Salivary sex steroid hormones in female bactrian camels (Camelus bactrianus) during different reproductive stages

Abstract

The study aimed to verify the usage of salivary sex steroid hormones monitored in captive bactrian camels (Camelus bactrianus) as a new non-invasive method in this species. Saliva of 5 adult female camels housed in the Prague zoological garden were sampled for more than 1 year in maximum interval of 10 days and concentrations of progesterone (P4) and oestradiol (E2) were measured. The concentrations of P4 (n = 312) and E2 (n = 310) were both significantly (p < 0.0001) affected by pregnancy status of animals. Mean (±SE) P4 concentrations in non-pregnant stages were 2.234 (±0.220) nmol/l, while during the 2nd third of pregnancy it was 5.105 (±0.858) nmol/l. E2 concentrations differed significantly between non-pregnant stages with mean value 0.037 (±0.005) nmol/l and during the 3rd third of pregnancy when reached 0.098 (±0.012) nmol/l. The seasonal differences in non-pregnant female camels were also evaluated. While no significant seasonal deviations were found in E2 concentrations, P4 values were significantly higher in summer than in spring. The study concluded that salivary P4 and E2 measurements are suitable for monitoring different reproductive stages in half-tamed female camels. The autumn and winter seasons seemed to be the best for pregnancy diagnosis in camels bred in Europe.