John A. Smith DVM, MS, MAM
BROILER PLACEMENT DENSITY: IMPACTS ON PERFORMANCE, HEALTH
DENSITY AND ABF PRODUCTION Ò It
has been suggested that looser density aids or is necessary for ABF production to reduce NE Ò I do not know and if I did, I could not tell you!! Ò Looser density does improve performance, but at the expense of profit per unit area Ò This talk will review controlled studies in pen trials, and discuss a real-life example in commercial ABF birds
LITTLE INFORMATION ON DENSITY AND NE Ò There
is only one paper in the literature directly addressing effect of density on NE: É Tsiouris,
V et. al. High stocking density as a predisposing factor for necrotic enteritis in broiler chicks. Avian Pathol. 44:59-66, 2015.
Ò 4
pens of 60 each, straight run Cobb 500. 2 pens at 15 birds/m2 (low), 2 at 30/birds m2 (high) Ò One low and one high pen challenged with a standard cocci-Cl. perfringens challenge @ 17-20 days of age, other two pens unchallenged controls
DENSITY AND NE Ò The
challenge caused no mortality but did impair weight gain and FCR in both the low and high density groups Ò Density did NOT impair weight gain or FCR in either the control or challenged groups, and in fact weight gain and FCR were numerically BETTER in the high density pens in both the control and challenged groups! Ò Stopped at 21 days; effects may occur later
DENSITY AND NE Ò High
density did statistically increase NE lesion scores in the challenged groups, demonstrating a significant interaction between density and challenge Ò There were also higher levels of Cl. perfringens in ceca of the birds in the higher density pens Ò So, density may have an adverse effect, but did not cause economic impacts in this study
DENSITY, WELFARE, AND ECONOMICS Ò Various
customers, welfare certifying agencies, and audit instruments specify differing densities due to welfare concerns Ò Scientific data to validate the varying recommendations are scarce Ò We as an industry have two reasons to desire sound guidelines: economic and ethical Ò This talk will focus on the economics
2007 DENSITY RANGES (ESTEVEZ) Ò FMI-NCCR
6 lb/ft2 Ò RSPCA 6.14 lb/ft2 Ò Switzerland, Sweden 6.13-7.35 lb/ft2 Ò EU 6.76-8.6 lb/ft2 Ò NCC 6.5-9.0 lb/ft2 Ò UK 8.17 lb/ft2 Ò Denmark/Netherlands 9.2-11.6 lb/ft2 Ò “Health and welfare compromised if space <6.95-7.77 lb/ft2” Ò
Estevez, I. Density allowances for broilers: Where to set the limits? Poult Sci 86:1265-1272. 2007
PROS FOR HIGH DENSITY: FOLLOW THE $$ É Reduced
fuel cost for brooding É Reduced labor cost (grower pay per pound) É Reduced capital costs for housing and equipment per head or pound—if you own the housing É Generally speaking, profit per unit area is highest at the highest densities—to a limit É Most researchers agree that environmental quality has more impact than raw density; however, in the real world, density does impact environment
CONS FOR HIGH DENSITY: Ò Decreased
performance:
É Daily
gain É Final weight for age É Feed conversion Ò Litter
quality, foot pad issues Ò Scratches, carcass quality Ò Air quality, disease pressure, livability, condemnation
WHERE IS THE ECONOMIC TIPPING POINT?? Ò Ethical
issues aside: Ò Could we improve the bottom line (cost per pound of meat through evisceration) by cutting density and increasing grower pay per pound to keep the grower solvent? Ò If so, where is the tipping point??? Ò Is it the same in ABF and conventional production?
PEN TRIALS VARY TREMENDOUSLY IN TERMS OF MATERIALS AND METHODS: Ò Pen
sizes, total birds per pen—does not replicate the situation in a 50’ X 500’ house!! Ò Feed space per bird—some control, many don’t, and speculate feeder space is part of the effect Ò How to separate general density effect from feeder space effect; could you increase density if you increased feeder space? Ò Nipples per bird—same issues; most claim the water space is NOT an issue
PEN TRIALS VARY TREMENDOUSLY IN TERMS OF MATERIALS AND METHODS CONTINUED: Ò Ventilation
in pen trials is usually carefully controlled (IACUC); in real world, increased density may impact air quality, temperature Ò Some pen trials keep the density the same by adjusting pen size for mortality, some don’t Ò Almost none do the equivalent of partial brooding then turn out, although some assess density effects at different ages during a trial
PEN TRIALS VARY TREMENDOUSLY IN TERMS OF MATERIALS AND METHODS CONTINUED: Ò Pen
trials vary tremendously in:
É Final
age, final weight; these have changed É Sexed or straight run; sex effects do vary Ò Many
examine effects at different age points in the same trial, and effects often vary with age, sex, and weight at the point of examination Ò Many trials exist from the 1980’s to now; the bird has changed tremendously; how far back can we go and still be germane for today?
