G Lagriffoul

French National Institute for Agricultural Research, Paris, Ile-de-France, France

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Publications (26)27.86 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Text: French dairy sheep breeding schemes require a significant number of alive AI rams due to the fresh semen constraints. This number may be reduced significantly (by 25% to 45%) in the case of genomic selection (GS). For the AI rams, in a GS design, a genomic selection rate (r1) at 3-month-old, completed by a progeny selection rate (r2) at 2.5-year-old, is replacing the only progeny selection rate (r) at 2.5-year-old performed in a classical scheme. Compared to actual optimum (r) of 0.5, r1 and r2values of respectively 0.3 and 0.8 allow an annual genetic gain increased by 15%, at same breeding cost of the AI rams. Genomic selection will be implemented in 2015 in Lacaune and in a near future in Manech breed. Keywords: Dairy sheep Lacaune, Manech Genomic breeding scheme
    10th World Congress on Genetics Applied to Livestock Production; 08/2014
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    ABSTRACT: Abstract Text: Genomic selection opens new perspectives for breeding programs of dairy ruminants. In France, several projects have enabled the creation of reference populations in dairy sheep and goats. Early studies have shown that the reliability of genomic evaluations using a GBLUP method in these species is lower than in Holstein dairy cattle breed. The single-step approach gives best predictions for candidates at birth (genomic evaluation accuracy obtained by cross validation for milk yield of 0.47 in Lacaune dairy sheep and 0.43 in goats’ breeds). The multi-breed approach is effective in goats by blending Alpine and Saanen breeds, but not in sheep. Finally, switching to genomic selection is planned in Lacaune dairy sheep and is under consideration for other sheep breeds. In goats, inclusion of major genes in genomic evaluations should be explored before switching to genomic breeding programs. Keywords: Dairy goats Dairy sheep Genomic selection
    10th World Congress on Genetics Applied to Livestock Production; 08/2014
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    ABSTRACT: Genomic selection opens new perspectives for breeding programs of dairy ruminants. In France, several projects have enabled the creation of reference popula-tions in dairy sheep and goats. Early studies have shown that the reliability of genomic evaluations using a GBLUP method in these species is lower than in Holstein dairy cattle breed. The single-step approach gives best predictions for candidates at birth (genomic evaluation accuracy ob-tained by cross validation for milk yield of 0.47 in Lacaune dairy sheep and 0.43 in goats' breeds). The multi-breed approach is effective in goats by blending Alpine and Saanen breeds, but not in sheep. Finally, switching to ge-nomic selection is planned in Lacaune dairy sheep and is under consideration for other sheep breeds. In goats, inclu-sion of major genes in genomic evaluations should be ex-plored before switching to genomic breeding programs.
    10 th World Congress of Genetics Applied to Livestock Production, Vancouver, Canada; 08/2014
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    ABSTRACT: A total of 416,670 lactations for 189,101 ewes from 3,603 sires and distributed across 1,978 herd-year groups were used to estimate genetic and environmental parameters of standardized milk yield (SMY(T)), fertility in ewe lambs (PR(1)), and fertility in adult ewes (PR(A)). Parameters were estimated with a multiple-trait sire linear model. Heritabilities for SMY(T), PR(1), and PR(A) were 0.27 (0.009), 0.04 (0.004), and 0.05 (0.004), respectively. These results were in accordance with the literature. The genetic correlation between PR(1) and PR(A) was 0.55, indicating that fertility is not the same trait in ewe lambs and adult ewes. The genetic correlation between milk yield and lamb fertility was not significantly different from zero. The genetic correlation between milk yield and fertility in adult ewe (-0.23) was in the range of antagonistic correlations reported in dairy cattle. Consequently, these results show that selection for milk yield can induce an indirect decrease in fertility. Nevertheless, no phenotypic decrease in fertility in artificial insemination matings has been observed in this population. This is the first time that correlation between milk yield and fertility is reported in sheep and further investigations are needed to confirm this result.
