Have you already seen the original Chinese list of the "Twelve Branches" before they were overlaid onto the animal zodiac? The Japanese juunichi beasties now use the "Branch" kanji, but there's an earlier list of meanings that doesn't seem to've ported online into Wikipedia etc.: 子 = "bud, young shoot, beginning of all things"; 丑 = literally "tied" but more loosely "the growth of things" and so on.

Source: Chinese Geomancy by Evelyn Lip, Singapore: Times Books International, 1979; I was particularly happy to find this book because it's a discussion of feng shui that predates the Western New-Ageification of the concept. (I still cherish the memory of seeing a book called "Celtic Feng Shui".)