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In sheep production, artificial rearing used to save lambs born from large litters often results in uncertain profitability. The objective of this study was to achieve an early multiparameter characterization on a large number of lambs raised in artificial rearing, under standardized conditions to understand their future. A total of 715 Romane lambs, from 5 birth periods, were followed until weaning. Early characteristics such as birth weight, vigour, temperature, and growth were recorded on all lambs and serum IgG assays performed on only one part. Behavioural reactivity at 21 days was characterized by a test on 30% of the lambs. The main reason for artificially feeding a lamb is related to a problem of the ewe in 36% of the cases or of the lamb in 22% of the cases and related to the litter size for the remaining cases. Lambs were weaned on average at 12.5 2.4 kg and at 38 4.7 days of age. The 13% mortality rate is uniformly spread before and after 10 days. The weight at birth and the vigour are related to the survival and growth of the lamb. During the test at 21 days, the lambs who are looking for less proximity to human are the ones with the best vigour and the fastest growth. Beyond the control of the environment, our results confirm that the success of artificial rearing is conditioned by the early physical state and temperament of the young lamb., Dans les troupeaux ovins de race à viande, l’allaitement artificiel utilisé pour sauver des agneaux surnuméraires se traduit souvent par une rentabilité incertaine. L’objectif de cette étude était de réaliser une caractérisation multiparamétrique précoce sur un grand nombre d'agneaux élevés en allaitement artificiel, en conditions standardisées pour comprendre leur devenir. Un total de 715 agneaux de race Romane, issus de 5 périodes de naissance, ont été suivis jusqu’au sevrage. Des caractéristiques précoces telles que le poids à la naissance, la vigueur, la température, la croissance ont été enregistrées sur l’ensemble des agneaux et le dosage des IgG sériques effectué sur une partie seulement. La réactivité comportementale à 21 jours a été caractérisée au travers d’un test sur 30% des agneaux. La principale raison de mise en allaitement artificiel est liée à un problème détecté chez la brebis dans 36% des cas ou chez l’agneau dans 22% des cas et est liée à la portée multiple pour les cas restants. Les agneaux ont été sevrés à un poids moyen de 12,5 2,4 kg et à un âge moyen de 38 4,7 jours. Le taux de mortalité de 13% se répartit de façon équivalente avant et après 10 jours. Le poids à la naissance et la vigueur sont liés à la survie et la croissance de l’agneau. Lors du test à 21 jours, les agneaux qui recherchent moins la proximité de l’homme sont ceux qui ont la meilleure vigueur et la plus forte croissance. Au-delà de l’importance de la maitrise de l’environnement, nos résultats confirment que la réussite de l’allaitement artificiel est conditionnée par l’état physique et le tempérament du jeune agneau.

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International audience; Maternal behaviour is vital for the offspring survival. In animal production, improvement of maternal behaviour is becoming increasingly important in order to improve lamb survival particularly in extensive systems. Breed differences in maternal behaviour and genetic variation within breed have previously been described in several farm species. However, any study has investigated genetic loci underlying such behaviour in sheep. The aim of the study was to identify QTL associated with maternal behaviours in sheep using ovineSNP50 beadchip. Ewes reared outside were genotyped (n=470) and individually phenotyped after lambing for maternal behaviours in two standardized behavioural tests. QTL detection was performed by linkage, association and joint linkage and association analyses. Six main QTL regions identified on chromosomes 4, 13, 16, 21, and 23 showed significant associations with vocalizations. Four main QTL regions identified on chromosomes 4, 9, and 23 showed significant associations with maternal behaviour scores. Some of these QTLs contain interesting candidate genes, previously described to be associated with behaviours, which may explain a substantial amount of the genetic variation in maternal behaviours in sheep.

