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81.
82.
Two calves given a mean of 16.1 g and 16.4 g ripe Castanospermum australe seeds/kg body weight daily for 13 and 16 days respectively developed haemorrhagic gastroenteritis. The first calf died. The second calf had mild myocardial degeneration and necrosis and mild nephrosis at necropsy. Two calves given a mean of 16.8 g unripe C. australe seeds/kg body weight daily for 18 days remained clinically normal and had mild gastritis at necropsy. The activity of alpha-glucosidase was reduced in the mononuclear cells of peripheral blood and in skeletal muscle. This was attributed to the presence of the indolizidine alkaloid, castanospermine, in the seeds. The toxin causing the gastroenteritis and other lesions is unknown.  相似文献   
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In spite of several quality control procedures used by Australia to ensure the wholesomeness of export meat, a number of pesticide residue violations were identified in the Australian product exported to the USA in May 1987. The pesticides involved were the organochlorines, dieldrin and heptachlor. The problems were caused by the persistence of organochlorines in soils and their illicit use or contamination of storage facilities. Animals grazing contaminated pasture, ingesting contaminated feed or held in contaminated yards over a period, bioaccumulated residues in their adipose tissues which eventually exceeded maximum residue limits (MRL) and caused violations. Though there was no immediate public health risk, the Australian Quarantine and Inspection Service (AQIS) of the Commonwealth Department of Primary Industries and Energy (DPIE), acted expeditiously to determine and eliminate the factors causing these problems, which threatened Australia's beef export industry worth in excess of two billion dollars annually. An overall strategic plan, "The Integrated Action Plan", was formulated and implemented by AQIS with the assistance of the relevant Departments of the States and the Northern Territory (NT), meat processing and export industries and livestock producer bodies. As a result of this action, the likely sources of contamination were identified and controlled. The National Residue Survey (NRS) was enhanced, a National Residue Data Base (NRDB) was established and a centralised computer system interactive with abattoirs, laboratories and animal health authorities developed. The cattle farm identity tail tag system already in place, capable of tracing cattle to the farm of origin was refined and trace back systems for sheep and pigs were utilised.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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The relative activity of an SH dependent enzyme, papain, is decreased by increasing the ratio of oxidizing disulfide to reducing thiol in solution. The same applies to papain adsorbed on negatively charged clay particles, but the effect is more pronounced if positively charged disulfides can be formed in the thiol-disulfide exchange equilibrium. Disulfides with a double positive charge are apparently more strongly attracted to clay than are singly charged, neutral, or negatively charged products of exchange. Preferential attraction of oxidizing disulfides to the particulate surfaces increases local, microenvironmental oxidizing potentials.  相似文献   
88.
Objective   To determine the efficacy of triclabendazole (TCBZ) against 28-day-old, early immature liver fluke in cattle and its pharmacokinetics following administration by the oral or topical (pour-on) route.
Procedures   Cattle (n = 18) were infected with 500 TCBZ-susceptible liver fluke metacercariae and randomly allocated to three groups. At 28 days after infection, the groups were: (1) untreated controls; (2) treated with oral TCBZ at 12 mg/kg in combination with oxfendazole and selenium (TOS); (3) treated with pour-on TCBZ at 30 mg/kg in combination with abamectin (TA). Blood samples were taken immediately prior to treatment and serially after treatment to assess the plasma profile of TCBZ metabolites. Ten weeks after treatment all animals were slaughtered and total liver fluke counts, fluke egg counts and liver pathology were assessed.
Results   Both the TOS and TA treatments resulted in significant reductions of 28-day-old liver fluke, as assessed by fluke counts and fluke egg counts at slaughter, and the reductions following TOS treatment were significantly greater than those following TA treatment. The blood profile of TCBZ metabolites in TOS-treated animals showed a significantly greater area under the plasma concentration time curve and a higher maximum observed concentration than those treated with TA. There was significantly less liver pathology in TOS-treated animals than in the TA-treated animals.
Conclusion   TCBZ administered orally at 12 mg/kg resulted in greater efficacy against 28-day-old, early immature liver fluke than was achieved by topical administration at 30 mg/kg. Plasma metabolites of TCBZ were higher and liver pathology was less in TOS-treated animals than in TA-treated animals.  相似文献   
89.
Resistance to 16 antimicrobial agents was monitored in 109,125 Salmonella cultures isolated from animals, their environment and feedstuffs between 1988 and 1999. The sensitivity of the 6512 isolates of Salmonella enterica enterica serotype Dublin to all the antimicrobial agents tested varied from 98.2 per cent in 1997 to 99.7 per cent in 1990 and 1996. In contrast, among 28,053 isolates of Salmonella enterica enterica serotype Typhimurium, there was a marked decrease in their sensitivity to all the antimicrobial agents tested, from 57.4 per cent in 1992 to 7.6 per cent in 1995, owing to the widespread occurrence in farm animals of S Typhimurium isolates of the definitive type DT104, resistant to ampicillin, sulphonamides, streptomycin, chloramphenicol and tetracyclines, although the percentage of sensitive isolates increased to 18.4 per cent in 1999, when the incidence of DT104 had decreased. Some isolates of DT104 also showed an increase in resistance to potentiated sulphonamides (2.4 per cent in 1989 to 19.2 per cent in 1999) and nalidixic acid (0 per cent in 1992, 3.8 per cent in 1995 to a peak of 16.9 per cent in 1998). In 1996, 5.1 per cent of 1086 isolates of S Typhimurium from cattle and 35.9 per cent of 192 isolates of S Typhimurium from poultry showed resistance to nalidixic acid. Of the other 74,528 Salmonella isolates, the percentage of strains sensitive to all the antimicrobials tested decreased slightly from 88.2 per cent in 1988 to 70.6 per cent in 1996 and then increased slightly to 73.7 per cent in 1999. The commonest of these other Salmonella serotypes was Salmonella Enteritidis (20,982), which remained predominantly susceptible (ranging from 81.4 to 97.4 per cent) during the study period. Few isolates were resistant to commonly used veterinary antimicrobials, for example, furazolidone, the use of which was banned in 1990, and the aminoglycoside, apramycin.  相似文献   
90.
Haematological investigation is an important part of disease diagnosis. This is particularly so when investigating individual animal disease. It may also be important when investigating diseases in groups of animals, but the opportunity to perform necropsies to directly detect disease processes often diminishes its usefulness. Haematological investigation is essentially similar for all species. The presence of nucleated erythrocytes and thrombocytes in nonmammals requires alteration of haemoglobin measurement and cell counting. In addition, it may cause some confusion in identification of cells in peripheral blood films. Examination of blood films is an important component of haematological investigation and provides useful information on erythroid, leukocytic and platelet/thrombocytic alterations. Interpretation of alterations is essentially similar for all species. However, cell identification can at times be difficult. There are five basic leukocytes in all species: neutrophil (mammals) or heterophil (nonmammals), eosinophil, basophil, lymphocyte and monocyte. In nonmammals it may be difficult at times to distinguish between heterophils and eosinophils. In addition, lymphocytes may be confused with thrombocytes. However, a common-sense approach to the examination of the peripheral blood film will minimise this confusion.  相似文献   
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