Dairy Cattle Nutrition Flashcards
Describe the production cycle from the reproductive perspective
- gestation period is 280 days
- cows inseminated again 85 days after parturition
- cows will calve at the end of the dry period
Describe the production cycle from the milk perspective
- at calving, milking begins
- lactation is 305 days, followed by 60 days of dry period before calving
Describe the production cycle from the calf perspective
- female cows kept on artificial milk
- weaned at 35-45 days
- reared for 420 days
When are the cows usually culled?
after 3-4 lactations
When is peak lactation?
4-10 weeks after calving
Describe what happens to the following during lactation:
- fat and protein content
- dry matter intake
- body weight and BCS
- fat and protein content decreases until week 10, then stabilizes
- dry matter intake increases with lactation
- body weight and BCS decreases during peak lactation, and increases afterwards
What is straw?
Describe its nutritional value
- the non-grain part of crops such as wheat or oats
- low in energy, protein, minerals, vitamins
- little nutritional value, used to add fiber to diet
When does Phase 1 of feeding occur?
What is happening?
- occurs during the first 70 days of lactation
- highest milk production
When does Phase 2 of feeding occur?
What is happening?
- occurs 70-140 days after calving
- decreasing milk production
- highest DM intake
- trying to maintain milk production as long as possible
When does Phase 3 of feeding occur?
What is happening?
- occurs 140-305 days after calving
- continual decrease in milk production
When does Phase 4 of feeding occur?
What is happening?
- the dry period, 40-60 days
- beginning of a new lactation period
What is the Traditional method of feeding cows?
- roughages and concentrates are fed ad libitum, but separately
- or concentrates are fed individually according to needs
Describe the Traditional method of feeding
- roughages and concentrates feed ad libitum, but separately
- roughages fed in bunks to whole herd, or in mangers in barn
- concentrate fed individually in mangers or milking parlor
Describe the Challenge or Lead Feeding method of feeding
- feeding higher levels of concentrate to challenge the cow to reach maximum potential milk production
- provides more concentrates in early lactation, and less in late lactation
- at max milk production, concentrate feeding should be constant
What is TMR?
- total mixed ration
- ingredients blended together and fed free choice
- cows divided into groups
What are the essential characteristics of milk replacer?
10-20% fat
> 20% protein
< .15% fiber
What should the BCS be after calving?
Early lactation?
Mid lactation?
End of lactation?
after calving: 3.0-3.5
early: 2.0-2.5
mid: 3.0
end: 3.5
Describe Ketosis
- results from impaired carbohydrate and VFA metabolism
- high blood ketone level and low blood glucose level
- occurs when energy needs are above energy intake
What are possible causes of ketosis?
- glucose drained through milk production
- inadequate energy intake at calving
What is the treatment for ketosis?
- IV dextrose to increased blood sugar
- drenching: oral propylene glycol
What is grass tetany?
- inadequate blood magnesium levels, potentially fatal
- common in lactating animals grazing on lush pastures
What are the symptoms of grass tetany?
- stiff movement
- loss of appetite
- frequent urination
- convulsions
What are the symptoms of abomasal displacement?
- discomfort and pain
- reduced intake of feed and water
- reduced milk yield
- reduced volume of feces
- “ping” sound over right ribs
What are the symptoms of ketosis?
- reduced feed intake and milk yield
- cows appear starved, depressed, and dull
- rumen is inactive
- acteone odor
- weight loss
- unexplained increase in milk fat content
Describe Lactic Acidosis
- results from abnormal fermentation in the rumen
- clinical: rumen pH below 5
- subclinical: pH 5-5.5 (common in dairy)
- usually due to rations too high in grain and lacking effective fiber
What are the symptoms of lactic acidosis?
- loss of appetite
- high pulse rate, low skin temp
- diarrhea, dehydration
- drop in urine pH and rumen pH
- laminitis
Describe Milk Fever
- parturient paresis
- occurs in mature cows within 48 hrs after calving
- calcium intake is not sufficient for high milk production, and starts depleting bone reserves
- low blood calcium, lack of muscle strength and contractility
What are the symptoms of milk fever?
- hind limb stiffness, partial paralysis
- poor appetite, reduced rumen movement
- slow respiration
- dry muzzle, low body temp, cold ears
How do you treat milk fever?
calcium salts IV
Describe nitrate poisoning
- occurs when excess nitrates in feed or water are converted to nitrites by the microbes in the rumen
- nitrite will be absorbed, interacting with hemoglobin and reducing oxygen carrying capacity
What are the symptoms of nitrate poisoning?
- accelerated respiration and pulse
- diarrhea, frequent urination
- decreased appetite
- weakness, trembling, staggering
- frothing at the mouth
- dark blood
What is bloat/ruminal tympany
excessive accumulation of gases in the rumen
Upper Sieve of Shaker Box
- pore size
- TMR percentage
- 0.75 in. pores
- 2-8% TMR
Middle Sieve of Shaker Box
- pore size
- TMR percentage
- 0.31 in. pores
- 30-50% TMR
Lower Sieve of Shaker Box
- pore size
- TMR percentage
- 0.16 in. pores
- 10-20% TMR
Bottom pan of Shaker Box
- pore size
- TMR percentage
- no pores (particles < 0.16 in.)
- 30-40% TMR
