COMPARISON OF ESTRUS SIGNS IN REPEAT BREEDING CATTLE WITH OVULATORY DISTURBANCE AND NORMAL OVULATION

Abstract

An investigation was conducted to record the behavioural and physical signs at different periods
of estrus in 75 stall fed repeat breeding crossbred cows and heifers of Assam with anovulation, delayed
ovulation and normal ovulation. Restlessness and bellowing were predominant behavioural signs of
estrus. Animals with delayed ovulation and anovulation had 72.73 a.nd 25.00 per cent incidence of
restlessness, respectively upto 36 hrs of estrus, while the animals with normal ovulation did not show
restlessness beyond 24 hrs of estrus. Restlessness persisted upto 48 hrs of estrus in a small
percentage of animals (9.09) with delayed ovulation. Bellowing was observed till 24 hrs of estrus in
animals with anovulation, delayed ovulation and normal ovulation. At 12 and 24 hrs post onset of
estrus, the percentage of animals showing bellowing was higher with delayed ovulation (100.00 and
50.00) and anovulalion (90.00 and 10.00) than with normal ovulation (78.79 and 6.06). Bellowing persisted
upto 36 hrs after the onset of estrus in animals with delayed ovulation. Among the physical signs of
estrus, swelling of vulva was found in higher percentage of animals with both delayed ovulation ( 100.00
and 95.45) and anovulation (100.00 and 65.00) as compared to normal ovulation (87 .88 and 18.18) at
24 and 36 hrs post onset of estrus, respectively. Animals with delayed ovulation (36.36%) and anovulation
(5.00%) showed swelling of vulva till 48 hrs of estrus while no animal with normal ovulation had beyond
36 hrs of estrus. The number of animals showing pink colouration of the vaginal mucous membrane
was higher with delayed ovulation (59.09%) and anovulation (25.00%) as compared to normal ovulation
(9.09%) at 48 hrs after onset of estrus. Thin consistency of the vaginal mucus was found to be more
number in animals with delayed ovulation (81.82%) and anovulation (60.00%) at 12 hrs after onset of
estrus, while most of the animals with normal ovulation (64.52%) had thick consistency of the vaginal
mucus during the same period.