The effect of pyrazine odor on body weight and the weight of various organs in chicks (Gallus gallus domesticus)

Embryonic and posthatch long-term exposure to the odor of 2-methoxy-3-isobu tyl-pyrazine (2M3IP) was examined for its potential physiological consequen ces as reflected in changes in BW and organ weights in domestic chicks (Gal lus gallus domesticus). Experiments were run from Day 1 of incubation to th e age of 3 wk with a total of 360 fertile chicken eggs. The experimental de sign consisted of four treatment groups: PP chicks were exposed to 2M3IP du ring both incubation and posthatch rearing; PC chicks were exposed to 2M3IP during incubation only; CP chicks were exposed to 2M3IP during rearing per iod only; CC control chicks were not exposed to 2M3IP. Chicks were weighed immediately after hatch and at 3 wk of age, when they were necropsied. Vari ous organs (thyroid, adrenal, testes, comb, liver, spleen, abdominal fat, a nd the bursa of Fabricius) were removed and weighed. Body weights of both s exes in the PP group were reduced. This reduction was significant in males relative to both CP and CC groups and in females only relative to the CP gr oup. Effects of 2M3IP exposure on the examined organs were as follows: in m ales, adrenal gland weight significantly increased in the PP group vs all o ther groups. No weight differences were found between the other inspected o rgans among the four treatments. In females, comb weight significantly decr eased compared with the rest of the groups when 2M3IP exposure occurred dur ing incubation (PC). Further investigation is needed to study the mechanism s that underlie the differential effects of pyrazine odor on male and femal e chicks.