Detecting Effect Of Progesterone Immunosensor On Dairy Cattle Pregnancy And Reproductive Disorders

Progesterone is a gonadal hormone that may reflect ovarian activity as an accurate indicator.It is the most effective method to prevent and treat reproductive disorders in dairy cows bymonitoring progesterone concentration in milk. Since progesterone level is relatively low indairy cows, it need to be accurately detected using an more efficient,sensitive and specificmethod.In this study,dairy cows reproductive hormones in plasma and milk,especiallyprogesterone, were measured by a optimized biosensor and commercial ELISA kits for estrus,pregnancy,and reproductive disorders to determine the detecting performance of progesteronebiosensor.It may provide a scientific foundation for clinical application in dairy cows in thefuture.First of all,in this experiment a progesterone derivative,11α-hydroxyprogesteronehemisuccinate, was a hapten that could be coupled with OVA by the agent DDC into completeantigen(P4-OVA), which was proved successfully by immunoassay. On this basis, progesteronebiosensor was optimized as followed reaction condition that linear range was0.31~50ng/mL,the detecting limit was0.31ng/mL.A standard curve equation is y=-4.9461x+8.7982(R2=0.9932). The specificity of progesterone biosensor was satisfactory because there was nocross reactivities to corticosterone, cortisol and androstenedione.Secondly,in this experiment concentration of estradiol(E2), luteinizing hormone(LH)，follicle-stimulating hormone (FSH) and progesterone (P4) in plasma from pregnant cows wasdetected using the commercial hormones kits, while concentration of progesterone in milk fromthe same cows was measured using the optimized biosensor. After compared with progesteronelevel in plasma, a positive correlation for progesterone between plasma and milk was confirmedby two methods. A detecting range of progesterone in milk for pregnant cows is10ng/mL-15ng/mL using the optimized biosensor.Besides,in this experiment concentration of E2, LH, FSH and P4in plasma from estrus cowswas detected using the commercial hormones kits, while concentration of progesterone in milkfrom the same cows was measured using the optimized biosensor. After compared withprogesterone level in plasma,a positive correlation for progesterone between plasma and milkwas confirmed by two methods.A detecting range of progesterone in milk for heat cows was 4~10ng/mL using the optimized biosensor.Finally,in this experiment concentration of E2, LH,FSH and P4in plasma from anestruscows was detected using the commercial hormones kits,while concentration of progesterone inmilk from the same cows was measured using the optimized biosensor.After compared withprogesterone level in plasma,a positive correlation for progesterone between plasma and milkwas confirmed by two methods.A detecting range of progesterone in milk for cows withpersistent,corpus luteumi,ovary static, and corpusluteum cystic was in turn10~16ng/mL,3~7ng/mLand12~18ng/mL using the optimized biosensor.In this study,progesterone in milk from dairy cows was measured using a optimizedbiosensor for estrus,pregnancy and reproductive disorders in order to offer correspondingdetecting ranges.It may provide a methodological foundation for clinical application in dairycows in the future.