Canadian journal of comparative medicine and veterinary science最新文献

A complement-fixation (CF) antigen which has been prepared from Theileria infected erythrocytes is capable of reacting to specific serum antibodies of deer acutely infected with Theileria. No sera from 17 deer known to be free of Theileria infection reacted positively to the CF test. Of 35 tests on sera from 12 infected deer having a parasitemia of 2% or less and no accompanying anemia, only 10 (29%) were positive, 2 (6%) were suspicious, and 23 (66%) were negative. Of 65 tests on 8 acutely infected deer, 49 (75%) were positive, 4 (6%) were suspicious and 12 (18%) were negative. Of the 8 deer in which acute theileriasis occurred all reacted to Theileria antigen at one time or another.A significant correlation was found between CF titers and the degree of parasitemia in acute infections. Rabbits were hyperimmunized using erythrocytes from either normal or Theileria infected deer. Reciprocal absorption of the hyperimmune sera with Theileria and normal erythrocytic antigens demonstrated the presence of antibodies specific for Theileria.

A METHOD IS DESCRIBED FOR THE QUANTITATIVE STUDY IN VITRO OF THE BOVINE MILK LEUCOCYTE: staphylococci interaction which is capable of demonstrating differences between groups of leucocytes, and, to some extent, stains of Staph. aureus. By means of this method it has been possible to show statistically, that significant differences can occur, between quarters of the same udder, in the numbers of leucocytes competent to ingest staphylococci, and also in the numbers of staphylococci ingested. Between 4 strains of Staph. aureus significant differences were noted in their ability to multiply in the presence of milk leucocytes; in the production of leucocidal factors; and in the reduction of Resazurin in whole, normal milk.

The virus of transmissible gastroenteritis produced sprue-like lesions in the small intestines of young pigs. These lesions were characterized by villous shortening, fusing and blunting in the jejunum and ileum. There was decreased height of the brush border and morphologic alteration of the villous epithelial cells from simple columnar to a variable cuboidal type. Accompanying these microscopic lesions were histochemical changes characterized by decreased staining intensity of acid phosphatase, alkaline phosphatase, adenosine triphosphatase, leucine aminopeptidase, succinic dehydrogenase and malic dehydrogenase in the affected intestinal mucosa. The clinical nature of transmissible gastroenteritis in the pig together with the histopathologic and histochemical changes may provide a useful experimental model for obtaining additional basic information on enteric disturbances.

Physical, biochemical, and cytologic properties of synovial fluid from normal equine tarsal joints were investigated. Tarsal synovial fluid was pale yellow, clear, free of flocculent material, and did not clot. Volume varied in direct proportion to individual tarsal joint size. Relative viscosity was related to volume, polymerization and quantity of hyaluronic acid, and protein concentration. Mucinous precipitate quality (hyaluronic acid polymerization) was uniformly high. Results of certain analyses of serum were compared with those of tarsal synovial fluid. Tarsal synovial fluid protein concentration was low in conjunction with a high A:G ratio. Serum: synovial fluid sugar ratio was 1.24:1. Serum ALP, ACP, LDH, GOT, and GPT activity levels were higher than their corresponding levels of activity in tarsal synovial fluid. Serum ALD activity level was slightly lower than its tarsal synovial fluid counterpart. Total erythrocyte counts ranged markedly, while total leukocyte counts were uniform and low. Lymphocytes were the predominant synovial fluid cell type.

Poloxalene, a nonionic surfactant, was fed to beef cattle on a legume ration or a high grain ration to observe its effect on bloat. It was also fed to lactating dairy cows to note any effect on yield or composition of milk. Poloxalene was beneficial in the prevention of bloat with both legume and grain rations. It had no effect on per cent fat, protein, solids-not-fat, or yield of milk.

Krebs citric acid cycle enzymes have been studied in rice moth larvae (Corcyra cephalonica St) reared in groundnut meal control and contaminated with A. flavus, wheat bran control and wheat bran contaminated with A. flavus and also wheat bran containing aflatoxin. It was observed that the activity of enzymes other than succinic oxidase, succinic dehydrogenase and isocitric dehydrogenase were reduced significantly in larvae reared in contaminated groundnut meal when compared with the control. In the case of larvae reared in contaminated wheat bran all the enzymes except succinic oxidase were inhibited when compared to the control larvae. It was also observed that the inhibition of these enzymes is greater in the case of larvae reared in contaminated wheat bran than in contaminated groundnut meal. The higher toxicity of wheat bran has been discussed.

Diazoxide was given to 12 pigs and 12 lambs during 2 days prior to slaughter at a level of 20 mg/kg of body weight at each of three feedings. During this period it increased (P>.01) the weight gain of pigs by 2.08 kg and lambs by 1.55 kg over that of paired controls. The cold carcass dressing percentage was 0.76 percentage units higher (P>.05) in pigs and 2.03 (P>.01) in lambs treated with diazoxide and the water content of the carcass per kg of initial weight was increased (P>.01) by 6.3% in pigs and 9.7% in lambs.

Five young seals and three mature seals were branded using liquid nitrogen cooled branding tools with xylol as a wetting agent. Preliminary results are encouraging as presented by photographic evidence.

A number of branding tools of various metals and various sizes in combination with several wetting agents were cooled with liquid nitrogen and applied for different lengths of time to calves and mature cattle. White hair appeared in the shape of the brand on the animals in place of dark hair when the application was properly carried out. Best results can be obtained by using metal irons at least 25 millimeters thick and 14 millimeters wide with xylol as a wetting agent for ten seconds in young or thin skinned animals and up to twenty seconds in mature or thick skinned animals.

Four gnotobiotic pigs were infected with an enteropathogenic strain of Escherichia coli, and 4 were infected with a nonenteropathogenic strain of E. coli. Pigs killed in pairs at 6, 12, 24, and 48 hours PI. Four pigs were maintained as germfree controls. The discussions were based on the results of 1) clinical observations, 2) necropsy observations, 3) counts of viable E. coli in segments of the small intestine, 4) attempts to isolate E. coli from the heart, liver, and bile, 5) microscopic examination of fixed intestinal sections to determine the location of E. coli and morphologic evidence of the host response, and (6) determinations of the pH of the contents of the various portions of the gastrointestinal tract. No diarrhea, fluid accumulation, or impairment of the digestive capacity were noted in the pigs infected with the nonenteropathogenic strain of E. coli. The number of viable E. coli detected in the respective segments of the homogenized small intestine was similar in pigs infected with either strain. Diarrhea occurred continuously starting 18 hours PI in the pigs infected with the enteropathogenic strain and killed 24 or 48 hours PI. The pH of the contents of the cecum and colon became markedly more alkaline simultaneously with the increase in the heterogeneity and fluid content of the cecum and colon and thus appeared to correlate well with the onset of the clinical diarrhea. No enteritis was detected grossly or microscopically. The characteristics that determine the enteropathogenicity of a strain of E. coli could not be defined from the results, but it was noted that the host response appeared to be quite similar to that of infant rabbits experimentally infected with Vibrio cholera.