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The effect of probiotics and acidifying preparations on Campylobacter colonization of the alimentary tract of chickens for slaughter has been presented. The following preparations were given to one-day-old chickens: All-Lac, Acid Pack-4 Way, Cerbiogalli, Biogen Dp, Toyocerin, Humokarbowit and Formic Stabil 49 in doses recommended by producers. An aqueous solution of lactic acid was administered to chicks aged from 2 to 5 days and then repeated at the age of 12-15 days. A liquid culture of Cympylobacter jejuni (Lior 6, density = 100 000 cfu per one ml at 0.5 ml per animal) was administered orally. Bacteriological examination of faeces swabs and of the liver, and the contents of small intestine and caecum made it possible to determine the degree of colonization of the alimentary tract by Campylobacter jejuni. During the experiment morphological changes in organs were monitored and body weight gains were recorded. The findings showed a total elimination of Campylobacter sp. in the digestive tract of the chickens receiving All-Lac, Cerbiogalli and Biogen Dp. The efficacy of Acid Pack-4 Way and Toyocerin on day 14 after their administration was 83.3% and 75%, and 87.5% and 75% on day 21, respectively. In birds receiving Humokarbovit, Formic Stabil 49 and lactid acid, the degree of C. jejuni isolation was always high irrespective of the day of examination. The presence of C. jejuni in the livers of injected chickens was found only in the groups receiving lactid acid and Humokarbowit (33.3% and 16.7%, respectively; in control groups - 66.6%). Significant morphological changes were noticed in the caecum of the birds without administration of any feed supplements.
The present study was carried out to determine the presence of virulent factors in C. jejuni isolated from the alimentary tracts and livers of layer and broiler chickens. A tissue culture assay in vivo and invasivenes test in vitro on chicken embryos to detect the presence of the virulent factors mentioned above. It was found that the polymixyn extract of C. jejuni exhibited cytotoxic effects which were most clear in chicken kidney cells (94% of C. jejuni: the titer ranged from 4 log 2 to 12 log 2). Chicken embryo fibroblasts were less sensitive to Campylobacter filtrates (84% of C. jejuni: the titer ranged from 1 log 2 to 9 log 2). The lowest sensitivity was found in Vero cells. The invasive factor was determined in C. jejuni after the inoculation of 11-day-old chicken embryos onto the chorioallantoic membrane and into the allantoic cavity. There was a correlation between mortality of embryos and reisolation C. jejuni from their livers. However, this relationship was not observed after the inoculation of the embryos into the allantoic cavity.
The results of serological examinations of chickens after their experimental immunization with inactivated Campylobacter jejuni vaccine given subcutaneously (two groups aged from 10-18 days and 21-28 days) or infected orally on day 3 or broilers and laying hens infected under field conditions have been presented. The level of specific antibodies in sera of immunized chickens (OD ELISA mean values in chickens aged between 10-18 days were 0.316 and aged between 21-28 days (0.475) did not protect them from experimental infection carried out in week two after the second dose of the vaccine. However, two or three day delays in Campylobacter colonization were observed following infection with C. jejuni (strain Lio 1). Maternal antibodies (OD ELISA - 0.480) in chickens aged 3 days infected per os did not protect them from the infection. The analysis of OD ELISA values obtained from hens infected under field conditions demonstrated the relationship between these values and the age and clinical status of poultry. In older and clinically sick birds the values were significantly higher (0.837-1.351 in hens and 0.461-1.532 in chickens) than those in clinically healthy birds (0.417-0.863 and 0.264-0.490, respectively. The serological tests applied (ELISA and AGP) proved to be useful to detect antibodies against Campylobacter infections. Precipitating antibodies were found more often in poultry infected parenterally in field conditions, and in sick birds.
The studies were carried out on 570 broiler chickens, 600 layers and 400 that were hatching eggs. The rate of infection by Campylobacter sp. and the dynamics of the alimentary tract colonization were determined under field conditions. In addition the samples of feed, water and litter were collected for the studies during the production period. Depending on the age of broiler chickens, the rate of infection with Campylobacter sp. ranged from 30.8 (on day 14) after hatching to 66.7% on day 47 after hatching. In layers the infection comparised 60.3% of birds under study. Among the isolated strains C. jejuni biotype 1 predominated. The eggs of newly hatched chicks, feed and water were free from Campylobacter sp. However, the bacteria were isolated from litter. The data obtained in this study exclude vertical transmission of the germs, but confirm that litter contributes to the spread of flock infection.
Wielkotowarowa produkcja zwierząt sprzyja szerzeniu się wielu chorób zakaźnych. Istotną rolę w szybkim rozprzestrzenianiu się chorób w obrębie stada odgrywa bezpośredni kontakt zwierząt chorych bądź nosicieli ze zdrowymi oraz transmisja zarazków przez przenosicieli (wektory) biologicznych i mechanicznych (myszy, szczury, owady, środki transportu, obsługa). Wzajemny kontakt ludzi i zwierząt, a także spożywanie zakażonego mięsa czy innych środków spożywczych pochodzenia zwierzęcego stanowi zagrożenie zdrowia ludzi. W pracy omówione zostaną wybrane choroby odzwierzęce (zoonozy) i „food borne diseases”, stanowiące istotne zagrożenie dla społeczeństw zindustrializowanych w XXI wieku, jak np. nowy wariant choroby Creutzfeldta-Jakoba (vCJD), influenza ptaków o wysokiej zjadliwości (HPAI) oraz kampylobakterioza i salmonellozy.
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