In the daily production of dairy cows, we often encounter reproductive disorders such as cows not being able to estrus normally or even not being able to conceive. There are many reasons for dairy cow reproductive disorders based on the analysis of the B-ultrasound images of cows, which occur all year round. According to the diagnosis and causes of the B-ultrasound reactions of cows, the diseases that cause dairy cow reproductive disorders include: retained placenta, endometritis, ovarian cysts, and persistent corpus luteum.

(I) Observation of dairy cow endometritis with B-ultrasound machine

1. Causes. Dairy cow endometritis is caused by infection with pathogenic microorganisms, including bacteria, fungi, mycoplasma and other pathogenic microorganisms. And the pathogens of dairy cow endometritis have a certain regionality. The types of bacteria and the proportions of various bacteria that cause dairy cow endometritis in different regions and under different conditions are also different. In addition, other factors such as the lack of trace elements in the diet and the imbalance of mineral ratios lead to reduced disease resistance of dairy cows, which are also prone to this disease. There are also some external reasons, such as unscientific management, poor sanitary conditions in the delivery room, trauma caused by improper induction of labor and afterbirth stripping, improper midwifery, damaged birth canal, accumulation of postpartum lochia, improper operation during mating, etc. These reasons may lead to the introduction of environmental pathogens into dairy cows and cause endometritis.

2. Symptoms. According to the pathological process and the nature of inflammation, it can be divided into acute mucopurulent endometritis, acute fibrinous endometritis, chronic catarrhal endometritis, chronic purulent endometritis and latent endometritis. It usually occurs within one week after delivery. In mild cases, there are no systemic symptoms, estrus is normal, but conception cannot occur; severe cases are accompanied by systemic symptoms, such as fever, rapid breathing, mental depression, decreased appetite, and reduced rumination. The affected cow arches its waist, raises its tail, and sometimes strains. From time to time, a large amount of dirty or brown-yellow mucus-purulent secretions flow out of the vagina, which have a fishy smell and contain flocs or afterbirth fragments. They often adhere to the tail root and form dry scabs. Rectal examination shows that the uterine horns become thicker and the uterine wall thickens. If exudate accumulates in the uterus, it will feel volatile when touched. 3. Treatment. Traditional Chinese medicine treatment: Use Chinese medicine to perfuse and flush the uterus. First, use 3g of borax dissolved in 100 ml of saline to flush. After the reflux fluid is discharged, inject 100-150 ml of Angelica powder (Angelica 10g, Chuanxiong 10g, Red and White Peony 5g each, Scutellaria 10g, Atractylodes 5g, add 300ml of water to decoct, filter with filter paper), once every other day, for 2-3 times in a row. Or take Chinese medicine prescriptions: Euryale ferox, Psoralea corylifolia, Raspberry, Fenugreek 35g each, Allium leek seed, Schisandra chinensis 32g each, Cistanche deserticola, Poria, Astragalus, Cnidium monnieri, Actinolite, Epimedium, Polygala tenuifolia 30g each, Fennel 24g, Cinnamon 20g. Grind into fine powder, mix with boiling water, wait until it is warm and then take it orally, 1 dose per day, for 3 to 4 days.

Western medicine treatment: mainly use antibacterial and anti-inflammatory drugs to eliminate inflammation, prevent further spread of infection, remove exudates in the uterus, and promote uterine contraction. (1) Systemic administration: Use large doses of antibacterial drugs, and pay attention to fluid replacement and cardiotonic. If the body temperature is too high, use sedatives and antipyretic drugs. (2) Uterine cleaning and perfusion: Use 0.9% saline, 2% sodium bicarbonate solution, 0.5% rivonol solution, and 0.1% potassium permanganate solution. After repeatedly flushing the uterus 2 to 3 times, drain all the cleaning fluid and flush again every other day.

(II) Observation of retained placenta in endometritis in dairy cows using B-ultrasound machine

Retained placenta in dairy cows means that the dairy cow has not been able to expel the placenta normally for more than 12 hours after calving. If not treated in time, it often has an adverse effect on the cow's subsequent estrus, mating and pregnancy.

