3.7 Feeding Lactating Sows - T3

Question 1

What are the 2 main objectives for lactating sows? What might these mean for energy intake?

Answer 1

1. Maximize litter performance
   - high milk production
   - minimal mobilization of maternal body tissue
2. Long term productivity
   - successful rebreeding
   - reproductive longevity

Want to maximize energy intake during lactation by maximizing feed intake

Question 2

What are 3 important factors of FI for lactating sows to consider?

Answer 2

1. Key aspect of nutrition of lactating sow
   - but challenging bc sow is very stressed and need tissues to shrink after farrowing
   - limiting factor for milk production
2. Milk production limits
   - piglet growth and survival
3. Maintain body composition
   - for easy rebreeding
   - for longevity

Question 3

FI during lactation (from gestation to early lactation)

Answer 3

1. FI in gestation
   - avoid overfeeding; by increasing fat reserves the FA arriving at the brain increase which signals a cascade to reduce FI
2. Postpartum FI depression
   - lethargy, stress
   - limited gut volume
3. FI increases gradually in lactation

Question 4

What is the critical factor for successfully increasing FI directly after farrowing?

Answer 4

Have sows at ideal body condition at farrowing

Question 5

How does feed intake differ between parities?

Answer 5

Feed intake increases from 1st to 6th parity
- heavier multiparious sows -> higher maintenance req

Question 6

How does FI change with litter size?

Answer 6

FI increases with litter size

Question 7

What does FI differ with for lactating sows?

Answer 7

1. Parity
2. Litter size
3. Genotypes and farms

Question 8

What happens if sows are overfed in gestation?

Answer 8

High backfat = high lipid in blood = signals satiety

Question 9

What happens if sows receive a low protein diet during gestation?

Answer 9

May reduce lactation feed intake

Question 10

What factors affect lactation FI and how?

Answer 10

Overfeeding sows in gestation will decrease their FI during lactation

Question 11

A sow that has a ___ FI during gestation tends to have a ___ FI during lactation

Answer 11

1. higher/lower
2. lower/higher

Question 12

What is the lactation feeding strategy?

Answer 12

1. Switch to lactation diet when sows are moved to farrowing crate
2. After farrowing set up feed allowance quickly
   - reach ad libitum within 7-9 days
3. Remaining lactation
   - fed ad libitum
4. After weaning: ad libitum dry sow diet
   - to recover BW losses and be able to be bred again more easily

Question 13

What is the limiting factor to temperature and FI? How can pigs be kept cool?

Answer 13

Ability to dispose of HI
- drip coolers or snout coolers
- heat conductive flooring
- diets with low HI

Question 14

What are 3 strategies to reduce HI when formulating diets?

Answer 14

1. reduce fiber
2. reduce protein
3. increase fat

Question 15

Other than temperature, what are 4 other factors affecting FI?

Answer 15

1. Air quality
2. Light
   - 16h of light promote higher FI than 8h
3. Feeders, feeding and feed
   - bowl type
   - feed more than once a day
   - pellets
   - wet better than dry
   - high energy diets
4. WATER!
   - need sufficient water flow

Question 16

Milk energy content

Answer 16

• 30-40% fat on DM basis
• impact of litter size
• efficiency of energy utlization

Question 17

Lysine (AA) in milk

Answer 17

• important for litter gain; in order for piglets to deposit protein they need to get Lys
• body mobilization; high aa and protein to minimize amount of lean mass lost from sow during lactation

Question 18

How is milk production estimated?

Answer 18

By indirect methods
- weigh-suckle-weigh
- litter weight gain

Question 19

What 4 factors affect milk production?

Answer 19

1. Milk yield
   - genotype
   - peaks in wk 3-4
2. Sow: size, body reserves, nutrition, parity
   - higher parity sows produce more
3. Piglets: number, weight, vigor -> suckling stimulus
4. Fat sows may produce less milk than lean sows

Question 20

What happens to milk composition as time passes following farrowing? (fat, lactose, protein, IgG’s, energy)

Answer 20

Fat%: increases
Lactose%: increases
Protein%: decreases
IgG’s: decrease
Energy: decreases

Question 21

More milk =

Answer 21

Higher nutrient output = higher requirements
- must ensure diet is more nutrient dense or maximize sow’s FI so she can sustain milk production without losing BW

Question 22

What 3 factors affect nutrient requirements of lactating sows?

Answer 22

1. Sow maintenance
2. Milk production
   - accounts for daily litter gain and litter size
3. Change of sow BW and composition
   - losing body lipid -> energy
   - losing body lean -> energy and AA

Question 23

Body weight loss composition of lactating sows

Answer 23

Typically
- 60-70% fat
- 9-14% protein

Ratio of fat to protein loss depends on
- dietary protein: energy ratio
- milk production
- body composition
- metabolic need of sow (older sows have higher metabolic needs)

Question 24

Body weight loss and performance

Answer 24

Backfat loss
- target: minimum 10 mm backfat
- lower than that can reduce milk production

Protein loss
- acceptable: 10-12% of body protein mass
- higher than that -> reduced milk prodution

Greater body losses -> longer wean-to-estrus interval

Question 25

How can we increase energy intake for lactating sows?

Answer 25

1. Increase FI
2. Increase energy density of diets

Question 26

Are AA requirements or energy requirements easier to satisfy for a lactating sow?

Answer 26

AA requirements
- use high energy diets with sufficient amino acids to cover requirements and achieve the highest energy intake possible

Question 27

What should lactation diets be high in?

Answer 27

• High in energy
• High in protein and lysine
• High in calcium (for milk production and prevention of excessive bone calcium loss)

Question 28

What is the greatest factor for requirements of lactating sows?

Answer 28

Milk production

Req = maintenance + milk production + change in body comp