    Journal of Dairy Science 11/2008; 91(10):4047-52. · 2.57 Impact Factor
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    ABSTRACT: Artificial inseminations (n = 678 168) recorded during 5 years in five French artificial insemination (AI) centres (2 'Lacaune', 1 'Manech tête rousse', 1 'Manech tête noire' and 1 'Basco béarnaise') were analysed to determine environmental and genetic factors affecting the insemination results. Analyses within centre-breed were performed using a linear model, which jointly estimates male and female fertility. This model combined four categories of data: the environmental effects related to the female, those related to the male, the non-sex-specific effects and finally the pedigree data of these males and females. After selection, the environmental female effects considered were age, synchronisation (0/1) on the previous year, total number of synchronisations during the female reproductive life, time interval between previous lambing and insemination, already dry or still lactating (0/1) when inseminated, and milk quantity produced during the previous year expressed as quartiles intra herd * year. The environmental male effects were motility and concentration of the semen. The non-sex-specific effects were the inseminator, the interaction herd * year nested within the inseminator, considered as random effects and the interaction year * season considered as a fixed effect. The main variation factors of AI success were relative to non-sex-specific effects and to female effects. Heritability estimates varied from 0.001 to 0.005 for male fertility and from 0.040 to 0.078 for female fertility. Repeatability estimates varied from 0.007 to 0.015 for male fertility and from 0.104 to 0.136 for female fertility. These parameters indicate that genetic improvement of AI results through a classical polygenic selection would be difficult. Moreover, in spite of the large quantity of variation factors fitted by the joint model, a very large residual variance remained unexplained.
    animal 07/2008; 2(7):979-86. · 1.65 Impact Factor
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    ABSTRACT: The outcome of an insemination depends on male and female fertility. Nevertheless, few studies have incorporated genetic evaluation of these 2 traits jointly. The aim of this work was to compare genetic parameter estimates of male and female fertility defined as success or failure to artificial insemination (AI), using 8 different models. The first 2 models were simple repeatability models studying fertility of one sex and ignoring any information of the other. Models 3 and 4 took into account the information of the other sex by the inclusion of its random permanent environmental effect, whereas models 5 and 6 included fixed effects of the other sex. Models 7 and 8 were joint genetic evaluation models of male and female fertility ignoring or considering genetic correlation. Data were composed of 147,018 AI of the Manech Tête Rousse breed recorded from 2000 to 2004 corresponding to 79,352 ewes and 963 rams. The pedigree file included 120,989 individuals. Variance component estimates from the different models were quite similar; heritabilities varied from 0.050 to 0.053 for female fertility and were near 0.003 for male fertility. Correlations among estimated breeding values in the same sex using different models were higher than 0.99. The genetic correlation between male and female fertility was not significantly different from 0. These results show that for French dairy sheep with extensive use of AI, estimation of breeding values for male and female fertility might be implemented with quite simple models.
    Journal of Dairy Science 09/2007; 90(8):3917-23. · 2.57 Impact Factor
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    ABSTRACT: Data from 51,107 and 11,839 ejaculates collected on rams of the "Lacaune" and "Manech tête rousse" breeds, respectively, were analysed to determine environmental and genetic factors affecting semen production traits (ejaculate volume, semen concentration, number of spermatozoa and motility) in young (< or = 1 year) and adult (> or = 2 years) rams. Fixed effects and variance components were estimated using multiple trait animal models within each breed. For all traits, the main environmental effects identified were year, season, number of ejaculations, daily variation, interval from previous to current collection and age. Heritability estimates were moderate for volume, concentration and number of spermatozoa (0.12 to 0.33) and lower for motility (0.02 to 0.14). Genetic correlations between ages differed from 1 for all traits (0.14 to 0.90), indicating that semen characteristics corresponded to different traits in young and adult rams. Genetic and phenotypic correlations among traits within age category were globally similar for the different breeds and categories of animals.
