Dairy Cow Production & Management Flashcards
what are operational management functions of a dairy farm
crop production
labour
cash flow
replacement rearing
nutrition
milk production
machinery
animal health
where is the profit period of the lactation curve
during peak milk yield
what are the benchmarks in the calving year
what are the two types of data the are encountered in dairy outcome assessment
data with a range of values
- milk
- days in milk
- scc
- dcc
data with only 2 outcomes (binary data)
what are the ideal BCS throughout the lifecycle of a dairy cow
what are the issues with overconditioned cows
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
what are the issues with thin cows at calving
poor yield
poor persistency of lactation
poor fertility
immune suppression
how do you preserve the lactation curve
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
what are the benchmarks in the dry period
early dry period 60-39 days prior to calving
close up 21 days prior to calving
what is the transition period
transition period
21 days prior to calving – 21 days post calving
what is the voluntary waiting period
40-50 DIM depending on cow health and BCS
what % of cows should be pregnant at 50-100 DIM
50%
what % of cows should be pregnant at 200 DIM
90%
less than 10% should be open
at what DIM should a cow have produced 50% of her annual profit
100 DIM
what are the reasons cows leave dairies
- infertility
- mastitis
- lameness
- production
- disease
- other
what do low calf losses and good heifer rearing allow
high cull rates
herd expansion
what do high calf losses and poor heifer rearing mean
often must buy replacements
culling thought to be expenisve – only as ‘cost’
why is cow activity important
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
does cow comfort matter
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
what is stress
Caused by stressor
Routine coping strategies
Hunger, thirst
Social change and separation
Stocking density
Ability to rest
Lameness
Disease
Individual variations in response
what are stress hormones
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
what are cow requirements
Feed-quality and accessibility
Water-quality and accessibility
Space
Light
Air
Rest
Time to compensate!
what are measures of cow comfort
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
how is the freestall use index measured
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!
what are the seasonal dairy systems
Autumn Sept-Dec
Spring mid February
Tight block empt-ideally 6-9 weeks
what are the all year round calving systems
All year round calving
Housed all year
Partial grazing
TMR feeding
Partial TMR
Component feeding
what are the typical maintenance energy requirements of a dairy cow
60-65MJ
what are the typical production energy requirements of a dairy cow
5.6MJ per kg milk
what are the liveweight gain energy requirements of a dairy cow
34MJ/kg
what are the energy requirements for pregnancy
23MJ
what are the energy requirements for live weight loss
-28MJ/kg
how much energy would a 600kg cow pregnant, gaining 0.5kg/day producing 29kg milk/day
200-210MJ/kg
with TMR systems DMI can exceed 4% body weight
approx 24kg/d
