Livestock Feeding
AnS 320
“Swine Feeding and Management”
Lecture #1
Dr. John F. Patience
Department of Animal Science
201B Kildee Hall
Phone: 294-5132
Email: jfp@iastate.edu
PRODUCTION CONTINUUM
What occurs in one phase
of production often affects
outcomes in later phases.
Or
Diagnosing problems in one
phase of production often
requires consideration of
what is happening in earlier
phases.
Breeding
Farrowing
Nursery
Growout
Feeding and Management: Sows
Framework for Developing
Feeding Programs
Nutrient
Requirements
Nutrient
Supply
Feeding
Program
Profitability
Pork
Quality
Functional
Properties
Sustainability
Life cycle feeding
 Gestation feeding affects:
 Sow condition at farrowing
 Feed intake during lactation
 Sows that get too fat in gestation eat less in lactation
 Piglet birth weight
 Response is very small
 Cost of feeding the breeding herd
 Feeding too much feed or too rich a diet increases feed costs
with no benefits, possibly detriments
 Well-being of the sow
 Thin sows are easily chilled and more susceptible for illness
Life cycle feeding
 Lactation feeding affects:
 Sow condition at weaning

Affects subsequent reproduction
 Litter weaning weights
 Sows will “milk off their back” but this is both inefficient and
ineffective, compared to feeding the sow correctly
 Cost of feeding the breeding herd
 Feeding too much feed or too rich a diet increases feed costs
with no benefits, possibly detriments
 Well-being of the sow
 Thin sows are easily chilled and more susceptible for illness
Feeding and Management: Gestation
Example Gestation Diets
Mixed parity diet
Ingredient
Young parity
diet
Old parity
diet
Corn-soy diet
Soy hull diet
1,626
1,548
1,548
1,617
Soybean meal, 46.5% CP
291
271
271
202
Soy hulls
---
100
100
100
Monocalcium phosphate,
21% P
32
31
31
29
Limestone
28
27
27
29
Salt
10
10
10
10
Vitamin premix with phytase
5
5
5
5
Trace mineral premix
3
3
3
3
Sow add pack
5
5
5
5
2,000
2,000
2,000
2,000
Corn or milo
Total
Example Gestation Diets
Mixed parity diet
Calculated analysis
Corn-soy diet Soy hull diet
Young
Old parity
parity diet
diet
TID Lysine, %
0.56
0.55
0.55
0.46
Total lysine, %
0.65
0.65
0.65
0.55
TID Lysine:ME ratio, g/Mcal
1.71
1.71
1.71
1.44
TID Methionine:lysine ratio,%
38
38
38
41
TID Met & Cys:lysine ratio, %
78
78
78
85
TID Threonine:lysine ratio, %
76
76
76
80
TID Tryptophan:lysine ratio, %
23
22
22
23
ME, kcal/lb
1,484
1,451
1,451
1,451
Protein, %
13.7
13.4
13.4
12.1
Calcium, %
0.90
0.90
0.90
0.90
Phosphorus, %
0.66
0.64
0.64
0.61
Available phosphorus, %
0.39
0.38
0.38
0.35
0.45
0.44
0.44
0.42
Available phosphorus equiv, %a
aThe
available phosphorus equivalency includes the phosphorus release due to inclusion of phytase in the vitamin premix.
Gestation feeding challenges
1. Optimize lifetime sow productivity, as a means of
maximizing herd profitability
2. Over-feeding sows in gestation reduces feed
intake in lactation
3. Under-feeding sows in gestation impairs
reproductive performance and animal well-being
(shoulder sores)
4. Avoid mycotoxins; this may be the worst place to
feed mycotoxin contaminated feed
Gestation feeding targets
1. Body condition score between 3 and 3.5 – for ALL
sows (on a 5-point scale)
 Avoid sows that are too fat or too thin
2. Backfat levels of 0.75” to 0.80” at farrowing
(measured at last rib, 2.5” to 3.0” off the midline)
 Avoid bf less than 0.55” at weaning
3. Adjust feed intake according to body weight and
backfat
4. Very thin sows have higher maintenance energy
requirements, because they have lower insulation
levels and are often more active.
Gestation feeding program
1. Sows must be limit fed during gestation;
otherwise they become too fat
2. Do not feed more than 4 to 5 lb per day for the
first 3 weeks after breeding; excess intake lowers
fetal survival
3. Feed 4.0 to 4.5 lb of a corn-soybean meal diet per
day, adjusting as required for body condition
4. Increase feed allowance by 2 lb during the last 21
days of gestation
 Increases gut capacity to support maximum intake in
lactation
 Recognizes that most fetal growth occurs during the
final 3 weeks of gestation.
 Exception if over-fat sows
Limit feeding gestating sows
 Easily accomplished in gestation stalls

