The Reproductive Cycle

Cattle reproductive cycle

Calves

Voluntary waiting period

Breed after this date

Calving

Voluntary waiting period

1st breeding – anytime after VWP

Later breedings

Conception

Cycle from one calving until the next calving

The Reproductive Cycle

Gestation

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

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

Dairy reproductive terms – linear display

Calves

Bred for 1st time

Days to 1st service

Days Open

Number of days between calving and conception

Calculated on a herd basis – not for an individual animal

Calves

Bred for 1st time and conceives

Days open

Days to 1st service

Days open & Days to first service - linear display

Days open + Days to first service - linear display

Calves

Bred for 1st time

Bred again and conceives

Days to 1st service

Days open

Reproductive terms – linear display

Calves

Bred for 1st time - 1st service

Bred again (3rd service) and conceives

Days open

Bred again- 2nd service

Days to 1st service

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

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

Reproductive terms – linear display

Calves

Calves again

Calving interval

Holstein-Fresian cattle

Grolier Electronic Publishing, Inc.

Reproduction

Biological Efficiency

Production Efficiency

Profitability

Improving Reproductive efficiency

Shortening Post-partum interval

Submission Rates

Conception Rates

Post-Partum Interval

Dairy Cows Mean=26 days(15-50 Days)

Beef Cows Mean=55 days(25-180 Day)

Aim to have a calf per cow

per year with peak lactation

to correspond with peak

grass growth

Postpartum reproduction - cattle

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

Heat Detection Rate

Conception Rate

Pregnancy Rate

Main Factors Affecting Pregnancy Rate

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

Conception rate

60 50 40 30

90 96 91 83 71

70 91 82 73 61

50 76 68 59 48

HeatDetectionRate %

40 67 59 50 4059

Heat Detection

Breeding

• Use of AI

• Heat detection

• Factors affecting conception rate

Primary Sign of Heat

Secondary Signs of Heat

• Sliming

• Restlessness

• Mounting activity

• Trailing other cows

• Bellowing

• Mounting or dirt marks

• Skin Marks

• Met-oestrous bleeding

Mucous vaginal discharge

Chin resting

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

Target of reproductive performance

• One calf one year Calves Young Stock

• 305 milking days Milk production

Fertility indices in dairy cattle

• Calving interval 365 d• Calving to conceive 85 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 24 m

1. Transmitter with pressuresensitive button on top

))))))))

))))))))

))))))))

))))))))

)

2. Mounted onto cow’s rumpusing a patch and adhesive

3. The receiver accepts the mounting activity signal from the transmitter

Receiver

4. Information is transferred tocomputer for processing by

HeatWatch software.

~1/2 mile range

Heat Watch

New technologies tools

• Pre-implantation genetic diagnostic embryo screening

• Genomics, Proteomics Bioinformatics

Transitional period managements

• Before calving 2-3 weeks

• Calving period

• Post-caving period 2-3 weeks

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

Reproductive cycle

• Gestation 115 days• Lactation 21-28

days• Interval from weaning to estrus 5 days• Total days per cycle 141-148

days

Farrowing index = 2.5 -2.6

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

Reproductive problem

• Anestrus

• Conception failure

• Pregnancy failure

Anestrus

• Delay estrus – Weaning to estrus 4-6 days

• Absence of estrus behavior• Subestrus

- Boar estrus detection accurate 98 %- Stimulate 20 minute per days

Treatment of anestrus

• True anestrus

• 400 IU eCG and 200IU hCG (PG600)– Estrus 87.6 %