Flashcards in Protein and Energy Imblanace Ruminants Deck (25)
What chop length should fibre in the diet be?
2-4cm - optimum scratch factor to stimulate rumenal movements
How long should a cow spend lying down per day?
What is the drop test?
Drop to knees on cubicle - see how comfortable it is
What is the CCI?
Cow Comfrot Index = No. cows lying down ruminating 1hr prior to feeding
- should be at least 60%, 85% best
WHy may the feed a cow intake be different than the prescribed diet?
Palatability of diet
Distribution between cows - space
How much head space should each cow have at a trough?
What trough factos may influence food intake?
Physical condition - sharp edgers
Clean - old food should not be left under fresh!
How does cow behaviour affect drinking troughs?
- Should be enough space for group of cows to drink together - social animals
- check floor surrounding trough - can they access it?
What is TDS?
Total dissolved solids ?? CHECL
Should DMI be estimated or measured?
> Measured - estimates often innacurate
> DMI for all foods (inc. oils etc.) should be incorporated
> Squeeze silage - if water comes out >20% water content
How may required DMI be calculated in lactating cows?
DMI = 2.5% BW + 10% milk yield
Why may analysis of feed components be inaccurate?
- analysis inaccurate
- sample not representatice (levels of silage clamp, no. of g rass cuts)
- when sample taken
What is true TMR? How do majority of systems differ?
Everything fed in total mixed ration
- majority of dairy herds fed some concentrates in the parlour too
What may moulds in the silage produce?
Is self feed silage a good ide?
No - if silage sufficiently tightly packed to protect from spoilage then cows will not be able to eat it.
- often usd in conjunction with an electric fence -> stress -> v food intake
What problems may grazing grass present?
- overestimate energy value of grazed grass esp. in long dry summer (stemmy fibrous grasses)
- bloat from clover rich pastures
- Mg deficiency (grass staggers)
- over eating lush pasture or grains -> bloat/acidosis
How can overeating at pasture be prevented?
Buffer feed - silage, hay or TMR to supplement grass before turning out
What level should milk fat be at? What is this proportional to and may cause this to drop?
- proportional to fibre level in diet
- if concentrate:forage ratio >60:40 will drop significantly (as acetate levels drop and propionate levels ^)
- spring grass low in fibre -> v milk fat
- Low bulk tank milk fat: SARA (but differnet groups within herd likely to differ significantly and counteract this affect/hide low milk fat cows)
What level should milk protein be at? When may this drop and is it easy to correct?
- drops after inadequate energy intake
- very difficult to correct quicjly
How is dung scored? How is optimum dung recognisable?
1 - 5, 1 loose and watery, 5 stiff and dry
3 optuimum - sounds like slow hand clap
How can BCS be used to assess feeding?
Compare cows in different stages of life cycle
- freshly calved (early lac)
- 2.4 weeks post calve (mid lac)
- late lac
What is the optimum BCS for a cow to calve at?
What is the most important stage of lactation to look at? Why? What BCS should they start/finish at?
- critical 6 weeks either side of calving
- problems here ->
> poor DMI post calve
> metabolic disease
> poor milk production
> poor fert
- SHOULD NOT LOSE WEIGHT DURING THE DRY PERIOD, will lead to fatty liver and metabolic problems
- Should be dried off at same BCS they will calve at (~3)
How should dry cows be divided?
1. Dry off - 14d pre calving [far off or early dry group]
2. 14d pre calving -> calving [transition or close up cows] In this group diet similar to that they will receive post calving to allow gradual rumen changes