Estrus Detection In Cows (Heat detection)

Estrus Detection In Cows (Heat detection):
Do you know that you can detect the heat period of cows just by observing?
Cow’s reproductive cycle has 4 phases; proestrus, estrus, metestrus and diestrus. Estrus is the period that cow is fertile and it lasts around 24 hours. Heat periods occur every 21 days.
The hormone levels of estrogen, LH get increased in this period and the progesterone levels get decreased in the circulation.
Without wasting much time let’s go for the heat signs:-
1.Standing to be mounted – this is the most common and accurate sign of estrus and the mounting is performed by other cows(not bulls).
2.Mounting on other cows.
3.Swelling and redding of the vulva – prior to estrus and remains for a short period of time.
4.Mucus discharge – clear viscous mucous strands on vagina, tail, thighs, planks, perineal region. 
This is due to the elevation of blood estrogen levels.
5.Chin resting and back rubbing – prior to mounting on another cow.
6.Sniffing and licking genitalia.
7.Bellowing- frequently .
10.Decreased feed intake.
11.Lip curling.
12.Head raising  etc: