Dairy Cattle

Question 1

How much on average do dairy cows produce daily?

Answer 1

6.5 gallons/day

24-25L

Question 2

How far into pregnancy do we “dry off” cows (after their first pregnancy)?

Answer 2

7months

Question 3

What happens to bull calves?

Answer 3

Usually sold as day-old calves

–>veal or dairy beef

Question 4

Life span of a dairy cow?

Answer 4

20 years.. but usually only live to about 8.

Only profitable for about 3-5 lactations

Question 5

Milk production is limited ____% by heredity and ____% by environment.

Answer 5

25% hereditary;

75% environment

Question 6

When do we want a heifer to have her first calf?

Answer 6

About her 2nd birthday

Question 7

A cow in lactation and fed CORRECTLY will use what portion of feed for maintenance and what portion for milk production?

Answer 7

Half and half! (No pun intended…)

Question 8

In a dairy cow and in the first 5 weeks of lactation, what happens to the fat content of milk?

Answer 8

It’s going to decrease, but the volume produced will increase

Question 9

In which part of the lactation curve do cows produce the highest amount of milk per day?

Answer 9

4-10 wks…

Question 10

Most common roughages used as basis of rations on dairies?

Answer 10

Hay and silage!

Question 11

What do dairy cattle have to be supplemented?

Answer 11

Concentrate feeding

And grains!

Question 12

ADF?

Answer 12

Acid detergent fibre

ADF= cellulose + lignin + ash

Question 13

NDF?

Answer 13

Neutral detergent fibre

NDF= hemicellulose* + cellulose + lignin + ash

Question 14

DM = ?

Answer 14

(Dry weight/fresh weight) x 100

Question 15

In dairy cattle, what percentage of DM should come from roughages?

Answer 15

60-80%

The rest ->grain/concentrates

Question 16

When poor quality hay is used, how do we compensate?

Answer 16

More concentrates

Question 17

As a green chop crop matures, how do cows’ eating behavior change?

Answer 17

They eat less of the green chop!! So they’re taking in LESS energy!!!*

Question 18

What cows would we feed straw to?

Answer 18

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

Question 19

Limiting factor in milk production?

Answer 19

Energy content

Question 20

Oats have higher _____ content, but corn has higher _____ content.

Answer 20

Protein;

Energy

Question 21

Barley is higher in protein, but has the same overall energy value for dairy cattle, than what other grain?

Answer 21

Corn

Question 22

Regarding protein supplements for dairy cows, what is more important?

Answer 22

QUANTITY!

Question 23

What do fish meal, meat meal, and blood meal have in common as protein supplements in dairy cows?

Answer 23

They are NOT recommended

Question 24

What should the Ca:P be for dairy cows?

Answer 24

1.2:1 to 2:1

Question 25

What type of Nitrogen supplement is feed-grade urea?

Answer 25

A NON-protein nitrogen supplement

Question 26

Adequate calcium sources for dairy cows mentioned in class are...

Answer 26

Limestone and dicalcium phosphate!

Question 27

How much of milk is water?

Answer 27

85%

Question 28

What VFAs are desirable to be absorbed and used as energy sources?

Answer 28

Acetate, propionate, and butyrate

Question 29

Advantages of rumen micro organisms

Answer 29

Digest/ferment hemicellulose and cellulose-->VFAs Convert inexpensive non-protein N sources --> protein Make their own B-vits (*remember Polioencephalomalacia*) Break down some toxins

Question 30

Normal pH in the rumen of a dairy cow?

Answer 30

6.5

Question 31

Most adequate (high quality) forage for high-yield lactating dairy cows?

Answer 31

Corn silage!

Question 32

What will feeding high level of soluble carbohydrates to dairy cows lead to?

Answer 32

Acidosis, low milk fat

Question 33

What level of soluble carbohydrates is recommended to feeding lactating dairy cows?

Answer 33

30-35%

Question 34

Most expensive part of the ration in feeding lactating dairy cows?

Answer 34

Grains and protein supplements

Question 35

Dairy cow feeding can be divided into 4 different phases according to production status. Peak production occurs during phase ___, while highest DM matter intake occurs during phase ___.

Answer 35

1; | 2.

Question 36

Which phase in the lactating dairy cattle would have the highest needs in nutrients?

Answer 36

Phase 1

Question 37

How is colostrum composition regulated?

Answer 37

Hormones (estrogen + progesterone)

Question 38

How much colostrum does a dairy calf need?

Answer 38

2 gallons by 12 hours! *1st gallon in the first 2 hours!

Question 39

What is absolutely essential to avoid failure of passive transfer?!

Answer 39

Colostrum!

Question 40

What's the deal with artificial colostrum?

Answer 40

Nutritionally "correct" but it doesn't include Ig's

Question 41

What are some signs of failure of passive transfer?

Answer 41

Scours, Discharge (eyes and nose), Polyarthritis (joints/stance), Depression

Question 42

What are the essential characteristics of milk replacer (fat and protein)?

Answer 42

20%+ fat | >20% protein

Question 43

When do we wean calves from artificial rearing?

Answer 43

6-8 weeks | *introduce palatable pellets gradually from week 1*

Question 44

How long do heifers take to reach maturity and be serviced?

Answer 44

400 days

Question 45

What is the basis of heifer nutrition?

Answer 45

Good quality forage (hay or pasture)

Question 46

When using the Penn State Shaker box, the TMR (% of total weight) in the upper sieve is_____, whereas the TMR in the lower sieve is ____.

Answer 46

2-8 in upper; | 10-20 in lower

Question 47

When using the Penn State Shaker box, the TMR (% of total weight) in the Middle Sieve is _____, whereas the bottom pan is ____.

Answer 47

Middle: 30-50; Bottom: 30-40

Question 48

What is the BCS range for dairy cows?

Answer 48

1-5 *beef cattle is on a scale of 1-9*

Question 49

What should the BCS of a dairy cow be in early lactation (end of phase 1)?

Answer 49

2.0-2.5

Question 50

What should the BCS be for a dairy cow in mid lactation?

Answer 50

3.0

Question 51

At the end of lactation, what should a dairy cow's BCS be?

Answer 51

3.5 (should be building reserves for the next lactation)

Question 52

3 C's in Manurology?

Answer 52

Color Consistency Content

Question 53

Cattle feeding on TMR should have what color feces?

Answer 53

Yellow/olive

Question 54

What does the Penn state shaker box tell us?

Answer 54

Proportions of how the TMR "shakes out" /related to fiber content and particle size

Question 55

At mid-lactation, what should a dairy cow's BCS be?

Answer 55

3.0

Question 56

Which side is the abomasum more likely to "float up" ?

Answer 56

Left

Question 57

How do we treat ketosis when cows are in this negative energy balance?

Answer 57

IV dextrose! Use the jugular vein!

Question 58

How do we treat grass tetany?

Answer 58

Injectable Mg2+ sulphate under the skin

Question 59

What will lactic acidosis lead to?

Answer 59

Laminitis

Question 60

Which breed is notoriously susceptible to milk fever?

Answer 60

Jerseys

Question 61

How do we treat milk fever?

Answer 61

IV calcium salts

Question 62

In a drought, what metabolic disorder would we worry about most?

Answer 62

Nitrate poisoning | *remember: methemoglobin/brown blood because nitrite cannot be converted to ammonia- reacts with hemoglobin*

Question 63

Which MD is related to low fiber and HIGH grain intake?

Answer 63

Acidosis

Question 64

Which MD is caused by calcium deficiency?

Answer 64

Milk fever

Question 65

Which MD is caused by Magnesium deficiency?

Answer 65

Grass Tetany