Breeding information and Signs of heat (estrous cycle) at different time periods in cows
Awadhesh Kishore and Rakhi Sharma*
Sarvoday Mahavidyalaya, Chaumuhan-281406, Mathura (INDIA)
*Institute for Development of Technology for Rural Advancement, Mathura-281004 (INDIA)
Crossbred heifers attain puberty, age at sexual maturity early compared to local breeds. Weight at first insemination in two heifers is similar. Estrous cycle continues for 21 days and heat period for 24-36 hours. Major heat signs include social behaviour, excitement, bellowing, fluctuation in milk yield, mucus discharge, mounting other animals, standing still when other mounts and frequency of urination.
Age at sexual maturity, Animal breeding, Bellowing, Cows, Crossbred, Estrous cycle, Heat periods, Heifers, Insemination, Local breeds, Milk yield, Mounting, Mucus discharge, Puberty, Urination.
The local heifers attain puberty around 30-35 months whereas the same crossbred heifers attain around 12 months of age. The age at sexual maturity in local ones is about 30-35 months as against about 15-18 months in the crossbred heifers. The weight of the heifer at the time of their first insemination ought to be 250-275 kg for Holstein Friesian and 225-250 kg for Jersey crossbred.
The average period of heat (estrous cycle) in cows is 21 days with a range of 18-24 days. In indigenous cows heat period remains for 24-36 hours out of which first 0-8 hours are mounting phase called early heat period, 12-18 hours are standing phase called mid heat period and last 24 hours called late heat period.
Signs of heat period:
The animal remains restless and tries to get isolated from other cows in the course of early heat period. In the course of mid heat period mixed characteristics are shown while in the course of late heat period, animal returns to normal behaviour.
In the course of the early heat period, cow shows specific signs which are more pronounced in the course of mid heat period but in the course of late heat period the signs are disappeared.
Bellowing is a common sign of heat period in cows. In the course of early heat period, sometimes bellowing is observed which was often occurred in the course of mid heat period but in the course of late heat period it is very seldom noted.
Milk yield is significantly fluctuated in the course of heat period. In the course of early heat period, milk yield decreased drastically which continues in the course of mid heat period but in the course of late heat period it Starts increasing.
Mucus Discharge from vulva:
Mucus discharge from vulva in the course of early heat period is Clear, watery and does not break while falling down from vulva and flows, while in the course of mid heat period it is turbid and opaque and does not break while falling. In the course of late heat period, mucus discharge from vulva is seen seldom.
Mounting other animals:
Mounting other animals is Very seldom seen in the course of early heat period, which was observed often while the course of mid heat period. In the course of late heat period this signs is seen seldom.
Standing still when other cow or bull mounts:
The cow in heat remains standing when other cow or bull mounts her. The sign is observed sometimes in the course of early heat period Very often in the course of the second half of the mid-heat and indicates right time for insemination. In the course of late heat period, this sign is not frequent and seldom observed.
Frequency of urination is directly related to the occurrence of heat period in cows. In the course of early heat period it is frequent which is again increased while the course of mid heat period but in the course of late heat period the frequency of urination becomes normal.