Dairy Nutrition Flashcards
what does a higher DMI allow
Higher performance
Lower nutrient density rations
- Improved rumen health
- Lower cost per unit
Increased use of forage
Significant cost savings
what % accounts for diet and animal factors for change in DMI and what % accounts for management factors
30% is diet and animal factors
70% is management factors
how many litres do cows drink a day
Cows drink approx 14x a day:
5-7L each time
Prefer to drink together, alternating with feeding
what % reduction in DMI can a 40% reduction in water intake lead
a 40% reduction in water intake can lead to a 16-24% decline in DMI
what are the major anti-quality water factors
Total dissolved solids (the sum of inorganic matter dissolved in the water, also known as the salinity of water) where levels >7,000ppm
Sulphur, sulphates >2,000ppm
Nitrates >130ppm
Iron >0.3ppm
when do cows drink most of their water for the day
50-60% post milking
how much water trough space should be allowed per cow
0.7m exiting the parlour
what are the areas of bunk management that can be reviewed
Animal grouping
Physical facilities
The environment
Mixing of feed
Physical nature of the feed
Timing and frequency of feeding
Management of the feed face
Feed quality
Feed palatability
Feed stability
describe cows feeding behaviour
Cows are habitual, social, curious and hierarchical
They tend to feed and drink as a group
Social facilitation
Cows show peak intakes post milking and following the allocation of fresh feed
how should heifers be managed in regards to the feed bunk
The argument for separate grouping of heifers stems from two factors:
- They are generally the smallest and most subordinate animals in a herd —> most susceptible to stress of group changes and bullying
- The differences in feed behaviour and intake between older and younger cows
*
when is the right time to mix groups of cows
Ideally in the second lactation
Post-calving heifer group
- Once in calf
- Few weeks
Dry period
- 6-8 weeks pre-calving
how can cow aggression to eachother be reduced
Housing cows in adjacent lots or groups, permitting some limited close proximity and physical contact
By moving larger number of cows at one time rather than by moving only a few?
By providing a regular routine for moving cows and adequate feeding space for the size of the group
By making the move following the afternoon/evening milking
what are influences of DMI
Complete diet (ex. TIMR) (+20-30%)
Out-of-parlour feeders (+5-10%)
Mixed forages (+5%)
Self feed silage (-5-10%)
Electric wire at feed face (-10-20%)
Poorly preserved silage (-10-30%)
what is the difference in DMI for poast and rail vs headlock design
cows feed for longer and spent less time inactive standing at the feed area with the post and rail design but lower hierarchial cows were displaced more often than with the headlock design
how should bunks be built to aid cow feed access
Feed 15-40cm from standing height
- <15cm: less reach and more weight on front feet
- >40cm commands more bunk space; tossing
what are the surfaces of the bunk that are preferable
Cows prefer smoother surfaces
Light coloured or well lit feed areas better
what types of surfaces can be used for the bunk
Tiles
Skim concrete
Pipe
Parlour liner
what are unpalatable components of a ration
Calcium soap fats in excess not good
Ash content (limestone, minerals, bicarb etc)
Unpalatable ingredients (urea, rape)
Dry, ‘burnt’ silage
what should the dry cow ration be like
they are not rubbish disposal units
2x feeding
how often should bunks be cleaned
every day
cows have refined sense of smell
don’t create your own TMR inoculant
what is the major ingredient that drives DMI
good quality forage
major determinant of ration palatability
The only way to achieve high yields, cost effectively with good animal health is to feed high quality forage
why is forage important in the diet
Typically >50% (by DM) of dairy rations
Quality largest determinant of cow performance
how should the silage face be managed
maintain a clean face
Bucket? Shear grab? Auger?
what is important in the environment to promote DMI
Good ventilation is essential for reducing humidity, noxious gases, pathogens and drafts which increase comfort and lower stress
what does the effect of temp have on DMI
increase heat stress reduces DMI
what can go wrong in feeding
poor maintenance of feeds
inaccurate quantities
poor mix
poor distribution
what needs to be considered when measuring quantaties in the TMR
Cow numbers change
DM variation for by-products and forages can be marked and therefore frequently very different from that which has been estimated for rationing
Weigh scales can be wrong
Difficulties in cutting silage blocks to require weights or dropping straights from a loader bucket into the mixer wagon
what are factors that contribute to poor mix
Ingredient characteristics
Improper sequence of addition
Incorrect mix time
Mixer overload
Inconsistent TMRs
Worn or broken mixing components
Ingredient build-up
what can lead to multiple ‘rations’ being consumed by cows
sorting
what factors may affect DMI intake on farm
Social grouping — heifers with cows
Mixing of animals
Availability of water
Water quality
Environment — light and air
Feed space
Water space
Feed barrier design
Eating surface
Unpalatable ration ingredients
Feeding frequency
Heat stress
Time budget
Inconsistent feeding
Other diseases — lameness etc
