3.5 Feeding GF pt. 2 - T3

Question 1

What happens if we OVERESTIMATE feed intake?

Answer 1

We make diets less dense and pigs aren’t getting the nutrients they require
- grow slower and take longer to finish = we reduce performance

Question 2

What happens if we UNDERESTIMATE feed intake?

Answer 2

We make diets more nutrient dense which doesn’t make the pigs more, instead we are wasting nutrients and money!

Question 3

What are 4 different feeding strategies that we are trying to balance?

Answer 3

1. Minimize feed cost
2. Maximize revenue
3. Minimize nutrient excretion
4. Minimize variation in slaughter weights

Question 4

What are 3 strategies that we can use to meet feeding goals?

Answer 4

1. Phase feeding
   - adjust nutrient concentration to changing requirements
   - different than weaning phase feeding where we are changing a lot of the ingredients, here we are focused more on concentration
2. Split sex feeding
   - account for different req for gilts and barrows
   - barrows have higher FI = gilts get more nutrient dense diets
3. Feed restriction
   - limit carcass fatness in UNIMPROVED genotypes
   - usually not done in North America bc we don’t have fat genotypes

Question 5

Why does the concentration of dietary lys decrease for grower-finisher pigs?

Answer 5

• bc when body wt increases they increase FI
• can reduce % lys bc they will be eating more

Question 6

What happens if single phase feeding is used for grower finishers?

Answer 6

• at lower body weights will be underfeeding reqs
• at higher body weights will be overfeeding reqs

Question 7

What are 4 benefits of phase feeding?

Answer 7

1. Reduces times with insufficient or excess nutrients in the diets
2. Optimize performance at all stages of growth
3. Shorten growing period
   - more pigs/place and pigs/yr possible
4. Can save on feed cost

Question 8

What 2 things are required to implement phase feeding cost effectively?

Answer 8

1. Mixing diets on farm
2. Bins to store diets

Question 9

How does protein deposition rate differ between gilts and barrows?

Answer 9

Gilts are more effective at depositing protein at higher body weights

Question 10

Why is split sex feeding used?

Answer 10

Requirements and FI is different btw barrows and gilts
- nutrient concentration needs to be greater for gilts
- barrows: may need to reduce dietary energy in finisher phase

Question 11

What is required to implement split sex feeding cost effectively?

Answer 11

Organize production so gilts are all on one side of a row of pens and barrows are on the other side in a row = can use one bin of feed for each side

Question 12

What 3 factors are we considering when choosing feedstuffs?

Answer 12

1. Cost of nutrient
   - energy should be ~70% of cost, AA ~20%, and then minerals (P)
2. Suitability
   - may differ btw grower and finisher pigs
   - lower energy cereals (barley, oats): use less in grower phase bc insufficient energy can restrict protein deposition
   - limit unsaturated fats for finishers bc fat profile of diet affects fat profile of meat
3. Continuity of diet
   - use of similar feedstuffs may reduce the change of FI decreasing

Question 13

Risk management of co-products (commonly used in GF diets)

Answer 13

• Usually high in fiber and protein, lower in starch and oil
• Feed quality evaluation: Energy (NE vs DE/ME), AA (AID, SID, TID), mycotoxins and minerals (concentrated in co-products), description of phytate, fiber, starch
• Co-products are highly variable bc of varation in the crop and during processing
• Feed technologies: processing and additives (enzymes)

Question 14

What are co-products?

Answer 14

What is remaining after a major component is removed

Question 15

What is a “safety margin”?

Answer 15

When you intentionally overformulate your diet (more nutrient dense), to meet the minimum nutrient req
- can be expensive

Question 16

What 4 factors can be used to assess quality of feedstuffs?

Answer 16

1. Palatability
   - high fiber = high viscosity of digesta = reduces FI
2. Free of toxic substances, mold
3. No reduction of physical quality of meat or off-flavour
4. Limited variability of nutrient content in ingredients
   - “safety-margins”

Question 17

How should diet formulations be analyzed?

Answer 17

BEST
- analyze main ingredients
- most important: energy, protein, Ca, P

IF no means to analyze
- use book values + safety margin to assure nutrient content
- safety margins will increase diet cost

Question 18

What can free amino acids replace? What do you want to ensure you use the correct formulation of?

Answer 18

Can replace part or all of protein feeds in diet

Use correct energy formulation
- pigs tend to grow fatter when given free AA
- reduce dietary energy content, formulate for NE
- free AA reduce CP content which reduces HI = more energy available for growing

Question 19

Is the use of free amino acids economical?

Answer 19

Almost always cost effective to use free aa
- high cost of cereals relative to protein ingredients may cause the inclusion of free AA to be uneconomical

Question 20

What happens when a feed additive such as phytase is added to a diet? What is the problem?

Answer 20

1. Reduction of P excretion
   - cost offset by reduction of emission of di-calcium phosphate
2. Problem
   - CFIA list total P as a quality criterion for feed for sale
   - Diets containing less P than listed requires special declaration

Question 21

What are 3 other additives other than phytase?

Answer 21

1. Antibiotics
   - most effective in young pigs
2. Organic acids, pre/pro-biotics
   - less effective in grower-finisher pigs
3. Ractopamine (Paylean)
   - increase the size of muscle fibers
   - increase leanness, DP, wt gain, FE