The effect of frozen semen on the conception rate of cattle detected by veterinary B-ultrasound

When the cow is inseminated, the quantity and quality of sperm in the bull's frozen semen are directly related to the conception rate, so quality identification must be carried out after semen collection, before freezing, and after thawing. At present, the main quality identification items are sperm motility after thawing, acrosome integrity rate, abnormal sperm rate and sperm survival time after thawing. The presence of bacteria in semen will change the physical and chemical properties of semen, such as semen pH value, osmotic pressure, etc., and bacteria can also infect the reproductive tract of female livestock by producing oxygen free radicals or directly damaging sperm, thereby reducing the conception rate. If such semen is used for insemination, it can be measured by veterinary B-ultrasound that the empty pregnancy rate of the cow will increase, and the use of veterinary B-ultrasound can find that the probability of uterine infection is also very high, so the number of bacteria in semen is also an important indicator of quality detection. The survival time of sperm after thawing refers to the total survival time of sperm in vitro under certain conditions after thawing. Sperm survives differently in different temperature environments, and the survival time is short when the temperature is high.

The abnormal sperm rate of frozen semen refers to the proportion of sperm with abnormal morphology and structure in the total number of sperm. There are many types of sperm abnormalities, which can be roughly divided into head deformity, neck deformity, mid-segment deformity and tail main segment deformity. In the study of human sperm, as the sperm deformity rate increases, the possibility of natural conception decreases, and the time of primary pregnancy is prolonged; when the deformity rate of semen is too high, the empty pregnancy rate will also be too high when using veterinary B-ultrasound after mating.

The effect of uterine cleansing before estrus on the conception rate of cattle by veterinary B-ultrasound

The method of uterine cleansing for cattle includes injecting drugs into the cervix 5-7 days before estrus. It is best to do it under the guidance of veterinary B-ultrasound. This is because: when cattle are in estrus, the cervix opens, and bacteria in the vagina and cervix will invade the uterus and cause inflammation. It can be seen from veterinary B-ultrasound that this method causes more uterine inflammation. After artificial insemination, embryo implantation is hindered, and sperm is infected when passing through the reproductive tract. Veterinary B-ultrasound will often find that the empty pregnancy rate is high at this time. There are relatively few studies on the residual time and amount of drugs in the cow's uterus and the impact on the embryo. For cows with endometritis, the residual amount of ciprofloxacin hydrochloride after a single dose of 2.5g ciprofloxacin per head is used for uterine infusion, and the weaning period is 4d. Because this method of uterine cleansing is to infuse drugs when the uterus opens before estrus, it avoids bacteria from entering the uterus, and also creates good conditions and environment for sperm to enter the uterus and fallopian tubes, and reduces the impact of drug residues on conception. The effect of uterine cleansing on conception rate, some people used ciprofloxacin to clean the uterus and treated the uterine inflammation cows. The conception rate during estrus is 61.2%, which is much higher than the conception rate of cows without uterine cleansing. It can be seen that uterine cleansing is extremely important for improving the conception rate. The effect of uterine cleansing after insemination on the conception rate of cattle detected by veterinary B-ultrasound

In the late postpartum period of cattle, there will be many new bacteria in the uterus of cattle. These bacteria are newly entered into the uterus, and as long as the cervix is open, bacteria may invade. Veterinary B-ultrasound examination of cows before mating found that more than 50% of cows had varying degrees of inflammation in their uterus. It is determined that bacteria should be present. From this, we can conclude that during the estrus period of cows, when the cervix is open, bacteria may invade and affect the conception rate, so sterilization before and after mating can increase the conception rate of cattle.

There are currently two main methods for cleaning the uterus of cattle. One is to infuse drugs into the uterus according to fertilization theory 12 hours after insemination, close to ovulation. It is best to infuse drugs into cows under the monitoring of veterinary B-ultrasound. According to fertilization theory, after artificial insemination of dairy cows, it takes less than 2-15 minutes for sperm to reach the fertilization site. The ovaries ovulate 28-32 hours after estrus, and the eggs maintain fertilization capacity in the fallopian tube for 18-20 hours. After sperm and eggs are fertilized in the ampulla, it takes 12-84 hours to enter the uterus. Purification of the uterus is to use the time required for the fertilized egg to enter the uterus from the fallopian tube to infuse drugs into the cow's uterus under the monitoring of veterinary B-ultrasound, so that the drugs reach a certain part. Kill bacteria, eliminate inflammation, and facilitate embryo implantation. Generally, drugs are infused into the uterus 12 hours after insemination.

Veterinary B-ultrasound detection of the effect of carotene on the conception rate of cattle

Carotene is closely related to the normal function of the corpus luteum of the ovary of cattle. Carotene may act as an antioxidant for fat peroxides to hinder the peroxide effect of lipids, thereby protecting the steroid-producing cells of the follicles and uterus from damage by oxidative reactions. On the other hand, the high content of carotene in the corpus luteum may affect the synthesis of ovarian steroids. Vitamin A cannot replace carotene for the reproduction of cattle. Carotene deficiency leads to latent estrus, low conception rate, miscarriage, stillbirth, etc. in cows, so when using veterinary B-ultrasound for examination, more fetal deaths can be seen. Sometimes in some cattle farms, veterinary B-ultrasound will also find that the empty rate of cows is high.

Carotene concentration in the blood of donor and recipient cows for embryo transplantation. After analysis, some people concluded that donor cows with more embryos have high carotene concentrations (more than 20ug/ml); recipients with high pregnancy rates measured by veterinary B-ultrasound have high blood carotene concentrations (1l-26ug/m1). From 10 days before delivery to 90 days after delivery, 500 mg of synthetic carotene is supplied every day, and the estrus of cows is obvious and the conception rate is improved. When the blood carotene is lower than 1.0µg/ml, it will cause serious reproductive obstacles in dairy cows. When the carotene content is low, veterinary B-ultrasound will reveal embryonic death, lack of estrus, and reduced conception rate. When the carotene content in the blood increases, the reproductive function will also improve.