Morfometria de oocistos de espécies do gênero Eimeria de bezerras de duas faixas etárias e de acordo com a intensidade de infecção

Abstract

The presence of eimerian oocysts in the feces of cattle is very frequent and affects especially young animals. In general the infection is multispecific and the occurrence varies according the age of the host animals. The aim of this study was evaluate the average variation in the size of oocysts of Eimeria, according to the categories of variables: age of the calves (0 to 100 and 101 to 180 days of age) and intensity of infection. And through two techniques to characterize the morphometry of the genus Eimeria, in the municipality of Pirai, RJ. From August 2010 to June 2011 weekly were collected fresh fecal samples and placed in indentified plastic bags under refrigeration until processing. At the end of the study were collected 1512 fecal samples. A portion of feces was processed following the technique of centrifugal flotation in sugar saturated solution for counting oocyst per grams of feces (OPG). Another portion was added solution of potassium dichromate at 2.5% in the proportion (1:2) to sporulation that occurred at room temperature for identification percentage of the genus Eimeria. Based on morphological and morphometric characteristics of oocysts were identified nine species of Eimeria: E. ellipsoidalis (39,7%), E. alabamensis (18,4%), E. bovis (12,1%), E. zuernii (11,4%), E. subspherica (7,3%), E. cylindrica (6,0%), E. auburnensis (3,6%), E. wyomingensis (1,0%) and E. canadensis (0,6%). In the present study, calves up to 100 days showed higher infection intensity (%) and in both age groups there was fewer samples classified as high intensity. After statistical analysis can be seen there was no correlation (p> 0.05) among the technical measures, showing that one is independent from other. Based on the analysis of the oocysts of the species E. ellipsoidalis, can observe that the age of the animals influence the shape of oocysts in both measurement resources. However, no significant difference (p> 0.05) in the morphometry of oocysts according to the intensity of infection