不同日龄家兔对2种兔球虫易感性的对比研究

SUSCEPTIBILITY OF RABBITS AT DIFFERENT AGES IRRESIDUA INFECTION

兔球虫专性寄生于兔消化系统（肝脏及肠道），所引起的兔球虫病对养兔业危害极大。兔球虫病对断奶后至3月龄的幼兔危害最大，本文用5000个中型艾美耳球虫和无残艾美耳球虫卵囊分别接种30、50和70日龄的新西兰白兔，通过统计兔排出的球虫卵囊量来分析不同日龄幼兔的易感性。结果显示，中型艾美耳球虫感染时，70日龄兔卵囊排出总量仅为3．7×10^7，明显低于30日龄（1．03×10^7）、50日龄（6．5×10^8）兔，且差异显著；而无残艾美耳球虫感染也得到相似的结果。同时，30日龄兔在感染后临床症状明显，精神萎靡，便秘、腹泻现象交替出现。该结果表明断奶前后（30日龄左右）幼兔对两种球虫的易感性最强。

Weaning rabbits under the age of 3 months are most susceptible to coccidiosis, which is caused by the infection of 11 Eimeria species. However, no data is available about the susceptibility of rabbits under the age of 3 months. In this study, groups of rabbits at different ages （30 d, 50 d and 70 d） were infected with same dose of sporulated oocysts of Eimeria media or E. irresidua. Oocysts shed in feces during day 1 and day 5 after the infection were counted daily. The total number of ooeysts production of 70 d old rabbits infected with E. media only was 3.7 × 10^7 , obviously less than 30 d old rabbits （ 1.03 ×l0^8 ） and 50 d rabbits （6, 5 × 10^7 ）. The same phenomenon was seen in rabbits infected with E. irresidua. At the same time, the clinical symptoms of the younger rabbits were obvious, reflecting depression, constipation and diarrhea. These results indicated that weaning rabbits at the age of 30 days are the most susceptible and thus provides clues to the control of eoeeidiosis in young rabbits.