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1.
The sulfonylurea herbicide prosulfuron, 1-(4-methoxy-6-methyltriazin-2-yl)-3-[2-(3,3,3-trifluoropropyl)phenylsulfonyl]urea, is used for the selective control of broadleaf weeds in corn, sorghum, and cereal grains. To investigate its fate in soils, this study examined the effects of soil pH and water content on the rates of dissipation processes and the products formed under aerobic conditions. Radiometry and chromatography analyses were used to quantify the degradation products and bound residues formed in incubations of 10 different soils. The pH-dependent hydrolysis of the sulfonylurea bridge to form phenyl sulfonamide was the primary transformation process. Significant microbial degradation of prosulfuron occurred in 2 of the 10 soils, yielding (14)CO(2) and desmethyl prosulfuron among the major products. The time required for 50% dissipation of the herbicide (DT(50)) was determined for each soil and water content treatment. At equivalent water contents, prosulfuron DT(50) values were positively correlated with soil pH (P < 0.0001), varying from 6.5 days at pH 5.4 to 122.9 days at pH 7.9. Soil pH and water content strongly influence the fate of sulfonylurea herbicides in agricultural fields. Differences in the effect of soil water content on dissipation kinetics in a comparison of two soils were attributed to differences in soil pH, texture, and the ability of indigenous microorganisms to transform the herbicide. 相似文献
2.
The prevalence of hoof lesions and lameness in 4899 heifers and cows was determined at claw trimming one time in a cross-sectional study on 101 Swedish dairy farms, 1996-1998. The percentage of affected animals was 41% for heel-horn erosion, 30% for sole haemorrhages, 27% for erosive dermatitis, 21% for abnormal claw shape, 14% for white-line haemorrhages, 8.8% for white-line fissures, 8.6% for sole ulcers, 3.3% for double soles, 2.3% for verrucose dermatitis, and 1.8% for interdigital hyperplasia (IH). Seventy-two percent of all animals had at least one hoof lesion. The prevalence of lameness was 5.1%; most hoof lesions did not cause lameness. Differences between herds were substantial; the herd-specific, animal-level prevalence of lesions ranged from 25 to 98% and of lameness from 0 to 33%. Sole haemorrhages were found in all herds. The proportion of variance at the between-herd level was particularly high for heel-horn erosion (62%) and abnormal claw shape (54%). Strong correlations between lesions were found within hooves (and animals), e.g. for heel-horn erosion and dermatitis (Spearman's rank correlation, r(s)=0.36 and 0.37, respectively) and for sole and white-line haemorrhages (r(s)=0.25 and 0.28). Most hoof lesions affected hind and front hooves bilaterally, whereas the correlation between hind and front hooves generally was lower. Herds that ranked high for prevalence of sole ulcer also ranked high for sole haemorrhages and for abnormal claw shape and herds that ranked high for dermatitis also ranked high for heel-horn erosion, verrucose dermatitis and IH. Abnormal claw shape was strongly associated with sole ulcer (r(s)=0.41 at cow level)-suggesting the importance of maintaining a correct claw shape for the prevention of hoof-horn lesions. 相似文献
3.
The aims of this follow-up study were: (a) to evaluate the role of ECT technology as a risk factor for several diseases; and (b) to determine if the effects of these diseases on cows' reproductive performance and as risk factors for culling are influenced by exposure to ECTs. Diseases considered were retained placenta, metritis, ketosis, cystic ovaries, silent heat, milk fever, clinical mastitis, and foot and leg problems. We used historical and contemporary controls (with control herds selected to match the experimental herds for size and location). Data consisted of 10264 Swedish Red and White (SRB) and 5461 Swedish Friesian (SLB) lactation records in 150 herds of which 33 used cow-trainers. Logistic regression was used to estimate the effects of parity and exposure to electric cow-trainers on the risks of diseases and the effects of diseases and exposure to electric cow-trainers on risk of culling. The least-squares procedure was used to estimate the effects of diseases on reproductive performance.
The dominant effects associated with use of electric cow-trainers were an increased risk for silent heat, clinical mastitis, ketosis and culling relative to cows in herds not using cow-trainers. Diseases had negative effects on reproductive performance and the effects were larger for cows in herds using cow-trainers. In herds using electric cow-trainers, the largest increase in the interval from first service to conception (58 days) was caused by the occurrences of silent heat, cystic ovaries and the combination of two or more diseases. Retained placenta, metritis, cystic ovaries, clinical mastitis and a combination of two or more diseases increased the risk of culling about two times relative to healthy primiparous cows with the increase being greater for cows in herds using cow-trainers. Silent heat did not increase risk of culling in control groups, but was the largest risk factor for culling in the exposed group. We concluded that exposure to electric cow-trainers increased the incidence risk of silent heat, clinical mastitis, and ketosis and changed silent heat from a neutral disease with respect to culling to a major risk factor. Finally, exposure to cow-trainers increased the general negative effect of diseases on the cows' reproductive performance and risk for culling. 相似文献
4.