FIVE TRIALS Year
Breed
Sex
Pen Size , Ft2
Final Age, Days
1992
Hubbard x Hubbard
SR
24
49
2002
Ross x Ross
F
151
38, 42
2005
Ross x Cobb 500
M
45
49
2006
Ross x Ross 708
M
60
35
2006
Ross x Cobb
M
45
49
1. Cravener TL, Roush WB, Mashaly MM. Broiler production under varying population densities. Poult Sci, 1992, 71:427-33 2. Feddes JJ, Emmanuel EJ, Zuidhoft MJ. Broiler performance, body weight variance, feed and water intake, and carcass quality at different stocking densities. Poult Sci 2002, 81:774-9 3. Dozier WA, Thaxton JP, Branton SL, et al. Stocking density effects on growth performance and processing yields of heavy broilers. Poult Sci 2005, 84:1332-8 4. Dozier WA, Thaxton JP, Purswell JL, et al. Stocking density effects on male broilers grown to 1.8 Kg body weight. Poult Sci 2006, 85:344-51 5. Thaxton JP, Dozier WA, Branton SL, et al. Stocking density and physiological adaptive responses of broilers. Poult Sci 2006, 85:819-24
FIVE TRIALS Year
Feeder Space
Drinker Space
Density Adjusted?
Lights
1992
Adjusted 2.7”/bird
Fixed, 1 Plasson
No
24 hours
2002
Fixed, 177 “/pen
5, 10, 15, 20
Yes
23 hours
2005
Fixed, 1 pan/pen
Fixed, 9 nipples
No
Increasing, Max 5 D
2006
Fixed, 2 tube feeders
Fixed, 15 nipples No
Increasing, Max 5 D
2006
Fixed, 1 pan/pen
Fixed, 9 nipples
Increasing, Max 5 D
No
Only Feddes 2002 specified coccidiosis and NE control; Bacitracin Zinc Others do not mention coccidiosis control
CURRENT NCC GUIDELINES Ò Bird
Weight Range and Maximum Stocking Density: É Below 4.5 lbs live weight = 6.5 pounds per ft2 É 4.6 to 5.5 lbs live weight = 7.5 pounds per ft2 É 5.6 to 7.5 lbs live weight = 8.5 pounds per ft2 É More than 7.5 lbs live weight = 9.0 pounds per ft2 Ò EU: 6.76-8.6 lb/ft2
TRIAL 1, 1992, 49 DAYS, SR, CRAVENER Ft2/bird
Lb/Ft2
Weight
Birds/pen
0.54
7.76
4.17B
42
0.75
5.85
4.40A
30
0.97
4.70
4.54A
24
1.18
3.83
4.52A
20
NCC: 6.5 for <4.5lb Ft2/bird
FCR
% Mortality
% Blisters/burns
0.54
2.25
1.9B
30.4A
0.75
2.20
5.2A
2.5B
0.97
2.22
0B
0.63B
1.18
2.33
2.5AB
0B
TRIAL 1, 1992, 49 DAYS, SR Ò BW:
trend with density, statistically the three looser densities better than the densest Ò FCR: Was better at higher density at 5 weeks, but NS at 6 or 7 weeks Ò Mortality: no clear pattern or trend Ò Blisters and burns: trend with density, but statistically, the three looser densities better than the densest
TRIAL 1, 1992, 49 DAYS, SR Heterophil to Lymphocyte ratio is an indicator of stress; high is bad, low is good Ò Could not document stress from crowding; many other studies find similar results Ò Profit potential was highest at 0.54 Ft2/bird Ò
Ft2/bird
H:L Ratio
0.54
.282B
0.75
.297B
0.97
.424A
1.18
.445A
“Main behavioral categories remained mostly unchanged even at high densities under experimental and commercial conditions.” (Estevez)
TRIAL 2, 2002, 38-42 DAYS, â&#x2122;&#x20AC;, FEDDES Ft2/bird
Lb/Ft2
Weight
BW CV %
Birds/pen
0.45
9.605a
4.18b
13.0b
260
0.60
7.086b
4.25b
13.6b
195
0.75
5.857c
4.39a
13.4b
156
0.90
5.714d
4.21a
15.3a
130
NCC 6.5 <4.5 lb Ft2/bird
Feed Consumed
FCR
Water Consumed
Water/feed
0.45
6.61b
1.72
5,546a
1.85a
0.60
6.75b
1.72
5,420a
1.75b
0.75
7.00a
1.73
5.399a
1.70c
0.90
6.58b
1.70
5,093b
1.70c
TRIAL 2, 2002, 38-42 DAYS, ♀ Ò BW
again increased with decreasing density, but peaked at the next-to-lowest density; CV actually increased at the lowest density Ò FCR again was not significantly impacted Ò Water consumption appears to increase with density; nipple numbers in this trial did not significantly impact water consumption Ò Mortality again was not impacted by density Ò Density did not impact breast yield
