Namakemono-san is right. You got the katakana character read mistakenly.
キヅ (read "kizu") should be キジ (read "kiji," meaning pheasant)
The sentence means: (He) gave a millet dumpling to the pheasant and got it to become a companion on his journey. (Probably from the story of "Momotaro (Peach Boy).")
HTH!