Animal Reproduction/Theriogenology https://www.youtube.com/channel/UCHzZhYqMy10vsVRZdddEkUg

1. THER 608
Physiology of Reproduction
Prof. Dr. Nasim Ahmad
Physiology of Estrous Cycle
Estrus detection: significance, signs,
methods of detection, timing of
insemination
1

2. Significance of ED
• Lesser no. of repeat breeder cows
• Decreased no. of services per conception
• Decreased calving interval
• Per cow/buffalo increase in the
productivity and income of the farmer
• Decreased culling percentage due to
reproductive reasons
2

3. Estrus Signs
(cows & buffaloes)
Primary Sign
• Stands to be mounted (Standing Heat)
Secondary Signs
• Active (nervous, Licking other cows,
Excitement
• Clear Mucus discharge (best sign)
• Mounting on other females (she will come in
heat later)
• Vulvar swelling (general sign)
• Reduced feed intake (general sign)
• Raised Tail head, Roughened (late sign)
• Micturition, Bellowing
• Milk let down reappear just after milking
(“Dokey”) 1-2 (in buffaloes)
3

4. Behavioral
signs of
estrus
•Economic
Significance
•Calf a year
•Ideal 60-90
days
postpartum
successful
rebreeding
4

5. STANDING HEAT IN COWS: A
SURE SIGN OF ESTRUS
Note:
Buffaloes do
not show
homosexual
behavior
5

6. 6

7. Note: Buffaloes don’t show homosexual behavior
7

8. 8

9. CLEAR MUCUS DISCHARGE : A VERY
GOOD SIGN OF ESTRUS
9

10. SIGNS OF ESTRUS: CHANGES IN
THE VULVA
NO ESTRUS
AFTER ESTRUS
BEFORE ESTRUS
MAIN ESTRUS
PREGNANCY
10

11. estrus
Day Before Day after 11

12. SIGNS OF ESTRUS: CHANGES IN THE
APPEARANCE OF CERVIX
PRE ESTRUS
POST ESTRUS PREGNANCY
MAIN ESTRUS
NO ESTRUS
12

13. MATURE FOLLICLE
13

14. 34% 22%
21% 23%
Methods of Detection
Two to three times a day heat check is needed (visual method)
Note: 66%
Buffaloes show
estrus activity
during 6 pm to
mid night
•Efficient
•Accurate
14

15. Barn estrus
and
breeding
chart
15

16. Chin-ball marker
16
e deviated bulls
ctomized bulls
ogenized cows

17. Aids to estrus detection in cow
P4 milk test
Penile deviated bulls
Uterine tone
17

18. Optimum time of insemination in relation to
onset of (standing) estrus (AM-PM rule)
•Fertilizable life of ova about 6 -12 hrs after ovulation
•Fertilizable life of sperm in female reproductive tract is 24-48 hrs 18

19. Duration after termination of standing
oestrus (h)
16 18 20 22 24 26 28 30
Pre-standing oestrus (h)
9 -8 -6 -4 -2 0 2 4 6 8 10 12 14
Standing oestrus (h)
L.H ( Roelofs et al., 2004)
A.I
IMPLICATIONS FOR TIMING OF OVULATION
IN RELATION TO OESTRUS BEHAVIOUR IN
BUFFALOES
Hours in relation to onset of standing oestrus
200
150
100
50
0
Oestrusbehavioralscore
A.I
• Increased activity
• Vulvular swelling
• Frequent urination
• Mucous discharge clear
and thin
Too early to breed
• Mucous thicker & cloudy
• Restless
• Will not stand
• Sniffing the vulva of another
buffalo
Fair to poor fertilityBest time to breed
19

20. Managemental activities helpful for
Better ED
• Clear identification (branding/ear tagging)
• Record keeping
• Only one man should be made responsible for
this job
• He should know the primary & secondary signs
of heat
• Accurate timing of AI
• Every heat detection aid should be accompanied
with visual observation
• Interval between milking and offering of fodder is
ideal time for visual observation
• Estrus activity chart of breeding females
• Observing heat signs after AI has the same
importance as before AI. Why??
20

21. Favorable conditions for cows to show
estrus
• Free interaction of cows to show estrus
behavior especially mounting activity
• Adequate numbers of cows present in
the grouping
• Cows able to have good footing for
successful mounting in respect of
ground conditions
• Cows should not have feet and leg
problems that discourage them from
mounting 21

22. Mount detection aids
22

23. Pedometers: Measures walking
activity
Thank you23