Effects of thyroid hormones and prolactin on food intake and weight changes in young male reindeer ( Rangifer tarandus tarandus )

• Published in: Canadian Journal of Zoology
• Main Authors: Ryg, Morten, Jacobsen, Endre
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1982
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Rangifer tarandus
• Online Access: http://dx.doi.org/10.1139/z82-205; http://www.nrcresearchpress.com/doi/pdf/10.1139/z82-205

Yearling male reindeer were treated with thyroid hormones and prolactin to see if reported seasonal variations in these hormones could participate in the control of the growth cycle in Cervidae. Both prolactin and thyroid hormone injections were followed by increased food intake. The effect was not additive, and no interactions were seen. Weight gain decreased after treatment with thyroid hormone, alone or in combination with prolactin. Weight gain increased in animals treated with prolactin alone. We conclude that changes in prolactin secretion may be important for the regulation of the growth cycle, but that the role of changes in thyroid hormone secretion is unclear.