[Differentiation of the species of Eimeria parasite of sheep by the use of linear regression and morphologic algorithms]. / Diferenciação das espécies de Eimeria parasitas de ovinos pelo uso da regressão linear e algoritmos morfológicos.

With the aims to evaluate the use of the linear regression analysis as a technique to detect interespecifc morphometric differences and to develop algorithms for differentiating oocysts from the Eimeria species, fecal samples of Santa Inês sheep, has been used. Empiric algorithms have been developed based on quantitative and qualitative data from the oocysts morphology. The linear regression of the length and width of the oocysts has been tested. There was no significant difference among the measures from the oocysts of the species E. bakuensis, E. faurei and E. ovinoidalis in lambs and in adults. From the five polar cap provided species, E. ahsata was differentiated from E. intricata and from E. bakuensis based on the straight lines angular coefficient. Concerning the species that do not present polar cap, E. parva and E. pallida were more subject to confusion. Even so, with the application of the algorithm, it was possible to cluster them into different strips. The efficiency presented by the algorithm for gathering these species was 77% and 64%, respectively. Regarding to the species with polar cap, the lowest efficiency presented by the algorithm was to cluster E. bakuensis, though it was above 50%.

[Natural infection with species of the genus Eimeria in small ruminant raised in two municipalities of the State Rio de Janeiro]. / Infecção natural por espécies do gênero Eimeria em pequenos ruminantes criados em dois municípios do Estado do Rio de Janeiro.

In order to identify Eimerian species, verify their frequencies and intensity of infection, besides the dynamics of environmental contamination by oocysts during two years, fecal samples were collected from Alpine goats and their cross-breeding and Santa Inês sheep, raised separated in Mountainous Region of the State of Rio de Janeiro. A centrifuge-flotation method was used to obtain the number of oocysts per gram of feces (OoPG). Nine species of Eimeria were identified in goats and ten in sheep. In both species of hosts, the infection intensity, was low in adults and proportionally high in kids and lambs. The frequencies varied among the species and the most frequent in sheep was E. ovinoidalis and the correlated species E. ninakohlyakimovae presented the major frequency in goats, except in kids. The natural infection was common, probably maintained by adults and also by favourable environmental conditions to dissemination and maintenance of oocysts.