Dairy Cow Production & Management

Question 1

what are operational management functions of a dairy farm

Answer 1

crop production

labour

cash flow

replacement rearing

nutrition

milk production

machinery

animal health

Question 2

where is the profit period of the lactation curve

Answer 2

during peak milk yield

Question 3

what are the benchmarks in the calving year

Answer 3

Question 4

what are the two types of data the are encountered in dairy outcome assessment

Answer 4

data with a range of values

• milk
• days in milk
• scc
• dcc

data with only 2 outcomes (binary data)

Question 5

what are the ideal BCS throughout the lifecycle of a dairy cow

Answer 5

Question 6

what are the issues with overconditioned cows

Answer 6

Have poorer reproductive performance

• Longer period of negative energy balance

Have higher incidence of:

• Fatty liver
• Metritis/retained placenta
• Other metabolic diseases

Have poorer total lactational milk yield

Question 7

what are the issues with thin cows at calving

Answer 7

poor yield

poor persistency of lactation

poor fertility

immune suppression

Question 8

how do you preserve the lactation curve

Answer 8

peak lactation 6 weeks post calving

1 litre lost at peak = 220 litres lost for the rest of lactation

her yield will drop 2.2% per week

Question 9

what are the benchmarks in the dry period

Answer 9

early dry period 60-39 days prior to calving

close up 21 days prior to calving

Question 10

what is the transition period

Answer 10

transition period

21 days prior to calving – 21 days post calving

Question 11

what is the voluntary waiting period

Answer 11

40-50 DIM depending on cow health and BCS

Question 12

what % of cows should be pregnant at 50-100 DIM

Answer 12

50%

Question 13

what % of cows should be pregnant at 200 DIM

Answer 13

90%

less than 10% should be open

Question 14

at what DIM should a cow have produced 50% of her annual profit

Answer 14

100 DIM

Question 15

what are the reasons cows leave dairies

Answer 15

1. infertility
2. mastitis
3. lameness
4. production
5. disease
6. other

Question 16

what do low calf losses and good heifer rearing allow

Answer 16

high cull rates

herd expansion

Question 17

what do high calf losses and poor heifer rearing mean

Answer 17

often must buy replacements

culling thought to be expenisve – only as ‘cost’

Question 18

why is cow activity important

Answer 18

Cows expressing normal patterns of behaviour are more likely to experience less stress and express their full genetic potential in terms of milk production and reproduction

Question 19

does cow comfort matter

Answer 19

Stress is relieved by the inability of an animal to cope with is environment, a phenomenon that is often reflected in a failure to achieve genetic potential

Field data from dairy cows show that stressors such as milk fever or lameness increase the calving to conception interval by 13-14 days and an extra 0.5 inseminations are required per conception

Question 20

what is stress

Answer 20

Caused by stressor

Routine coping strategies

Hunger, thirst

Social change and separation

Stocking density

Ability to rest

Lameness

Disease

Individual variations in response

Question 21

what are stress hormones

Answer 21

Sympathetic nervous system

Adrenaline/noradrenaline

Glucocorticoids-cortisol

Both produced by adrenal glands in response to ACTH

ACTH produced by pituitary in response to releasing factors produced in brain

Short, medium and long term effects

Immunosuppression

Energy metabolism

Question 22

what are cow requirements

Answer 22

Feed-quality and accessibility

Water-quality and accessibility

Space

Light

Air

Rest

Time to compensate!

Question 23

what are measures of cow comfort

Answer 23

Lying index = # of cows lying/total # of cows in the pen

Free stall use index = # of cows lying/total # of cows lying or standing but not eating/drinking

Cow comfort index = # of cows lying/total # of cows lying or standing in a stall

Question 24

how is the freestall use index measured

Answer 24

Count all cows not feeding or drinking

90% or greater should be laying down making milk

5% or less should be standing in the stall

Cows should lay down within 5 minutes of approaching the stall

Cows should lay down within 1 minute of entering a stall

Measure 2-4 hours post milking

20% cows should be eating or drinking!

Question 25

what are the seasonal dairy systems

Answer 25

Autumn Sept-Dec

Spring mid February

Tight block empt-ideally 6-9 weeks

Question 26

what are the all year round calving systems

Answer 26

All year round calving

Housed all year

Partial grazing

TMR feeding

Partial TMR

Component feeding

Question 27

what are the typical maintenance energy requirements of a dairy cow

Answer 27

60-65MJ

Question 28

what are the typical production energy requirements of a dairy cow

Answer 28

5.6MJ per kg milk

Question 29

what are the liveweight gain energy requirements of a dairy cow

Answer 29

34MJ/kg

Question 30

what are the energy requirements for pregnancy

Answer 30

23MJ

Question 31

what are the energy requirements for live weight loss

Answer 31

-28MJ/kg

Question 32

how much energy would a 600kg cow pregnant, gaining 0.5kg/day producing 29kg milk/day

Answer 32

200-210MJ/kg

with TMR systems DMI can exceed 4% body weight

approx 24kg/d