Typical Signs of Estrus in Cows and Points to Note When Estrus Is Abnormal

Bos, the cattle tribe, is a tribe under the subfamily Bovinae; crossbreeding produces fertile offspring, and they are mammals. A cow refers to a female bovine. It can produce milk and can bear offspring.So what are the typical signs of estrus in cows? What problems should be noted when estrus is abnormal?

What are the typical signs of estrus in cows?

1. Early estrus. The cow has just begun estrus; the symptoms are bellowing, leaving the herd, walking along the exercise yard, and trying to approach other cattle; mounting other cattle; the vulva is mildly swollen, and the mucosa is moist and flushed; sniffing the hindquarters of other cattle, unwilling to accept being mounted by other cattle; milk production decreases.

2. Peak estrus (lasting about 18 hours). Its characteristics are standing to accept being mounted by other cattle, mounting other cattle; frequent bellowing, excitement and restlessness; poor appetite or refusal to eat; decreased milk production.

3. The period when estrus is about to end. The cow shows refusal to accept being mounted by other cattle, sniffs other cattle; tries to mount other cattle; appetite is normal, milk production rises again; mucus may be discharged from the vulva.

The symptomatic changes throughout the entire estrous period are a gradual process, and the duration of estrus varies among individuals. The suitable breeding time should be shortly after the cow enters late estrus. According to experience, generally if estrus occurs in the morning, breed in the afternoon; or if estrus occurs in the afternoon, breed the next morning. When the weather is hot in summer, the breeding time should be appropriately moved earlier, and slightly delayed in winter. For old and weak cows, the duration of estrus is relatively short and ovulation is early, so they should be bred early; for young cows, the duration of estrus is relatively long and ovulation is late, so they should be bred late. Usually, with proper breeding timing, one insemination is enough; only when delayed ovulation is diagnosed by touching the follicles through rectal examination is a second insemination needed.

What problems should be noted when estrus in cows is abnormal?

If a cow does not come into estrus when it should, delaying breeding, it will cause economic losses to the breeder. The causes of cows not coming into estrus are various, including disease factors, nutritional factors, environmental factors, etc. Breeders should carefully examine the cow's condition, and should especially note the following problems:

1. Poor feeding management, the cow is too thin or too fat.

2. The cow has previously had conditions such as retained placenta, metritis, vaginitis and ovarian cysts.

3. The feed quality in the diet is poor, crude protein is too high or too low, and there is a lack of certain trace elements (selenium, zinc, etc.) or vitamins A, E, etc.

4. Poor management, the cowshed is damp and cold, water intake is insufficient, and there is a lack of exercise.

5. Incorrect methods of assisted delivery and breeding insemination, failure to disinfect when examining the vagina, etc.; improper operating methods can damage the vaginal and uterine mucosa, causing bacteria to enter or causing traumatic reproductive organ diseases.