This document reviews strategies to mitigate negative impacts on carcass yield from feeding by-product diets high in fiber to finishing pigs. It discusses how increased fiber from ingredients like DDGS reduces carcass yield by increasing gut fill. Several strategies are examined, including adding fat, ractopamine, or changing feed form, but none fully overcome the yield reduction from high fiber diets. The key strategy shown to restore yield is withdrawing pigs from high fiber diets to a corn-soybean meal diet prior to slaughter, with withdrawal periods of 10-20 days before market found to maximize growth performance and carcass yield. A university study validating this commercial field study approach is summarized.

1. The importance of implementing a by-product
withdraw strategy prior to slaughter in finishing
pigs: A review of strategies that mitigate the
negative impacts on carcass yield.
K.F. Coble*, J.M. DeRouchey, M.D. Tokach, S.S. Dritz,
R.D. Goodband, and J.C. Woodworth
Kansas State University
Allen D. Leman Swine Conference
Monday, September 21, 2015

2. Introduction
• By-product ingredients, such as dried distillers
grains with solubles (DDGS), have become an
important ingredient in swine diets in the last
decade.
0
10
20
30
40
50
DDGSProduction,MT
Historic Distillers Grains Production from U.S.
Ethanol Biorefineries
-Renewable Fuels Association

3. By-products in Swine Diets
• Can potentially offer a source of lower cost
energy and amino acids and increased level of
available phosphorus
• At the possible expense of:
– Feed efficiency and gain
– Fat quality (iodine value)
– Carcass yield = ↓HCW
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-www.alibaba.com

4. Byproduct vs. Originating Grain Source
Item1 Corn vs. DDGS2 Wheat3 vs. Midds
CP 8.24 27.36 14.46 15.76
Energy, kcal/kg
ME 3,395 3,396 3,215 2,968
NE 2,672 2,343 2,472 2,113
STTD of P, % 34 65 56 56
Crude fiber, % 1.98 8.92 2.57 5.15
NDF, % 9.11 30.46 10.60 34.97
ADF, % 2.88 12.01 3.55 5.98
1 2012 NRC. 11th Revised Edition. Nutrient Requirements for Swine.
2 Corn DDGS, >6 and <9% Oil.
3 Wheat, Hard Red

5. Presentation Outline
• Reduced yield from feeding high fiber diets
• Strategies that do not fully overcome reduced
yield when fed a high fiber diet
– Added fat in finishing
– Addition of ractopamine in late finishing
– By-product diets fed in different forms
• By-product withdrawal strategies prior to
slaughter that will overcome reduced yield
when fed a high fiber diet

6. Turlington (1984)
• Investigated the effects of increasing high fiber
by-products in corn-soybean meal-based diets
– Soybean hulls - 0 to 21% (NDF = 8.3 to 19.5%)
– Oat hulls – 0 to 18% (NDF = 8.9 to 19.0%)
– Wheat bran – 0 to 37.5% (NDF = 9.2 to 18.9)
• Finishing pigs from approximately 30 to 90 kg
• Collected and weighed the contents in the large
intestine and cecum
• Reported no trial × treatment interactions; data
reported as main effects of NDF

7. Effect of NDF on Carcass Yield
74.8
74.3
74.0
72.9
2.4 2.5
3.2
3.5
0
1
2
3
4
72
73
74
75
76
0 3.3 6.6 9.9
Yield Gut fill
Added NDF , %
CarcassYield,%
Gutfill,kg
Linear NDF: P < 0.01
CV = 2.27
- Adapted from Turlington, 1984

8. Effect of NDF on GIT Content Weight
410 452 491 531
1,131
1,429
1,780
1,854
0
400
800
1200
1600
2000
0 3.3 6.6 9.9
Gastrointestinaltract(GIT)contents,g
Cecum Colon
- Adapted from Turlington, 1984
Cecum
Quadratic: P < 0.10
CV = 36.39
Added NDF , %
Colon
Linear: P < 0.01
CV = 28.27

