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991.
In 9 experiments the vitamin A content of the livers of 64 newborn (still births and deaths up to 48 h p.p.) and 69 weaned piglets, 122 growers and 110 fattening pigs was investigated after slaughtering or autopsy. Liver samples were taken from 78 growers by means of biopsy after latarotomy. A fluorometric analysis of the plasma vitamin A level was made. At the time of birth the vitamin A content of the piglet livers was less than 100 IU/g and did not show any differences between the experiments. At the time of weaning, however, the livers of piglets from large-scale production showed a three times higher content (175 IU/g liver) in comparison to those from traditional production. Highly significant linear relations were established between the vitamin A content of the feed and the liver. According to these, a liver content of vitamin A of approximately equal to 30 IU/g is ensured by approximately equal to 2,000 IU in weaning piglets and by approximately equal to 800 IU vitamin A/kg feed in fattening pigs. The vitamin A activity of the beta-carotene in weaners was ascertained as less than 100 IU/mg. The plasma vitamin A level indicated the vitamin A status only in the range of deficient supply. A different plasma content could not be detected between 1,000 and 4,000 IU vitamin A/kg feed. According to this, a semilogarithmic relation was calculated according to the model of a saturation curve between the vitamin A content of the plasma and the liver. The threshold value for the decrease of the plasma level under 45 IU vitamin A/dl is 35 IU/g liver. Due to the low definiteness measure (B = 0.52) the relation cannot be applied to the individual animal. A contamination of 1,000 mg nitrite/kg feed had a low, and in the course of the experiment decreasing, influence on the vitamin A content of plasma and liver. 相似文献
992.
993.
C L?mmler I W Wibawan 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1990,37(3):173-176
Streptococcal group-specific antigens and B-streptococcal type antigens were solubilized with a murolytic enzyme from Staphylococcus hyicus. This facilitated the effective serogrouping and serotyping of streptococci isolated from humans and various animals. 相似文献
994.
Nine strains of paramyxovirus isolated from racing pigeons in southern Bohemia, Moravia and western Slovakia in 1983 were identified by the haemagglutination-inhibition test with antisera to seven types of paramyxovirus and three types of influenza A virus as PMV-1, Newcastle disease virus, in all cases. The haemagglutination activity and pathogenicity of the isolates for chicken embryos, chicken fibroblast cultures, and chickens of different age were determined. The mean death time of chicken embryos (MDT/MLD) was 52.8 to 95.4 h, the average being 75.7 h. The intracerebral pathogenicity index (ICPI8) was on an average 1.42 +/- 0.10 (P = 0.95). Experimental infection of chickens at the age of one, two, three and eight weeks did not cause any clinical disease but increased the level of haemagglutination-inhibiting (HI) serum antibodies up to 1 : 256 within three weeks. The course of heat inactivation of pigeon viruses at the temperature of 56 degrees C was practically identical with the inactivation of the velogenic viscerotropic strain California/1082/71. On the basis of the results, the pigeon isolates may be considered the Newcastle disease virus of velogenic viscerotropic type whose pathogenicity for chickens has been reduced to the level of mesogenic strains by long-time passaging in pigeons. 相似文献
995.
996.
Two groups of 12 and 6 rats were inoculated with Fasciola hepatica and Schistosoma mansoni, respectively. The Schistosoma-inoculated group, as well as 6 Fasciola-inoculated rats and 6 uninfected rats were challenged 8 weeks later with F. hepatica. A control group of 6 rats was left unexposed. Eight weeks after the challenge exposure all rats were necropsied and subjected to post-mortem examination. The number of Fasciola recovered after challenge was lower in both groups of rats primarily infected with F. hepatica or S. mansoni. F. hepatica-induced pathological changes were observed in all infected rats, but were pronounced in the group which was first exposed at the time of challenge of the primarily infected groups. No Schistosoma eggs or adults were detected in Schistosoma-inoculated rats. The results demonstrated that rats primarily infected with F. hepatica acquired resistance against a challenge exposure to the homologous parasite. Also S. mansoni, even without patency, can provide partial protection against F. hepatica infection. 相似文献
997.
Trace element levels in liver and kidney from cattle, swine and poultry slaughtered in Canada.
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G O Korsrud J B Meldrum C D Salisbury B J Houlahan P W Saschenbrecker F Tittiger 《Canadian journal of veterinary research》1985,49(2):159-163
Levels of arsenic, cadmium, copper, mercury and lead were determined in approximately 650 samples of liver and kidney from cattle, swine and poultry slaughtered in Canada during 1979-81. In addition zinc levels were determined in livers and kidneys from swine, and selenium and zinc levels were determined in the livers and kidneys from cattle. Depending on the element several methods of atomic absorption spectroscopy were used to analyze samples including flame, hydride generation, cold vapour generation and graphite furnace atomization. Analyses were also done by plasma emission spectroscopy. Levels of arsenic over 2.0 micrograms/g were detected in 0.9% of swine livers and 0.3% of swine kidneys. Cadmium levels higher than 1.0 micrograms/g were detected in 0.3% of cattle livers, 10.8% of cattle kidneys, 1.8% of swine kidneys, 0.4% of poultry livers and 0.3% of poultry kidneys. Levels of copper over 150 micrograms/g were detected in 0.4% of cattle and swine livers. Levels of lead over 2.0 micrograms/g were detected in 1.4% of poultry livers and 1.6% of poultry kidneys. The highest level of mercury detected in all species was 0.25 micrograms/g and the highest level of selenium was 1.9 micrograms/g. Zinc levels of over 100 micrograms/g were detected in 1.7% of cattle livers, 0.2% of cattle kidneys and 5.0% of swine livers. 相似文献
998.
B Niederw?hrmeier R B?hm 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1990,37(9):684-695
The evaluation and application of an enzyme-immunoassay (EIA) for the detection of Pseudomonas (Ps.) aeruginosa and Ps. mallei is described. Polystyrene beads (1/4') as the solid-phase are prepared by coating the balls with purified IgG from the serum of rabbits (9-12 micrograms/bead) in Coating-Buffer pH 9.6. After washing the balls they are saturated with 10% BSA or 10% FCS in PBS-Tween 20. The bacteria bound to the coated balls are detected by the specific peroxidase labelled IgG. This EIA using Ps. aeruginosa (P9) as a model is able to detect this bacterium within 5 hours, with stored coated balls 3.5 hours, with a detection limit of 10(4) CFU. Nine Pseudomonas-strains react stronger than other strains. These cross-reactions can be substantially reduced by absorbing the P9-conjugate with the cells of Ps. stutzeri (P15). With the other Pseudomonas-strains a high specificity is found with the P9-conjugate. After modifying this EIA for the detection of Ps. mallei (P18) the strains Ps. mallei (P57), Ps. pseudomallei (P17) and Ps. cepacia (P67) react with the P18-conjugate. With the other tested strains a high specificity is found at 10(7) CFU. The polystyrene bead-EIA is recommended as a sensitive and specific test for the detection of Ps. aeruginosa in about 5 resp. 3.5 hours. It only requires normal laboratory equipment and is thus a highly practicable method for routine diagnostic of Ps. aeruginosa. 相似文献
999.
1000.