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81.
The objective of this retrospective field study was to evaluate the effect of chronic clinical endometritis (CCE) on days open in German Holstein Friesian cows. Two hundred and sixty‐four cows diagnosed with CCE from day 14 to 42 postpartum were included in this study. A Cox’s proportional hazards regression model with stepwise forward selection for days open was used and the variables type of vaginal discharge, ovarian cysts and a marked loss of body condition score proved to be significant with hazard ratios of 1.5, 2.0 and 1.9 respectively. Although not remaining in the model, a weak positive effect of treatment for CCE and a negative effect of high milk production could also be found in the univariate analysis. These results suggest that the suppression of fertility of animals diagnosed with CCE varies according to the different symptoms, which could be used to support decisions regarding treatment. Management factors such as a marked loss in body condition and high milk production prolonged the number of days open of animals with CCE. 相似文献
82.
SUMMARY The analysis of records for 75 821 herd tests on 23 700 cows in the Macalister Irrigation District of East Gippsland, using a model that also included stage of lactation, herd and cow effects, found a strong relationship between somatic cell count and milk production. Unit increases in the natural logarithm of the somatic cell count were associated with decreases in production of up to 2.6% in the range 54 598 to 403 429 cells per mL. This is equivalent to a decrease of 1.9% for a doubling of cell count from 100 000 to 200 000 cells per mL. Subclinical mastitis was assessed to be a significant source of loss in milk production in the study area. 相似文献
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M Faisal B A Weeks W K Vogelbein R J Huggett 《Veterinary immunology and immunopathology》1991,29(3-4):339-351
There is a general agreement that exposure to high concentrations of polynuclear aromatic hydrocarbons (PAH) in sediments is associated with high frequencies of neoplasms in feral fish species. Since PAH modulate the activity of murine and amphibian natural cytotoxic (killer) cells, a leukocyte subpopulation that is believed to play an important role in immunosurveillance, we wished to determine if fish exposed to PAH could have an altered natural cytotoxic cell (NCC) activity. In the present study, mummichog (Fundulus heteroclitus L.) were collected from two sites in the Elizabeth River, VA that are heavily contaminated with PAH, and from a relatively unpolluted reference site in the York River, VA. The cytotoxic activity of anterior kidney and splenic leukocytes was tested against the tumor cell line K562. The leukocytes from Elizabeth River fish displayed a significant depression of the in vitro tumorilytic activity as compared with leukocytes from the York River fish. Analysis of leukocyte-tumor cell conjugates indicated that Elizabeth River fish leukocytes were unable to recognize and subsequently bind to the tumor target cells. This suggests an aberration in the early events of the cytotoxic mechanism. By keeping the fish in cleaner York River water for up to 28 weeks the suppressed NCC activity was reversed totally in one site, which is slightly contaminated, and partially in the other site, which is heavily polluted with creosote from an operating wood treatment plant. This indicates that the decreased NCC activity was related, at least in part, to exposure to the chemical pollutants in the Elizabeth River sediments. 相似文献
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Use of enzyme-linked immunoassays for antibody to types C and D botulinum toxins for investigations of botulism in cattle 总被引:3,自引:0,他引:3
The development of specific enzyme-linked immunosorbent assays (ELISA) for antibody to types C and D Clostridium botulinum toxins for investigation of botulism in cattle is described. Partially purified type C and D toxins were used as antigens to develop these ELISAs. Specificity of the ELISAs was evaluated on sera from 333 adult beef and dairy cattle from areas with no history or evidence of botulism in animals or water birds. The test was also evaluated on sera from 41 herds that included herds vaccinated against botulism, confirmed botulism cases and herds from areas where the disease is considered endemic. The ELISAs detected the presence of antibody to botulinum toxins in samples from vaccinated cattle and both convalescent and clinically normal animals from unvaccinated herds with outbreaks of botulism. Antibody was also found in unvaccinated animals from herds in which there had been no diagnosed botulism cases in areas where botulism was considered endemic. Sera from some unvaccinated cattle with high ELISA reactivity was shown to be protective for mice in botulinum toxin neutralisation tests. The use of these tests in investigations of botulism in cattle is discussed. 相似文献
88.
An evaluation of calf castration by intra-testicular injection of a lactic acid solution 总被引:1,自引:0,他引:1
G. FORDYCE NJ BEAMAN AR LAING PB HODGE† C. CAMPERO† RK SHEPHERD¶ 《Australian veterinary journal》1989,66(9):272-276
This experiment evaluated intra-testicular injection of a sclerosing drug, lactic acid, for castration of bulls. Its use was compared in 58 Brahman cross calves (50 to 128kg) with the general practice of open surgical castration. Chemical castration appeared to be more painful than surgical castration, though post-operative swelling and pain appeared similar for both methods. Chemical castration took 3 times longer than surgical castration (58 sec v 20 sec; P less than 0.01). Scrotal necrosis occurred in 25% of chemically-castrated calves and appeared due to drug leakage from the testes under the high pressure of injection. Healing time for chemical castrates was approximately twice that for surgical castrates. Five chemically-castrated calves (18%) retained one testis. Though all 5 were rendered sterile, each maintained androgenesis. This led to secondary male behaviour which caused management problems. Castration method did not influence post-operative growth. It is concluded that lactic acid administration is not a suitable alternative to the open surgical technique for castration of Brahman cross calves. 相似文献
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