Feeding Management

DY SCI 233 - Unit 2

Describe the aerobic phase of fermentation.

Oxygen is consumed by respiration, sugars are used, and heat is generated.

Describe the lag phase of fermentation

Oxygen is depleted. Acid-producing bacteria (LABs) begin growing.

Describe the fermentation phase.

Bacteria produce acid, reducing pH. Bacteria die after pH drops.

Describe the stable phase of fermentation.

pH is lowered and microbial population is dead/dormant

Define Homofermentative

More efficient type of fermentation; results in less dry matter and energy loss

Define heterofermentative

Less desirable form of fermentation; produces acetic acid and carbon dioxide

Rank the types of fermentation (4 types) by their DM recovery and energy efficiency rates (highest to lowest)

• Homolactic

• Heterolactic

• Yeast

• Clostridial

What is the likely cause of a strong vinegar smell (acetic acid)

Too slow pH drop, slow filling, fermentation too long, high ash/protein

What is the likely cause of a putrid, slimy, skunky smell? (butyric acid)

Silage too wet, too slow pH drop, not well covered

What is the likely cause of an ammonia, fishy smell? (amines)

Silage too wet, too slow pH drop, poorly covered

What is the likely cause of an alcohol smell? (yeast, starchy crops)

Too slow pH drop, excess air in silo, slow pack, poor pack

What is the likely cause of a burnt tobacco smell? (heat damaged proteins)

Silage too dry, excess air in silo, slow pack, poor pack

Define Porosity

a measure of pore space between particles

Define “Gas Filled Porosity”

the non-saturated space between particles

For every ____ pounds being delivered to the bunk per hour you need ____ pounds packing weight.

2000, 800

Name four ways to eliminate oxygen in a bunk.

• Oxygen-limiting plastics

• Side wall covers

• Inspect for holes regularily

• Gravel bags along the edges of the covers

Define “feed costs per day”

limited value

Define “feed costs per kg of milk”

reflects milk yield, shrink, and feed costs

Define “income over feed costs”

reflects profit margin

Define “feed costs per kg of dry matter”

reflects feed ingredient selection

Define “feed efficiency”

evaluates feed conversion to milk yield (lb of milk/lb of DMI)

How do we calculate feed efficiency?

ECM / Dry Matter Intake(lbs)

Define “shrink”

the amount of a diet provided to the cow that the cow never gets to eat

What are the four rations on a farm?

• the ration formulated by the nutritionist

• the ration implemented by the managers

• the ration mixed/fed by the feeders

• the ration consumed by the cows

What is the cost of shrink to a farm?

10 to 15 cents per cow per day

What is our goal for shrink loss?

Less than 5%

Name ways to reduce sorting.

• feed smaller amounts of TMR more frequently

• reduce refusal amounts

• Add less hay/straw to a mix or process finer

• Add water or LFS to a mix

• more frequent feed push-ups

What factors cause slug feeding?

• limited bunk space

• limited feed access time

• inconsistent feeding schedule

• infrequent TMR push-ups

Outline the daily time budget of a cow:

• 12-14 hours lying

• 5 hours eating

• 2-3 hours standing/walking

• 30 minutes drinking

• 2.5-3.5 hours milking

How does lying time impact milk production?

Increased lying time increases milk production

How much bunk space does a cow need?

• >24 linear inches per milking cow

• 30 linear inches per transition cow

How frequently should feed be pushed up?

4-12 times daily

What are the necessary water trough measurements?

• 2” length per cow

• 24-33” height per

• 3” minimum depth

For rotational grazing, when do you allow cows to graze and when do you relocate them?

• 6-12” = best time to graze

• remove cows at 3-4”

Within the phases of plant maturation, when is the best time to graze?

after internode elongation and before stem elongation

What is the “daily planner” of grazing lactating diary cows?

• 8-10 hours rumination

• 4-6 hours resting

• 2-4 hours milking

• 1-2 hours supplement consumption

• 6-9 hours grazing???