PubMed HealthSearch

Biomedical subjects

J Claxton

Publications and source records attributed to J Claxton.

5 recordsLinked to original sources

Parasite burdens and host susceptibility of Zebu and N'Dama cattle in village herds in Gambia.

Helminth and tick burdens of N'Dama cattle kept in village herds were compared with parasite burdens in Zebu cattle introduced into the same herds. The animals were monitored regularly for tick and helminth burdens, and blood samples were examined for differential white cell counts. The Zebu were found to have significantly higher numbers of endo- and ectoparasites. The N'Dama had significantly higher levels of circulating eosinophils than the Zebu during peak parasite burdens. No difference in antibody levels to Amblyomma variegatum infestation could be detected between the two breeds. It is suggested that observed differences in susceptibility to endo- and ectoparasites between the two breeds cannot be totally attributed to environmental naivety of the Zebu, but must be partially owing to enhanced innate resistance factors in the N'Dama.

Animals

Study of TAMe (p-tosyl-L-arginine methyl ester) esterase activity of bovine plasma.

The TAMe (p-tosyl-L-arginine methyl ester) esterase activity of mature and immature bovine plasma was studied and compared with the activity of this enzyme in human plasma. Kaolin activation of 2 minutes was required to produce maximal activation in cattle, as compared with 1 minute activation in man. The kaolin-activated TAMe esterase values in bovine plasma were approximately one-half the values found in human plasma. The activity of this enzyme was statistically greater in immature than in mature cattle (P less than 0.05) at kaolin activation times of 1, 2, 15, and 20 minutes.

Animals

Infleuce of dietary levels of vitamin E and selenium on tissue and blood parameters in pigs.

Eighteen barrows approximately three weeks of age were used in a 3 X 3 factorial arrangement to investigate the effect of level of supplemental vitamin E and selenium on tissue and blood parameters. Tissue selenium concentrations increased in a quadratic manner with increased selenium intake with kidney tissue containing considerably greater concentrations than liver, heart or muscle. Supplementation of the diet caused a three-fold increase in serum selenium within the first week with a slight tendency to further increases in subsequent weeks. Serum vitamin E of unsupplemented pigs declined by fifty percent during the experiment, whereas supplemental vitamin E resulted in increased serum vitamin E. There was a considerable viration in percent peroxide hemolysis. Correlation of -0.63 between percent peroxide hemolysis and vitamin E intake and -0.85 between percent peroxide hemolysis and serum vitamin E were observed.

Animal Nutritional Physiological Phenomena