Breeding goals in French dairy sheep breeds

Selecting milk composition and mastitis resistance by using a part lactation sampling design in French Manech red faced dairy sheep breed F. Barillet ...
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Selecting milk composition and mastitis resistance by using a part lactation sampling design in French Manech red faced dairy sheep breed F. Barillet 1, J.M. Astruc 2, G. Lagriffoul 2, X. Aguerre 3, B. Bonaïti 4 1

INRA – UR 631 Toulouse, France 2 IE - Toulouse, France 3 CDEO Ordiarp, France 4 INRA – UR 337 Jouy-en-Josas, France 36th ICAR Session, Niagara Falls, USA, 2008

Génétique Animale 1

Breeding goals in French dairy sheep breeds

Roquefort area : LACAUNE breed Breeding goals : 50 % ( milk traits) + 50 % ( SCC (mastitis) & udder ) Plus PrP gene (scrapie resistance)

PYRENEEAN MOUTAINS MANECH RED FACED BREED

Breeding goals : 100 % milk traits Plus PrP gene (scrapie resistance) accounting in the future for SCC (mastitis) in Manech red faced breed 36th ICAR Session, Niagara Falls, USA, 2008 2

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BREEDING BREEDING SCHEME SCHEME IN IN MANECH MANECH RED RED FACED FACED (2001 (2001)) 210 flocks in AC recording

65,825 ewes

640 rams born from assortative matings

Nucleus flocks

220 rams in breeding centres of young rams

Animal insemination 1 AI centre (AI) 13,800 AI

130 sampling rams

400 rams

Commercial flocks

32,400 AI 90 proven rams

73 flocks in D recording 19,000 ewes 850 Flocks without recording / 150,000 ewes 36th ICAR Session, Niagara Falls, USA, 2008 3

Published estimates of genetic trend for milk yield in dairy sheep (milk yield expressed as mature equivalent lactation) (J.M. Astruc et al., 2002; A. Carta et al., 2004; A. Legarra et al., 2003)

Country

Breed

Period

Annual genetic trend % in population litres mean

AI rate in the nucleus flocks

FRANCE

Lacaune Manech (Blond-faced)

1986-1999 1986-1999

2.2 % 2.3 %

5.8 l 4.2 l

85 % 54 %

ITALY

Sarda

1990-2002

1.2 %

2.0 l

12 %

SPAIN

Latxa (Blond-faced) Latxa (Black-faced)

xxxx-2003 xxxx-2003

2.9 l 3.0 l

36th ICAR Session, Niagara Falls, USA, 2008 4

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Phenotypic, genetic and environmental trends in Manech red faced breed for milk yield (expressed in mature equivalent lactation) 190

Milk yield (litres)

Between 1985 and 2006 - Annual phenotypic gain : 5.4 litres - Annual genetic gain : 4.2 litres

170 150 130

L

110 90

96 97

94 95

Breeding Value

98 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06

Milk yield (phenotype)

93

91 92

89 90

87 88

85 86

70

Flock x year effect

YEAR

36th ICAR Session, Niagara Falls, USA, 2008 5

60

GENETIC TREND FOR MANECH RED FACED RAMS (animal-model evaluation)

5

40 30

3 2 1 0 -1

20

-2

Fat Content EBV

20 02

20 01

99 20 00

98

97

96

95

94

93

92

91

0

Protein Content EBV

-3 Now -4 on milk composition -5 20 04

Main effort on PrP selection

20 03

10

19 90

MILK YIELD (litres)

ANNUAL GENETIC GAIN bettween 1990 and 2004 4.0 litres for Milk yield - 0.28 g/l for Fat content - 0.11 g/l for Protein content

FAT AND PROTEIN CONTENT gl-1

4 50

YEAR OF BIRTH

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Evolution of the AI in Manech red faced breed according to the PrP genotype of the rams 70000 AI rams ARR/ARR ƒ The specific situation of the Manech red faced breed

Number of AI

60000

(specific for affected flocks)

50000

AI rams ARR/ARR

40000 30000

AI rams ARR/ARQ

20000 10000 0 2000

AI rams ARQ/ARQ

2001

2002

2003

2004

36th ICAR Session, Niagara Falls, USA, 2008 7

Milk composition and SCC recording (1/2)

