Norman (1982) proposes that dú 犢 ‘calf’ is a loanword from Altaic languages, and the hypothesis is often cited by later scholars. Based on the recently unearthed documents and texts, a new phonological analysis of Old Chinese, and the cross-language phonetic corresponding rules, this paper argues that dú is not a loanword but a native Chinese word. Unearthed documents from the pre-Qin period provide earlier uses of dú than those from the Han dynasty mentioned previously. Combining the time of early uses, the xiesheng series and character interchanges related to dú, and a new reconstruction of the Old Chinese sources of the Middle Chinese initial *d-, the paper argues that there is no phonetic correspondence between dú and the Altaic t-initial morphemes. The paper also points out that a basic condition of establishing a loanword hypothesis through historical documents is that the cross-language phonetic correspondence should exist at the time reflected by the earliest uses of the word.