9. Increasing DDGS on Carcass Yield
71.5
72.5
73.5
74.5
75.5
76.5
0 10 20 30 40 50
Carcassyield,%
DDGS, %
Jacela et al., 2011 Graham et al., 2014 (2)
Whitney et al., 2006 Graham et al., 2014 (1-1)
Graham et al., 2014 (1-2)
0.030%
0.022%
0.035%
0.049%0.052%
Average slope = 0.038%

10. Increasing NDF from DDGS on Carcass Yield
71.5
72.5
73.5
74.5
75.5
76.5
8.0 12.0 16.0 20.0
CarcassYield,%
NDF, %
Whitney et al., 2006 Jacela et al., 2011
Graham et al., 2014 (1-1) Graham et al., 2014 (1-2)
Graham et al., 2014 (2)
0.131%
0.117%
0.154%
0.229%
0.210%
Average slope = 0.168%

11. Increasing NDF on Carcass Yield
71.5
72.5
73.5
74.5
75.5
76.5
8.0 12.0 16.0 20.0
CarcassYield,%
NDF, %
Whitney et al., 2006 Jacela et al., 2011
Graham et al., 2014 (1-1) Graham et al., 2014 (1-2)
Graham et al., 2014 (2) Asmus et al., 2014
Salyer et al., 2012 Goehring et al., 2012
0.131%
0.117%
0.154%
0.162%
0.229%
0.210% 0.118%
0.158%
Average slope = 0.162%

12. Including By-products High in Fiber
• Residual digestive contents in the GI tract from
feeding a high-fiber diet impacts carcass yield;
therefore resulting in a lighter carcass than
predicted by the final live weight exiting the barn.
• Reduced carcass yield is dependent upon level of by-
product ingredient, but not sources or oil content
(DDGS)
• Important to consider when evaluating by-product
economics.

13. Dietary Strategies that Improve Yield
• Several dietary strategies have demonstrated
improvements in carcass yield in corn-soy diets
– Added dietary fat
– Ractopamine HCl (RAC)
– Feed form
• Can the use of these overcome the reduction in
yield associated with high fiber diets fed until
marketing?

14. Adding Dietary Fat
• Several suggest adding fat in corn-soy diets
improves carcass yield by increasing HCW
• Will adding fat help overcome the reduction in
yield associated with high fiber diets?
– Salyer et al. (2012): 30% wheat midds with 2.5 or
5% added CWG
– Davis et al. (2015): 30% DDGS with 5% added
tallow
– Coble et al. (2015): 30% DDGS with 5% added fat
fed for the last 20 d prior to slaughter

15. Midds and Added Fat on Carcass Yield
73.3
73.9
73.4
72.8
72.9
72.8
71.5
72.0
72.5
73.0
73.5
74.0
74.5CarcassYield,%
Salyer et al., 2012
Midds, %: 0 20
CWG, %: 0 2.5 5.0 0 2.5 5.0
CWG × Midds: P > 0.82
Midds: P = 0.04
CWG: P = 0.67
SEM = 0.40

16. DDGS and Added Fat on Carcass Yield
78.8
79.6
78.3
79.4
76.0
77.0
78.0
79.0
80.0
81.0
CarcassYield,%
Tallow × DDGS: P > 0.54
DDGS: P = 0.10
Tallow: P = 0.01
PSE = 0.19
Davis et al., 2015
DDGS, %: 0 30
Tallow, %: 0 5 0 5

17. Added Fat prior to Slaughter
• 20-d experiment investigated the interactive effects
of 30% DDGS and 5% added fat prior to slaughter
on growth performance and carcass characteristics
of finishing pigs.
• All pigs fed a common diet containing 30% DDGS
until 20 d prior to slaughter, then pigs were fed:
– 2 diet types: corn-soy diet with or without 30% DDGS
– 2 fat levels: 0 or 5% added fat
• 2 studies (commercial and university) were
included into 1 summary

