33个小型鸡场球虫流行病学调查

对天津、河北、山东等地33个小型养鸡场做了球虫病原学流行调查。根据卵囊形态，最短潜在期．裂殖体部位和大小，病变等具有鉴别意义的特征做综合鉴定。结果显示，33个鸡场都有球虫的感染。共鉴定出7个种．其中有28个鸡场有堆形艾美耳球虫(E．acervulina)，占84．84％．26个场有柔嫩艾美耳球虫(E．tenella)．占78．78％．25个场有巨型艾美耳球虫(E．maxima)，占75．8％，早熟艾美耳球虫(E．praecox)，和缓艾美耳球虫(E．mitis)，布氏艾美耳球虫(E．brunetti)和毒害艾美耳球虫(E．necatrix)各1个场有．各占3％。只有一个鸡场单独感染一种球虫．其余都是混合感染2种或2种以上球虫，其中有2个鸡场混合感染4种球虫。

PREVALENCE OF COCCIDIA ON 33 POULTRY FARMS IN CHINA

An investigation of prevalence of Coccidia on 33 poultry farms in Shandong, Hebei and Tianjin of China was conducted. Fecal samples were collected from the farms where coccidiosis vaccince had never been used before, therefore the results could reflect the true situation of coccidia prevalence. Programed procedure was employed to identified the species present in the samples. All seven Eimeria species in chickens were found. E. acervulina, E. tenella, and E. maxima were found on 28, 26 and 25 farms respectively. E. praecox, E. mitis, E. necatrix and E. brunetti each were found only on 1 farm. 30 of 33 farms were positive for 2 or 3 species. 1 farm was positive for only 1 species. 2 of 33 farms were positive for 4 species. These results confirmed the presence of seven species of Coccidia in China poultry and demonstrated a prevalence and intensity for rarely reported E. praecox, E. mitis and E. brunetti.