Stengärde L Holtenius K Emanuelson U Hultgren J Niskanen R Tråvén M 《Veterinary journal (London, England : 1997)》2011,190(1):124-130
Sixty dairy herds were studied to investigate the association between long-term incidence of displaced abomasum and clinical ketosis and body condition score and blood profiles, including parameters estimating energy metabolism and hepatic lipidosis in the periparturient period and early lactation. Blood samples were taken around parturition and in early lactation from cows without apparent clinical symptoms of metabolic disorders. A difference in metabolism between high and low incidence herds was shown post-partum by a lower metabolic index (the revised Quantitative Insulin Sensitivity Check Index, RQUICKI), and tendencies for higher concentrations of glucose, insulin and non-esterified fatty acids in the high incidence herds. High incidence herds had more cows and produced on average 1400kg energy-corrected milk per cow per year more than the low incidence herds. No differences were found in parameters reflecting liver cell damage. In the first 3weeks post-partum the RQUICKI was a more sensitive marker of herds with a high incidence of displaced abomasum and clinical ketosis than any of the individual parameters, but further research is needed before practical applications of the RQUICKI can be foreseen. 相似文献
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Barbara J. Watrous DVM Thomas W. Riebold DVM Pamela C. Wagner DVM MS Bruce D. Hultgren DVM PhD 《Veterinary radiology & ultrasound》1987,28(2):49-52
Angiography in a horse was used to confirm a pseudoaneurysm of the dorsal metatarsal artery originating from trauma. Gradual clinical resolution of the pseudoaneurysm occurred within days following the procedure. A follow-up angiogram confirmed the clinical impression. An etiology of the spontaneous resolution is presented. Probable influences included technical factors of the injection procedure that caused prolonged presence of the contrast medium within the aneurysmal sac and factors that enhance thrombus formation during angiography. 相似文献
7.
A J Kaneps B D Hultgren T W Riebold G M Shires 《American journal of veterinary research》1984,45(3):581-582
Surgical incisions were made in the skin and superficial digital flexor tendons in horses. A low intensity laser therapy device was used to treat the limbs. After laser therapy was completed, skin and superficial digital flexor tendons from incised laser-irradiated, incised-control, and nonincised-control limbs were compared microscopically. Qualitative differences between laser irradiated and nonirradiated tissues were not found. The laser therapy device used in this study may be of insufficient power to affect wound healing. 相似文献
8.
Lena Steng?rde Madeleine Tr?vén Ulf Emanuelson Kjell Holtenius Jan Hultgren Rauni Niskanen 《Acta veterinaria Scandinavica》2008,50(1):31
Background
Body condition score and blood profiles have been used to monitor management and herd health in dairy cows. The aim of this study was to examine BCS and extended metabolic profiles, reflecting both energy metabolism and liver status around calving in high-producing herds with a high incidence of abomasal displacement and ketosis and to evaluate if such profiles can be used at herd level to pinpoint specific herd problems.Methods
Body condition score and metabolic profiles around calving in five high-producing herds with high incidences of abomasal displacement and ketosis were assessed using linear mixed models (94 cows, 326 examinations). Cows were examined and blood sampled every three weeks from four weeks ante partum (ap) to nine weeks postpartum (pp). Blood parameters studied were glucose, fructosamine, non-esterified fatty acids (NEFA), insulin, β-hydroxybutyrate, aspartate aminotransferase, glutamate dehydrogenase, haptoglobin and cholesterol.Results
All herds had overconditioned dry cows that lost body condition substantially the first 4–6 weeks pp. Two herds had elevated levels of NEFA ap and three herds had elevated levels pp. One herd had low levels of insulin ap and low levels of cholesterol pp. Haptoglobin was detected pp in all herds and its usefulness is discussed.Conclusion
NEFA was the parameter that most closely reflected the body condition losses while these losses were not seen in glucose and fructosamine levels. Insulin and cholesterol were potentially useful in herd profiles but need further investigation. Increased glutamate dehydrogenase suggested liver cell damage in all herds. 相似文献9.
J. Hultgren 《Veterinary research communications》1990,14(4):287-298
The literature on the electrical properties of the body and sensitivity to steady electric current in humans and farm animals is reviewed and the problem of stray voltage is examined. Stray voltage poses a problem to animal health and protection in cattle and pigs and possibly also in other animals. Dairy cattle can perceive alternating currents exceeding 1 mA between the mouth and all four hooves. Behavioural effects in cows usually occur above 3 mA. In practice, the major influence on dairy cows appears to be behavioural. In experimental research on sensitivity to electric current, the effects studied should be related primarily to the actual current densities or electric fields in the affected tissues rather than to the total voltages applied. Under normal conditions, herdsmen are less likely to be affected by stray voltage than their animals. 相似文献
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