18. Added Fat prior to Slaughter
73.1
73.3
72.8
72.6
71.0
71.5
72.0
72.5
73.0
73.5
74.0
CarcassYield,%
DDGS, %: 0 30
Tallow, %: 0 5 0 5
Coble et al., 2015
Fat × DDGS: P > 0.294
DDGS: P = 0.001
Fat: P = 0.633
SEM = 0.132

19. Adding Ractopamine HCl (RAC)
• Apple et al. (2007) reviewed past literature
suggesting that carcass yield improves from 75.3 to
76.2% (P = 0.058) in finishing pigs when fed up to 20
mg/kg of RAC.
– 0.5% improvement in yield with 10 mg/kg
• Graham et al. (2014): Fed two diet types with or
without 10 mg/kg RAC at two durations
• Corn-soy (Low fiber) or 30% DDGS/19%Midds
(High fiber)

20. High fiber diets and RAC on carcass yield
74.2
73.7
72.8
75.1
74.6
73.6
71.0
73.0
75.0
77.0 Control
RAC
d 0 to 49: Corn-soy High fiber High fiber
d 49 to 73: Corn-soy Corn-soy High fiber
No fiber × RAC effect
Withdrawal: P < 0.01
RAC: P = 0.01
SEM = 0.19
Carcassyield,%
Graham et al., 2014

21. Feed Form on Carcass Yield
• Overwhelming research demonstrating an
improvement in feed efficiency and average daily
gain (4-6%) for pelleted diets compared to meal
diets in grow-finish pigs.
• Nemechek et al. (2013) investigated the effects of
diet form (meal vs pellet) and diet type (corn-soy
vs. high fiber).

22. Diet Form and Type on Carcass Yield
75.1
74.7
74.1
75.0
74.8
73.4
72.5
73.5
74.5
75.5
76.5
CarcassYield,%
Meal Pellet
d 0 to 64: Corn-soy High fiber High fiber
d 64 to 81: Corn-soy Corn-soy High fiber
Diet form × fiber regimen: P < 0.876
Fiber regimen: P < 0.001
Meal vs pellet: P = 0.28
SEM = 0.240
Nemechek et al., 2013

23. What Strategies Will Restore Carcass Yield?
• Asmus et al. (2014) evaluated withdrawal
strategies by switching pigs from a 30% DDGS and
19% Midds diet to corn-soy diet during the last
phase (3 wk prior to slaughter) on carcass yield
– Low fiber (corn-soy), medium fiber (15% DDGS
and 9.5% Midds) and high fiber (30% DDGS and
19% Midds) diets were fed
– Measured intestinal weights for each withdrawal
strategy

24. Fiber Withdrawal Prior to Slaughter
73.2
72.9
71.6
73.0
72.4
71.7
69
70
71
72
73
74CarcassYield,%
d 0 to 43: Low High High High High High
d 43 to 67: Low Low Medium High High High
d 67 to 90: Low Low Medium Low Medium High
Asmus et al., 2014
Duration linear: P = 0.002
Fiber Level: P = 0.01
SEM = 0.26

25. Full Large Intestinal Weight
3.0
3.2
3.7
3.0
3.4
4.0
1
2
3
4
5FullLIWeight,kg
d 0 to 43: Low High High High High High
d 43 to 67: Low Low Medium High High High
d 67 to 90: Low Low Medium Low Medium High
Asmus et al., 2014
Duration, linear: P = 0.01
Fiber Level: P = 0.02
SEM = 0.26

26. Optimizing Withdrawal Strategies
1) To determine the timing of high-fiber ingredient
removal from the diet prior to marketing to
optimize growth performance, carcass
characteristics (yield and HCW)
2) Validate the response observed in a university
controlled experiment in a commercial field study

27. Material and Methods (Exp. 1)
• 288 pigs (PIC 327 x 1050; initially 38.4 kg BW) were
used in an 88-d study.
• Pens of pigs were randomly allotted to 1 of 6 dietary
feeding strategies with 8 pigs per pen and 6
replications per treatment.
• Dietary strategies consisted of:
– Control diet (corn-soybean meal; NDF=9.3%) fed d 0 to 88.
– High-fiber diet (30% DDGS and 19% wheat middlings;
NDF=19%) fed d 0 to 88 with no withdrawal period.
– High-fiber diet fed until 20, 15, 10, or 5 d prior to slaughter
after which pigs were switched to the corn-soy control.
– Diets were fed in 4 dietary phases and in meal form.
Coble et al., 2013

