Dairy nutrition--Almeida pt. 1 Flashcards
percentage of dairy farms that are family owned
97%
Average size of a dairy herd?
179 cows
T/F: Milk production is increasing but the number of dairy cows is decreasing
True
T/F: Larger dairy farms have higher costs and higher profits
False: Larger dairy farms have lower costs and higher profits
Cattle breeds (7) specialized in milk production? Which is the most common?
Ayrshire, Brown Swiss, Guernsey, Holstein-Friesland (most common), Jersey, Milking shorthorn, red and white
Dairy cow production cycle?
1) Heifers/cows inseminated (AI)
2) Gestation period: 280 days
3) At calving, milking begins
4) Lactation takes 305 days, followed by 60 days of dry period
6) Animals are inseminated again 85 days after parturition and will calve at the end of the dry period
Female calves are kept on artificial milk, weaned at _____ days, and reared for another ____ days.
35-45; 420
T/F: Dairy farms only have births once a year and calves are all at the same stage in the birthing cycle
False: dairy farms have births year-round and cows are in different stages of the cycle
Dairy cows have a lifespan of how many years?
20
T/F: Dairy cows are only profitable for 3-5 lactations, because of lameness, mastitis, and infertility
True
When are dairy cows normally culled?
After 3-5 lactations
When is peak lactation?
Weeks 4-10, followed by decrease until drying off
Fat and protein content decreases until week ___ and then stabilizes
10
DMI increases with _____.
lactation
Body weight and BCS ____ during peak lactation, ____ afterwards (less milk but gestation)
decreases; increases
What do phases 1, 2, 3, and 4 represent during weeks of lactation?
Peak milk, peak DMI, restoration period, dry period (respectively)
Feed costs are about ___ of the total cost of producing milk
40-50%
What are balanced rations and when do milk production cows need to be fed them?
in intensive/commercial milk production cows have to be fed balanced rations = adequate to their productive state and milk production
milk production is always limited by the genetic and environmental components (%):
25% hereditary, 75% environment
What are nutrients used for in dairy cows?
1) Growth in the immature animal
2) Pregnancy (esp. last 3 mo)
3) Fattening/regaining normal weight lost during lactation
4) Maintenance
5) Lactation/milk production
A cow in lactation and fed correctly will use what nutrient proportions for feed and milk production?
1/2 feed for maintenance and 1/2 feed for milk production
A cow in lactation and inadequately fed will:
draw body reserves for maintenance needs and milk production will drop
T/F: Roughages are the cheapest and affordable source of nutrients
True (I know the sentence doesn’t make sense, that’s how it’s written in his notes) \_(--)__/
Because milk production is very demanding, dairy cattle have to be supplemented:
Concentrate feeding and grains
In cattle, 60-80% of the DM should come from _____ and the rest from ______.
roughages; concentrates and/or grain
Feeding value of hay depends on:
Kind of hay/botanical composition (graminae/legume), stage of maturity when cut, harvesting method
When is it ideal to produce hay?
mid Spring
Tell me everything about green chop (4 things)
1) forage harvested and chopped daily
2) fed in bunks
3) moisture content and nutritional value change considerably throughout year
4) as crop matures, cows will eat less of the green chop–less energy intake
Do silages have a higher or lower moisture content than dry roughages?
Higher
Corn silage–whatchu know bout it
1) One of the most popular roughages for dairy cattle
2) Made when kernels have reached the ‘dent’ stage
3) easily stored/handled
4) requires less labor
5) contains 50% grain in a DM basis
6) 8% DM is protein
7) low on minerals
6+7 = supplementation needed
Strawwwwww
1) non-grain part of crops (wheat/oats)
2) low in energy, protein, minerals, vitamins
3) little nutrient value (it kinda sucks)
4) mainly adds fiber = nicer pooping
5) when used, cows must be supplemented with concentrates
6) cheap alternative for feeding dry cows and older heifers (sucks for them)
Pasture
1) requires good management
2) reduces labor at feeding
3) reduces manure handling
4) ideal for dry cows/old heifers
When pasture is fed to lactating cows, it may cause what? (7 things)
drop in milk production drop in milk fat bloating flavors in milk (ew) reduced grain intake watery feces difficulty in getting cows into milking parlor (lol)
T/F: lactating cows get plenty of dry matter if pasture is the major source of roughage
FALSE–lactating cows rarely get enough DM if pasture is the major source of roughage
management practices for pastures to reduce problems
limit grazing time (1-2 hr/d)
feed dry forage before allowing cows on happy pasture
bring cows to barn several hours before feeding
feed silage/hay at this time
T/F: Pastures are to be used as supplementary roughages
true
T/F: Grains are included in dairy rations primarily for protein content
FALSE–primarily for ENERGY content
What is a limiting factor in milk production (if low)?
Energy content
grains contain ____% TDN
70-80
Grains that are ground too fine =
lower digestibility and % milk fat
finely ground grain may also lead to acidosis! :(
CORN
most commonly used grain in dairy rations
high energy
palatable
if grown on farm = cheaper supplement
corn and corn cob meal = 90% TDN
cows tend to feed better when corn is used in the ration
T/F: oats are a shitty feed for dairy cows
FALSE–oats are excellent for dairy cows, and also humans (FYI, no one really cares about humans)
Compared to corn, how do oats rack up in:
Energy content
Digestibility
Protein content
What do they add to the grain mix?
lower energy content than corn
lower digestibility than corn
higher protein content than corn
add fiber to the grain mix!
Oats should not replace more than ___ of corn in the ration
half
Whatchu know about barley
1) same overall energy value for dairy cattle as corn
2) higher in protein than corn
3) not more than 1/2 of the grain ration
Whatchu know ‘bout wheat?
high in energy and protein
diary cows like wheat
high price–not used in dairy rations
not more than 1/2 of the grain ration