ultrasonic diagnosis is one of the most reliable methods for diagnosing pregnancy in ewes. It has developed from type A and type D to type B, and its scope of use has also developed from diagnosing pregnancy to predicting the number of fetuses and monitoring the growth and development of the fetus. Zhengzhou Boxianglai Electronic Technology Co., Ltd. uses many years of practical experience to give a detailed introduction to the use of veterinary B-ultrasound in ewe detection.

Methods of using veterinary B-ultrasound for ewes

1. Restraint: Ewes generally take a natural standing posture, with assistants supporting them and keeping quiet, or assistants clamp the neck of the ewe with their legs, or use a simple restraint frame to restrain them. Side-lying restraint can slightly advance the diagnosis date and improve the accuracy of diagnosis, but it is inconvenient to use in large groups. Type B exploration of early pregnancy can be done in side-lying, supine or standing positions.

2. Exploration site and method: abdominal wall exploration, in the early pregnancy, on both sides of the breasts and the hairless area directly in front of the breasts, or between the two breasts. It can be performed on the right abdominal wall in the middle and late pregnancy. There is no need to shear hair in the hairless area, but shearing is required for lateral abdominal wall exploration, and restraint is required for rectal exploration. The exploration method is basically the same as that of pigs. The examiner squats on one side of the sheep body, applies coupling agent locally or to the probe, and then places the probe close to the skin, facing the pelvic inlet, and performs a fixed-point fan-shaped scan. Scanning can be done from the front to the back of the breast, from both sides of the breast to the middle, or from the middle of the breast to both sides. The fetal sac is not large in early pregnancy, and the embryo is very small, so it needs to be scanned slowly and carefully to be detected. The examiner can also squat behind the sheep's buttocks, hold the probe and extend it from the middle of the two hind legs of the sheep to the breast for scanning. If the udder of the dairy goat is too large, or the hair on the side of the abdominal wall is too long, which affects the clear view of the exploration site, the assistant can lift the hind legs on the exploration side to expose the exploration site, but there is no need to shear the hair.

B-ultrasound for sheep

Exploration method for predicting the number of fetuses: Ewes do not carry as many fetuses as pigs, and the exploration method is slightly different. The ewe changes to supine position, or semi-supine restraint, fully exposing the area from the front of the breast to the navel, and can be appropriately sheared. Coupling agent is applied to a larger area, and generally scans from the midline to both sides. The D-type instrument is used to detect the fetal heart beat and the location of the detection to determine single or multiple births. Do not judge simply by the difference in fetal heart rate, let alone the frequency of fetal blood sound, which is prone to errors. For the B-type instrument, the probe can slide and scan the detection site to judge by the actual embryo detected. Some people have suggested that the number of fetuses can be predicted based on the number of fetal sacs detected in early pregnancy, but it is not very reliable.

The probe frequency is 2.25, 2.5, 3.5, 4.5 and 5.OMHz. It is better to use 5.0MHz in early pregnancy and 2.25MHz in late pregnancy.

The judgment method of veterinary B-ultrasound detection of ewes

1. Diagnosis of early pregnancy: For non-pregnant ewes and ewes within 25 days of pregnancy, the uterus is located in the pelvic cavity, the uterine body is in the center above the bladder, and the two uterine horns are vertical to the front and lower sides of the bladder. At 15 days of pregnancy, the fetal sac is spread out in a filamentous shape, 100-15Omm long, and located in the uterine horn on the same side as the corpus luteum.

At 17-20 days, the fetal sac extends to the opposite uterine horn and is filled with fluid. Therefore, it is possible to diagnose pregnancy by detecting the fetal sac, fetal body or placenta between 20-30 days after mating using a B-type instrument. A 5.0MHz real-time scanning rectal probe can be used for diagnosis. The probe is inserted into the rectum about 15cm, passes over the bladder, and turns 45 degrees to both sides for scanning. If the uterus has drooped into the abdominal cavity, the probe should continue to extend forward until it can be scanned. At 23 days of pregnancy, there is a small band-shaped anechoic area (amniotic fluid) under the bladder. At 25 days, it is a smaller irregular anechoic area in which the fetal body can be seen, but the fetal heartbeat cannot be seen. At 30 days, the irregular anechoic area expands and moves to the front and lower part of the bladder. The edge of the anechoic area or the small button-shaped echo in it is the maternal and fetal placenta. The fetal body can be seen in the amniotic sac, and the fetal heartbeat can be seen with careful observation. Verified by lambing, the accuracy of diagnosing early pregnancy is about 97%. A fan-scanning probe can also be used to scan the front of the breast.

2. Predicting the number of fetuses: The ewe is lying on its back or standing, and the abdominal wall or rectum is explored. First, confirm that the ewe is pregnant, and then carefully explore within the range of the pregnant uterus to correctly determine the number of fetuses. The accuracy of the exploration time is the highest at 45-50 days of pregnancy. For more than 100 days of pregnancy, the probe cannot scan the entire fetus due to the growth of the fetus, which affects the accuracy. The main error in prediction is that the second lamb cannot be detected for twins, the third lamb cannot be detected for triples, or a single lamb is misdiagnosed as twins. Prediction for more than 3 lambs is still difficult.

3. Measuring the placenta: The real-time ultrasound scanner can measure the diameter of the uterine fungus. By measuring the diameter of the uterine fungus, it is found that the average diameter of the uterine fungus has an obvious curve relationship with the number of days of pregnancy. The uterine fungus develops to its largest diameter on the 80th day of pregnancy. Sheep have a cotyledonary placenta, which appears as a disc-shaped strong echo area on the sonogram.

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