When a cow is in heat, it shows the following signs:-
- Alert, restless behaviour
- Aggressive behavior like butting
- Mounting other cows
- Standing still when mounted by other cows
- Chin pressing on other cows
- Dilated and enlarged vulva – vulva is the external reproductive organ of the cow
- Sniffing, licking of vulva, lip curling
- Produces clear discharge from the vulva
- Its milk production drops
- Increased urination
The heat period in a cow lasts about 30 hours. This period can be divided in to 3 parts –
- Coming on heat – This is when it exhibits all the other signs of heat apart from standing still to be mounted by other cows.
- Standing heat – The cow stands still to be mounted by other cows. This is the peak fertile period. The cow must be bred soon after this as 12-24 hours later it will start going out of heat.
- Going out of heat – It stops to display the signs of heat and finally it produces a bloody discharge that indicates the end of the fertile period. If a cow is bred between when it came on heat and this discharge, then it is a good guide that the timing of insemination was correct.
Figure: Most fertile time to breed cows
Note: It is difficult to detect heat in cows that are in zero grazing (tie stalls). Farmers practicing this kind of farming are advised to let out the cows once a day in order to detect for heat signs.
The period between one heat and the next is about 21 days. Here are some important factors related to breeding that you need to put in to consideration:
- A heifer is ready to be bred at the age of 14-18 months
- A cow will resume heat 38th – 42nd day after giving birth
- It is recommended to breed your cow 2-3 months after giving birth
- The gestation period of a cow is 9.5 months
- In terms of intervals, aim at one calf per cow per year.