The Collaborative International Dictionary of English v.0.48:
Heifer \Heif"er\, n. [OE. hayfare, AS. he['a]hfore, he['a]fore; the second part of this word seems akin to AS. fearr bull, ox; akin to OHG. farro, G. farre, D. vaars, heifer, G. f[aum]rse, and perh. to Gr. ?, ?, calf, heifer.] (Zool.) A young cow. [1913 Webster]WordNet (r) 3.0 (2006):
heifer n 1: young cow