Rumen–reticulum characteristics, scaling relationships, and ontogeny in white-tailed deer (Odocoileus virginianus)

• Published in: Canadian journal of zoology Vol. 90; no. 11; pp. 1351 - 1358
• Main Authors: LUNA, R. S, DUARTE, A, WECKERLY, F. W
• Format: Journal Article
• Language: English
• Published: Ottawa NRC Research Press 01.11.2012; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Anatomy & physiology; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Body mass; Deer; Developmental biology; digesta mass; Fundamental and applied biological sciences. Psychology; Mammalia; masse corporelle; masse du digesta; Odocoileus virginianus; ontogenetic; Ontogeny; ontogénétique; Physical growth; Physiological aspects; Rumen; rumen–reticulum; Ruminantia; réticulo-rumen; scaling; Thermoregulation. Hibernation. Estivation. Ecophysiology and environmental effects; Vertebrata; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Weight; White-tailed deer; Zoology; échelle; Canada; Vertebrata; Mammalia; Growth; Efficiency; Body weight; Rumen; Artiodactyla; Digestion; Ungulata; Odocoileus virginianus
• DOI: 10.1139/cjz-2012-0122
• ISSN: 1480-3283; 0008-4301

Scaling relationships between body mass and gut capacity are valuable to predicting digestive efficiency. Interspecific scaling relationships between body mass and gut capacity have consistently estimated a slope of 1.0; however, intraspecific scaling relationships between body mass and gut capacity have been highly variable. We examined the influence of demands of growth and production on scaling relationships of body mass and rumen–reticulum characteristics in white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) because little is known about how juvenile and subadult ruminants accommodate increased digesta masses. We sampled 108 animals over a 2-year period and assessed the influence of body mass, time of kill, crude protein (%), and acid detergent fiber (%) in the rumen, lactation, sex, and back fat on rumen–reticulum organ mass, rumen–reticulum capacity, wet mass of the digesta, and the dry mass of the digesta. Juvenile and subadult white-tailed deer had rumen–reticulum organ masses, capacity, and digesta masses that were similar to adults because body mass and rumen–reticulum scaling relationships all had scalars similar to 1.0. Thus, under the confines of our study, ontogeny plays only a minor role in the physiological characteristics of the rumen–reticulum and the scaling relationships of body mass and rumen–reticulum capacity.