Meeting Abstract

2.2  Jan. 4  Early photoperiod and temperature affect growth and sexual maturation in male guinea pigs BAUER, B.C.**; WOMASTEK, I.; DITTAMI, J.; HUBER, S.; University of Veterinary Medicine Vienna, Austria; University of Veterinary Medicine Vienna, Austria; University of Vienna, Vienna; University of Veterinary Medicine Vienna, Austria barbara.bauer@vu-wien.ac.at

Seasonally breeding mammals use environmental cues like photoperiod, temperature and food abundance to accurately time growth and reproductive onset. Evidence from laboratory rodents and humans indicates that components of a photoperiodic and temperature sensitive system might still be preserved even in non-seasonally breeding species. We used the domestic guinea pig (Cavia aperea f. porcellus) to investigate whether early photoperiod and temperature might affect juvenile growth patterns and sexual maturation in this non-seasonally breeding species. We found that in males, growth and testosterone titers during puberty were significantly affected by pre- and early postnatal photoperiodic and temperature conditions. Males gestated and lactated in LD 16:8 / 25�C grew significantly faster and had higher testosterone levels at an earlier age than males gestated and lactated in LD 8:16 / 15�C. Whereas in females, no significant treatment effect on growth patterns or the onset of puberty was found. We therefore conclude that in juvenile guinea pigs, reproductive development and growth might be more sensitive to environmental conditions in males than in females. This work was supported by the Austrian Science Fund (P18089-B03) and the Austrian Academy of Sciences (APART).