    Genetics Selection Evolution 01/2007; 39(4):405-19. · 3.49 Impact Factor
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    ABSTRACT: The objective of this study was to build a character process model taking into account serial correlations for the analysis of repeated measurements of semen volume in AI rams. For each ram, measurements were repeated within and across years. Therefore, we considered a model including three environmental effects: the long-term environmental effect, which is a random year(*)subject effect, the short-term environmental effect, which is a random within year subject(*)collection effect, and the classical measurement error. We used a four-step approach to build the model. The first step explored graphically the serial correlations. The second step compared four models with different correlation structures for the short-term environmental effect. We selected fixed effects in the third step. In the fourth step, we compared four correlation structures for the long-term environmental effect. The model, which fitted best the data, used a spatial power correlation structure for the short-term environmental effect and a first order autoregressive process for the long-term environmental effect. The heritability estimate was 0.27 (0.04), the within year repeatability decreased from 0.56 to 0.44 and the repeatability across years decreased from 0.43 to 0.37.
    Genetics Selection Evolution 01/2007; 39(1):55-71. · 3.49 Impact Factor
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    ABSTRACT: Abstract Data from 51 107 and 11 839 ejaculates collected on rams of the "Lacaune" and "Manech tête rousse" breeds, respectively, were analysed to determine environmental and genetic factors affecting semen production traits (ejaculate volume, semen concentration, number of spermatozoa and motility) in young (≤1 year) and adult (≥2 years) rams. Fixed effects and variance components were estimated using multiple trait animal models within each breed. For all traits, the main environmental effects identified were year, season, number of ejaculations, daily variation, interval from previous to current collection and age. Heritability estimates were moderate for volume, concentration and number of spermatozoa (0.12 to 0.33) and lower for motility (0.02 to 0.14). Genetic correlations between ages differed from 1 for all traits (0.14 to 0.90), indicating that semen characteristics corresponded to different traits in young and adult rams. Genetic and phenotypic correlations among traits within age category were globally similar for the different breeds and categories of animals.
    Genetics Selection Evolution 01/2007; · 3.49 Impact Factor
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    ABSTRACT: The milking ability of Lacaune ewes was characterised by derived traits of milk flow patterns, in an INRA experimental farm, from a divergent selection experiment in order to estimate the correlated effects of selection for protein and fat yields. The analysis of selected divergent line effects (involving 34 616 data and 1204 ewes) indicated an indirect improvement of milking traits (+17% for maximum milk flow and -10% for latency time) with a 25% increase in milk yield. Genetic parameters were estimated by multi-trait analysis with an animal model, on 751 primiparous ewes. The heritabilities of the traits expressed on an annual basis were high, especially for maximum flow (0.54) and for latency time (0.55). The heritabilities were intermediate for average flow (0.30), time at maximum flow (0.42) and phase of increasing flow (0.43), and low for the phase of decreasing flow (0.16) and the plateau of high flow (0.07). When considering test-day data, the heritabilities of maximum flow and latency time remained intermediate and stable throughout the lactation. Genetic correlations between milk yield and milking traits were all favourable, but latency time was less milk yield dependent (-0.22) than maximum flow (+0.46). It is concluded that the current dairy ewe selection based on milk solid yield is not antagonistic to milking ability.
    Genetics Selection Evolution 01/2006; 38(2):183-200. · 3.49 Impact Factor
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    ABSTRACT: In four flocks, 215 dairy ewes were monthly sampled, throughout lactation, in order to study the relationship between subclinical intramammary infections (IMI) and milk individual SCC (iSCC). A decision rule proposes to consider an udder as healthy (specificity = 75%) if every iSCC are lower than 0.500 × 10 6 cells/ml and infected (sensitivity = 82%) if at least two iSCC are higher than 1 or 1.2 million cells/ml. At a flock level (annual geometric mean of bulk SCC), this rule allows the estimation of the prevalence of subclinical IMI: an annual bulk SCC of 0.650 × 10 6 cells/ml corresponds to a prevalence of 15%. These results are discussed.
