Benefits of Selecting for Commercial Performance

Benefits of Selecting for Commercial Performance

Benefits of Selecting
for Commercial
Performance
David Casey
PIC
Introduction
• Traditionally genetic improvement made in
purebred lines in nucleus conditions
– High health, well managed, good nutrition
• Pure lines crossed and perform in different
commercial environments
• Assumption or “hope” is that the best
animals at the nucleus level are the best in
commercial environments
– rg purebred and crossbred traits = 1
Introduction
• rg purebred and crossbred traits
– Growth
– Backfat
– Repro
.19 to .99
.21 to .88
.21 to .52
(Brandt and Taubert 1998;
Lutaaya et al. 2001)
(Nakavisut et al 2005)
• Breeding objective should be performance
at the commercial level
• Crossbred and purebred selection methods
superior to purebred selection in many
situations
(Bijma and Van Arendonk 1998;
Lutaaya et al. 2002)
Objective
• Predict the value of collecting crossbred
data and using a crossbred selection
objective for sire and dam line indexes
Modeling
• No. of observations – Sire line index
– Purebred
•
•
•
•
16 litters/boar
AGE, BF, LD, G-Fmort - all
ADFI - boars
pH – 1 gilt/litter
– Crossbred
• 10 litters/boar
• AGE, BF, LD, pH, G-Fmort – all
• ADFI – none
• Modeled from perspective of purebred pig
at off-test – selection candidate
Modeling
• No. of observations –Dam line index
– Purebred
• 8 litters/boar
• LEGS, AGE, BF, G-Fmort - all
• Reproduction traits – mother and aunts
– Crossbred
•
•
•
•
23 litters/boar
G-Fmort – all
AGE, BF– males
Reproduction traits except LWWT – gilts
• Pure and crossbred data were treated as
separate traits
Modeling
• rg purebred and crossbred traits - Sire line index
Trait
Age 90 Kg Carcass
Avg. Daily Intake
Backfat
Loin Depth
Loin pH-24 hr
G-F Mortality
Genetic Correlation
+0.58
+0.55
+0.81
+0.75
+0.72
+0.80
Modeling
• rg purebred and crossbred traits - Dam line index
Trait
Total number born
Stillborn
Pre-wean survival
Litter weaning weight
Sow Mortality
Leg Score
Genetic Correlation
+0.77
+0.78
+1.00
+1.00
+0.07
+0.62
Modeling
• Selection intensity 1.3
• Generation interval 1 year
• Genetic response for each crossbred trait
multiplied by economic value and
cumulated for 5 years discounting 5%/year
interest rate
Modeling Results – Sire Line
Data
Source
5 Yr Cum. Difference
Response/
from
Objective
Pig
baseline
Pure
Pure
Pure+Cross Cross
$ 6.15
$ 7.73
$1.58 (26%)
Modeling Results – Sire Line
Genetic SD units
0.3
0.2
P data; P obj
P+C data; C obj
0.1
0.0
-0.1
-0.2
-0.3
AGE
ADFI
BF
LD
pH
GF-mort
Modeling Results – Dam Line
Data
Source
5 Yr Cum. Difference
Response/
from
Objective
Pig
baseline
Pure
Pure
Pure+Cross Cross
$ 4.69
$ 5.56
$0.87 (19%)
Modeling Results – Dam Line
0.3
Genetic SD units
P data; P obj
0.2
P+C data; C obj
0.1
0.0
-0.1
-0.2
-0.3
TNB
Still
PWS
Leg
LWWT
Field Data – Sire Line
• 2 genetic evaluations
– Purebred data
– Purebred and Crossbred data
• 70 herd boars from one line with 80
crossbred offspring each >5600 pigs
• Top 20% boars for AGE, BF, LD, pH
identified w/ and w/out crossbred data
• Compared crossbred progeny performance
Field Data – Sire line
Age at 90 kg carcass
LSMeans of Progeny Age to 90 kg
carcass of top 20% sires
171.0
170.5
170.0
169.5
169.0
168.5
168.0
167.5
Difference 2.0 days
P data; P objective
P+C data; C objective
Field Data – Sire line
LSMeans of Progeny Backfat at 10th rib
of top 20% sires
Backfat, mm
16.8
Difference 0.7 mm
16.6
16.4
16.2
16.0
15.8
15.6
P data; P objective
P+C data; C objective
Field Data – Sire line
Loin Depth, mm
LSMeans of Progeny Loin Depth at 10th
rib of top 20% sires
69.9
69.8
69.7
69.6
69.5
69.4
69.3
69.2
69.1
69.0
68.9
Difference 0.6 mm
P data; P objective
P+C data; C objective
Field Data – Sire line
pH
LSMeans of Progeny Loin pH 24 hr post
mortem of top 20% sires
5.81
5.80
5.79
5.78
5.77
5.76
5.75
5.74
Difference 0.04
P data; P objective
P+C data; C objective
Conclusions
• Modeling results show
– Collecting crossbred data and using a
crossbred objective increases economic
response by
• 26% - Sire line index
• 19% - Dam line index
Conclusions
• Field data show
– Collecting crossbred data and using a
crossbred objective results in more accurate
selection of sires
– substantial impact on growth, lean, loin pH
Thank You