Reading PipKelpy's story about a grown heifer coming back onto her mother makes me think it's worth using the Quiet Wean nose tags anyway, because the calf learns that it can't suckle and seems to remember and not try to get the teat in its mouth. When Hillie and Flare ran together with Flare as an adult, Flare would sometimes stand as though suckling, with her head dipped towards the udder, but she never attempted to get the teat, even when Hillie's new calf was suckling alongside. So I surmised that standing like that was comforting, even without the actual suckling.