    Small Ruminant Research 01/2006; 62:27-31. · 1.12 Impact Factor
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    11èmes Rencontres Recherches Ruminants, Paris, France; 12/2004
  • International Symposium "Future of Sheep and Goats Dairy Sector", Zaragoza, Spain; 10/2004
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    R Rupp, G Lagriffoul, J M Astruc, F Barillet
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    ABSTRACT: Records from 94,445 and 45,499 French Lacaune dairy ewes in first and second lactations, respectively, were used to estimate genetic parameters for somatic cell scores. Somatic cell count data came from an extensive recording scheme and sample testing that began in 1999 using the flocks enrolled in the official milk recording system. Somatic cell count data were from 2 to 4 test days per lactation. Lactation average and single test-day somatic cell scores were considered in multitrait sire models. The heritability estimate of lactation somatic cell score was close to 0.13 and similar for first and second parity. Heritabilities of somatic cell scores increased from first to fourth test day (from 0.07 to 0.11 in first lactation and from 0.05 to 0.13 in second lactation). Genetic correlations between somatic cell scores were high, usually more than 0.91, but lower between first test day and later test days in first lactation (0.64 to 0.88). The genetic correlations between lactation somatic cell score and milk yield, between lactation somatic cell score and fat content, and between lactation somatic cell score and protein content were 0.18, 0.04, and 0.03 in first lactation, respectively. The genetic antagonism between test day somatic cell score and milk yield measured in first lactation increased from beginning to the end of the lactation (0.05 to 0.23). This antagonism was slightly lower for somatic cell score in second lactation (from 0.09 to 0.14, and 0.08 for lactation mean). Environmental correlations in first lactation between lactation somatic cell score and milk yield, between lactation somatic cell score and fat content, and between lactation somatic cell score and protein content were -0.18, 0.13, and 0.30, respectively.
    Journal of Dairy Science 05/2003; 86(4):1476-81. · 2.57 Impact Factor
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    Rencontres Recherches Ruminants. 01/2003; 10:400.
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    ABSTRACT: A first genetic analysis of milk flow kinetics of Lacaune ewes collected with an INRA electronic jar are presented. The data set included 9288 morning individual milk flows of 751 ewes in first and second lactation recorded between 1997 and 2001 in INRA experimental flock. The heritability estimates range from 0.35 to 0.43 for LMMY, from 0.57 to 0.62 for LLLT et 0.50 for LPEAK. Genetic correlations between parities showed that kinetic traits are the same in first and second lactation. Moreover, genetic correlations between LMMY and milkability traits indicated an indirect favourable genetic response on milkability when selecting on milk yield.
    7th World COngress of Genetics Applied to Livestock Production, Montpellier, France; 08/2002
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    Rencontres Recherches Ruminants. 01/2002; 9:81.
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    ABSTRACT: The situation of the Lacaune dairy sheep breed has evolved dramatically during the last 40 years. In the 1960s, this dual purpose breed had a low milk yield and was compared in its local basin of production (the Roquefort area) with foreign high milk yield breeds, i.e. Friesian and Sarda breeds. The results showed very disappointing performances, both for lamb production for the Sarda breed, and for mortality for genotypes with more than 50% Friesian genes, the Friesian breed appearing to be poorly adapted to the local conditions. Therefore, in the 1970s a synthetic line called FSL (3/8 Friesian, 3/8 Sarda, 2/8 Lacaune) was created to avoid having more than 50% of the genes coming from an imported breed. Since the Lacaune genetic improvement program had become fully efficient in the 1980s, a crossbreeding strategy was disregarded in the Roquefort area. The Lacaune breed is now one of the high milk yield breeds, efficiently selected for milk yield and milk composition, type traits, and, in the near future, also for somatic cell count and udder score. Since 1992, 17 countries have officially imported Lacaune germplasm from France. However, to our knowledge, few comparisons are available, except in Spain with the Churra and Manchega breeds, and initially in Switzerland and Germany, and then in Canada, with the Friesian breed. The results appeared to be favorable for the Lacaune breed, in agreement with French experiments carried out with two divergent (high and low milk yield) Lacaune lines for a group of production traits including feed efficiency and milkability. However, we suggest to candidate importers: (i) to import Lacaune from the French Breeders Association to obtain the best available germplasm; (ii) to verify the adaptation of the Lacaune breed to their local breeding conditions, and/or to improve their husbandry systems (especially feeding) to account for the high milk yield of the breed.
    Livestock Production Science 01/2001;
  • International Symposium on the milking of Small Ruminants, Athens, Greece; 09/1998
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    Options Méditerranéennes, Série A. 01/1997; 33:43-57.