Nutrition

Question 1

Rumen principles

Answer 1

Food -> Rumen bugs
> VFA, methane, CO2
> VFA absorbed

Question 2

Dry period aim

Answer 2

Enable cows to transition from pregnancy to lactation with minimal issues whilst achieving their milk yield potential

Question 3

Dry cow DMI

Answer 3

Reduces as dry period progresses
14kg start (2.5%BW) -> 10kg
Day of calving v. little eaten

Question 4

Periparturient demands

Answer 4

Start of lactation - lots of energy
1° - Glucose (precursor lactose)
VFA (propionic acid) contributes to gluconeogenesis
Rely on reserves

Question 5

Mobilisation of fat

Answer 5

Adipose (NEB)
NEFA released (liver processing)
Converts to triglycerides in excess
- stored in liver (problematic)

Question 6

Obesity in dairy herd

Answer 6

Fat mobilisation syndrome (early Lac)
Less DMI when dry
Less DMI early lactation
Fatty liver - high NEFA, poor insulin, inflammation

Question 7

Dry cow overfeeding

Answer 7

Little CS difference
Gain in visceral fat
Less immune function

Question 8

Traditional diet

Answer 8

Far off - low energy, high fibre
100 MJ/ day
M/D ~ 8 MJ / day
Close - transition diet (less DMI more energy)
110 MJ/ day
M/D ~ 10 MJ ME/kg DM

Question 9

Diet as fed

Answer 9

Fibre quality (prickly)
Length (2.5-10cm)
Concentrate:fodder Max60:40
Food in front of cows 24hr
(5 remains)

Question 10

Monitoring observations

Answer 10

BCS changes
DMI (how much eating)
Cudding
Rumen fill
Faeces
Cleanliness
Lying time

Question 11

Condition scoring

Answer 11

Key periods-
Dry period (3)
Early lactation (2.5)
DP -> EL -0.5 BCS

Question 12

Monitoring nutritional status

Answer 12

BHB
NEFA
Glucose
Fat
Protein
Urea
Ca

Question 13

Monitoring tests

Answer 13

Beta hydroxybutyrate
- ketone, NEB, fresh cows
NEFA
- evidence of fat mobilisation
- dry cows <2wks of calving
Urea
- balance of protein and FME

Question 14

Metabolic profiles

Answer 14

2 wks post diet change
- EL, MidL, DP
Random cows

Question 15

Milk quality as nutrition monitor

Answer 15

Milk protein
- low=NEB,
Urea
- rumen protein spillover
Butterfat
- low (low fibre), high (high fibre)
- v. high excess fat mobilisation
Fat: protein ration
- energy vs fibre in action

Question 16

Examination of rumen function

Answer 16

Rumen fill scoring
Faeces
Faecal sieving - mucus, fibre length,
grain
Rumen pH
Protozoal assessment
Rumenocentesis/ oral samples
pH measuring boluses

Question 17

The four diets

Answer 17

Cows require
Nutritionists formula
Farmer mixed
Cows Receive
Should be identical

Question 18

Lactating cow feed systems

Answer 18

Grazing/ housed
Traditional
TMR
Hybrid
Buffer feeding

Question 19

Traditional

Answer 19

Fibre fed at barrier
[] fed to yield in parl.

Question 20

TMR

Answer 20

Total mixed ration
Diet set for given yield
Maximises DMI
Mixer wagons

Question 21

Hybrid

Answer 21

Pro –
Acc rationing
Extras for high yielder
Not over feed low yiel
Con –
Eats less at barrier
Less long fibre
SARA risk

Question 22

Grazing

Answer 22

High H2O %
So less DMI
Natural

Question 23

DMI

Answer 23

Lactating 3% BW DMI
Alt - 2.5%BW +0.1/L
Correction factors
TMR +
Poor pres silage -

Question 24

Feed access

Answer 24

Minimise stress
60cm milkers
80 cm dry
Water
9cm trough space/cow
24hr access