National audience; It has been reported that grooming behaviour may be related to status (calving, stress), health (mastitis) and production (milk yield). Consequently, accurate long-term monitoring of grooming behaviour could advantageously serve as a PLF solution to give alarms or well-being indicators. The main activities of dairy cows (resting, moving, eating, and so on) can be monitored indoors 24/7 using a real-time location system (RTLS). During the EU-PLF project (2012-16), the CowView RTLS (GEA) was assessed on 160 cows, equipped with tags, in our freestall barn enhanced with mechanical swinging brushes (Delaval). From the large positioning dataset collected (1 location/animal/s), we extracted grooming behaviour (scratching using the brush) with good sensitivity (80%) and a suitable positive predictive value (60%). The accuracy of our grooming detection algorithm was evaluated by comparing the results output against video analyses. Then, 23 dairy cows were monitored for 32 days, and patterns of grooming activity were analysed to study variations between cows and between days. 24-h video recording was re-visualized to explain the false detections observed, i.e. a cow detected in the brush area without grooming or a cow classified as grooming but not localized in the area. The kinetics of daily time spent grooming showed high day-today and inter-individual variations. Noisy tags appeared to be responsible for most of the false detections. Once smoothed, the kinetics modelled offer promising applications for detecting alterations in cow grooming behaviour patterns.

International audience; In sheep, social reactivity and reactivity to humans are relevant behavioral responses that are used to investigate the behavioral adaptation of farm animals to various rearing conditions. Such traits were previously reported as heritable and associated with several QTLs. However, few behavior-related genotype by environment (G x E) interactions have been reported to date. The experiment was performed on 2,989 male and female lambs issued from 30 sires. Every sire had progeny reared under both intensive and extensive conditions. After weaning, all lambs were individually exposed to two standardized behavioral tests. A broad range of behaviors including vocalizations, locomotion, localization, vigilance, and flight distance were assessed. Two complementary statistic approaches, with and without assumptions on the biological significance of behaviors, were performed to investigate social reactivity and reactivity to humans. G x E interactions were investigated based on the genetic correlations estimated for each factor or trait between farming conditions; those significantly different from 1 indicating a G x E. Environmental effects showed that social reactivity and reactivity to humans were higher in intensively reared lambs. The heritability of factors or traits used to measure social reactivity and reactivity to humans was similar in both rearing conditions. Estimated heritabilities were high for vocalizations in response to social isolation, moderate for locomotion and vigilance in response to social isolation, and low for both flight distance to an approaching human and proximity to a motionless human. No significant G x E interaction was found for vocalizations. G x E interactions were found for locomotion, vigilance and flight distance. Genetic correlations between both environments were low to moderate for vigilance, locomotion and flight distance. Vocalization in response to social isolation with or without human presence was identified as a robust trait and could be used to improve sheep sociability, independently of the environment. A G x E interaction was observed for behavioral reactivity to humans. Although moderate, the genetic correlation for this trait between intensive and extensive conditions could be used to select sires in the same environment by taking into account the G x E and to produce in different environments progenies that are less reactive to humans.

