HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Loudon, A. S. I. Articles by McNeilly, A. S. Search for Related Content PubMed PubMed Citation Articles by Loudon, A. S. I. Articles by McNeilly, A. S.

Non-domesticated seasonally breeding ungulates exhibit marked seasonal changes in metabolic rate, voluntary food intake (VFI), pelage growth and moult and hormone secretion. It is not known whether these seasonal rhythms are regulated by the same central processes which control the onset and termination of the breeding season. Here we compare two closely related deer species which have significantly different mating and calving seasons. Seasonal changes in VFI, liveweight, coat growth, plasma prolactin and tri-iodothyronine (T₃), and the timing of the breeding season were examined over a 15-month period in six adult post-pubertal red and Père David's deer from January to April the following year. The timing of the seasonal changes in prolactin, T₃, VFI and coat growth were all significantly advanced by 56, 23, 60 and 54 days respectively in the Père David's deer. The times of onset and termination of the breeding season of Père David's deer were also significantly advanced by 90 days, but in both species, the breeding season was of similar duration (160 ± 5 (S.E.M.) days). Changes in liveweight of adult red deer could be explained by changes in VFI rather than efficiency of utilization. This was not the case in Père David's deer and may indicate seasonal changes in the efficiency of energy utilization. In order to establish whether these species differences develop with age, we undertook a second study in which seasonal changes in VFI, growth, plasma prolactin concentrations and the timing of the onset of the breeding season were recorded for ten red deer and six Père David's deer from 6 to 18 months of age. Both species exhibited a similar decline in VFI in the first autumn of life. Subsequently, the Père David's deer exhibited an advance in the timing of the seasonal peak in VFI and prolactin (21 and 66 days respectively); puberty occurred 3 months earlier than in red deer. The earlier breeding season of the Père David's deer was associated with a significant advance in a range of seasonal endocrine and physiological parameters. These species differences may develop with age. Our data indicate that seasonal patterns of metabolism and growth may be closely linked to those mechanisms which also regulate the onset and termination of the breeding season.

Journal of Endocrinology (1989) 122, 733–745

This article has been cited by other articles:

				R. Kuntz, C. Kubalek, T. Ruf, F. Tataruch, and W. Arnold Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) I. Energy intake J. Exp. Biol., November 15, 2006; 209(22): 4557 - 4565. [Abstract] [Full Text] [PDF]

				A J Craven, A J Nixon, M G Ashby, C J Ormandy, K Blazek, R J Wilkins, and A J Pearson Prolactin delays hair regrowth in mice. J. Endocrinol., November 1, 2006; 191(2): 415 - 425. [Abstract] [Full Text] [PDF]

				S. Zhou, F. R. A. Cagampang, J. A. Stirland, A. S. I. Loudon, and S. J. Hopkins Different Photoperiods Affect Proliferation of Lymphocytes but Not Expression of Cellular, Humoral, or Innate Immunity in Hamsters J Biol Rhythms, October 1, 2002; 17(5): 392 - 405. [Abstract] [PDF]