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51.
52.
An indirect "sandwich" enzyme-linked immunosorbent assay (ELISA) using polyvalent and monovalent antisera was compared with the 50% complement fixation (CF50) test for the detection of foot-and-mouth disease (FMD) O, A, and C virus types. ELISA was more sensitive than CF50 tests when polyvalent antisera were used for detecting the 3 types of virus in epithelial samples, whereas ELISA using monovalent antisera was the least sensitive technique. The ELISA performed with polyvalent antisera was 9 times more sensitive for detecting FMD virus than that with monovalent antisera. However, viral isolation in cell culture was the most sensitive detection system. The combined use of ELISA with polyvalent antisera and cell culture inoculations was the most effective procedure for identifying FMD virus in epithelial samples from the field.  相似文献   
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54.
Nineteen Clostridium perfringens Type C strains and ten foreign control strains of subtypes C1, C3, and C4 were tested for their toxin formation and spore resistance to heat. The 19 Type C strains had been isolated from unweaned piglets in the context of necrotising enteritis outbreaks in the GDR. The Clostridium perfringens Type C strains formed beta-toxin, but they failed to form epsilon-toxin or gamma-toxin, alpha-toxin was successfully recorded from 15 of the 19 strains tested from unweaned piglets. The minor-lethal toxin fractions were also tested, with delta-toxin being recorded from all strains, non-alpha-delta-theta-toxin from six, theta-toxin from five, and K-toxin from one. Tests for delta-toxin, lambda-toxin, and mu-toxin were negative. The Clostridium perfringens Type C strains isolated in the GDR from unweaned piglets with necrotising enteritis were, basically, identical with those described in Denmark by von Hogh (1967) with regard to toxin formation. Clostridium perfringens strains cultured in broilers with necrotising enteritis were characterised by regular toxin production in the context of alpha, theta, delta as well as non-alpha-delta-theta. They failed to form beta, epsilon, gamma and lambda, while mu-toxin was formed by them quite irregularly. They, consequently, are Type A strains. Resistance to chloramphenicol and/or oxytetracycline was exhibited by 78.5 per cent of 237 tested Clostridium perfringens strains which had been isolated from unweaned piglets and broilers with necrotosing enteritis. Multiple resistance was recorded from 33.9 per cent. All strains were susceptible to penicillin, nitrofurantoin, and erythromycin.  相似文献   
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56.
The literature concerning pathogenesis, pathological physiology and pathological anatomy in bovine, caprine and ovine mastitis is reviewed. The evoluation of infectious mastitis is divided in the three following phases: transmission-, invasion- and establishphase. The pathological anatomy about Mastitis acuta haemorrhagica et necroticans, Mastitis catarrhalis acuta, Mastitis catarrhalis chronica, Mastitis suppurativa and Mastitis granulomatosa is discussed.  相似文献   
57.
The in vitro metabolism of the chiral isomers of fonofos and fonofos oxon in the presence of mouse liver mixed-function oxidase and serum esterase was investigated. The metabolism of 35S-labeled phenyl-(S)P-fonofos mediated by mixed-function oxidase took place stereoselectively, resulting predominantly in (R)P-fonofos oxon. Similarly, (R)P-fonofos was converted to (S)P-oxon. In each case, however, a significant amount of racemization occurred. Other products were diphenyl disulfide and diphenyl disulfide oxide. In addition to stereospecificity, the oxidative metabolism of (R)P-fonofos proceeded at a rate faster than that of (S)P-fonofos. Stereoselective rate differences also were observed in mouse or rat serum-catalzyed degradation of the fonofos oxon enantiomers, the (S)P isomer being degraded about twofold faster than its enantiomer. The differences in toxicities of the isomers of fonofos and fonofos oxon were consistent with the in vitro metabolism data.  相似文献   
58.
Testicular tissue and blood samples (V. spermatica interna) were taken from 32 boars during castration. The animals were different age groups. Against this background, studies were conducted into the correlations between testicular and plasma testosterone, on the one hand, and the amount of interstitial cells of Leydig in testicular tissue as well as the latters' cell nuclei volumes, on the other. The results seemed to support the conclusion that any age-dependent increase of testicular and plasma testosterone concentrations was caused unambigously by an absolute increase in volume of androgenic testicular tissue, in concomitance with testicular growth, in other words, by rise in the total number of interstitial cells of Leydig.  相似文献   
59.
4 digestibility trials (4 male sheep per group) and 2 growth trials were carried out with 24 (V 1) and 32 (V 2) fattening lambs to investigate the effect of abundant oral Fe doses on the digestibility of crude nutrients in a ration of barley + dried green feed and on the results of fattening and carcass yields. Fe supplementation (less than 1400 mg per sheep/day) did not significantly change the digestibility coefficients of crude nutrients. Increasing Fe levels in the concentrates decreased the rates of liveweight increase and food consumption in both growth trials. Well-established statistical evidence was provided for the decline in absolute carcass yields resulting from the lower weight of the lambs at the end of the fattening period after Fe supplementation.  相似文献   
60.
In 1956 a disease of nursing pigs previously unreported in Denmark, was observed in several swine herds. The disease syndrome appeared identical with that later described by Roe and Alexander in 1958 and by S. F. Cartwright and M. Lucas in 1968. Since 1956 there have been no reports of such outbreaks in Danish herds. To investigate whether the virus is still present, a survey was carried out to detect neutralizing antibodies in sera from a number of boars using a micro technique. In 144 sera from Jutland 12% had titers ranging from 10 to 32 ND-50, 22% from 32 to 90, 37% from 90 to 256, 14% from 256 to 724 and 3% above 724 ND-50 with a total of 86% positive. Of 174 sera from the rest of the country 16% had titers ranging from 10 to 32 ND-50, 18% from 32 to 90, 28% from 90 to 256, 13% from 256 to 724 and 3% exceeding 724 ND-50 with a total of 79% positive.  相似文献   
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