TRIAL 2, 2002, 38-42 DAYS, â&#x2122;&#x20AC; Ft2/bird
% Condemnation
% Scratches
0.45
2.3
31
0.60
1.3
31
0.75
0.7
26
0.90
1.3
30
TRIAL 3, 2005, 49 DAYS, â&#x2122;&#x201A;, DOZIER Ft2/bird
Lb/Ft2
Weight
Feed Consumed
FCR
Birds/pen
0.79
9.22
6.53
11.86
1.847
56
0.89
8.19
6.70
12.21
1.826
50
1.01
7.17
6.81
12.24
1.825
43
1.18
6.14
6.96
12.41
1.814
37
p
NCC 8.5
0.011
0.029
0.093
Ft2/bird
% Mortality
% Moisture
Pad Score
% Scratches
% Tears
0.79
7.5
46.6
1.0
53.5
14.5
0.89
7.3
43.7
0.9
58.7
13.3
1.01
7.8
39.3
0.6
51.4
15.5
1.18
3.6
38.8
0.5
41.9
13.5
p
0.188
0.025
0.001
0.021
0.965
TRIAL 3, 2005, 49 DAYS, â&#x2122;&#x201A; Ft2/bird
Birds/Nipple
Feed Inch/bird
Fillet %
Tender %
0.79
6.2
0.77
16.3
3.61
0.89
5.6
0.86
16.5
3.56
1.01
4.8
1.00
16.6
3.55
1.18
4.1
1.16
16.4
3.55
0.720
0.129
p
TRIAL 3, 2005, 49 DAYS, ♂ Ò Growth
rate and FCR were better as density increased at 17 days (more warmth for brooding), but this effect was lost with age Ò Rate of growth was more adversely affected as the birds progressed in BW, and for 1-49 days the effect was significant on BW and feed consumption, and approached significance for FCR (p=0.093).
TRIAL 3, 2005, 49 DAYS, ♂ Ò Some
of the growth suppression may be due to restricted feeder space Ò Litter moisture, pad lesions, and scratches increased significantly with density, but lameness did not Ò Breast yield % was not significantly affected, but the decrease in BW means less meat
TRIAL 4, 2006, 35 DAYS, â&#x2122;&#x201A;, DOZIER Ft2/bird
Lb/Ft2
Weight
Feed Consumed
FCR
Birds/pen
0.50
7.78
3.95
6.09
1.580
120
0.57
6.76
3.95
6.06
1.571
105
0.67
6.14
4.12
6.28
1.558
90
0.80
5.12
4.19
6.30
1.535
75
p
NCC 6.5
0.0001
0.0001
0.0001
Ft2/bird
% Mortality
% Moisture
Pad Score
% Scratches
% Tears
0.50
1.9
43.3
1.238
45.8
15.6
0.57
1.5
36.4
0.963
57.9
12.9
0.67
1.9
36.0
0.750
58.3
11.5
0.80
2.2
29.6
0.375
50.0
8.3
p
0.545
0.0001
0.0001
0.594
0.146
TRIAL 4, 2006, 35 DAYS, â&#x2122;&#x201A; Ft2/bird
Birds/Nipple
Feed In/bird
Fillet %
Tender %
0.50
8
0.75
15.6
3.60
0.57
7
0.87
15.8
3.64
0.67
6
1.02
15.9
3.52
0.80
5
1.22
16.1
3.56
0.006
0.196
p Ft2/bird
Hetero:Lymph
Corticosteroids
Glucose
Cholesterol
0.50
0.90
897
264
132
0.57
1.03
963
250
136
0.67
0.94
911
248
135
0.80
0.92
912
242
131
p
0.95
0.96
0.11
0.77
TRIAL 4, 2006, 35 DAYS, ♂ Ò Similar
results with bigger birds Ò BW gain better with higher density early, but lost by 35 days Ò Increasing density negatively impacts BW, feed consumption, and FCR Ò Total mortality not affected
TRIAL 4, 2006, 35 DAYS, ♂ Ò Density
did not influence physiological indicators of stress Ò As in previous trial, litter moisture and foot pad lesions were impacted Ò Contrary to Trial 3, scratches were not affected, and fillet yield was affected Ò “A universal stocking density is not appropriate for broilers of various body weights”
TRIAL5, 2006, 49 DAYS, ♂, THAXTON Ò This
trial was similar to the last two, but looked mainly at the physiological measures of stress Ò In two trials, density varied from 4.10 to 11.26 lb/ft2 Ò Density did NOT cause changes in corticosterone, glucose, cholesterol, total nitrites, or the heterophil:lymphocyte ratio indicative of stress
SUMMARY: IMPACT OF INCREASING DENSITY Study
Age
Weight
FCR
Mortality
Foot Pads Stress
Cravener
49
