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Biomedical subjects

T E Blackwell

Publications and source records attributed to T E Blackwell.

12 recordsLinked to original sources
PubMed1994

Production practices, calf health and mortality on six white veal farms in Ontario.

A group of 4863 white veal calves reared on six commercial white veal farms in Ontario were followed through production to describe calf characteristics and production levels. Patterns of morbidity, mortality, and culling were investigated at the farm, room and individual level. The majority of the calves were male Holsteins, with approximately half originating from Ontario. The mean average daily gain for shipped calves over the entire production period was 1.1 kg/day (SE = 0.002). The overall percentage of calves receiving at least one individual treatment was 59%, with an average number of treatment days per calf of 3.3. The majority of calves receiving one or more treatment days were first treated between the fourth and seventh week of production. The mortality rate was 3.7%, and 5.1% of the calves were culled. Pneumonia was the largest single cause of death. Peak death and cull losses occurred during the seventh and eighth week of production.

Animal Husbandry↗
PubMed1994

Production indices, calf health and mortality on seven red veal farms in Ontario.

Production, morbidity, mortality and culling were investigated on seven commercial red veal farms in Ontario. The total number of calves included in the study group was 2251. The mean exit weight of marketed calves was 291 kg, with an average daily gain of 1.52 kg/day over the entire production period. The percentage of calves receiving one or more treatment days was 55%, with an average number of individual treatment days per treated calf of 3.9. An increasing number of treatment days, particularly up to eight days of treatment, was associated with decreasing average daily gain, and an increased probability of being lost from production due to death or culling. The percentage of calves which died during production was 5.4, with 0.8% of calves culled.

Animals↗
PubMed1992

Clinical signs, treatment, and postmortem lesions in dairy goats with enterotoxemia: 13 cases (1979-1982).

Enterotoxemia attributable to Clostridium perfringens type D in goats is difficult to diagnose because of a lack of specific clinical signs or postmortem lesions, on which to base the diagnosis. This report describes the clinical signs, postmortem lesions, and clinical responses to treatment and vaccination in 4 goat herds, in which a diagnosis of enterotoxemia was confirmed. Four clinical cases had the diagnosis confirmed on the basis of signs of diarrhea or sudden death and the isolation of C perfringens and epsilon toxin from the feces at the time of admission. The 10 necropsy cases were diagnosed on the basis of the isolation of C perfringens (not typed) or epsilon toxin from the intestinal contents of goats that died with clinical signs compatible with enterotoxemia and without lesions associated with a second serious disease. Enterocolitis was the most consistent lesion reported at necropsy in the 10 goats with enterotoxemia. Ovine enterotoxemia vaccines were of limited value in preventing enterotoxemia. These observations imply that naturally induced enterotoxemia in goats involves a different pathophysiologic mechanism than that associated with enterotoxemia in sheep.

Animals↗
PubMed1991

Differences in signs and lesions in sheep and goats with enterotoxemia induced by intraduodenal infusion of Clostridium perfringens type D.

Enterotoxemia was induced in 4 lambs and 4 goat kids by continuous intraduodenal infusion of a whole culture of Clostridium perfringens type D. Clinical signs, hematologic values, biochemical alterations, and postmortem lesions in the lambs and goat kids were compared. The 4 lambs and 4 goat kids died within 25 hours of beginning the infusions. Lesions were not observed in the gastrointestinal tract of the 4 lambs; however, severe hemorrhagic enterocolitis was found in the 4 goat kids. This difference between the lambs and goat kids in the lesions caused by experimentally induced enterotoxemia may explain the discrepancies reported between sheep and goats in clinical signs, response to treatment, and efficacy of vaccination observed in naturally induced enterotoxemia in the 2 species.

Animals↗
PubMed1989

Goitrogenic effects in offspring of swine fed sulfadimethoxine and ormetoprim in late gestation.

Effects of feeding sulfadimethoxine and ormetoprim to sows and gilts in late gestation were evaluated. One sow and 2 gilts were randomly selected and were fed 1 of 3 rations: (1) a gestation ration from farm A, where congenital goiter in newborn pigs was a problem, (2) gestation ration from farm A containing 275 g of sulfadimethoxine and 55 g of ormetoprim/100 kg of ration, or (3) standard swine gestation ration containing 275 g of sulfadimethoxine and 55 g of ormetoprim/100 kg of ration. Sows and gilts were fed the appropriate ration for 22 to 58 days before farrowing. The numbers of stillborn or weak pigs did not increase in any group. However, congenital goiter was detected in all pigs from swine fed medicated rations 2 and 3. Congenital goiter was not present in pigs from swine given gestation ration 1.

Animal Feed↗
PubMed1986

Detection of antibodies to Mycoplasma felis in horses.

Mycoplasma felis has been isolated from horses with pleuritis, and limited research indicates that mycoplasma pleuritis can be reproduced in horses. The serodiagnostic potential of the indirect hemagglutination and the metabolism-inhibition tests was evaluated by testing 177 horses for antibodies to M felis. Seven horses with M felis pleuritis developed antibodies, and 6 horses with sterile or bacterial pleuritis had high titers suggesting a previous M felis infection. Six horses with pleuritis (one sterile and five bacterial) had low or no titers to M felis. Only one of 30 horses with conditions other than respiratory diseases seroconverted during hospitalization and the remaining horses had low titers. Seventy-eight foals, 4 to 6 months old, from one farm did not have titers, whereas 7 out of 50 yearlings from the same farm had high titers in the indirect hemagglutination test and titers in the metabolism-inhibition test. It appears that both tests are suitable for serodiagnosis of M felis infection in horses.

Animals↗
PubMed1983

Mycoplasma felis as a cause of pleuritis in horses.

Mycoplasma felis was the only organism recovered from the thoracic cavity of a horse with pleuritis. Large numbers of mildly degenerative neutrophils were in the pleural fluid. The horse developed a serologic response to M felis and recovered during hospitalization. Experimentally, a pony was inoculated in the thoracic cavity with a pure culture of the M felis isolate suspended in the pony's serum. A control pony was inoculated with serum only. Within 48 hours, the principal pony developed fever, increased respiratory rate, pleural effusion, and signs of pain. A highly cellular exudate with nondegenerative neutrophils and large numbers of M felis was recovered from the thoracic cavity. The control pony remained normal. The principal pony developed an antibody response to M felis. The control pony did not. Fourteen days after inoculation, both ponies were euthanatized. Necropsy revealed pleural inflammation in the principal pony. Pleural lesions were not found in the control pony.

Animals↗
PubMed1983

Enterotoxemia in the goat: the humoral response and local tissue reaction following vaccination with two different bacterin-toxoids.

A vaccination trial involving 72 goats was designed to compare the epsilon antitoxin titres and local reactions at the injection sites, of two commercial enterotoxemia vaccines. Three dosage regimens were used for each vaccine (12 goats per group). Although no significant differences were noted in humoral immune response between the two vaccines (P = 0.05), one vaccine regime resulted in low titres (P = 0.05) on two occasions. Local tissue reactions at injection sites persisted for six months in 53% of the goats regardless of vaccine used or dosage administered. No immunological basis for the reported differences in vaccine efficacy between sheep and goats was observed in this trial.

Animals↗