1. Causes: There are many reasons for retained placenta in dairy cows. Lack of calcium, salt, various minerals, vitamins and other trace elements in the diet is a nutritional reason; in the daily feeding process, poor feeding management leads to overweight or overweight dairy cows, narrow birth canals, or weak contractions of dairy cows, which can easily lead to retained placenta in dairy cows. In addition, long-term barn feeding of dairy cows, lack of proper exercise and light in the late pregnancy, or excessive prenatal fatigue can also easily lead to retained placenta in dairy cows.

2. Symptoms: Retained placenta can be divided into partial retained placenta and complete retained placenta. In the case of partially retained placenta, part of the earthy red placenta of the sick cow hangs outside the vulva, with the broken ends of the umbilical cord blood vessels and large and small cotyledons on it, and most of the placenta is retained in the uterus. In the case of total retained placenta, all the placenta is stagnant in the uterus and vagina, with only a small amount of fetal membrane hanging outside the vulva, or the placenta is invisible. There are generally no systemic symptoms in the early stage of retained placenta. After 1 to 2 days, the placenta begins to decay and decompose, and foul-smelling liquid mixed with placenta fragments is discharged from the vagina. The affected cows continue to have symptoms such as fever, depression, loss of appetite, decreased milk secretion, hunched back, straining, abdominal pain and restlessness.

3. Treatment: (1) Chinese medicine can be used for treatment. Take Chinese medicine with added Shenghua Decoction: 90g of Angelica sinensis, 69g of Chuanxiong, 150g of Leonurus japonicus, 60g of Codonopsis pilosula, 60g of Astragalus membranaceus, 30g of Peach Kernel, 25g of Safflower, 60g of Atractylodes macrocephala, 60g of Hawthorn, and 15g of Roasted Licorice, decocted in water.

(2) Western medicine treatment can be subcutaneously or intramuscularly injected with 50-100IU of posterior pituitary hormone within 12 hours after delivery, and then injected again 2 to 4 hours later. Or take 2g of oxytetracycline and add 500ml of 10% saline to dissolve and warm, then inject into the uterus to shrink the placenta and promote the discharge of the placenta.

(3) If the placenta still does not come out after 24 hours, surgical removal should be performed. Infusing 1000-2000ml of 10% sodium chloride solution into the uterus 1-2 hours before surgery can promote the relaxation of the connection between the fetus and the mother's placenta, making it easier to remove. If the placenta is corrupt, the corrupt liquid in the uterus can be discharged with a siphon, and then the uterus can be flushed with 0.1% chlorhexidine solution, followed by the administration of antibacterial drugs for 2-3 consecutive days to prevent infection.

(III) Observation of ovarian cysts in endometritis of dairy cows using B-ultrasound machine

1. Causes: There are many causes of ovarian cysts, among which the lack of VA, selenium and other elements or estrogen and soluble protein in the cows will increase the incidence of ovarian cysts; lack of exercise and excessive intake of concentrates in dairy cows are also prone to this disease; the occurrence of naturally occurring cysts is related to excessive secretion of follicle-stimulating hormone and low secretion of luteinizing hormone by the pituitary gland; in addition, the occurrence of ovarian cysts is also related to genetics, and stress caused by changes in the natural environment also affects the occurrence of this disease.

2. Symptoms: Ovarian cysts in dairy cows are mainly divided into two categories, one is corpus luteum cysts and the other is follicle cysts. (1) Corpus luteum cysts are mainly manifested by the cow not being in estrus for a long time after giving birth, closed vulva, dry cervix and vagina, and a small amount of secretions attached to the tail root. Rectal examination shows that the ovaries on one or both sides are significantly enlarged, which is different from normal ovaries. There are multiple large cysts on the ovaries, which can be felt to be filled with fluid, thick walls, and fluctuating when squeezed.

