Mitchell, GillianRoberts, D.G.Van Sittert, Sybrand J.2016-02-102015-09Mitchell, G, Roberts, DG & Van Sittert, SJ 2015, 'The digestive morphophysiology of wild, free-living, giraffes', Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology, vol. 187, pp. 119-129.1095-6433 (print)1531-4332 (online)10.1016/j.cbpa.2015.05.015http://hdl.handle.net/2263/51303We have measured rumen-complex (rumen, reticulum, omasum, abomasum) and intestine (small and large combined) mass in 32 wild giraffes of both sexes with body masses ranging from 289 to 1441 kg, and parotid gland mass, tongue length and mass, masseter and mandible mass in 9 other giraffes ranging in body mass from 181 to 1396 kg. We have estimated metabolic and energy production rates, feed intake and home range size. Interspecific analysis of mature ruminants show that components of the digestive system increase linearly (Mb1) or positively allometric (MbN1)with bodymasswhile variables associatedwith feed intake scalewithmetabolic rate (Mb.75). Conversely, in giraffes ontogenetic increases in rumen-complex masswere negatively allometric (Mbb1), and increases in intestine mass, parotid gland mass, masseter mass, and mandible mass were isometric (Mb1). The relative masseter muscle mass (0.14% of Mb) and the relative parotid mass (0.03% of Mb) are smaller than in other ruminants. Increases in tongue length scale with head length0.72 andMb.32 and tongue mass with Mb.69. Absolute mass of the gastrointestinal tract increased throughout growth but its relative mass declined from 20% to 15% of Mb. Rumen-complex fermentation provides ca 43% of daily energy needs, large intestine fermentation 24% and 33% by digestion of soluble carbohydrates, proteins, and lipids. Dry matter intake (kg) was 2.4% of body mass in juveniles and 1.6% in adults. Energy requirements increased from 35 Mj/day to 190 Mj/day. Browse production rate sustains a core home range of 2.2–11.8 km2.en© 2015 Elsevier Inc. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, vol. 187, pp. 119-129, 2015. doi : 10.1016/j.cbpa.2015.05.015.GiraffeDigestionAnatomyPhysiologyEcologyVeterinary science articles SDG-15SDG-15: Life on landPostprint Article