Feeding and nutrition of dairy and beef heifers, fattening of beefs

Question 1

When does heifer nutrition begin?

Answer 1

When the calf is 5-6mnths at 200kg

Question 2

Dairy heiufers- type of growth (3)

Answer 2

1. Isometric growth from birth to weaning 0-3mnths (remember weaning takes places at 80-90 days)
2. Allometric growth from day 90- the BW incr at the onset of puberty is WEIGHT not age dependent - there is a critical period when fat is deposited in the udder thus decr milk prod
3. Isometric growth again until calving

Question 3

Timeline: ages, weights and events

Answer 3

• 0: 40-50kg
• 3mnths: 80-110kg WEANING
• 5-6mnths: 200kg
• 10mnths: PUBERTY
• 15mnths: 330-350kg: INSEM
• 24mnths: 520kg 1ST CALVING

Question 4

Timeline ages and types of growth

Answer 4

• 0-3mnths: Isometric
• 3-10mnths: allometric
• 10-24mnths: isometric

Question 5

Length of gestation

Answer 5

283 days

Question 6

Body condition at 2 critical times

Answer 6

At insem

• Age: 13-15mnths
• Withers: 110-120cm
• BW: min 350kg

At heifer rearing (same time as calving)

• Age: 24mnths
• Withers: 130cm
• BW: 520kg
• BCS: 3.5

Question 7

Rearing intensities- what are the 5 method of rearing

Answer 7

Rearing=feeding level

1. Very slow
2. Intense
3. Moderate
4. Physio intense
5. Combined

Question 8

Rearing intensities: very slow

Answer 8

Low BW gain

Late breeding at 18 mnths

Question 9

Rearing intensities: intense

Answer 9

800-900g daily gain

Breeding before 18mnths

Improved milk yield BUT overfattened

Question 10

Rearing intensities: moderate

Answer 10

Small frame

700g daily gain

Breeding before 18mnths

Question 11

Rearing intensities: Physio intense

Answer 11

1000-1200g daily gain

Breeding at 12-13mnths

Economical but difficult calving

Question 12

Nutrient requirements of dairy heifers (6)

Answer 12

1. NEm
2. NEg
3. CP
4. CF
5. Protein
6. Energy: Protein ratio

Question 13

Nutrient requirement of dairy heifers: NEm

Answer 13

0.3514 x BW to the power of 0.75

23-24 MJ/kg DM

Question 14

Nutrient requirement of dairy heifers: NEg

Answer 14

26.8 MJ/kg DM

Question 15

Nutrient requirement of dairy heifers: CP

Answer 15

10-11%

Is low because ovaries are sensitive to NH3

Question 16

Nutrient requirement of dairy heifers: CF

Answer 16

6%

Question 17

Nutrient requirement of dairy heifers: Protein

Answer 17

MP= microbial protein and UDP

Question 18

Nutrient requirement of dairy heifers: protein:E ratio

Answer 18

positive protein balance– incr urea– ammonia toxicosis (damaging to the ovaries)

Question 19

Feeds for dairy heifers (4)

Answer 19

1. Roughages
2. Concentrates
3. NPN supplements
4. Green forages

Question 20

Feeds for dairy heifers: Roughages

Answer 20

Should incr when there are incr VFA’s in the blood!- 13mg/L

• Hays
• Maize stalk
• Silages and pasture

Question 21

Feeds for dairy heifers: concentrates

Answer 21

Small quantites

Should incr when the VFA’s of blood are low-9mg/L

Question 22

Feeds for dairy heifers:: NPN supplement

Answer 22

When the MP balance is neg

Question 23

Feeds for dairy heifers: green forages

Answer 23

6-7mnths: 15-18kg

9-12mnths: 20-25kg

Question 24

Feeding of dairy heifers in the winter time

Answer 24

Silage: 5-10kg

Conc: 2-3kg

Hay: 1-3kg

Question 25

Beef heifers timeline: age, weight and events

Answer 25

* 0 mnths: 35-40kg * 6-7mnths: 240kg WEANING * 13-15mnths: 240-360kg MATING * 16-20mnths: 400-450kg * 24mnths: 470kg CALVING

Question 26

Beef heifers timeline: period 1 (5)

Answer 26

1. goal: fast development to weaning 2. No grazing 3. Forages: 10-15kg- hay, straw and silage 4. Conc: 1.5-2.5kg- barley:oat:corn 1:1:1 5. Vits and mins

Question 27

Beef heifers timeline: period 2 (6)

Answer 27

1. From weaning until mating 2. BW is 70% of the adult weight 3. 700-750g daily gain 4. Feed of good digestibility 5. Mate 2 wks before cows 6. Flushing

Question 28

Beef heifers timeline: Period 3 and 4 (5)

Answer 28

1. mating to calving 2. On pasture 3. Feed: corn stubble, protein and vit A 4. 400g daily gain 5. BCS of 6!! (nebraska system, about 2.5 in dairy cow system)

Question 29

Beef heifers timeline: period 4 (2)

Answer 29

1. Suckling 2. Mother is 85-90% of adult weight

Question 30

Nutrient content of feed for beef heifers- 2 things to mention

Answer 30

E for maint and milk prod Protein

Question 31

Beef heifers: E for maint and milk prod

Answer 31

NEm: 0.322 x BW to the power of 0.75 NEl: 4.184 MJ/ kg of milk

Question 32

Beef heifers: protein

Answer 32

* Factorial calculation: obtains CP% by calculating intake and loss * MP system

Question 33

Feed of beef heifers (7)

Answer 33

1. As cheap as possible 2. grazing and hays 3. (conc) 4. Sorghum 5. Green wheat 6. Whole corn plants 7. NO NPN- not enough E for the microbiome

Question 34

Fattening of beefs- the 2 types of meat

Answer 34

Veal\< 1yr and from dairy cow Beef \>1yr

Question 35

For growing bulls- what are the 2 fattening methods?

Answer 35

Traditional and intensive Here: length of fattening from weaning vs Daily BWG vs End BW vs feeds * Traditional: 16-18mnths vs 1000g vs 500-600kg vs forage * Intensive: 13-15 mnths vs 1200g vs 500-600kg vs conc

Question 36

For angus, what are the 2 fattening methods?

Answer 36

Heifer and bull Length of fattening from weaning vs daily BWG vs end BW vs feed * Heifer: 9-10mnths vs 1300g vs 550-600kg vs sorghum silage, oat and grass * Bull: 9-10mnths vs 1500g vs \>650kg vs lucerne haylage and corn gluten feed

Question 37

Methods of fattening (7)

Answer 37

1. calf fattening system 2. Baby beef 3. Young bull fattening 4. Intensive young bull fattening 5. Young dairy heifer 6. Steers 7. Improve old dairy cow

Question 38

Summer feeding of fattening beefs

Answer 38

See cows! Incr the conc

Question 39

Winter feeding of fattening beefs

Answer 39

Silage Protein supplements