28. Stripping Large Intestine

29. Average Daily Gain (Exp. 1; d 0 to 88)
1.00 0.98 1.00 0.99 0.99 0.99
0.4
0.6
0.8
1.0
1.2
ADG,kg
Corn-Soy 20 d 15 d 10 d 5 d 0 d
High-fiber ingredient withdrawal prior to market, d
Corn-soy vs 0 d: P = 0.613
No Withdraw effects: P > 0.655
SEM = 0.014
Coble et al., 2013

30. Gain:Feed (Exp. 1; d 0 to 88)
0.358
0.344
0.340
0.339
0.336
0.341
0.30
0.32
0.34
0.36
G:F
Corn-Soy 20 d 15 d 10 d 5 d 0 d
Corn-soy vs 0 d: P = 0.001
No Withdraw effects: P > 0.147
SEM = 0.003
High-fiber ingredient withdrawal prior to market, d
Coble et al., 2013

31. Final BW (Exp. 1; d 88)
126.0
124.9
126.0
125.2
125.8 125.7
120
122
124
126
128
BW,kg
Corn-Soy 20 d 15 d 10 d 5 d 0 d
Corn-soy vs 0 d: P = 0.904
No Withdraw effects: P > 0.834
SEM = 1.93
High-fiber ingredient withdrawal prior to market, d
Coble et al., 2013

32. Carcass Yield (Exp. 1)
72.7 72.5 72.5
72.2
72.0
71.2
70
71
72
73
74
CarcassYield,%
Corn-Soy 20 d 15 d 10 d 5 d 0 d
Corn-soy vs 0 d: P = 0.001
Withdraw effects, quadratic: P < 0.039
SEM = 0.21
High-fiber ingredient withdrawal prior to market, d
Coble et al., 2013

33. Hot Carcass Weight (Exp. 1)
92.2
91.0
91.4 91.1
90.7
89.3
86
88
90
92
94
HCW,kg
Corn-Soy 20 d 15 d 10 d 5 d 0 d
Corn-soy vs 0 d: P = 0.140
No Withdraw effects: P > 0.334
SEM = 1.39
High-fiber ingredient withdrawal prior to market, d
Coble et al., 2013

34. Full Large Intestine Weight (Exp. 1)
2.90 2.96
3.41
2.90
3.19
4.10
2.0
3.0
4.0
5.0
Weight,kg
Corn-Soy 20 d 15 d 10 d 5 d 0 d
Corn-soy vs 0 d: P = 0.003
Withdraw effects, linear: P < 0.018
SEM = 0.283
High-fiber ingredient withdrawal prior to market, d
Coble et al., 2013

35. Rinsed Large Intestine Weight (Exp. 1)
1.79 1.75
2.00
1.79 1.86 1.91
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Weight,kg
Corn-Soy 20 d 15 d 10 d 5 d 0 d
Corn-soy vs 0 d: P = 0.333
No Withdraw effects: P > 0.530
SEM = 0.095
High-fiber ingredient withdrawal prior to market, d
Coble et al., 2013

36. Material and Methods (Exp. 2)
• 1,089 pigs (PIC 337 x 1050; initially 44.5 kg) were
used in a 96-d study.
• Pens of pigs were randomly allotted to 1 of 6 dietary
feeding strategies with 25 to 27 pigs per pen and 7
replications pre treatment.
• Dietary strategies consisted of:
– Control (corn-soy diet; NDF=6%) fed d 0 to 96.
– High-fiber diet (30% DDGS and 19% wheat middlings; NDF=19%)
fed d 0 to 96.
– High-fiber diet fed until 24, 19, 14, or 9 d prior to slaughter after
which pigs were switched to the corn-soy control.
– Diets were fed in 4 dietary phases and in the meal form.
– Inclement weather led to power outage at processing plant,
increasing withdrawal schedule by 4 d.
Coble et al., 2013

