Abstract:
The aim of this study was to investigate the effect of cinnamon bark oil (CBO) on heat stress
(HS)-induced changes in sperm production, testicular lipid peroxidation, testicular apoptosis,
and androgenic receptor (AR) density in developing Japanese quails. Fifteen-day-old 90 male
chicks were assigned to two main groups. The first group (45 chicks) was kept in a thermoneutral
room at 22 C for 24 h/day. The second group (45 chicks) was kept in a roomwith high
ambient temperature at 34 C for 8 h/day (from9AM–5 PM) and at 22 C for 16 h/day. Each of
these two main groups was then divided into three subgroups (CBO groups 0, 250, 500 ppm)
consisting of 15 chicks (six treatment groups in 2 3 factorial order). Each of subgroups was
replicated for three times and each replicate included five chicks. Heat stress caused significant
decreases in body weight, spermatid and testicular sperm numbers, the density of testicular
Bcl-2 (antiapoptotic marker) and AR immunopositivity, and significant increases in testicular
lipid peroxidation level, the density of testicular Bax (apoptoticmarker) immunopositivity, and a
Bax/Bcl-2 ratio along with some histopathologic damages. However, 250 and 500 ppm CBO
supplementation provided significant improvements inHS-induced increased level of testicular
lipid peroxidation, decreased number of spermatid and testicular sperm, decreased densities of
Bcl-2 and AR immunopositivity, and some deteriorated testicular histopathologic lesions. In
addition, although HS did not significantly affect the testicular glutathione level, addition of both
250 and 500 ppm CBO to diet of quails reared in both HS and thermoneutral conditions caused a
significant increase when compared with quails without any consumption of CBO. In conclusion,
HS-induced lipid peroxidation causes testicular damage in developing male Japanese quails and,
consumption of CBO, which has antiperoxidative effect, protects their testes against HS.
