Estrus cycle: the average estrus cycle of adult cows is about 2 1 day, and that of bred cows is about 20 da
Estrus cycle: the average estrus cycle of adult cows is about 2 1 day, and that of bred cows is about 20 days, including 1-3 days in the pre-estrus, 18 hours in the estrus, 3-4 days in the late estrus and12-/kl.
Estrus symptoms: frequent urination, swollen vulva, increased mucus and egg white, loose outside the cervix, willing to accept crawling.
1. How many days does it take for a cow to be in estrus?
1, estrus cycle
(1) The estrus cycle of dairy cows refers to the period from the first estrus to the next estrus, and the specific time will be affected by factors such as temperature, light, labor, feeding management and physical condition.
(2) If it is an adult cow, the average estrus cycle is about 2 1 day (18-25 days). If it is a bred cow, the average estrus cycle is about 20 days (18-24 days).
(3) The estrus cycle of dairy cows can be subdivided into pre-estrus, post-estrus and post-estrus, in which pre-estrus is about 1-3 days, post-estrus is about 18 hours, post-estrus is about 3-4 days, and post-estrus is about 12- 15 days.
2, postpartum estrus time
(1) Postpartum estrus refers to the period from the end of delivery to the beginning of the next estrus.
(2) If it is a local yellow cattle, it usually enters estrus about 60- 100 days after delivery. If it is beef cattle, it usually enters estrus about 40- 104 days after delivery. If it is a cow, it usually enters estrus about 30-72 days after delivery. If it is a buffalo, it usually enters estrus about 42- 147 days after delivery. If it is a cow, it usually estrus around 265438+ 0-54 days after delivery.
Second, the symptoms of estrus in cattle
1，Preestrus
In the pre-estrus period, cows are mainly characterized by mental anxiety, frequent urination, pink wet vagina, slightly swollen vulva and crawling over bulls.
2. Estrus
In estrus, cows are mainly characterized by obvious swelling of vulva, increased mucus and transparent egg white, relaxation outside the cervix, active tail lifting, willing to accept the bull's climbing and standing still.
3. Late estrus
In the late estrus, cows gradually calm down, vaginal mucus secretion decreases and becomes sticky, corpus luteum appears on the ovary and matures gradually, and progesterone secretion gradually increases, so they no longer accept climbing (50% of adult cows and 90% of breeding cows will shed a little blood from the vagina).