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Flashcards in Dairy Cattle Deck (65):
1

How much on average do dairy cows produce daily?

6.5 gallons/day
(24-25L)

2

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

7months

3

What happens to bull calves?

Usually sold as day-old calves
-->veal or dairy beef

4

Life span of a dairy cow?

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

Only profitable for about 3-5 lactations

5

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

25% hereditary;
75% environment

6

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

About her 2nd birthday

7

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...)

8

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

9

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

4-10 wks...

10

Most common roughages used as basis of rations on dairies?

Hay and silage!

11

What do dairy cattle have to be supplemented?

Concentrate feeding
And grains!

12

ADF?

Acid detergent fibre

ADF= cellulose + lignin + ash

13

NDF?

Neutral detergent fibre

NDF= hemicellulose* + cellulose + lignin + ash

14

DM = ?

(Dry weight/fresh weight) x 100

15

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

60-80%

The rest ->grain/concentrates

16

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

More concentrates

17

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!!!*

18

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

19

Limiting factor in milk production?

Energy content

20

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

Protein;
Energy

21

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

Corn

22

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

QUANTITY!

23

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

They are NOT recommended

24

What should the Ca:P be for dairy cows?

1.2:1 to 2:1

25

What type of Nitrogen supplement is feed-grade urea?

A NON-protein nitrogen supplement

26

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

Limestone and dicalcium phosphate!

27

How much of milk is water?

85%

28

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

Acetate, propionate, and butyrate

29

Advantages of rumen micro organisms

Digest/ferment hemicellulose and cellulose-->VFAs

Convert inexpensive non-protein N sources --> protein

Make their own B-vits (*remember Polioencephalomalacia*)

Break down some toxins

30

Normal pH in the rumen of a dairy cow?

6.5

31

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

Corn silage!

32

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

Acidosis, low milk fat

33

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

30-35%

34

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

Grains and protein supplements

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 ___.

1;
2.

36

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

Phase 1

37

How is colostrum composition regulated?

Hormones (estrogen + progesterone)

38

How much colostrum does a dairy calf need?

2 gallons by 12 hours!

*1st gallon in the first 2 hours!

39

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

Colostrum!

40

What's the deal with artificial colostrum?

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

41

What are some signs of failure of passive transfer?

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

42

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

20%+ fat
>20% protein

43

When do we wean calves from artificial rearing?

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

44

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

400 days

45

What is the basis of heifer nutrition?

Good quality forage (hay or pasture)

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 ____.

2-8 in upper;
10-20 in lower

47

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

Middle: 30-50;
Bottom: 30-40

48

What is the BCS range for dairy cows?

1-5

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

49

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

2.0-2.5

50

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

3.0

51

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

3.5 (should be building reserves for the next lactation)

52

3 C's in Manurology?

Color
Consistency
Content

53

Cattle feeding on TMR should have what color feces?

Yellow/olive

54

What does the Penn state shaker box tell us?

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

55

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

3.0

56

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

Left

57

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

IV dextrose! Use the jugular vein!

58

How do we treat grass tetany?

Injectable Mg2+ sulphate under the skin

59

What will lactic acidosis lead to?

Laminitis

60

Which breed is notoriously susceptible to milk fever?

Jerseys

61

How do we treat milk fever?

IV calcium salts

62

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

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

63

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

Acidosis

64

Which MD is caused by calcium deficiency?

Milk fever

65

Which MD is caused by Magnesium deficiency?

Grass Tetany