Comparison of Finishing
Systems: Performance, and
Carcass Composition
Jessica Gentry1 and John McGlone2
1Middle
Tennessee State University
2Pork Industry Institute, Texas Tech
University
2003 Midwest Animal Science
Meetings
Background
• Pigs may be reared in a wide variety
of systems.
• Indoor vs. outdoor production system
provides the greatest contrast in
environment.
• Indoor systems are more common
today.
• Outdoor systems may command a
premium in some niche markets (ex.,
Niman Ranch program).
Housing for Grower/Finisher
Pigs in the United States
Facility type:
Percent
Total confinement
69.9
Open building, no
outside access
Open building,
outside access
Outside lot
19.7
Pasture
9.2
0.8
0.4
NAHMS, 2001
Outdoor Pig Production
• Growing interest in outdoor pig
production:
– Low capital cost of outdoor systems.
– Work well in arid climates.
– Animal welfare regulations.
– Potential niche marketing
benefits of “natural”,
“free range”, “antibiotic-free”,
and
“sustainable” products.
Outdoor Pig Production
• Low capital cost
– varies from 40 to 70% of the cost for
conventional indoor systems
(Thornton, 1988).
• Can achieve similar gross margins as
indoor systems (Edwards, 1995).
• Outdoor pigs have a calmer behavior
(Warriss et al., 1983).
• Less susceptible to stress in
connection with transport (Barton-Gade &
Blaabjerg, 1989).
Sustainable Agriculture
Systems
• Essential to preserve, protect, and improve
the environment and animal’s experiences.
• Sustainable swine production involves use of
production techniques to:
– Enhance profits
– Improve environmental
and socioeconomic
conditions on the farm
(Honeyman, 1996)
Outdoor vs. Indoor Finishing
• Environmental effects on
performance and carcass
measures have yielded widely
differing conclusions
(Warriss et al., 1983; van der Wal et al., 1993,
Enfalt et al., 1997; Sather et al., 1997; Gentry et
al., 2001; Olsson et al., 2003).
Impact of
Alternative and
Indoor Housing
Systems on
Health
Health
• Limited research has been
published on the impact of
alternative finishing systems on pig
health.
• Pigs on bedding had fewer foot pad
lesions and tended to have fewer
respiratory problems than pigs on
slatted flooring (Gentry et al., 2001).
Percentage of Foot and
Lung Lesions
Feet
Clear
All lesions
Severe
Lungs
Clear
All lesions
Severe
Bedded, %
Slats, %
68
32
31
45
55
9
68
32
6
76
24
13
Gentry et al., 2001
Impact of Housing
Systems on
Performance
and Carcass
Composition
Growth Effects of Alternative vs.
Conventional Systems for Finisher Pigs
Live
Wt.
Warriss et al, 1983
van der Wal et al, 1993
Authors
Sather et al, 1997- winter
- summer
Enfalt et al, 1997
Beattie et al, 2000
Olsson et al, 2003
ADG
Feed
Intake
F:G
LR
Backfat
ns
-
-
-
-18.0%
ns
-
-
-
ns
ns
+8.9%
-
-15.9%
ns
11.2%
-16.4% -12.8%
ns
-15.8%
-
+ 5.0% +16.0% +6.0%
ns
+8.5%
-
ns
ns
-
-15%
-9.0%
+26.8%
-
+35.4%
*A positive value indicates an increase for the alternative
production system compared to the indoor system; ns =
effects not significantly different (P > 0.05).
Bedded vs. Slatted Flooring
(JAS 2001, 80:1781-1790)
Objective
• To evaluate the effects of pig
rearing environment (bedded vs.
slatted flooring) on growth and
carcass quality.
Bedding vs. Slatted Flooring
• Indoor-born pigs finished on concrete
slats or bedding (fescue hulls).
• PIC genotype, fed corn-SBM ration.
• Processed at Excel, Marshall, MO.
• n = 50 loins per treatment.
Results
• Pigs finished on bedding:
Had more severe foot lesions but a
lower percentage of foot lesions
(32% bedding vs. 55% slats).
Heavier (+ 8 kg).
Had more backfat (+ 0.5 cm at last
rib measurement).
• For loin quality measures, there
were no significant differences.
Diverse Birth and Rearing
Environments for Pigs: Effects
on Growth and Meat Quality
(JAS 2001, 80:1707-1715)
Objective
• To determine the effects of diverse
birth and rearing environments on pig
performance and meat quality.
