Heterogeneity of the chicken ALD muscle: evidence for a minor, twitch fiber type.

Examination of the anterior latissimus dorsi muscle of the chicken using histochemical, immunofluorescent, and ultrastructural techniques revealed the presence of a minor muscle fiber type which was similar but not identical to the fast-twitch fibers of the posterior latissimus dorsi muscle. Heterogeneity of muscle fiber type appeared within the 1st week after hatching.