Effects Of Different Dietary On Insulin Signaling Pathway And JAK-STAT Signaling Pathway Of Breast Tissue In Lactating Dairy Cows

The objective of this study was to determine the relationship between different dietary andserum hormone secretion level, abundance of hormone receptor and genes mRNA in breasttissues of lactating dairy cows by the way of RT-PCR.10lactating Holstein dairy cows wererandomly assigned to tow treatments:1) corn straw treatment (CS),2) mixed forage treatment(MF). the whole experiment period was divided into two parts，one part was pre-experimentwhich was2weeks and another part was formal experiment which was4weeks．INS and LEP,ADPN, IGF-1, GH, PRL and E2were detected by ELASA and RIA. Mammary gland hormonereceptor, insulin signaling pathway downstream gene mRNA expression abundance wasassessed by the RT-PCR.The results show that:1) the CS group and MF group cows milk protein yield are notsignificant difference (P>0.05), CS group milk protein yield an average of0.76kg/d, MFgroup milk protein yield an average of0.83kg/d. MF group milk protein yield increased.2) Which compared with CS group, serum insulin and adiponectin of MF group hassignificant higher than CS group (P <0.05). Serum insulin level of MF group was higher thancontrol group0.13times and serum adiponectin level higher than control group content0.50times. However, IGF-1, PRL, LEP and E2concentration is not significant difference (P>0.05),but IGF-1and GH hormone concentration greater than that of the control group.3) INSR, PRLR, the CSF2BR receptor expression levels of mammary gland tissue of theMF group cows compared with that of the CS group significantly increased (P <0.05). Inaddition, GHR, AdipoR1and AdipoR2, ESR1and ESR2receptor expression levels of the MFgroup cows slightly higher than the CS group; PGR receptor expression of MF group is slightlylower than the CS group, but they were not significant difference (P>0.05).4) MF group is breast tissue IRS1, IRS4, S6K, JAK2mRNA expression of mammary glandtissue of the MF group cows was significantly higher than that of the CS group (P <0.05)respectively0.33,1.49,2.10times higher than that of control group and IRS1have visibleresponse by treatment. In addition, mTOR, Akt1and STAT5expression levels have increasedslightly, eIF4EBP1expression levels decreased slightly, but they were not significant difference(P>0.05). Feeding different dietary can improve the serum INS and Adiponectin hormone content,adjust and metabolism related gene mRNA expression level, along the strict signal transmissionnetwork will ultimately affect the expression of gene product.