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Flashcards in dairy production lex 8 Deck (13):

what is low MF associated with



what is the MF : MP ratio

o inverted components
- MP : MF ration
o ideally 0.8-0.9
o >0.95 possible SARA
o <0.75 suggests low energy
 possible ketosis in herd
o MP doesn’t change, MF does
 high raio = low MF


where does milk fat come from

o from
 body tissue
• ketones
 diet
• VFA from fibre breakdown
 intestinal absorption of FA
o more volatile
 can control


how is fibre associated with acidosis

o fibre and starch
 hard to digest
 scratches and stretches rumen wall to stim contractions- fermentation
 produces bicarb
• reduces acidosis
• imbalance between fibre and fermentable carbs
 increased fibre= decreased digestibility


what is acidosis

o rumen pH of < 6
 increased fat% = increased rumen pH
 increased fibre= increased pH
o reduces microbial protein yield and fibre digestion
o when low energy to high energy diets
 Risk of acidosis increases
 need transition diet


what is the impact of acidosis on production

Acidosis decreases dry matter intake
 decreases MY

 causes
• Lameness, ruminal parakeratosis, liver abscessation and death
• Low milk production, low milk fat and low milk protein


what is SURA

 subacute rumen acidosis


how can acidosis be diagnosed

 fecal changes
• bubbles (still fermenting) and runny
• undigested grains
 hoof changes
• subsolar hemorrhage, poverty lines, laminitis
 Rumen pH
 Diet analysis
 acidosis= poor fibre digestion = decreased MF


what is the starch component of grains

- grains
o starch and fibre content
 low
• e.g. brewers yiest
• fast digestion
 medium
• e.g. oats
 high
• wheat
• high risk of acidosis in high quantities
• rumen pH drops


how can acidosis be controlled

- controlling acidosis
o traditionally
 bicarb buffers
• not very affective
 low starch concentrates
 maintain fibre
• has to be eaten and digestible
 balance ration
o new
 manipulation of rumen pH
• ionophores
o rumen modifier
o ship away from burp gases
 increase propionate and decrease acetate
o e.g. monensin, virginiamycin
 decreases lactic acid production
• increase MV


how can MF % be impacted

- MF factors
o Feeding Frequency
o Ionophore use
o Body Condition
 thinner cows higher risk
o Ration Processing
o Fat Feeding
o Adaptation to the ration
 rumen microbes with transition diet
o Temperature and humidity
 higher temp = less grazing but still eating concentrate= increased risk of acidosis
o Age
o Water
o Reduced pasture palatability and true availability
 less grazing but still eating concentrate= increased risk of acidosis

o Low dietary protein


how is NEB related to production

o peak lacataiton
 4-6 weeks
o peak appetite
 6-8 weeks
o increased risk of acidosis


which breed has the highest MF production

o breeds
 jerseys highest MF

cross bred cows higher