37. Final Live BW (Exp. 2 - Commercial)
132.5
129.3 129.5
129.1
128.3 128.3
125
127
129
131
133
135
BW,kg
Corn-Soy 24 d 19 d 14 d 9 d 0 d
Corn-soy vs 0 d: P < 0.001
No Withdraw effects: P > 0.233
SEM = 1.58
Coble et al., 2013
High-fiber ingredient withdrawal prior to market, d

38. Carcass Yield (Exp. 2 - Commercial)
74.9
74.1
74.6 74.5 74.4
73.9
73.0
74.0
75.0
76.0
CarcassYield,%
Corn-Soy 24 d 19 d 14 d 9 d 0 d
Corn-soy vs 0 d: P = 0.194
No withdraw effects: P > 0.275
SEM = 0.50
Coble et al., 2013
High-fiber ingredient withdrawal prior to market, d

39. Hot Carcass Weight (Exp. 2 -Commercial)
99.1
95.8
96.6
96.2
95.5
94.8
92
94
96
98
100
HCW,kg
Corn-Soy 24 d 19 d 14 d 9 d 0 d
Corn-soy vs 0 d: P < 0.001
Withdraw effects, linear: P < 0.052
SEM = 0.91
Coble et al., 2013
High-fiber ingredient withdrawal prior to market, d

40. Income Over Feed Cost
Exp. 2 - Spring 2013 Prices
$25.96
$26.64
$28.88
$28.00 $27.75
$26.58
24
26
28
30
32
IOFC,$/pig
Corn-Soy 24 d 19 d 14 d 9 d 0 d
Gain, $ 111.54 105.95 107.25 106.65 105.44 104.20
Feed, $ 85.58 79.30 78.36 78.65 77.69 77.62
Corn-soy vs 0 d: P = 0.71
No withdraw effects: P > 0.16
SEM = 1.261
• Corn = $270/MT; SBM = $518/MT; DDGS = $265/MT; Midds = $265/MT.
• $1.70/kg carcass weight
High-fiber ingredient withdrawal prior to market, d

41. Income Over Feed Cost
Exp. 2 - September 2015 Prices
$42.71 $42.49
$44.24
$43.67 $43.21
$42.38
35
38
41
44
47
50
IOFC,$/pig
Corn-Soy 24 d 19 d 14 d 9 d 0 d
Coble et al., 2013
Gain, $ 89.69 84.82 85.96 85.43 84.38 83.30
Feed, $ 46.98 42.32 41.71 41.77 41.17 40.92
• Corn = $138/MT; SBM = $358/MT; DDGS = $129/MT; Midds = $149/MT.
• $1.48/kg carcass weight
High-fiber ingredient withdrawal prior to market, d
Corn-soy vs 0 d: P = 0786
No withdraw effects: P > 0.125
SEM = 1.107

42. Conclusions
• Overwhelming evidence to support that high fiber
diets fed until marketing reduces carcass yield (HCW).
• The indigestible fiber fraction in high fiber ingredients
remain in the large intestine, reducing the expected
HCW relative to live weight.
• Pigs fed the high fiber diet had 1.2 kg more digestive
contents remaining in the large intestine than the
corn-soy low fiber diet
– 5 d withdrawal to corn-soy, low fiber diet from the high
fiber diet reduced large intestine weight by almost 1 kg.

43. Conclusions
• Withdrawing pigs from a high fiber diet and
switching them to a corn-soy, low fiber diet
restores carcass yield when done for the last 15-
20 days prior to harvest.
– Other strategies (added fat or RAC) have not been
successful in fully restoring the lost yield from feeding
high fiber ingredients.
• Economic analysis under field conditions
supports the need for implementation on a
commercial basis.

44. Thank You!
Funding, wholly or in part, was provided by The
National Pork Board