level from winter 2021 revealed that the costs of RMS bedding varied with amount of RMS produced. Thus, RMS is a potential alternative bedding material for dairy cows in Sweden and can be a profitable option for large dairy herds. However, the high level of total bacteria in the material requires attention to bedding and milking routines as well as regular monitoring of herd health.

Mild and severe udder cleft dermatitis-Prevalence and risk factors in Swedish dairy herds.

Udder cleft dermatitis (UCD) is an inflammatory skin condition affecting the anterior parts of the udder of dairy cows. The lesions may present as mild or severe skin lesions and have been associated with mastitis and digital dermatitis. The full etiology and pathogenesis are not understood and no large-scale studies have investigated prevalence and risk factors. Therefore, the main objectives of the study were to investigate the prevalence of mild and severe UCD in Swedish dairy herds and to identify risk factors associated with such lesions. We also wanted to investigate risk factors for all cases of UCD and to determine whether UCD increases the risk for mastitis and culling. A random sample of 100 freestall dairy herds were included in the study, and each herd was visited once. Cows were registered as having no, mild, or severe UCD. Additional cow and herd data were obtained via observations, interviews, and the Swedish Official Milk Recording Scheme. The data were analyzed using logistic regression models to identify risk factors for mild and severe UCD. In total, data from 3,479 cows in 99 herds were analyzed. The prevalence of mild and severe UCD was 19 and 9%, respectively. Lesions were found in 98 of 99 herds but the within-herd prevalence of mild (0-43%) and severe (0-33%) UCD varied notably between herds. Breed (Swedish Red compared with Swedish Holstein), certain udder conformation traits, and higher parity were risk factors associated with increased risk of UCD. In addition, cows with hock lesions and cows in herds with high incidence of culling due to hoof and leg diseases had a higher risk for mild UCD. More days in milk and high milk yield were cow-related risk factors associated with severe UCD. Three housing-related factors (shorter cubicles, mattress as cubicle base, and cubicles installed before 2001 compared with 2001-2005), a high incidence of veterinary-treated clinical mastitis and culling due to udder diseases, and a low incidence of culling of first-parity cows in early lactation were herd-related risk factors associated with increased risk for severe UCD. In addition, cows in herds with a high proportion of heifers older than 17 mo that were not inseminated were associated with lower risk of all UCD. Finally, UCD was not associated with the outcomes milk somatic cell count, veterinary-treated clinical mastitis, or culling in the multivariable analyses. The etiology of UCD is most likely multifactorial, involving udder conformation traits and other cow-related risk factors as well as herd-related risk factors. The high prevalence of severe UCD lesions in Swedish dairy cows emphasizes the need for preventive measures and efficient treatments.

Efficacy of enrofloxacin for the treatment of acute clinical mastitis caused by Escherichia coli in dairy cows.

Evidence for the efficacy of antimicrobial treatments in Escherichia coli mastitis is limited. The aim of this double-blinded field trial was to investigate the efficacy of enrofloxacin compared with placebo, with a special focus on survival, in dairy cows with acute clinical mastitis caused by E. coli. Dairy cows (n=116) with acute clinical mastitis were included in the study. A clinical examination was performed and a milk sample from the affected udder quarter was collected for investigation of somatic cell count (SCC) and bacteriology on the first day of treatment (day 0) and at day 3 (clinical examination only), day 22 and day 28. Data regarding culled cows, SCC and daily milk yield were retrieved from monthly milk recording each month until 180 days after treatment. All cows were treated with either enrofloxacin or placebo once a day for three days, starting at day 0. After culturing, 56 cows with confirmed E. coli mastitis remained in the study. Nine (16 per cent) of them died within the first week. Enrofloxacin-treated cows had lower SCC compared with placebo-treated cows at first monthly milk recordings after being treated for mastitis. Treatment with enrofloxacin did not result in a higher probability of survival compared with placebo.

Comportamiento Anatomopatológico de los Tumores Cerebrales en el Hospital General “Lucía Iñiguez”, Año 2003 / Anatomopathologic Behavior of brain tumors in the General Hospital “Lucia Iñiguez” in 2003

Se realizó un estudio de serie de casos de 121 pacientes con tumores primarios del Sistema Nervioso Central diagnosticados a través de biopsias dirigidas por estereotaxia en el Departamento de Anatomía Patológica del Hospital General "Lucía Iñiguez Landín" durante el periodo comprendido desde Mayo de 1999 a Noviembre del 2003. Se valoraron las variedades histológicas más frecuentes en nuestro medio, la localización, edad y sexo de mayor incidencia...(AU)

Heating of food and haemoglobin adducts from carcinogens: possible precursor role of glycidol.

