Acidosis (Yr 4) Flashcards
how long does it take the rumen microbes to adapt to dietary change?
3 weeks
what is the product of microbial fermentation of carbohydrates?
volatile fatty acids (VFAs)
what is the general pathogenesis of rumen. acidosis?
excessive concentrates and insufficient fibre increases number of lactic acid producing microbes, lactic acid can’t be metabolised and hence builds up and makes the pH even more acidic
what is normal rumen pH?
6-7
what happens to digestion if rumen pH falls?
isn’t as efficient and undigested particles pass through rumen into hind gut
why do cows with acidosis get diarrhoea?
digestion efficiency falls os undigested particles pass through into Hund gut where they are fermented and produce an osmotic diarrhoea
what factors affect rumen pH?
how much acid (VFAs produced)
type of acid produced
rate of fermentation (fibre=slow)
rate of acid removal
buffering by saliva (chewing cud)
why does acidosis cause a rumenitis?
low pH destroys the papillae (this predisposes to another bought of SARA as less acid can be absorbed)
what is needed for cudding?
long fibre
what are some risk factors for SARA?
insufficient long fibre
inaccurate DM estimation
overmixing TMR
excessive concentrate feeding/slug feeding
poor dry cow management
irregular feeding
poor cow comfort
what is the cut of for SARA?
rumen pH <5.7
how do the faeces appear in SARA?
loose and soft
swishing tails (acid so sore bum)
undigested grain
long fibre present
what are the negative impacts of SARA?
reduced DMI
reduced digestibility (NEB)
immunosuppression
what effect will SARA have on production?
poor yields
milk quality - low butterfat (variable protein)
what knock on health effects does SARA cause?
displaced abomasum (VFAs cause atony)
digestive upset
ketosis (NEB)
lameness (laminitis and ulcers)
mastitis (dirty cows)
poor fertility
