Analysis And Evaluation Of The Quality Of Corpus Luteum Of Holstein Cattles By Ultrasound Sonography

Object:In order to analyze and evaluate the relationship between the quality of CL and the level of P₄ from morphology and hemodynamics,B-ultrasound radiography and color doppler ultrasound were used respectively in this study.Nowadays,there are few studies on the application of color doppler ultrasound to detect the quality of CL in the Uterus of Four Estrous Cycle Phases in dairy cows.However,not only is this way useful for Large Scale Dairy Farm to reduce costs,but also play a role in increasing the conception rate of dairy cows.By this,the relevant experiments of this study have been conducted as planned,laying a preliminary foundation for future applications in production and showing a certain practical application value.In addition,the establishment of CL ultrasound maps will offer a reference for the studies and training of technicians and can be applied to breed management.Methods:?1?Complete reproductive organs of 476 cows slaughtered in 2016-2019 were collected.The morphological and anatomical characteristics of ovaries with different physiological stages of the CL,ovaries suffering corpus luteum cyst and ovaries suffering follicular cysts were observed,after they were classified,labelled and dissected.?2?The CLs of 120 lactating cows at different stages of the estrous cycle were scanned through the rectal path using a portable B-ultrasound and color doppler ultrasound,and typical corpus luteum sonograms were selected and stored.?3?According to the estrous breeding record,B-ultrasound instrument was utilized to scan the CLs of 116 young cows and multiparous cows at 7th after estrus,and measure CLD,CLP,CLA and CLV by the built-in electronic ruler.Moreover,their blood samples were collected from the tail vein,and Enzyme-linked immunosorbent assay?ELISA?was utilized to detect the level of serum P₄,E₂ and LH.And they were grouped according to BCS and corpus luteum morphological indexes.Their corresponding hormone contents were also compared.?4?The 116 cows were examined carefully by animal color doppler ultrasound on the spot.Among them,there were 11 cows with different corpus luteum,5 cows with corpus luteum on the 7th day of the estrus synchronization,and 4cows with uterine disease.?5?The cows on day 7 after estrus mating were examined by animal color doppler ultrasound with the accumulative total of 26,including 17 cows with corpus luteum,and 9 without corpus luteum.Moreover,one case inside was diagnosed with follicular cysts,and there were multiple follicles.Another case inside was follicular cyst with multiple cysts.In addition,the contents of P₄ and LH in serum were detected by ELISA after the tail vein blood was collected from the cows with corpus luteum.The cows were grouped according to BCS,times of mating and whether there is a cavity in corpus luteum,and then the maximum velocity,minimum velocity and average velocity of luteal blood flow as well as the content of serum hormone were compared.Results:?1?The effects of ovarian appearance on rectal palpation were analyzed,and the question whether the internal structure can be obtained through ultrasound was demonstrated.?2?By scanning the corpus luteum on the 5th to 15th days of the estrous cycle of the cow,a typical corpus luteum sonogram was saved,and a corpus luteum ultrasound pattern was established on the 5th to 15th days.The typical corpus luteum ultrasound image was described and the sonograms of CL which seems difficult to diagnose were further analyzed and interpreted.?3?The results showed that BCS?2.5,2.5<BCS<3.0 and BCS?3.0 had significant differences on P₄?P<0.05?,CLP?5.0 and 5.0<CLP<7.0 had significant differences on P₄?P<0.05?,CLV?5.0and 5.0<CLV<7.0 have significant differences on P₄?P<0.05?;BCS?2.5,2.5<BCS<3.0 and BCS?3.0 have significant differences on E₂?P<0.05?,CLV?5.0 and 5.0<CLV<7.0 had significant difference on E₂?P<0.05?,CLV?5.0 and 5.0<CLV<7.0 were significantly different from E₂?P<0.05?.2.5<BCS<3.0 and BCS?3.0 had a significant difference on LH?P<0.05?.?4?The animal color doppler ultrasound system can measure the maximum diameter of the corpus luteum,the perimeter of the corpus luteum,the surface area of the corpus luteum and the volume of the corpus luteum under the condition of two-dimensional sectional B-mode ultrasound.Under color doppler ultrasound?CFM?conditions,the corpus luteum flow distribution can be observed.Blood velocity can be measured under pulsed doppler ultrasound?PW?conditions.?5?The cows were grouped according to BCS?BCS?3.0,BCS>3.0?,mating time?mating time?4,mating time>4?and whether there is a cavity in corpus luteum.There was no significant difference in the maximum,minimum and average velocity of blood flow in CL between the two group?P>0.05?,and there was no significant difference in serum P₄ and LH between the two groups?P>0.05?.Conclusion:Ultrasound can be used to study the structure of the ovaries under living conditions.Sonographic atlas of CL of cow at 5 to 15 days of the estrus cycle was established by using a portable B-ultrasound instrument,which provided a reference for accurate identification of CL and for breeding technicians to learn and directly applied to practical production.Using this method will help to judge the condition of CL,evaluate the quality of CL correctly and measure the index of CL.The perimeter and volume measured by ultrasonic of the CL in cows at the 7th day after estrus and mating can represent CL function.Color doppler ultrasound can be used to observe blood flow distribution in CL and measure the velocity of blood flow in CL.