2008 ADSA-ASAS Joint Annual Meeting Indianapolis, July 7-11 Genetic Parameters of Saturated and...
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Transcript of 2008 ADSA-ASAS Joint Annual Meeting Indianapolis, July 7-11 Genetic Parameters of Saturated and...
2008 ADSA-ASAS Joint Annual Meeting
Indianapolis, July 7-11
Genetic Parameters of Saturated and Monounsaturated Fatty Acids
Estimated by Test-Day Model in Walloon Dairy Cattle
H. Soyeurt1, C. Bastin1, P. Dardenne2, F. Dehareng2, and N. Gengler1,3
1 Gembloux Agricultural University, Animal Science Unit, Belgium2 Walloon Agricultural Research Centre, Quality Department, Belgium
3 National Fund for Scientific Research, Belgium
Introduction
Interest for human health Milk fatty acid composition:
Saturated (SAT): 70% Monounsaturated (MONO): 25% Polyunsaturated : 5%
Introduction
Interest for human health Milk fatty acid composition:
Saturated (SAT): 70% (vs. 30%) Monounsaturated (MONO): 25% (vs. 60%) Polyunsaturated : 5% (vs. 10%)
Introduction
Interest for human health Milk fatty acid composition:
Saturated (SAT): 70% (vs. 30%) Monounsaturated (MONO): 25% (vs. 60%) Polyunsaturated : 5% (vs. 10%)
Modifying the milk fatty acid profile
General Objective
Sources of variation: Feeding Genetic:
• Previous studies: Moderate heritability estimates• Constant genetic parameters throughout the
lactation?
Aim of this study: Estimate the genetic parameters for SAT and
MONO in bovine milk using multi-trait random regression test-day models
Materials & Methods
Data set: 4 < DIM < 366 100,799 TD records (1991-2007)
• Including 4,666 spectra (March 2005 – July 2007)
11,626 primiparous Holstein cows 18,573 animals in the pedigree
Materials & Methods
Estimation of SAT and MONO contents New PLS calibration equations 114 milk samples in the calibration set
Indicator of butter hardness = SAT:UNSAT
g/dL of milk R²cv RPD
SAT 0.97 5.78
MONO 0.93 3.65
Studied traits
10
20
30
40
50
60
70
80
90
100
10 20 30 40 50 60 70 80 90 100
Chromatographic values
MIR
val
ues
pp
p
Saturated (g/dl of milk)
Monounsaturated (g/dl of milk)
Validation on 14 milk samples
R=0.92
R=0.92
R= correlation between reference and MIR data
Studied traits
N Mean SD
Milk (kg/day) 100,799 22.54 6.13
Fat (g/100g of milk) 100,799 4.05 0.68
Protein (g/100g of milk) 100,799 3.32 0.34
SAT (g/100g of milk) 4,666 2.63 0.54
MONO (g/100g of milk) 4,666 1.08 0.26
SAT (g/100g of fat) 4,666 66.26 6.15
MONO (g/100g of fat) 4,666 27.55 4.80
SAT:UNSAT 4,666 2.06 0.55
Studied traits
N Mean SD
Milk (kg/day) 100,799 22.54 6.13
Fat (g/100g of milk) 100,799 4.05 0.68
Protein (g/100g of milk) 100,799 3.32 0.34
SAT (g/100g of milk) 4,666 2.63 0.54
MONO (g/100g of milk) 4,666 1.08 0.26
SAT (g/100g of fat) 4,666 66.26 6.15
MONO (g/100g of fat) 4,666 27.55 4.80
SAT:UNSAT 4,666 2.06 0.55
Studied traits
N Mean SD
Milk (kg/day) 100,799 22.54 6.13
Fat (g/100g of milk) 100,799 4.05 0.68
Protein (g/100g of milk) 100,799 3.32 0.34
SAT (g/100g of milk) 4,666 2.63 0.54
MONO (g/100g of milk) 4,666 1.08 0.26
SAT (g/100g of fat) 4,666 66.26 6.15
MONO (g/100g of fat) 4,666 27.55 4.80
SAT:UNSAT 4,666 2.06 0.55
Materials & Methods
Models: Fixed effects:
• Herd x date of test• Class of 15 days in milk• Class of age
Random effects:• Herd x year of calving• Permanent environment• Additive genetic effect• Residuals
Materials & Methods
Models: Fixed effects:
• Herd x date of test• Class of 15 days in milk• Class of age
Random effects:• Herd x year of calving• Permanent environment• Additive genetic effect• Residuals
Second order Legendre Polynomials
Results: Lactation Effect
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 40 80 120 160 200 240 280 320 360
Days in milk
Est
imat
es
ppp
SAT:UNSAT MONO (g/100 g of milk)
SAT (g/100 g of milk) Fat (g/100 g of milk)
Results: Season Effect
0
0.5
1
1.5
2
2.5
3
3.5
1 2 3 4 5 6 7 8 9 10 11 12
Month of test day
Est
imat
es
ppp
SAT:UNSAT MONO (g/100g of milk)
SAT (g/100g of milk)
0
0.1
0.2
0.3
0.4
0.5
0.6
1 3 5 7 9 11 13 15 17 19 21 23 25
Class of 15 days in milk
He
rita
bil
ity
Fat (g/100g of milk) SAT (g/100g of milk) MONO (g/100g of milk) SAT:UNSAT
Results: Heritability (milk)
0
0.1
0.2
0.3
0.4
0.5
0.6
1 3 5 7 9 11 13 15 17 19 21 23 25
Class of 15 days in milk
He
rita
bil
ity
Fat (g/100g of milk) SAT (g/100g of milk) MONO (g/100g of milk) SAT:UNSAT
Results: Heritability (milk)
0
0.1
0.2
0.3
0.4
0.5
0.6
1 3 5 7 9 11 13 15 17 19 21 23 25
Class of 15 days in milk
He
rita
bil
ity
Fat (g/100g of milk) SAT (g/100g of milk) MONO (g/100g of milk) SAT:UNSAT
Results: Heritability (milk)
Results: Heritability (fat)
0
0.1
0.2
0.3
0.4
0.5
5 35 65 95 125 155 185 215 245 275 305 335 365
Class of 15 days in milk
Her
itab
ility
SAT (g/100g of fat)MONO (g/100 g of fat)
0
2
4
6
8
10
12
14
16
0 50 100 150 200 250 300 350
Days in milk
Va
ria
nc
es (
g²/
100
g o
f fa
t²)
Herd x calving date Permanent Environment Genetic
Results: Variances (%SAT)
Mobilization of lipids from adipose tissue ???
Results
-1
-0.5
0
0.5
1
5 80 155 230 305
Days in milk
Gen
etic
corr
elat
ion
ppp
Milk (kg/day) - SAT (g/100g of milk) Fat - SAT (g/100g of milk) Protein - SAT (g/100g of milk)
SAT - MONO (g/100g of milk) SAT (g/100g of milk) - SAT:UNSAT
Conclusion
Results confirm the genetic variability of fatty acids
Genetic parameters of fatty acids change throughout the lactation: Highest heritability and additive genetic variance at
the beginning and at the end of the lactation Correlations between SAT and MONO change within
the lactation
Partly influenced by the fatty acid production??
Thank you for your attention
Acknowledgments
FNRS grants:
2.4507.02
F.4552.05
2.4623.08
Walloon Breeding Association
Milk Committee of Battice