The inability of cows to shed their placenta is one of the important reasons for slow uterine recovery, uterine infections, abnormal postpartum estrus, and difficulties in breeding and conception. In severe cases, it can lead to the loss of reproductive ability and cause significant economic losses. It is necessary to use imported cows to check the uterine recovery status using ultrasound after delivery.

Normally, 2 hours after calving, cows are injected with oxytocin to promote early placental excretion. Imported cows are checked for normality using ultrasound. If the placenta has not been expelled 9 hours after delivery, 5g of tetracycline can be dissolved in 500ml of physiological saline and injected into the uterus every 2 days. The placenta will naturally protrude for about 5-7 days, and then imported cattle can be used to check the condition of the uterus by B-ultrasound.

Postpartum cows often experience hormonal imbalances such as estrogen, oxytocin, and prostaglandins that promote uterine contractions; Diseases such as difficult delivery, inability to retract the placenta, uterine prolapse, endometritis, and hypocalcemia occur; As well as various reasons such as poor physical condition of postpartum cows, twin pregnancy or oversized fetuses, excessive fetal water, old and weak cows, and insufficient exercise, they can all cause delayed uterine recovery and affect normal postpartum reproduction. Therefore, imported cows should be regularly checked with B-ultrasound before and after delivery. Therefore, postpartum cows should actively take measures to promote uterine recovery and use imported cows for B-ultrasound monitoring of their condition.

The method to promote estrus in cows is to continue maintaining a low potassium level diet in the diet of postpartum cows; Adding yeast feed additives to promote the digestion of crude fiber in forage; Increase the feeding of high-quality long grass; Improve the nutrient concentration of the diet and increase high-quality protein feed to compensate for the reduced feed intake of postpartum cows; Regularly use imported cattle to check their estrus status with ultrasound. Otherwise, the dietary nutrition cannot meet the energy and nutritional needs of postpartum cows, and when the stored fat in the body is used, metabolic ketosis is prone to occur. Postpartum cows should have sufficient and quiet feeding and resting time and space, and should not be tied up for feeding as much as possible to ensure that postpartum cows have as much feeding and resting time as possible.