dairy production lex 8

Question 1

what is low MF associated with

Answer 1

acidosis

Question 2

what is the MF : MP ratio

Answer 2

o	inverted components
	MFMP
-	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

Question 3

where does milk fat come from

Answer 3

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

Question 4

how is fibre associated with acidosis

Answer 4

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

Question 5

what is acidosis

Answer 5

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

Question 6

what is the impact of acidosis on production

Answer 6

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

Question 7

what is SURA

Answer 7

 subacute rumen acidosis

Question 8

how can acidosis be diagnosed

Answer 8

	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

Question 9

what is the starch component of grains

Answer 9

-	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

Question 10

how can acidosis be controlled

Answer 10

-	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

Question 11

how can MF % be impacted

Answer 11

-	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

Question 12

how is NEB related to production

Answer 12

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

Question 13

which breed has the highest MF production

Answer 13

o breeds
 jerseys highest MF

cross bred cows higher