Biological aspects of the lingual papillae of the Arab Zebu cattle: a new perspicuity of its chad ecological adaptations

Abstract

Our research is the first to explore the ultrastructural features of the lingual papillary system of Arab Zebu cattle, highlighting their Chadian environmental adaptations. There were two types of papillary systems: gustatory (fungiform and circumvallate) and mechanical (filiform, conical, and lentiform). The dorsal surface of the apex and rostral parts of the body had well-developed filiform papillae, whereas the tip’s surface had mucosal folds, tubercles, and few filiform papillae. The torus lingua’s dorsal surface displayed few lentiform papillae, while two conical papillae subtypes and numerous circumvallate papillae were present on its lateral surfaces. A slight median ridge on the dorsal surface of the body had not been described previously. Six filiform papillae subtypes were identified: long and rod-like on the tip; tongue-like and elongated on the lateral area of the apex and body; transient conical and leaf-like on the median line. The accessory processes were: one pair (on long, tongue-like, and transient conical), two pairs (on leaf-like and elongated), and four pairs on the large conical papillae. The two fungiform papillae subtypes were surrounded by a groove and had taste pores (3–5 on the oval and 5–9 on the round papillae). The U-shaped annular bad were observed around the ovoid circumvallate papillae, and the circular bad were observed around the round ones. The circumvallate had taste pores (8–14 on the round’s dorsal and lateral surfaces and 6–10 on the ovoid’s lateral surface). The papillary system’s regional divergence was specialized for its harsh and semi-harsh diet.