| Ketosis of dairy cows is a metabolic disease with systemic functional disturbance, which was caused by the dysbolism or disorder of carbohydrate and volatile lipide. It often happened in high-yielding cows, characterized by low level of blood sugar and high leval of ketone bodies.Usually, Ketosis can be divided into clinical and subclinical ketosis according to clinical symptoms or the leval of blood ketone bodies of the cows, it can induce lower milk yield, increase incidence of other diseases, and harm the reproductive performance. There were very little reports about the relationship or mechanism between subclinical ketosis and reproductive performance in dairy cows in our country, so, this study was mainly about the effect and mechanism of subclinical ketosis on reproductive performance, which would provid a guide for the improvment of reproductive performance in dairy cows.1The influence of subclinical ketosis on obstetric diseases and status of conception after parturation41subclinical ketosis cows were chosen from the holstein cows with2-4parity as the test group (1.0mmol/L≤BHBA<2.6mmol/L). The control group (serum BHBA<1.0mmol/L) without ketosis was paired according to age, parity, milk yield and days in milk with41cows. Diagnosised conception with brightness ultrasonic diagnostic apparatus, count the incidence of obstetric disease, times of insemination before conception, conception rate of insemination, calving to conception interval. The result indicated that the incidence of retained placenta in the test group was24.39%, while it was12.20%in the control group, the difference between the two group was not significant (P>0.05). The incidence of clinical metritis in the test group was21.95%, while it was14.63%in the control group, the difference was also not significant (P>0.05). The conception rate of first insemination in the test group was36.59%, while it was46.34%in the control group, the difference between the two group was not significant (P>0.05). The conception rate of second insemination in the test group was42.31%, while it was40.91%in the control group, the difference was also not significant (P>0.05). The conception rate of third insemination in the test group was33.33%, while it was38.46%in the control group, the difference was also not significant (P>0.05). Times of insemination before conception in the test group was2.07, while it was1.82in the control group, the difference was also not significant (P>0.05).Calving to first conception interval in the test group was125.34d, while it was91.73d in the control group, the difference was also not significant (P>0.05).Although every index above was not significant in two groups, it can indicate that the state of health and reproductive performance in dairy cow with subclinical ketosis present a downtrend.2The influence of subclinical ketosis on uterine involution and the number of immunocytes in blood after parturation22cows with subclinical ketosis were chosen from test I as test group, the cows without ketosis in control group were chosen paired according to age, parity, milk yield, date of parturation from test I.15days after parturation, measured the diameter of cervix and uterine horn with brightness ultrasonic diagnostic apparatus, took the blood sample and make the white blood cell classification.40days after parturation, took and smeard cervical mucus, then count polymorphonuclear leukocytes in microscope. The result indicated that the diametres of cervix in test group were significantly larger than control group(P<0.05). Immunocytes, such as WBC, LYM and NEU, were significantly lower in the test group (P<0.05). The rate of different divided degree with infiltrated PMN in the cervix mucus of test group was much higher, the difference between two groups was not significant (P>0.05).In certain extent, the test indicated the uterine involution in the dairy with subclinical ketosis was delayed, and the uterine was much easier to produce inflammation.3The influence of subclinical ketosis on the secretion of related reproductive hormone after parturation8cows with subclinical ketosis were chosen from test I as test group, the cows without ketosis in control group was chosen paired according to age, parity, milk yield,date of parturation, calving to first insemination interval from test I. From calving to34days later, took the blood sample of dairy cow in experiment every two day, then measure the leval of P4in plasma.3days to9days after first insemination, took the blood sample of dairy cow in experiment every two day, measured the level of reproductive hormone, such as P4, E2, LH, FSH. The result indicated that the maximum or minimum level of P4in the test group was much higher than the control group from calving to34days later, the difference was also not significant (P>0.05). Calving to first ovulation interval in the test group was22.25d, while the control group was16.20d, the difference was significant P <0.05).3d to9d after insemination, the levels of reproductive hormone were analysed, the result indicated that the level of LH in test group was much lower than control group, the difference was significant (P<0.05). The concentration of FSH in plasma was significantly positive correlation with E2in the test group (r=0.692, P<0.01), and it also was significantly negative correlation with E2in the test group (r=-0.887, P<0.01). However, in the control group, the concentration of FSH in plasma was not significant correlation with other hormone(P>0.05). The concentration of LH in plasma was significantly positive correlation with P4in the test group (r=0.629, P<0.05), and it also was significantly negative correlation with E2in the test group (r=-0.481, P<0.01), however, in the control group, the concentration of LH in plasma was significantly positive correlation with P4(r=0.814, P<0.01), and it also was significantly positive correlation with E2(r=0.782, P<0.01). The concentration of P4in plasma was not significant correlation with E2in the test group (P>0.05), however, in the control group, the concentration of P4in plasma was significantly positive correlation with E2(r=0.794, P<0.01). The test demonstrated that ovary recovery in dairy cows with subclinical ketosis was delayed, the secretion of LH was under average, and the secretion of related reproductive hormone was abnormal in certain extent. |
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