A gross study of the compartmentalized stomach of two new-world camelids, the llama and guanaco.

Abstract

AbstractThe llama and guanaco stomach consisted of three compartments. A transverse pillar divided the large, first compartment into cranial and caudal sacs. Both sacs contained recessed glandular saccules. The saccules in the caudal sac were everted during the gastric contraction cycle. The non‐recessed surfaces of this compartment were covered by stratified squamous epithelium.The first compartment communicated on the right with a smaller, reniform second compartment. Except on the lesser curvature, this compartment contained deep cells which were lined by a papillated glandular mucosa.The ventricular groove, defined by a single muscular lip, coursed along the cranial sac of the first compartment, over the lesser curvature of the second compartment, and terminated at the tubular passage to the third compartment.The initial four‐fifths of the elongate third compartment contained mucigenous glands like those found in the saccules and cells of the first and second compartment Proper gastric glands and pyloric glands were confined to the terminal one‐fifth of the third compartment.Attempts to homologize the compartments of the camelid stomach with those of the Pecora or so‐called advanced ruminants were unsuccessful. The results of this study and concurrent physiologic investigations indicated that the processes of ruminant digestion can operate within wide anatomic boundaries, and that the camelid stomach with its extensive glandular mucosa is adapted for greater digestive efficiency than the advanced ruminant stomach.