Dairy Cattle Flashcards
How much on average do dairy cows produce daily?
6.5 gallons/day
24-25L
How far into pregnancy do we “dry off” cows (after their first pregnancy)?
7months
What happens to bull calves?
Usually sold as day-old calves
–>veal or dairy beef
Life span of a dairy cow?
20 years.. but usually only live to about 8.
Only profitable for about 3-5 lactations
Milk production is limited ____% by heredity and ____% by environment.
25% hereditary;
75% environment
When do we want a heifer to have her first calf?
About her 2nd birthday
A cow in lactation and fed CORRECTLY will use what portion of feed for maintenance and what portion for milk production?
Half and half! (No pun intended…)
In a dairy cow and in the first 5 weeks of lactation, what happens to the fat content of milk?
It’s going to decrease, but the volume produced will increase
In which part of the lactation curve do cows produce the highest amount of milk per day?
4-10 wks…
Most common roughages used as basis of rations on dairies?
Hay and silage!
What do dairy cattle have to be supplemented?
Concentrate feeding
And grains!
ADF?
Acid detergent fibre
ADF= cellulose + lignin + ash
NDF?
Neutral detergent fibre
NDF= hemicellulose* + cellulose + lignin + ash
DM = ?
(Dry weight/fresh weight) x 100
In dairy cattle, what percentage of DM should come from roughages?
60-80%
The rest ->grain/concentrates
When poor quality hay is used, how do we compensate?
More concentrates
As a green chop crop matures, how do cows’ eating behavior change?
They eat less of the green chop!! So they’re taking in LESS energy!!!*
What cows would we feed straw to?
Dry cows or older heifers ; it’s a cheap alternative and just adds fiber, keeping them from getting fat because it’s low in nutrient contents
Limiting factor in milk production?
Energy content
Oats have higher _____ content, but corn has higher _____ content.
Protein;
Energy
Barley is higher in protein, but has the same overall energy value for dairy cattle, than what other grain?
Corn
Regarding protein supplements for dairy cows, what is more important?
QUANTITY!
What do fish meal, meat meal, and blood meal have in common as protein supplements in dairy cows?
They are NOT recommended
What should the Ca:P be for dairy cows?
1.2:1 to 2:1
What type of Nitrogen supplement is feed-grade urea?
A NON-protein nitrogen supplement
Adequate calcium sources for dairy cows mentioned in class are…
Limestone and dicalcium phosphate!