ƒ Part-lactation sampling design already used in Manech red faced (MRF) breed for milk composition: fat and protein contents

ƒ Since 2002, part-lactation sampling design implemented in first lactation also for somatic cell count (SCC), i.e. assuming it is also relevant for SCC in MRF breed (despite no demonstrated in this breed compared to Lacaune for which is was done ) 36th ICAR Session, Niagara Falls, USA, 2008 8

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Milk composition and SCC recording (2/2)

ƒ Part-lactation sampling design available now for SCC in MRF breed since 2002

ƒ Are genetic parameters for milk traits and SCC (with such a simplified design) comparable in MRF breed and in Lacaune breed, i.e comparable in dairy sheep and dairy cattle ?

36th ICAR Session, Niagara Falls, USA, 2008 9

First simplification: AC design for milk yield Lambing

Weaning

Suckling (or suckling plus milking)

Drying off

MILKING ONLY

MONTHLY RECORDING OF MILK YIELD

AC Method X X X X X Milk yield (recording of one of the 2 daily milkings, example morning) 36th ICAR Session, Niagara Falls, USA, 2008 10

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Part-lactation sampling design Milk composition and SCC : part-lactation sampling within AC method for milk yield

AC method : record of 1 of the 2 milkings

Parities 1

X

X

X

X

X

X

Milk yield Sampling for FC, PC & SCC

36th ICAR Session, Niagara Falls, USA, 2008 11

Characteristics of the analysed MRF data Characteristics Breed Study period Animals in data (first lactation) Animals in pedigree

Manech red faced 2002-2007 58,378 118,313

Mean ± standard deviation of the traits Lactation number Length of milking period, d (after 30-d suckling period) Milk yield, litre Fat content, g/l (part lactation sampling) Protein content, g/l (part lactation sampling) Lactation SCS (LSCS) (part lactation sampling)

first lactation 132 d ± 42 149.2 l ± 63.1 61.1 g/l ± 8.8 47.8 g/l ± 3.9 3.36 ± 1.38

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Genetic parameters (Manech red faced breed) MY

FY

PY

FC

PC

LSCS

MILK yield

0,33

+0,87

+0,92

-0,39

-0,44

+0,21

FAT yield

+0,84

0,28

+0,91

+0,10

-0,16

+0,25

PROTEIN yield

+0,96 +0,82

0,30

-0,16

-0,06

+0,25

FAT content

-0,17

+0,34

-0,16

0,28

+0,60

+0,07

PROTEIN cont.

-0,34

-0,20

-0,04

+0,16

0,51

+0,07

LSCS

-0,26

-0,16

-0,17

+0,16

+0,38

0,10

Heritabilities on diagonal Genetic correlations above the diagonal Environmental correlations under

Genetic parameters 58,378 first lactations

between 2002 and 2007

36th ICAR Session, Niagara Falls, USA, 2008 13

Genetic parameters : comparison Lacaune (121,283 first lactations) et MRF (58,378 first lactations) héritabilities

Genetic correlation with milk yield (MY)

Milk Yield

0,32 et 0,33

Fat content

0,41 et 0,28

- 0,43 et - 0,39

Protein content

0,51 et 0,51

- 0,48 et - 0,44

LSCS

0,15 et 0,10

0,15 et 0.21

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Conclusion (1/2)

ƒ Validation of the part-lactation sampling design for SCC in MRF breed as in Lacaune breed (comparable genetic parameters for milk traits and SCC)

ƒ Genetic relationship between udder health (SCC) and milk production traits is antagonistic in dairy sheep as in dairy cattle (udder health will be deteriorated when selecting only milk traits) 36th ICAR Session, Niagara Falls, USA, 2008 15

Conclusion (2/2)

ƒ the part-lactation sampling design is relevant both for milk composition and SCC selection in dairy sheep

ƒ such a very simplified design (a very few test days recorded per ewe) needs to maintain relevant accuracy for each individual test day as presently defined in ICAR requirements for recording devices and for analytical quality analysis of sheep milk. 36th ICAR Session, Niagara Falls, USA, 2008 16

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Thank you for your attention

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