Pig Birth Environments
English style farrowing hut
Farrowing crate
Pig Finishing Environments
Alfalfa pasture, 212 m2/pig
Pen size: 12 x 102 m
Hut (9 x 15 m) for shelter
Wallow provided during summer
Concrete slatted
flooring Pen size:
2 x 3.6 m 1.2 m2/pig
Experimental Design
Pig birth environment
Indoor-born pigs
Outdoor-born pigs
Indoor
finishing
n = 12
Outdoor
finishing
n = 12
Indoor
finishing
n = 12
Pig rearing environment
Outdoor
finishing
n = 12
Animals
• n = 48 pigs/exp., 3 indoor-born and 3
outdoor-born pigs/pen.
• Replicated over seasons: summer and
winter group (96 pigs total).
• Placed on trial at weaning, similar
average weights in each pen.
• Newsham hybrids, halothane negative.
• Fed milo/SBM based ration.
• Processed at Seaboard, Guymon, OK.
Body Weight - Summer
Group
140
*
120
*
100
kg
80
60
*
40
*
20
0
d0
d 28
d 56
Indoor born
d 112
Outdoor born
* P < 0.05
d 143
ADG – Summer Group
a
0.85
kg/d
0.80
0.75
b
0.70
0.65
Indoor-born
Outdoor-born
P < 0.05, SEM = 0.03
F:G – Summer Group
1.4
kg:kg
1.3
a
b
1.2
1.1
1.0
Indoor-reared
Outdoor-reared
P = 0.02, SEM = 0.002
Last Rib Backfat – Summer
Group
3.4
a
3.2
3.0
cm
b
2.8
2.6
2.4
2.2
2.0
Indoor-reared
Outdoor-reared
P = 0.04, SEM = 0.10
Outdoor vs. Indoor Finishing:
Summer Group
Measure
No. of pigs
Birth
Indoor
Outdoor
12
12
Rearing
Indoor Outdoor
12
12
1st rib BF, cm
3.8
3.7
3.8
3.7
Last rib BF, cm
2.5
3.1
2.8b
3.6a
LEA, cm2
49.7b
54.6a
51.3
52.9
Marbling score
2.3
2.7
2.5
2.5
Shear force, kg
2.1
2.1
2.2a
2.0b
L*
49.5
49.2
50.5a
48.1b
a*
1.4b
2.4a
1.6
2.2
b*
10.2b
10.9a
10.5
10.7
a,b
Means in the same row within a main effect with
different superscripts differ (P < 0.05).
Winter Group
• Pigs born outdoors were heavier at
d 28, 56, and 112.
• Pigs finished outdoors were:
heavier at d 140, higher F:G.
more backfat.
higher a* values (redder color).
no differences in sensory or WBS
values.
Outdoor vs. Indoor Finishing:
Winter Group
Measure
No. of pigs
Birth
Indoor
Outdoor
12
12
Rearing
Indoor Outdoor
12
12
1st rib BF, cm
3.9b
4.3a
4.1
4.2
Last rib BF, cm
2.1b
2.5a
2.2
2.4
LEA, cm2
43.5
40.2
42.7
40.9
Marbling score
1.3
1.3
1.5a
1.1b
Shear force, kg
2.2
2.1
2.1
2.1
53.6
55.0
54.9
53.8
L*
a*
4.2b
5.0a
4.2b
5.0a
b*
8.9b
9.8a
9.2
9.6
a,b
Means in the same row within a main effect with
different superscripts differ (P < 0.05).
Summary:
Birth Environment
• Pig birth environment played a
significant role in growth
throughout the finishing period.
• Advantages of outdoor-born pigs
include:
– increased ADG.
– larger loineye area.
Summary:
Rearing Environment
• Advantages of outdoor-reared pigs
include:
– lower L* values & higher a* values.
• Disadvantages of outdoor-reared pigs:
– increased backfat.
– higher F:G ratio.
• Both birth and finishing systems
resulted in pigs that had carcasses with
acceptable quality.
TTU Sustainable Pork® Farm
• 330 sows on 108 acres.
• Center pivot over the site.
• Old World Blue Stem on USDA-CRP
land.
• Use of automated feeding.
• All sows can be bred by AI.
• PIC C-22 and Newsham lines
used.
• A scaled-up version was started in
Colorado with 10,000 sows.
Breeding and Gestation
Farrowing
Weaning through finishing
Winter
Summer
Conventional
Challenges
•
•
•
•
•
•
Weather, particularly in cold climates.
Maintenance of ground cover.
Image of older outdoor systems.
Parasite and microbial controls.
Appropriate genotypes.
Higher level of stockmanship required.
Implications
• Many options for successful pig finishing
systems.
• Pigs finished in alternative systems had:
– similar performance measures (or improved
in some cases).
– loins were acceptable in color, water holding
capacity, and quality.
• Success depends on many factors
including:
– Environment
– Genetics
– Management level
This research was supported in
part by a USDA Fund for Rural
America grant and the Texas
Tech University College of
Agricultural Sciences and Natural
Resources.
Thanks for your attention.
Questions?