Studies of adducts from reactive compounds to haemoglobin (Hb) by gas chromatography-tandem mass spectrometry according to the N-alkyl Edman method reveals the occurrence of N-(2,3-dihydroxypropyl)valine (diHOPrVal) at levels of 1-2 pmol/g Hb, in persons without known exposure. The hypothesis that this background originates from glycidol or related compounds during heating of food was tested in experiments with rats. Animals fed fried animal feed for 30 or 72 days showed an increase of the diHOPrVal level by about 50% compared with controls. Several arguments, such as the formation of reactive oxiranes by heat-induced dehydration of glycol configurations in glycerol and sugars, support the idea that glycidol (or e.g. glycidyl esters) are precursors of the adduct. In Hb samples, reduced for stabilisation of aldehyde adducts, relatively high levels of adducts determined as diHOPrVal were found, although without significant relation to frying of the feed. There is thus no indication that reduction in vivo of, for example, the Schiff base from glyceraldehyde, is a pathway for formation of the diHOPrVal. The background level of diHOPrVal in humans Hb is low, and the cancer risk associated with exposure to the specific alkylator-probably glycidol-formed in cooking, is therefore presumably low. The result implies, however, that low-molecular mass mutagenic oxiranes formed during the heating of food should be studied further.

Adducts with haemoglobin and with DNA in epichlorohydrin-exposed rats.

Epichlorohydrin (1-chloro-2,3-epoxypropane; ECH) is an important industrial chemical and a carcinogen in experimental animals. The main aims of the present study were to characterize the adduct formation in female Wistar rats and to identify adducts that could potentially be used in human biomonitoring studies. The total binding of radioactivity to haemoglobin in rats administered 0, 0. 11, 0.22, 0.43, or 0.97 mmol [3H]ECH/kg body weight by i.p. injection, and sacrificed 24 h after treatment, was linearly related to a dose up to 0.43 mmol/kg body weight. The binding at the highest dose was higher than predicted by extrapolation from lower doses, indicating saturation of a metabolic process for elimination of ECH. Ion-exchange chromatography of a globin hydrolysate showed one major radioactivity peak corresponding to S-(3-chloro-2-hydroxypropyl)cysteine. The half-life of this adduct was estimated as about 4 days by analysis of globin from rats administered 0.43 mmol/kg body weight and sacrificed after 1, 2 and 9 days. Crosslinking of the adduct, presumably with glutathione, appeared to be the predominant secondary reaction. Hydrolysis of N-(3-chloro-2-hydroxypropyl)valine, the primary reaction product of ECH with N-terminal valine, would give N-(2,3-dihydroxypropyl)valine. A sensitive gas chromatography/mass spectrometry method for the dihydroxypropyl adduct was used to follow its formation and removal after administration of nonlabelled ECH (0.11 mmol/kg body weight). The level of this adduct reached a maximum of about 20 pmol/g globin after a few weeks, corresponding to about 0.1% of the initial binding of ECH to globin. N-7-(3-Chloro-2-hydroxypropyl)guanine was detected in rats administered 0.97 mmol [3H]ECH/kg body weight and sacrificed 6 h after treatment. The adduct levels in haemoglobin and DNA were compared with previously reported adduct levels in male Fischer 344 rats exposed to propylene oxide. Despite its higher chemical reactivity, the capacity of ECH to alkylate macromolecules in vivo was found to be somewhat lower than that of propylene oxide.

Haemoglobin adducts of epoxybutanediol from exposure to 1,3-butadiene or butadiene epoxides.

Epoxybutanediol is one of the reactive metabolites of butadiene. It is formed via hydrolysis followed by oxidation of the primary metabolite of butadiene, epoxybutene, or via hydrolysis of diepoxybutane, a secondary metabolite of butadiene. Groups of male Sprague Dawley rats were treated by intraperitoneal injection of epoxybutene, epoxybutanediol or diepoxybutane. N-(2,3,4-Trihydroxybutyl)valine adducts in haemoglobin, formed from epoxybutanediol in its reaction with N-terminal valine, were measured using the N-alkyl Edman method followed by acetylation of the Edman derivatives and analysis by gas chromatography mass spectrometry. The same adducts were also measured in male Wistar rats exposed to butadiene by inhalation and in a few workers with occupational exposure to butadiene. Haemoglobin binding indexes, HBI, (pmol adduct/g per mumol of alkylating agent, or, for butadiene, per ppm x h), were calculated. The HBI for epoxybutanediol (about 10) is comparable to that of ethylene oxide in the rat demonstrating a similar capacity of the two compounds to alkylate nucleophilic sites in vivo. The HBI of diepoxybutane (about 8) for epoxybutanediol adduct formation is approximately the same as that of epoxybutanediol itself. Epoxybutanediol adduct formation was nonlinearly related to exposure in butadiene exposed rats. The epoxybutanediol-haemoglobin adduct levels were substantially higher than those of epoxybutene in both butadiene-exposed rats and humans suggesting an important role of epoxybutanediol in the toxicity of butadiene. Adducts of epoxybutanediol are probably useful for biomonitoring of human exposure to butadiene.

Monitoring of occupational exposure to epichlorohydrin by genetic effects and hemoglobin adducts.

