When examining the contents of the udder of lactating cows with Masttest, a subclinical form of mastitis was in 28.98% of the animals. Most often, the defeat of one lobe of the udder was noted (35.1%). The occurrence of subclinical mastitis in two udder lobes was recorded in 34.31% of cows, in three lobes - in 18.63%. The occurrence of a subclinical mastitis form  in all lobes of the mammary gland was only in 1.96% of animals. The course of treatment of cows with subclinical mastitis up to 5 days with mastomycin, vakkamast and mastivex is more effective compared to their use for 2-3 days. It is most expedient to use mastomycin, vakkamast, which are not inferior in therapeutic efficacy to the foreign preparation mastivex (Spain), but 1.6–1.7 times cheaper and exclude dependence on the market of foreign medicines.

The article presents the results of the overretained afterbirth expulsion in cows. It was found out that retention of placenta is recorded in 39.04% of cows. Most often, incomplete retention of placenta was noted in 36.98%,  and complete one in 2.05%. The efficiency of afterbirth expulsion with uteroton was 58.82%, with metrostim and metrostim in combination with enroflon - 64.71%. Fertility of cows turned out to be the highest after intramuscular use of metrostim in combination with intrauterine administration of enroflon (76.47%) with the best insemination index (1.6±0.01). According to experimental studies, for a conservative method of  overretained afterbirth expulsion in cows, it is advisable to use a myotropic drug in combination with a drug that has a bactericidal effect on the microflora of the uterine cavity. This helps to accelerate the involution of the uterus, increase fertility and prevent the occurrence of various forms of endometritis.

The article presents a technical solution for the intrauterine pressure sensor in cows, based on the use of the piezoelectric effect. The results obtained indicate a sufficiently high sensitivity of the sensor and reliable performance of the device that provides registration of uterine contractions in cows after calving. This can be used to conduct hysterographic studies in cows at various times after the fetus has been bred, as well as in the development of new drugs to correct the contractility of the uterine muscles. It has been established that after 6 hours the amplitudes of uterine contractions are more pronounced than 12 hours after the fetus has been removed.

The research is devoted to the study of the contractility of the myometrium in cows using a rubber balloon and a piezoelectric pressure sensor. It has been established that with an increase in time after calving, the number of uterine contractions, the values of intrauterine pressure and the contraction index in cows gradually decrease. The values of intrauterine pressure have a decisive influence on the value of the contraction index. The most convenient method for studying the contractile function of the uterus in cows can be considered the use of a piezoelectric sensor that can be connected to a computer system for processing the data obtained, which significantly speeds up the analysis and objectivity of the results of hysterographic studies.

The results of hematological and biochemical blood tests of cows with acute catarrhal-purulent endometritis showed a decrease in the concentration of erythrocytes, hemoglobin, hematocrit, platelets, an increase in the level of leukocytes, platelets, glucose, creatinine, alkaline phosphatase, LDH, AST, ALT compared with clinically healthy animals. Intrauterine administration of the Mitrek preparation for the treatment of cows with acute catarrhal-purulent endometritis had a positive effect on the normalization of the main indicators of metabolic processes in the animal body within 20 days after its use.