Sig
No pattern, Not Sig
NP, NS
Sig
Feddes
38-42
Sig
No pattern, Not Sig
Dozier
49
Sig
P=0.093
NP, NS
Sig
Dozier
35
Sig
P=0.0001
NP, NS
Sig
Thaxton
49
NP = No Pattern NS = Not Significant
Sig
NP, NS NS
REAL LIFE EXPERIENCE IN ABF BIRDS Ò We
began supplying a customer who desired HFAC Certification Ò Among other requirements (such as “environmental enrichment”), they require 1 ft2/bird on our 6.4 lb bird (6.4 lb/ft2) (NCC 8.5) Ò We assigned a small group of growers with 2house farms to comply with this program; average growers Ò Only 1 flock/week, so numbers are small
REAL LIFE EXPERIENCE Generally older farms (2 houses) Ò An average farm would have a deviation from prime cost of 0.00¢ Ò Average deviation for the HFAC farms prior to starting the HFAC program: Ò
1-year deviation from prime cost: +0.031¢ É 2-year deviation from prime cost: +0.006¢ É
1-year deviation company range: -0.64¢ to +0.72¢ (removing two outliers with major wrecks) Ò 2-year deviation company range: -0.49¢ to +0.53¢ (again removing two outliers with major wrecks) Ò
REAL LIFE EXPERIENCE Ò Ò Ò Ò Ò Ò Ò Ò
HFAC was ABF 6.4 lb contract, Hubbard M-99 x Cobb 500 Started 6/13/13, about 1 flock/week for 8 months Downloaded all settlements for the ABF 6.4 contract Sorted by density Compared flocks with 0.8 to 0.85 ft2/bird placement density (average 0.843) to the HFAC flocks at 1.0 density Same feeds, feeding schedule, breeds, etc, scattered evenly across the 8 months First 2 months: Deccox/Amprol; 3 months vaccine-Amprol; 3 months Nicarb-Coyden (no ionophores, no antibiotics) Minimal NE in the entire operation during this time
REAL LIFE EXPERIENCE: PERFORMANCE Density
Flocks
Age
BW
GPD
FCR
0.80-0.85
903
48.2
6.42
0.133
1.890
1.00
37
46.7
6.45
0.138
1.838
1.43
0.03
0.005
0.052
Difference Density
Adj. FCR
Livability
Condemn
Prime Cost
7-day Mort
0.80-0.85
1.856
96.40
1.031
16.608
1.12
1.00
1.803
97.22
0.952
16.189
0.92
Difference
0.053
0.824
0.079
-0.416
0.20
REAL LIFE EXPERIENCE: GROWER PAY Ò 50’
x 500’ = 25,000 ft2
É @0.85
= 29,412 head x 96.5% live = 28,383; @ 6.4 lb and $0.059 / lb = $10,717.41 per flock É @1.00 = 25,000 head x 97% live = 24,250; @ 6.4 lb and $0.069 / lb = $10,708.80 É 1¢ per pound more É For the US broiler industry, that is a LOT of money!
REAL LIFE EXPERIENCE: ECONOMICS Ò 1
M head; fixed chick, feed, overhead, vaccine, catch and haul, and processing costs that approximate current costs Ò Conventional: used 1.85 FCR, 96.5% livability, and 6.4 lb BW to figure tons of feed used; used $0.059/lb grower pay and 1.00% condemn Ò HFAC: used 1.80 FCR, 97% livability, and 6.4 lb BW to figure tons of feed used; used $0.069/lb grower pay and 0.95% condemn Ò Figured total live cost and total cost through evisceration
REAL LIFE EXPERIENCE: CONCLUSIONS Ò Total
live cost: HFAC 0.008¢/live pound better ($0.00008) Ò Cost through evisceration: HFAC 0.01¢/good pound better ($0.0001); $640.00 per week on 1 M 6.4 lb birds; About break even Ò Over time, would it be better, not as good??? Effect on best, worst growers? Ò Same metrics for conventional (not ABF)??; Vaccine only?? Ò Need 18% more square feet!!—Logistical efficiency
DENSITY AND NE Ò Vaccine
purveyors recommend brooding density long enough to achieve early cycling Ò Early performance is often better at higher density Ò Adverse effects of density tend to occur later in the grow-out Ò NE generally occurs +16 days of age Ò Will loose density help NE???