Automatic drops MUST be calibrated regularly, to ensure the sow
is receiving what you think she should be receiving.
 More difficult to achieve in group housing systems

Key rule: to successfully feed sows in group housed gestation,
remove competition for feed. The greater the competition among
sows for feed, the less successful the housing system will be.
 Options:
 Electronic sow feeders
 Walk-in-lock-in feeding stalls
 Trickle feeders
 Floor feeding, with multiple drops, spreading out supply of
feed throughout the pen. Including dividers within the pen
helps
Feeding Levels (lb/day) For Gestating Sows Based on
Backfat and Weight Category at Breeding
Flank to
flank, in
Estimated
weight, lb
< 36.3
Backfat at breeding, mm (in)
9-11
(.35-.43)
12-14
(.47-.55)
15-17
(.59-.67)
> 18
(.71)
< 325
5.0
(.20)
4.4
(.17)
3.9
(.15)
3.4
(.13)
36.4 - 39.2
325 - 400
5.5
(.22)
5.0
(.20)
4.4
(.17)
3.9
(.15)
39.3 - 41.8
400 - 475
5.9
(.23)
5.4
(.21)
4.9
(.19)
4.3
(.17)
41.9 - 44.0
475 - 550
6.4
(.25)
5.9
(.23)
5.4
(.21)
4.8
(.20)
> 44.0
550 - 650
6.9
(.27)
6.4
(.25)
5.8
(.23)
5.3
(.21)
Based on a diet containing 1,500 kcal ME/lb (corn-soybean meal).
Feeding and Management: Lactation
Example Lactation Diets
TID Lysine, %
Ingredient, lb/ton
0.80
0.85
0.90
0.95
1.00
1.05
Corn
1,435
1,395
1,356
1,316
1,277
1,238
Soybean meal, 46.5% CP
486
526
566
605
645
685
Choice white greasea
0-5%
0-5%
0-5%
0-5%
0-5%
0-5%
Monocalcium Phosphate, 21% P
28.5
28.5
28
28
28
27.5
Limestone
28
27.5
27.5
27.5
27
27
Salt
10
10
10
10
10
10
Vitamin premix with phytase
5
5
5
5
5
5
Trace mineral premix
3
3
3
3
3
3
Sow add pack
5
5
5
5
5
5
2,000
2,000
2,000
2,000
2,000
2,000
Total
a If
adding fat, substitute for grain on an equal weight basis
Example Lactation Diets
Calculated analysis
TID Lysine, %
0.80
0.85
0.90
0.95
1.00
1.05
Total Lysine, %
0.91
0.97
1.02
1.08
1.13
1.19
TID Lysine:ME ratio, g/Mcal
2.35
2.49
2.64
2.79
2.93
3.08
TID Methionine:lysine ratio, %
32
31
30
30
29
28
TID Met & Cys:lysine ratio, %
65
64
62
61
60
59
TID Threonine:lysine ratio, %
69
68
68
67
66
66
TID Tryptophan:lysine ratio, %
22
22
22
22
22
22
ME, kcal/lb
1,547
1,547
1,547
1,547
1,547
1,547
Protein, %
17.1
17.9
18.7
19.4
20.2
20.9
Calcium, %
0.90
0.90
0.90
0.90
0.90
0.90
Phosphorus, %
0.66
0.67
0.67
0.68
0.69
0.69
Available phosphorus, %
0.36
0.37
0.36
0.37
0.37
0.37
Available phosphorus equiv, %b
0.48
0.48
0.48
0.48
0.48
0.48
bThe
available phosphorus equivalency includes the phosphorus release due to
inclusion of phytase in the vitamin premix.
Feed intake
One of the greatest challenges in feeding the nursing
sow is maximizing feed intake
 Low feed intake leads to low nutrient intake
 Low nutrient intake leads to:




