- lying down for 12-14 hours

- eating for 3-4 hours

- drinking for 1 hour

- consuming 10-20 meals

- 10 hours of rumination

- producing 100-150 L of saliva, 3.5kg bicarb in it

- chew, crush and fragment forage

VFAs- acetate, butyrate, propionate

- higher levels of fibre in the ration-> higher proportion of acetate- main precursor of milk butterfat

- higher levels of concentrate-> higher propionate-> glucose for the cow

Ammonia- from effective rumen degradable protein ( ERDP)

Microbial cells- important source of protein for the cow

Gas- mainly CO2 40%, methane 40%, hydrogen 5% 

- keep rumen between 6.5-7, low ph could lead to acidosis

- long fibre in the diet

- cow comfort, health

- sufficient ERDP for rumen microbes

- sudden changes and or excessive quantities of highly fermentable energy 

DMI

Cow factors

Body weight

milk yield

stage of lactation- intake depressed by 2-3kg in freshly calved cows

stage of pregnancy- DMI decreases in late pregnancy

BCS- fat cows have reduced appetites

cow comfort

rumen health 

DMI

Food factors

Digestibility of food: intakes will increase as the digestibility of the feed increases

concentrates: offering concentrates foods with forage to cows can lead to 3 possible outcomes

Forages: rumen fill constrains intake

dietary deficiencies: diets deficient in ERDP may reduce DMI

Palatbility 

Mixed forages: increase intake

TMR diet: increase intake by 20-30% 

out of parlour feeders: increase intake

restriction of access to food

dry cows in late gestation: 12-15kg DMI/day

cows in mild lactation with peak DMI: 25-30kg DMI/day 

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want the grey gap to be small as possible 

- ensure optimum rumen health

- well mixed TMR ration

- adequate ad lib and enough trough space

- excellent cow comfort

- fresh water

- direct correlation between DMI in the day before calving and at day 21 after calving ( the higher the DMI prior to calving, the higher the DMI in early lactation) 

maintenance (70-80MJ) of ME/day for a Holstein cow, 

lactation requirements ( 5.0 MJ/kg milk at 4% butter fat, 3.4% protein)

Metabolisable protein ( MP) is composed of two parts: the microbial protein ( synthesised from ERDP and NPN) and the bypass protein DUP. 

Limit to supply Microbial crude protein from the rumen is dependent on:

- supply of ERDP

- supply of energy to the microbes ( FME) 

AIm is to optimise rumen microbial protein synthesis by ensuring optimal levels of both energy and protein at the same time in the rumen, diet synchrony

- Thus need to consider energy and protein at the same time

- note: Ruminants can also use non-protein nitrogen to synthesise microbial protein ( urea) 

fibre is essential energy source

measure the neutral detergent factor ( NDF)- the plant cell wall material, is correlated with rate of difestion and thus DMI. 

need long fibre ( 2.5-10cm long) (tickle factor) for rumen to work and ruminate- if its smaller, doesnt stimulate the rumen