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Reintroduction programmes are more and more frequently undertaken to save species threatened with extinction. However, they generally engender a genetic diversity loss and an inbreeding increase. These demogenetic effects reduce individuals’ fitness and increase the reintroduced population’s extinction risk, therefore compromising the reintroduction’s success. Numerous guidelines have been formulated by scientists and managers in order to limit these effects and their consequences. The Rhône streber, Zingel asper (Linnæus, 1758), is a critically endangered benthic percid endemic to the Rhône catchment. It was reintroduced in the Drôme river from the propagation in captivity of two source populations, the Beaume and Durance rivers. We evaluated the adopted strategy through a five years demogenetic monitoring of the reintroduced population based on the microsatellite data form 376 Rhône strebers sampled in the Drôme river. We also tested the effect of the source population and the individual genetic diversity on two life-history traits : growth and body condition. The guidelines’ application enabled to limit genetic diversity loss and inbreeding during the reintroduction of the Rhône streber in the Drôme river. Source population influenced growth and body condition but individual genetic diversity did not. The Durance source population, the most genetically diverse, showed no significant alteration of its life-history traits in the Drôme river. Lastly, a less favorable sector of the Drôme river for the species was identified. This study provides important feedback on the reintroduction programme which will be useful for the planning of potential future reintroductions.; Le recours à des opérations de réintroduction pour la sauvegarde d'espèces menacées d'extinction est de plus en plus fréquent. Cependant, de telles opérations engendrent généralement une perte de diversité génétique et une augmentation de la consanguinité. Ces effets démogénétiques font diminuer la valeur sélective des individus et augmenter le risque d'extinction de la population réintroduite, compromettant ainsi le succès des réintroductions. De nombreuses recommandations ont été formulées par les scientifiques et les gestionnaires dans le but de limiter ces effets et leurs conséquences. L'apron du Rhône, Zingel asper (Linnæus, 1758), est un percidé benthique en danger critique d'extinction endémique du bassin du Rhône. Il a été réintroduit dans la rivière Drôme à partir de la multiplication en captivité de deux souches, issues des rivières Beaume et Durance. Nous avons évalué la stratégie adoptée par le suivi démogénétique de la population réintroduite sur cinq années en analysant les données microsatellites issues de 376 aprons échantillonnés dans la Drôme. Nous avons testé également un éventuel effet de la souche et de la diversité génétique individuelle sur deux traits d'histoire de vie : la croissance et l'état corporel. L'application des recommandations a permis de limiter la perte de diversité génétique et la consanguinité lors de la réintroduction de l'apron du Rhône dans la rivière Drôme. La souche génétique influe sur la croissance et l'état corporel mais pas la diversité génétique individuelle. La souche Durance, la plus diverse du point de vue génétique, ne présente pas d'altération significative de ses traits d'histoire de vie dans la Drôme. Enfin, un secteur de la Drôme moins favorable pour l'espèce a été identifié. Cette étude est un retour d'expérience important sur lequel les gestionnaires pourront s'appuyer pour la planification de potentielles réintroductions futures.

In dairy production, the preservation of reproductive performances is crucial to ensure the sustainability, but several reproduction troubles exist such as abnormal cyclicity or infertility. These are potential culling criteria. The project called CowPILOT aims at finding solutions to monitor body condition individually to optimise reproduction success. In this project, the purpose of this study is to establish how breeders and breeding advisors use the cow body condition and to highlight profiles interested by an individual monitoring. Thus, 29 semi-structured interviews were led and analysed (14 breeding advisors and 15 breeders). Only three people are scoring the cows. According to the interviewees, the scoring of body condition is time-consuming and non-recoverable. Body condition is mostly used as an indicator of the breeding management at strategic moments: the evaluation of the cows’ food and 2/3 of the interviewees use it as a reproduction criterion. Individual monitoring is for breeders because breeding advisors come at the farm every two weeks at the best. Thanks to this overview, four profiles for the breeding advisors and four for the breeders were found. Only one breeder profile was different from the others. These breeders have already individual practices, such as the use of automatic concentrate feeder, and have reasonable workload and sometimes digital tools and reproduction monitoring. They could be interested in individual monitoring of body condition to optimise reproduction.; La pérennité d’un élevage bovin laitier implique le maintien des performances de reproduction. Or de nombreux problèmes de reproduction existent : cyclicités anormales ou infécondité qui en font des critères de réforme. Le projet CASDAR CowPILOT cherche à trouver des solutions pour le suivi individualisé de l’état corporel en vue d’optimiser la réussite à la reproduction. Au sein de ce projet, cette étude a comme objectif de dresser un état des lieux des pratiques d’utilisation de l’état corporel des conseillers et des éleveurs et d’identifier des profils intéressés par un suivi individuel de l’état corporel. Pour cela 29 entretiens semi-directifs ont été réalisés (14 conseillers et 15 éleveurs). Trois enquêtés réalisent de la notation considérée chronophage et non valorisable. L’état corporel est majoritairement utilisé comme un indicateur de conduite de troupeau à des moments stratégiques : il permet d’évaluer les rations et environ 2/3 des enquêtés l’utilise comme critère de mise à la reproduction. Le suivi individuel est à favoriser pour les éleveurs, puisque les conseillers ne sont sur l’exploitation qu’au maximum toutes les 2 semaines. A partir des pratiques, 4 profils ont été créés pour les conseillers et 4 pour les éleveurs. Seul un profil d’éleveurs se distingue : des éleveurs qui ont déjà des pratiques individuelles comme la présence d’un DAC et qui ont une charge de travail acceptable et parfois des outils numériques et un suivi reproduction. Ce profil d’éleveurs serait intéressé par le suivi individuel de l’état corporel en vue d’optimiser la reproduction.

