1. The Reproductive Cycle

2. Cattle reproductive cycle
Voluntary waiting period
Breed after this date
Calves

3. The Reproductive Cycle
1st breeding – anytime after VWP
Later breedings
Conception
Voluntary waiting period
Cycle from one calving until the next calving
Calving
Gestation
The Reproductive Cycle

4. Voluntary Waiting Period
Determined by herd owner
Fixed period following calving before attempting to breed cow
Usually between 40 and 70 days; is the same for all cows in the herd

5. Days to first service
Number of days between calving and when the animal is bred for the first time
Calculated on a herd basis – not for an individual animal
Animal may or may not conceive to this breeding/service

6. Dairy reproductive terms – linear display
Days to 1st service
Bred for 1st time
Calves

7. Days Open Number of days between calving and conception
Calculated on a herd basis – not for an individual animal

8. Days open & Days to first service - linear display
Days to 1st service
Bred for 1st time and conceives
Calves

9. Days open + Days to first service - linear display
Days to 1st service
Bred again and conceives
Bred for 1st time
Calves

10. Reproductive terms – linear display
Days open
Days to 1st service
Bred again (3rd service) and conceives
Bred again
- 2nd service
Bred for 1st time
- 1st service
Calves

11. Gestation period Number of days that a cow is pregnant
Number of days from conception to birth of the fetus
Average gestation: 279 days – there are breed differences

12. Calving Interval Period from one calving until the next
Measured in months
Calculated on a herd basis – not for an individual animal
Days open
+ Gestation period
Calving interval

13. Reproductive terms – linear display
Calving interval
Calves again
Calves

14. Reproduction Biological Efficiency Production Efficiency Profitability1

15. Improving Reproductive efficiency
Shortening Post-partum interval
Improving Reproductive efficiency
Submission Rates
Conception Rates

16. Post-Partum Interval Dairy Cows Mean=26 days (15-50 Days)
Beef Cows Mean=55 days ( Day)

17. Postpartum reproduction - cattle
Aim to have a calf per cow per year with peak lactation to correspond with peak grass growth 1 17

18. To Ensure Rapid Onset of Oestrous Cycles Post Calving
Cows calve in a moderate BCS
Ensure high DM intakes post calving & minimise BCS loss – Minimise Negative Energy Balance (NEB)
Calve heifers early
Consistently use Sire with strongly positive sub indices for Fertility

19. Main Factors Affecting Pregnancy Rate
Conception Rate
Pregnancy Rate
Heat Detection Rate

20. The Effect of Different Heat Detection and Conception Rate on % of Herd Pregnant at 90 Days After Onset of Breeding Season

21. Heat Detection

22. Breeding
Use of AI
Heat detection
Factors affecting conception rate

23. Primary Sign of Heat

24. Secondary Signs of Heat
Sliming
Restlessness
Mounting activity
Trailing other cows
Bellowing
Mounting or dirt marks
Skin Marks
Met-oestrous bleeding

25. Mucous vaginal discharge

26. Chin resting

27. Reproductive inefficiency in dairy
Anestrus
Failure to observe heat &
True anestrous
Failure to breed
Management decision
Failure to conceive
Fertilization failure (male size)
Fertilization (female size)
AI technique
Early embryonic death
Stillbirth / dystocia

28. Target of reproductive performance
One calf one year  Calves  Young Stock
305 milking days  Milk production

30. Fertility indices in dairy cattle
Calving interval d
Calving to conceive d
Mean calving to 1st service 65 d
Cows showing heat at 60 days PP 85 %
Conception rate to 1st service 70 %
Conception rate all service 58 %
Service per conception < 1.5
Average first calving m

31. Heat Watch Receiver ))))))))))))))))))))))))))))))))) ~1/2 mile range
1. Transmitter with pressure
sensitive button on top
)))))))))))))))))))))))))))))))))
2. Mounted onto cow’s rump
using a patch and adhesive
3. The receiver accepts the mounting
activity signal from the transmitter
Receiver
4. Information is transferred to
computer for processing by
HeatWatch software.
~1/2 mile range

35. New technologies tools
Pre-implantation genetic diagnostic embryo screening
Genomics, Proteomics Bioinformatics

38. Transitional period managements
Before calving 2-3 weeks
Calving period
Post-caving period 2-3 weeks

39. Reproductive efficiency in sow and gilt
Farrowing rate
Farrowing index
Conception rate
Non-productive or empty day
Piglet born per sow per year
Total number and number of born live

40. Reproductive cycle Gestation 115 days Lactation 21-28 days
Interval from weaning to estrus 5 days
Total days per cycle days
Farrowing index =

41. Targets for reproductive efficiency
Litters/sow/year >2.3
Farrowing rate > 85 %
Non-repeat rate >90 %
Liter size >11.5
Born live >11
Born dead <0.5
Mummified <0.5

42. Reproductive problem
Anestrus
Conception failure
Pregnancy failure

43. Anestrus Delay estrus Absence of estrus behavior Subestrus
Weaning to estrus days
Absence of estrus behavior
Subestrus
- Boar estrus detection  accurate 98 %
- Stimulate  20 minute per days

44. Treatment of anestrus True anestrus 400 IU eCG and 200IU hCG (PG600)