Akkadian:gurratu, agurratu 'ewe' MA [CAD a1 160], [AHw. 299]. // The form without a- is common and is taken as the basic one in [AHw.] (the variant form with a- is found once in a lexical list but is the basic one according to [CAD]). According to [Landsberger-Gurney 340], "agurratu ... is the Assyr. equivalent of Babyl. immertu or lah̊ru" (note that here Landsberger gives up his earlier suggestion according to which the present term is to be connected with Sem. terms for 'young animal' like Syr. guryā [Landsberger 1935-6 155]).
Notes: Sparsely attested and therefore not quite reliable. As for the the semantic difference, it is worth noting that an almost identical meaning correspondence is attested for the same languages in *bVb-, No. ... . Cf. Tna. gahret, gahrät 'antilope femmina' [Bass. 807].