Abstract. The objective of this study was to compare three genetic groups of ducks: P9 (French Pekin), K2
(bred from wild mallards – Anas platyrhynchos L. and Pekin duck), and KhO1 (hybrid of Khaki Campbell
drake and Orpington Fauve duck) after two breeding seasons for body weight and length, length of intestine and
its segments, percentage of other internal organs, and breast muscle microstructure. The study used 60 ducks,
20 birds (10 males and 10 females) from each genetic group. At 110 weeks of age, P9 ducks exhibited significantly (p