National audience; The evolution of sheep extensive farming systems including increased sizes of flocks, reduced support provided by humans and use of harsh environments implies that animals are required to have a greater level of behavioural autonomy in order to contribute to a sustainable production. Social reactivity and reactivity to humans are becoming particularly relevant traits, which have previously been reported with medium to high heritabilities (0.2 to 0.5). A genome wide association study of behavioural traits was carried on. Male and female Romane lambs (n=933) reared outside were individually phenotyped just after weaning in two tests based on the presence or absence of flock-mates and/or humans. The reactivity to isolation and humans was assessed by measuring bleats, locomotion, vigilance, flight distance towards humans. QTL detection was carried out on 9 half-sib families (103 lambs per family): lambs were genotyped using the Illumina ovineSNP50 beadchip. Data were analysed using linkage analysis and association analysis implemented with the QTLmap software. Among the main results, a region of the chromosomes OAR16 and OAR19 showed highly significant association at the 0.1% genome wide threshold with traits (high bleat and locomotion respectively) involved in the active social reactivity. Additional SNP associated with active social reactivity were found on chromosomes OAR2, 3, 5, 6, 8, 10, 12, 13, 17, 20, 21, 23, 24, 25 and 26 at the 1% or 5% chromosome wide threshold. Two QTL on chromosomes OAR12 and 21 showed highly significant association at the 0.1% genome wide threshold with traits (low bleat) involved in passive social reactivity. Additional SNP associated with the passive social reactivity (low bleat or vigilance) were found on chromosomes OAR26 at the 0.1% chromosome wide threshold, OAR3, 5, 7, 12, 13, 17, 20, 21, 22, 23 and 25 at the 5% chromosome wide threshold. Lastly, six QTL were also found to be associated with reactivity to humans on chromosome OAR23 at the 5% genome wide threshold, OAR2, 4, 12, 16 and 18 at the 5% chromosome wide threshold. These results will lead to better knowledge of genetic variability of behavioural traits in sheep. SNP polymorphisms found in this study may offer opportunities for improving behavioural adaptation in sheep.; L’évolution des systèmes d’élevage ovin allaitant conduit à une plus grande autonomie des animaux. Le comportement de l’animal devient alors un levier d’action pour faciliter l’adaptation des animaux et faciliter leur conduite. Nos travaux antérieurs sur ovins ont permis d’étudier la variabilité génétique de la réactivité sociale et à l’homme et montrent que ces caractères comportementaux sont moyennement à fortement héritables (h2=0,2 à 0,5). La poursuite de l’étude du déterminisme génétique de ces caractères comportementaux impliquait la recherche de locus à effet quantitatif (QTL). Un protocole de recherche de QTL basé sur un dispositif animal de 9 familles de pères et impliquant 931 agneaux génotypés avec la puce ovine 60kSNP a été conduit sur des ovins de race Romane. Des agneaux sevrés étaient soumis individuellement à des tests comportementaux basés sur la présence ou le retrait de congénères et/ou le contact avec l’homme pour évaluer leur réactivité sociale et à l’homme. Par la suite, la détection de QTL en lien avec la réactivité comportementale des agneaux était basée sur deux méthodes complémentaires d’analyse mises en œuvre avec le logiciel QTLMap : l’analyse de liaison multi-marqueurs et l’analyse d’association. Parmi les résultats, deux QTL très significatifs (seuil génomique 0.1%) associés à une réactivité active à l’isolement social ont été identifiés sur les chromosomes 16 et 19 (vocalisations hautes et locomotion respectivement). D’autres QTL associés à cette réactivité active ont été localisés sur les chromosomes 2, 3, 5, 6, 8, 10, 12, 13, 17, 20, 21, 23, 24, 25 et 26 aux seuils chromosomiques 1 ou 5%. Deux QTL très significatifs (seuil génomique 0.1%) associés à une réactivité passive à l’isolement social (vocalisations basses) ont été identifiés sur les chromosomes 12 et 21. D’autres QTL associés à cette réactivité passive (vocalisation basse ou vigilance) ont été localisés sur le chromosome 26 au seuil chromosomique 0.1% et sur les chromosomes 3, 5, 7, 12, 13, 17, 20, 21, 22, 23 et 25 au seuil chromosomique 5%. Enfin, six QTL associés à la réactivité à l’homme ont été mis en évidence sur les chromosomes 23 au seuil génomique 5%, et sur les chromosomes 2, 4, 12, 16 et 18 au seuil chromosomique 5%. Ces premiers QTL identifiés chez les ovins pour des caractères comportementaux contribuent à améliorer la connaissance du déterminisme génétique des caractères comportementaux chez les ovins. Ils permettent également d’envisager de renforcer l’adaptation des ovins à leur milieu d’élevage à partir de la prise en compte de caractères comportementaux sous réserve de leur intégration dans les objectifs de sélection.

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We wanted to investigate if relocation affects behaviour of dairy heifers. In the study 32 Holstein heifers were housed in pairs until they were 13 months old. 16 heifers stayed in the same pen with the same penmate (control). The pen and penmates of 16 heifers were changed 16 times between 11 and 13 months of age.