**2. Materials and Methods**

#### *2.1. Samples*

DNA extracts from 434 *C. xiaoi*-positive samples were used in this study, including those from Small Tail Han sheep (*Ovis aries*), Hu sheep (*Ovis aries*), Tibetan sheep (*Ovis aries*), Huanghuai goats (*Capra hircus*), and Black goats (*Capra hircus*) on 11 farms in Qinghai, Henan, Anhui, and Guangdong, China (Table 1). The *C. xiaoi*-positive samples were obtained from previous and ongoing studies of molecular epidemiology of cryptosporidiosis in sheep and goats in China [19]. All the samples were identified as positive for *C. xiaoi* by PCR and sequence analysis of an ~830-bp fragment of the small subunit (*SSU*) rRNA gene [20].