(2) Follicular cysts. Sick cows show frequent estrus, shortened estrus cycle, prolonged estrus period, strong sexual desire, extreme restlessness, loss of appetite, and frequent excretion of urine and feces. Sick cows climb on other cows, are anxious, dig the ground and cry, and sometimes attack people and animals. Milk production is reduced. During rectal examination, the cervical opening is enlarged, the wall is thick and soft, and there are multiple large cysts on the ovaries.

3. Treatment: (1) Corpus luteum cysts. In the past, rectal puncture or squeezing was usually used to remove luteinized fluid, but due to the high infection rate, difficulty in hemostasis, and the high possibility of causing oophoritis, it is rarely used. Prostaglandin enol 0.4-0.5 mg can be injected intramuscularly. Generally, the effect can be seen after 8 consecutive days. This method has few complications and a high cure rate.

(2) Follicular cysts: Use 400-600µg of luteinizing hormone for 3-4 days, or 100-200IU of human chorionic gonadotropin for 15-30 days to restore the normal estrus cycle. If the effect is not obvious, dexamethasone can be used for treatment, which is more effective. The basic method is: dexamethasone 10ml×4 vials, intravenous push, use for four days, and then check the ovarian changes of the cows.

(IV) Observation of persistent corpus luteum in endometritis of dairy cows with B-ultrasound machine

1. Cause: Persistent corpus luteum refers to the corpus luteum of pregnancy or estrus cycle of dairy cows that does not disappear after the normal time. Improper feeding and management, simple age, lack of vitamins and inorganic salts, and insufficient exercise of dairy cows all have an impact on the occurrence of this disease; other uterine diseases are also likely to cause this disease, such as endometritis, uterine fluid or pus accumulation, incomplete uterine involution after delivery, dead fetus or tumor in the uterus, etc., which can affect the retraction and absorption of the corpus luteum and become a persistent corpus luteum.

2. Symptoms: If the dairy cow does not estrus for a long time after delivery, this situation after mating can be misdiagnosed as pregnancy. However, if there is no fetus during rectal examination, it can be diagnosed as a persistent corpus luteum. It can be seen that the volume of one or both ovaries is enlarged, and the persistent corpus luteum exists in the ovary and protrudes from the surface of the ovary. Due to the different stages of the corpus luteum, some feel powdery when palpated, and some have a harder texture. The size and number of persistent corpus luteum vary, ranging from one to more than two. At the same time, the uterine contraction reaction is also relatively weak.

3. Treatment: (1) Western medicine treatment: ① Use prostaglandin (PGF2α) 5-10 mg for intramuscular injection once a day for 2 consecutive days. ② Mix 1500-3500 units of chorionic gonadotropin with 25ml of saline and inject intramuscularly. ③ Mix 100-200 units of follicle-stimulating hormone with 5-10ml of saline and inject intramuscularly. Inject once every 2 days, and 3 times as a course of treatment. ④ Reach into the rectum, grasp the ovary through the intestinal wall, pinch the ligament of the ovary with the index and middle fingers, and remove the corpus luteum at the base of the corpus luteum with the thumb. When taking this operation, inject VK to prevent bleeding. ⑤ Inject 100mg of progesterone intramuscularly, once a day. When injecting the second and third times, inject 50mg of diethylstilbestrol dipropionate at the same time.

(2) Traditional Chinese medicine treatment: ① Mix 20ml of turpentine and 20ml of ichthyol with milk and take it once a day for 6 days. ② 100g each of Xianlingpi, Actinolite, and Leonurus japonicus, 60g each of Angelica sinensis, Codonopsis pilosula, Red peony root, Psoralea corylifolia, Lycium barbarum, and Rehmannia glutinosa, decocted in water and taken orally once a day for 3 to 5 consecutive days, which has a significant effect on infertility caused by persistent corpus luteum in dairy cows.

Reproductive disorders in dairy cows are the result of the combined action of multiple factors. Comprehensive prevention and control measures should be taken to prevent and treat reproductive disorders in dairy cows. In normal times, scientific feeding should be carried out, the house should be kept clean, disinfection should be paid attention to during delivery, and the nutrition should be balanced according to the age, so as to achieve "prevention first, maintenance and prevention and treatment".