Protein And Energy Imbalances In Ruminants Flashcards
What factors affect productivity?
Genetics
Feeding - Diet
Environment
Management
Disease
What is the most expensive part of cow management?
Feeding
What rumen pH is ideal?
Neutral
How can a neutral pH be maintained in the rumen?
How can this be facilitated?
Saliva acts as a buffer
Produced by chewing and ruminating.
Therefore need a comfortable environment and enough time.
Needs fibre in diet 2-4cm in length.
Why does dietary fibre need to be 2-4 cm in length?
Below that, doesn’t stimulate rumination
How long does a cow need to lie down for per day?
What could disturb this?
14 hours/day
Feeding, cleaning, milking - cows are moved
What is meant by the term “time budget”
Amount of time cows spend doing things key things
E.g. eating, ruminating etc
How can you assess cow comfort?
Observe cows undisturbed in straw yards or cubicles
60% should be lying down/ruminating
1 hour before feeding (when they are disturbed) 85% should be lying down
What is the difference between nutrition and feeding?
Nutrition = what they are fed
Feeding = what they actually eat
When may feeding not equal nutrition?
If the food isn’t palatable/ fresh
How can trough space affect feeding?
How much trough space is needed per cow?
Each cow needs enough space, at least 60cm per cow
If not, cows will not get access to equal amounts of feed
Sometimes 1st lactation heifers are bullied by other cows and pushed to the back of the queue if limited feeding space
Other than space per cow, how can the trough affect feeding?
Physical condition of the trough - sharp or rough edges
Cleanliness - is fresh food put on old food? NEEDS TO BE CLEARED
How should water be presented to cows?
Plenty of CLEAN water
Enough space around the trough
high enough flow rate
Clean trough
Cool (in summer)
Correct TDS
Why do water troughs need to be big?
Cows like to drink in groups
What is DMI a measure of?
Dry matter Intake
How much the cows are actually eating
How can you estimate the required dry matter intake for a milking dairy cow?
When can’t this estimate be used?
2.5% of body weight plus 1% of milk yield
DRY COWS
What should you look for when assessing feed on farm?
Does it smell bad?
Is it mouldy?
Is it too soggy/dry?
Are the cows eating it?
What is a key benefit of feeding a TMR?
Don’t have temporary acidosis caused by just feeding carbs
Feed forage and concentrates together
What potential issues are associated with feeding TMR?
Sorting - cows only eat carbs because they taste better
Fibre length not long enough to stimulate rumen
What issues can occur as a result of a hole in a silage pit?
Silage should be anaerobic
When air enters - Secondary fermentation of silage and heating
SPOILED - not palatable, lower nutritional value
Moulds can produce mycotoxins
What feeding problems should you look for when on farm?
Insufficient feeding space
Rough edges of troughs, rails
Extremes of hot, cold, rain, light
Slippery floors
Self feeding from silage face
Very tight packed silage
Electric fences
What issues are associated with self feeding from silage faces?
Food can collapse on heads
Hard to pull out silage
BAD
What mistakes are commonly made regarding grazing?
Overestimating the value of grazed grass - quality is variable and difficult to assess. Long, dry summers =
POOR
Bloat from clover rich pastures
Magnesium deficiency
How can grazing issues be reduced?
Buffer feeding
Silage/hay/TMR to supplement grass
Prevents over eating of hungry cows
What is the ideal milk fat percentage?
4.2%
What dietary factors affect milk fat percentage?
FIBRE LEVEL
If concentrate:fibre is more than 60:40, milk fat will drop significantly
Acetate:proprionate ratio
Spring grass can be low in fibre
What condition is associated with low bulk milk fat?
What issues are associated with using this as the only method of diagnosis?
SARA
Different groups within herd may have different milk fat- can hide low individual percentages
What is the ideal milk protein percentage?
3.4%
What causes milk protein percentage to drop?
How long does this take to correct?
Drop in long term ENERGY intake
(NOT LACK OF PROTEIN)
Needs to be slowly built up
How is dung scored
1-5
From loose and watery to stiff
When might a score 1 stool be observed
(Loose and watery)
If given high concentrates
Describe the ideal cow shit.
Slow hand clap,
Doesn’t stick to boots
What should you do when BCSing cows?
Compare condition at different phases of the cow’s life cycle
- dry cows
- freshly calved
- 2-4 weeks post calving
- late lactation
What is the transition period?
Critical 6 weeks either side of calving
What can problems in the transition period result in?
Poor feed intake (DMI) post calving
Metabolic disease - ketosis, fatty liver, fat cow, LDA
Poor production
Poor fertility (won’t cycle properly)
What should the BCS of a dry cow be throughout the dry period?
BCS 3 or slightly lower
NEEDS TO STAY THE SAME
Why shouldn’t you make cows lose weight during the dry period?
Causes excess fat mobilisation making fatty liver etc more likely
When could you reduce the weight of cows
Reduce food a bit in LATE LACTATION
How can dry cows be divided into groups?
How should they be fed differently?
Transition cows - 14 days before calving to calving - SAME DIET DIFFERENT QUANTITIES
Far off cows - dry off until 14 days before calving
What are metabolic profiles?
What do they tell us?
Planned regular blood tests that look at the number of metabolites in normal healthy cows in the herd.
How well cows are handling the diet OBJECTIVELY
When should metabolic profiles be done?
On a regular, planned basis
4 times a year at crucial times
After Spring turn out
Mid/late Summer (variable pasture quality)
After housing
Late in winter housing period
Other then the 4 planned times, when else might you do a metabolic profile?
After MAJOR DIET CHANGES
Need to wait 10 days to allow cows to adjust
What cows should be sampled for metabolic profiling ?
Normal, healthy cows
NOT sick, unhealthy cows or ‘poor doers’
Sample 6 from: Early lactation (10-20d post calving) Mid lactation (100-200d post calving) Dry cows (within 14d calving- transition)
What common errors are made when performing metabolic profiles?
Sampling cows calved more than 20d
Failure to include lactation 1 cows in each group
Sampling immediately after diet change
Including poor or problem cows
