Exam 3: Lecture 19 - Dairy nutrition 3

Question 1

are what the limiting AAs in most feeds for dairy cows

Answer 1

lysine and methionine

Question 2

how can we provide extra lysine and methionine

Answer 2

soybean meal, dried brewers grain, blood or fish meal

Question 3

T/F: fish and blood meal are palatable at high inclusion rates

Answer 3

FALSE! Not palatable

Question 4

T/F: fish meal can reduce milk fat at high inclusion rates

Answer 4

true!

Question 5

high ___ in rations can interfere with fiber digestion

Answer 5

high fat

Question 6

molasses will be _______ fermented in the rumen

Answer 6

rapidly

Question 7

what % of protein are most dairy rations

Answer 7

16-18% high quality protein

Question 8

T/F: protein % should be towards the higher end in early lactation

Answer 8

true!

Question 9

what are the consequences of overfeeding protein

Answer 9

infertility and lameness

Question 10

how can overfeeding protein lead to infertility

Answer 10

excess ammonia/urea can delay maturation of oocyte or any developing embryo

Question 11

how can overfeeding protein lead to lameness

Answer 11

excess protein can lead to fermentation products via bacteria that impact foot health

Question 12

why is the balance between RDP/NPN and energy levels in the rumen important

Answer 12

microbes need energy from diet to use nitrogen from the diet to avoid ammonia acculumation

Question 13

how do we get excess ammonia production

Answer 13

excess RDP, soluble protein, or NPN

Question 14

what ingredient may be used to supplement lysine and methionine but is not very palatable?

A. soybean meal
B. corn gluten meal
C. fish meal
D. meat meal

Answer 14

C. fish meal

Question 15

what are the major macro-minerals required in the diet

Answer 15

Ca, P, Mg, K, Cl, S

Question 16

what macromineral is high in forage

Answer 16

potassium

Question 17

what are the ranges we should supplement Ca (above the NRC requirements)

Answer 17

range from 0.62-0.67% in diet for 68-kg cow

Question 18

if we add fats in the ration, what macrominerals should we increase

Answer 18

Ca and Mg by 20-25%

Question 19

T/F: Ca:P ratios are not as important as meeting requirements of Ca and P

Answer 19

true!

Question 20

__1___ deficiency is more common than _____2____ deficiency (macrominerals)

Answer 20

1. P
2. Ca

Question 21

T/F: P deficient soils more common and P levels in plants drop faster than Ca as plants mature

Answer 21

true!

Question 22

how much phosphorus should be included in dairy rations

Answer 22

about 0.35%

Question 23

how many lbs of water/lbs DMI do dairy cows need

Answer 23

2-4 lbs water/lbs DMI

Question 24

what do we increase the water intake to for milk

Answer 24

additional 3-5 lbs water/lb

Question 25

what are the factors affecting water intake

Answer 25

bw, milk yield, DM consumption, temp, humidity, water temp, quality and availability of water, moisture in feed

Question 26

what water temp do most cows prefer

Answer 26

63-82 degrees

Question 27

what are the dimensions of water troughs

Answer 27

2 inches/cow, 3 inches deep, height of 24-32 inches

Question 28

1 trough/watering device per how many cows

Answer 28

15-20 cows

Question 29

how do we assess water quality

Answer 29

odor, taste, pH, dissolved solids, hardness, toxic compounds, nitrates, sulfates, iron, bacteria, algae

Question 30

what happens with blue-green algae poisoning

Answer 30

ataxia, bloody diarrhea, convulsions, sudden death

Question 31

what mineral is affected by the level K in soil and lack can cause grass tetany? A. calcium B. magnesium C. phosphorus D. sodium

Answer 31

B. magnesiusm

Question 32

why do we have to maintain DMI in the close up dry cows

Answer 32

they are close to calving so bw drops so need to maintain adequate energy reserves for 6-8 weeks after calving

Question 33

what is the BCS we want to maintain in dry cows

Answer 33

BCS of 3-4

Question 34

when do we typically increase energy before calving

Answer 34

3 weeks prior to calving

Question 35

what are the 2 approaches for feeding dry cows

Answer 35

1. adapt rumen to grain diet 2. level/consistent NDF feeding

Question 36

how do we adapt rumen to grain diet

Answer 36

1. adapt rumen prior to calving 2. grain is ged to close-up cows 3. since there is a fall in DMI before calving, this increased energy density makes up for the drop in intake

Question 37

how do we do level/consistent NDF feeding

Answer 37

1. need to maintain rumens ability to digest fiber 2. feed very low energy, high fiber ration through calving and then add grain 3. efficient fiber utilization buffers rumen pH and avoids acidosis when grain is added to the lactating diet