The present work is focused on the determination of in vivo doses and studies of genetic effects in workers exposed to epichlorohydrin (ECH). The studied endpoints were hemoglobin (Hb) adducts, frequencies of hprt mutants, micronuclei in cytochalasin B blocked binucleated lymphocytes, sister chromatid exchanges (SCE) and high frequency cells (HFC). Blood samples were collected from office clerks and ECH exposed factory workers at an industrial plant in Germany. The workers were exposed to 0.11-0.23 ppm ECH in the air 45 h per week and to 0.2-2.6 ppm for 3 h per week. Some Swedish non-exposed subjects were also used for Hb adduct measurements. The genetic data, HFC and SCE, showed a significant difference between exposed and unexposed donors. In contrast to earlier studies on SCE, no impact of smoking was observed. Effects on micronuclei were on the borderline of significance, whereas there was no effect for HPRT mutants. The average Hb adduct level was higher in exposed than in non-exposed donors, although the difference was only significant when the exposed group was compared to Swedish controls. Smoking gave significantly increased adduct levels. The absence of significant correlations between individual data for Hb adducts and genetic effects, may be explained by the different periods of time covered by the responses in these endpoints. Whereas Hb adducts reflect the exposure during up to 4 months (i.e. the life span of human erythrocytes), the SCE, and particularly the HFC, seem to accumulate for years in a long-lived fraction of T-lymphocytes without DNA repair. Thus, the adduct data does not reflect the exposure backwards in time unless it can be shown that exposure conditions have remained unchanged. The origin of the background adduct levels in non-smoking control persons is at present not known.

Biomonitoring of epichlorohydrin by hemoglobin adducts.

A gas chromatographic mass spectrometric method for monitoring exposure to epichlorohydrin (ECH) by means of quantitative analysis of N-(2,3-dihydroxypropyl)valine in hemoglobin has been developed. The analysis is based on the modified Edman method for measurement of adducts to the N-terminal valine, one of the reactive sites of the globin chains. The presence of two hydroxyl groups in the adduct to be analyzed required special precautions to be introduced into the method, such as acetylation of the Edman derivative. An in vitro treated globin with [2H5]N-2,3-dihydroxypropyl adducts was used as internal standard. The limit of detection achieved is 4 fmol in analysis by tandem mass spectrometry. Adduct levels found in smokers (15 to 20 cigarettes per day) were between 6.5 and 11.2 pmol/g globin and for nonsmokers the adduct levels were close to the detection limit (about 2 pmol/g globin). In two rats, treated ip with 40 mg ECH/kg body wt and sacrificed after 30 days, the average adduct level was 44 pmol/g globin and that for two nonexposed rats was close to the detection level. The method will be useful for monitoring of exposure and for cancer risk estimation of ECH.

Haemoglobin adducts as biomarkers of occupational exposure to 1,3-butadiene.

Adducts of 1,2-epoxy-3-butene (EB) with haemoglobin were monitored in 17 workers from the 1,3-butadiene (BD) production unit of a petrochemical plant and in nine referents employed at the same factory but not exposed to BD. The air concentrations of BD were determined using stationary and personal monitoring. The ambient level of exposure of the plant workers handling butadiene containers (sampling and voiding) was on average 11.2 +/- 18.6 (mean +/- SD) mg/m3. Maintenance and laboratory workers were exposed to levels < or = 1.2 mg/m3. The particular haemoglobin adduct measured was 2-hydroxy-3-butenylvaline, formed by reaction of N-terminal valine with carbon 1 in EB. The adduct levels were increased (0.16 +/- 0.099 pmol/g; n = 10) in plant workers compared with the levels in maintenance and laboratory workers and controls (approximately 0.05 pmol/g; seven laboratory workers and nine controls evaluated). Thus, the method used for adduct determination--derivatization of 200-300 mg globin samples with penta-fluorophenyl isothiocyanate according to the N-alkyl Edman method and detection of the thiohydantoin derivatives by tandem mass spectrometry--is sufficiently sensitive to allow monitoring of exposure to BD down to the p.p.m. level.

Hemoglobin adducts for in vivo dose monitoring and cancer risk estimation.

For the estimation of cancer risks from environmental chemicals, knowledge of the target dose is essential, dose being defined as the time integral of concentration in target tissues. In vivo doses from chronic or intermittent exposures are best determined from established steady-state levels of macromolecule adducts of reactive compounds or intermediates. For dose monitoring, hemoglobin (Hb) is preferred to DNA for several reasons: accessibility in large amounts, availability of methods for chemical identification, and well-determined life span due to absence of repair. For these reasons, and because of the proportionality of rates of DNA and Hb adduct formation, Hb adduct levels give better information on cumulative DNA adduct levels than do direct measurement of DNA adducts. The scientific background of Hb adduct measurement, target dose determination, and risk estimation based on the relative genotoxic potency, with gamma-radiation as reference standard, is reviewed and exemplified. The sensitivity of the method for Hb adduct measurement permits determination of exposures where the associated annual cancer risk is less than 1 per million. Besides application for studies of metabolism by determination of in vivo doses in exposed animals and humans, as a basis for risk estimation, Hb adduct measurement is used for hygienic surveillance of occupational exposures. Determination of Hb adducts by mass-spectrometric techniques gives a tool for identification of reactive metabolites, not only in individuals with known exposure, but also for characterization of adducts to Hb from compounds acting as mutagens (initiators) in the background carcinogenesis. This is the large fraction of the total number of cancer cases that occur among individuals without known exposure.