Lower weaning weights
Loss of sow body condition
Increased sow culling
Impaired rebreeding and subsequent litter size
Effects of Lactation Feeding Level on Litter and
Pig Performance
Lactation Feeding
Item
Restricted
Ad libitum
SED
Probability, P <
38
40
---
---
d 3 (start creep)
11.0
10.9
0.3
0.75
d 21
10.4
10.4
0.3
0.93
Mortality, %
5.9
5.3
1.8
0.76
d 3 (start creep)
39.3
38.6
1.4
0.53
d 21
125.1
132.6
4.5
0.10
Total
94.7
102.9
3.9
0.04
ADG
5.20
5.64
0.21
0.04
No. of litters
Pigs/litter
Litter weight, lb
Litter BW gain, lb
NB – Restricted were fed 25% less than ab libitum
Lactation feeding program
 Small amount of feed on day of farrowing


Hungry sows are restless and more likely to over-lay piglets
Sows typically will not eat much feed; farrowing room is very
warm and fed deteriorates quickly
 Day 1 – 2: Limit fed modestly; do not want to limit feed
very much
 Days 3+: Keep fresh feed in front of the sows at all times
Feeding Strategy for Lactating Sows
Number of 4-pound scoops to feed at each feeding from day 0 to 2 of lactation
Feeding
Feed in feeder
AM
PM
Empty
1
1
< 2 lb
0
0.5
> 2 lb
0
0
Number of 4-pound scoops to feed at each feeding from day 2 to weaning
Feeding
Feed in feeder
AM
Noon
PM
Empty
2
2
2
< 2 lb
1
1
1
> 2 lb
0
0
1
Factors affecting feed intake - 1
 Feed delivery


Pigs cannot eat feed that isn’t in front of them! By the 3rd day of
lactation, sows should have feed in front of them all of the time
Feeding 3 to 4 times per day is preferred to feeding once or twice.
 Density of the diet
 Pigs eat more of a low density (low energy) diet, up to the
volumetric capacity of their stomach
 Temperature
 High temperature discourages feed intake; low temperature
encourages feed intake
 If the temperature is too cold, or conditions are drafty and damp,
part of the energy consumed by the sow will be needed to
maintain thermal homeostasis
Factors affecting feed intake - 2
 Genetics
 Some lines of pigs have a naturally higher appetite. If using a low
appetite line of pigs, even greater attention must be directed at
maximizing feed intake
 Palatability
 It is important to note that the important factor here is what the
pig considers palatable, not what the producer “thinks” is
palatable.
 Nutrient balance
 Imbalances among, for example, amino acids will reduce feed
intake
 Body condition and reproductive cycle feeding
 If sows are overfed in gestation, they will accrue more body fat
and this tends to impair feed intake during lactation
Factors affecting feed intake - 3
 Feeder design
 Large feed troughs tend to increase feed intake
 Wet/dry feeders tend to increase feed intake
 Access to water
 Water is particularly critical to a lactating sow
 A sow weaning 11 piglets at 3 weeks of age weighing 13 lb will be
producing an average of 2.5 gallons of milk per day!
Fibre in lactation diets
 Nursing sows are susceptible to constipation
 Constipation can be treated by using:
 Fiber
 Wheat midds (±20%)
 Soybean hulls (±10%)
 Alfalfa meal (±25%)
 Sugar beet pulp (7±%)
 Oats (±20%)
(Risk: Use of fibrous ingredients will lower diet energy density and
may compromise sow’s ability to consume sufficient energy
 Chemical laxatives
 MgSO4 (Epsom salts: 30 lb/ton)
 NaSO4 (Glauber salts: 60 lb/ton)
(Risk: Chemical laxatives are harsh; should be used carefully)
Lactation feeding quandary
 In order to maximize sow feed intake, she wants the room
kept as cool as possible
 In order to maximize piglet growth and well-being, they
want the room to be kept very warm
 If the room is kept too cool for the piglets, they will huddle
with the sow, increasing the risk of being over-lain
 Increased mortality due to overlays is often related to a room
temperature that is too cool
Compromise
 Keep the farrowing room temperature elevated during
farrowing and the first 24 to 36 hours post-farrowing, to get
the piglets off to a good start.
 Lower the temperature to 68 to 72⁰F thereafter and provide
zone heating for the piglets
 Feed intake declines by about 0.2 lb/d per ⁰F above 68⁰F