Alpacas fed calcium propionate seem to moderate their energy intake

• Published in: Journal of animal physiology and animal nutrition 2014-12, Vol.98 (6), p.1088-1094
• Main Authors: Lund, K. E, Milton, J. T. B, Maloney, S. K, Blache, D
• Format: Article
• Language: English
• Subjects: adaptation; Adaptation, Physiological; alpacas; amino acids; Animal Feed - analysis; Animal Nutritional Physiological Phenomena; Animals; calcium propionate; Camelids, New World - physiology; deamination; diet; Diet - veterinary; Dietary Supplements; energy intake; Energy Intake - drug effects; Energy Intake - physiology; Energy Metabolism - drug effects; Energy Metabolism - physiology; fibre; glucose; liver; metabolizable energy; Propionates - pharmacology; undegradable dietary protein; wethers
• ISSN: 0931-2439; 1439-0396
• DOI: 10.1111/jpn.12180

Alpacas have evolved digestive and metabolic adaptations that enable them to survive in environments where the available feed varies in nutritional quality. Alpacas are thought to derive glucose from the deamination of amino acids in the liver, rather than via the conversion of propionate like true ruminants. Because fibre growth is dependent on the availability of absorbed amino acids, alpacas using amino acids as a source of energy should leave less amino acids available for fibre growth. If alpacas were to obtain glucose from a source of propionate, such as calcium propionate, the dependence on amino acids would be reduced leaving more available for fibre growth. Calcium propionate was added to the ration fed to 32 alpaca wethers, and fibre production was measured to monitor important fibre attributes in response to calcium propionate. Although the diets supplemented with calcium propionate should have provided more energy than the diets without calcium propionate, the metabolisable energy intake of all animals was similar (p = 0.278). It seems that rather than sparing amino acids, the alpacas regulated their energy intake and refused to consume the additional energy offered as calcium propionate. Consequently, they produced less fibre, and the diameter of their fibre was smaller than those alpacas that were not fed calcium propionate. It seems that alpacas rely on their digestive and metabolic adaptations to efficiently obtain and conserve energy for their survival.