Nutritional Demands Of Pregnancy And Lactation In Dairy Cow (dairy Cow Life Cycle)

Question 1

How long should heifer earring ideally take?

Answer 1

2 years

Question 2

Describe the life cycle of a cow

Answer 2

1. Birth (calving)
2. Neonate – first hours
3. Milk feeding – pre-weaning
4. Weaning
5. Post-weaning
6. Breeding
7. Gestation
8. Calving
9. Lactating – post-partum
10. Lactating – Breeding
11. Lactating – pregnant
12. Dry period (pregnant)
13. Repeat 7-9 (× 3-4)
14. Cull

Question 3

Life cycle of dairy cow
1. Birth (calving)

Answer 3

Generally occurs at about 280 days post conception
Twinning – in high yielding up to 5- 10% - gestation period shorter (270d) in twins
Birthweight: 30 – 60 kg

-calf gets snatched away from mother ASAP. Gets moved as far away from mother as possible

Question 4

Life cycle of a dairy cow
2. Neonate- first hours

Answer 4

Calves taken away to dry and clean pen- either individual or shared pens

Feeding colostrum ASAP (first milk) is essential –
Only source of immunity (antibodies or IgG)
Energy
Influence the entire life of the animal

Naval is dipped with iodine ASAP

Question 5

What is the rule of 3Qs of colostrum
(And magic number)

Answer 5

Quantity: 4 litres
Quickness: fed in 4 hours
Quality: Milked out from the cows in 4 hours

Question 6

Life cycle of a dairy cow
3. Milk feeding- pre-weaning

Answer 6

Calves fed milk until weaning (50-80 days)

Fed in bucket (with/without teat) twice daily / ad libitum

Together with milk introduce from 2 weeks of age:
-Calf starter (cake, concentrate)
-Roughage (hay, straw, …)

Question 7

What kind of milk is given to calf

Answer 7

Whole milk/milk replacer

Question 8

How much milk should be fed to calf

Answer 8

20% BW/day (8-10 litres/day)

Question 9

What does introduction of roughage and calf stater at 2 weeks of age do for the calf?

Answer 9

-Improves growth rate (850g/d)
-Allows for a Better transition from milk feeding to solid feeding

Question 10

4. Weaning

Answer 10

At 60 days or so
Transition from milk feeding to solid feeding
Most stressful moment for calves
No other procedures or group changes
Do it gradually – step down

Question 11

What is the target amount of concentrate a farmer wants to give to a calf

Answer 11

1kg of concentrate/day

Question 12

What are the most common health problems occurring during first 4 stages of birth?

Answer 12

Diarrhoea
Pneumonia
Navel ill – Joint ill
Septicaemia, meningitis

Question 13

Life cycle of a dairy cow
5. Post-weaning (growing period)

Answer 13

Often neglected part of the cycle
Calves from 2-3 months onwards
Fed a ruminant ration:
Forage + concentrate (16% Proteins)
Still want calf to grow 850g/day

Question 14

Most common health problems occurring at post-weaning stage

Answer 14

Pneumonia
Gastrointestinal nematodes
Liver fluke
Lungworm
Dermatophytosis
Clostridial diseases
Infectious bovine keratoconjunctivitis

Question 15

Life cycle of a dairy cow
6. Breeding (heifer)

Answer 15

Mate heifers at about 55-60% adult bodyweight
370 kg
13 months (HF)
125-127 cm at the withers (HF)
1-2% freemartin (twin with male)
Good repro performance:
Use Artificial Insemination (AI) Use AI with Sexed Semen

Calve down at 24months
Producing an alive female calf

Question 16

Life cycle of a dairy cow
7. Gestation (heifer)

Answer 16

Nutrient requirement increase during pregnancy
-Not over feed – monitor BCS
-50% increase in late gestation
2-3 week before calving:
-Moved to the calving area where they birth (next to the calving cows)
-Fed a ration that makes them ready to start the lactation - ref Ca and energy metabolism

Question 17

Life cycle of a dairy cow
8. Calving (birth)

Answer 17

Transition from dry period to lactation
Starts the most critical period in any cow’s life and the highest risk period for mortality and morbidity

Question 18

Targets for heifers

Answer 18

98% of heifers born calving down at 24 months —>

85% of heifers born calving down at 24 months producing a heifer calf —>

Reduce death and disease
Maximise growth rate
Perfect repro performance

Question 19

Life cycle of a dairy cow
9. Lactation

Answer 19

The first couple of months after calving see most cows descend into negative energy balance

Question 20

Around what month do farmers look for peak milk production?

Answer 20

Around 1st month

Question 21

Lactation curves of a cowdepends on what factors?

Answer 21

-affected by genetics, age and nutritional factors
-Curves are steeper in multipara and Holsteins (breed of cow)

Question 22

Describe the lactation graph

Question 23

Life cycle of a dairy cow
9. Lactating – post partum

Answer 23

Post-partum or fresh period = first 3 weeks after calving
Most critical moment of lactation
Common health problems (RFM, metritis, ketosis, milk fever), especially in multipara/2nd+ lactation.
Anoestrus, no ovarian function

Early lactation, 20-50 days in milk (DIM)
First ovulation occur at 2-3 wks postpartum but is often associated with silent heat (ie no signs of heat/oestrus) due to lack of pre-existing corpus luteum
Uterine involution
Cows should not be inseminated during this period, wait until 45-60 DIM - (Voluntary Waiting Period - VWP)

Question 24

Life cycle of a dairy cow
10. Lactating – breeding

Answer 24

-Uterine involution should be complete by 30-35 DIM
-Maximal milk production coincides with period when we want the cow to become pregnant (ie from 45 to 100 days) = energy nadir

Question 25

Life cycle of a dairy cow
11. Lactating – pregnant

Answer 25

A good dairy cow should be pregnant for most of her lactation (280 days out of the 305 d lactation)
Last 60 days of pregnancy = dry period…

Question 26

Life cycle of a dairy cow
12. Dry period (pregnant)

Answer 26

Standard 60 days First 40 = far-off dry Last 20 = close-up
Rest for the mammary gland
Less nutritional demand
Less competition

Question 27

Life cycle of a dairy cow
13. Repeated calving and lactation

Answer 27

A common but usually unattainable target is to produce one calf per cow per year – this equates to a Calving Index (CI) of 365 d
To achieve CI 365 d = the calving to conception interval (CCI) must be 365 d – 280 d (gestation period) = 85 d (50 PP + 35 breeding)
This means first (successful) insemination must be before 85 d (CCI) – 21 d (interoestrus interval) = 64 d.
In practice, values of CI ~ 400 d are more commonly seen and probably more desirable
In strictly seasonal calving herds, there is a stronger imperative to have CI = 365 d (else cows fall out of synchrony with each other and results in severe efficiency loss).

Question 28

Life cycle of a dairy cow
14. Culled/dead

Answer 28

Mortality
Total loss for the farmer – Target less 3%
Culling:
Most cows are killed before they would die of natural causes. The only reason for culling cows is ‘the cow is not productive in my herd anymore’.
We still refer to the term of involuntary or forced culls and the main reasons are
Mastitis
Lameness
Infertility, …
Voluntary culls would be those where a cow is culled because her production was below expectation or where her type is poor.
The idea is to minimise the rate of involuntary culls so as to maximise the opportunity to replace cows of relatively low genetic merits.

Question 29

Some people think that more cows culled=…

Answer 29

Better management