关键词: 新疆褐牛, 早期妊娠, 生殖激素, 唾液检测, 血浆检测

Abstract: In order to explore the changes and differences of reproductive hormones in saliva and plasma of Xinjiang brown cattle in early pregnancy stage from day 0 to day 18，and to provide theoretical basis for the development of non⁃invasive pregnancy diagnosis technology and the analysis of physiological mechanism of early pregnancy maintenance，33 natural estrus Xinjiang brown cattle were selected in the experiment. Saliva and plasma samples were collected simultaneously on days 0，7，14 and 18 after mating. On the 35th day of mating，11 pregnant cattle and 11 non⁃pregnant cattle were screened by B⁃ultrasound. Enzyme⁃linked immunosorbent assay（ELISA） was used to detect the concentrations of progesterone（P₄），luteinizing hormone（LH），follicle⁃stimulating hormone（FSH） and estrogen（E₂）. The results showed that the LH mass concentration on the 14th day and the FSH concentration on the 18th day in the plasma samples of the pregnant group were significantly lower than those in the non⁃pregnant group，and the FSH concentration on the 18th day in the saliva samples of the pregnant group was significantly higher than that in the non⁃pregnant group. The comparison of hormone concentrations in blood and saliva at the same time point showed that the concentration of E₂ was significantly different between the two types of samples on days 7，14，18，and the concentration difference between body fluids on the 14th day of FSH was extremely significant. There was no significant difference in LH and P₄ concentration. The dynamic time series analysis showed that the change trend of LH mass concentration of the two types of samples was consistent and the concentration difference between the 14th day and 18th day groups was significant. The concentrations of P₄ in plasma and saliva were significantly different between day 0 and day 14，and the concentration of P₄ in plasma was significantly different between day 7 and day 14. After 7 d of pregnancy，the change trend of P4 in blood and saliva tended to be synchronized.In summary，for Xinjiang brown cattle during early pregnancy，saliva can reflect dynamic changes in reproductive hormones and detect differences in pregnancy⁃specific hormones，suggesting that saliva can serve as a non⁃invasive alternative to blood for early pregnancy monitoring.

Key words: Xinjiang brown cattle, Early pregnancy, Reproductive hormone, Saliva detection, Plasma detection