The body condition scores (BCS) of groups of ewes bred for reproduction were recorded in farms in Chlef region in Algeria from February 2012 to April 2013. The body condition and body reserves of the ewes varied according to i) the category of females concerned (lambing in September-October or in March-April) and ii) the farm. Taking into account the quantities of fodder distributed in supplement of pasture and body reserves enabled us to make a diagnosis on the feed in each situation. The interaction between the body condition of the ewes at mating and their reproduction performance was evidenced. Indeed, as BCS at mating increased, fertility and prolificacy improved. The ewes with BCS at mating higher than or equal to 3 obtained 100% fertility and 130% prolificacy rates, against 76% and 100%, respectively, for those with a BCS lower than 3.

International audience; Monitoring the growth and body condition of cows is essential for optimal management of modern dairy farms. However, monitoring is rarely performed on commercial farms. Modern technologies based on three-dimensional (3D) shape analysis could address this problem. The objective of the present study was to test and validate tools that can record and analyze 3D body shapes of animals. On 30 Holstein dairy cows, wither height (WH), heart girth (HG), chest depth (CD), hip width (HW), backside width (BaW) and ischial width (IW) were manually measured. These manual measurements were compared to those measured with a scanner (Morpho3D) that provided 3D images of the entire cow body. Correlations between manual and Morpho3D measurements were high: 0.89 for CD, 0.82 for HW, 0.78 for HG, 0.76 for BaW, 0.63 for IW and 0.62 for WH. The mean coefficient of variation of reproducibility for Morpho3D was 2.8%. Future development can provide new opportunities for dairy herd management based on determining animal body volume and surface area.

The herd dynamic milk (HDM) model is a dynamic model capable of simulating the performance of individual dairy animals (from birth to death), with a daily time step. Within this study, the HDM model is described and evaluated in relation to milk production, body condition score (BCS) and BCS change throughout lactation by comparing model simulations against data from published experimental studies. The model's response to variation in genetic potential, herbage allowance and concentrate supplementation was tested in a sensitivity analysis. Data from experiments in Ireland and France over a 3-year period (2009-11) were used to complete the evaluation. The aim of the Irish experiment was to determine the impact of different stocking rates (SRs) (SR1: 3.28 cow/ha, SR2: 2.51 cow/ha) on key physical, biological and economic performance. The aim of the French experiment was to evaluate over a prolonged time period, the ability of two breeds of dairy cows (Holstein and Normande) to produce and to reproduce under two feeding strategies (high level and low level) in the context of compact calving. The model evaluation was conducted at the herd level with separate evaluations for the primiparous and multiparous cows. The evaluation included the two extreme SRs for the Irish experiment, and an evaluation at the overall herd and individual animal level for the different breeds and feeding levels for the French data. The comparison of simulation and experimental data for all scenarios resulted in a relative prediction error, which was consistently

L’objectif de cette étude était de quantifier les relations entre chaque étape du processus de reproduction (cyclicité, chaleurs et fertilité), la production laitière et la gestion des réserves corporelles chez la vache laitière. Pour cela, 102 études soient 300 observations de traitements ont été collectées dans des articles obtenus sur des plateformes en ligne (ISI Web of Knowledge et Google Scholar). Afin d’éviter d’agréger des données issues d’études mobilisant des facteurs expérimentaux trop différents pour être analysés ensemble, un système de codage a été mis en place pour les distinguer et travailler sur des sous-ensembles de données. Les résultats des méta-analyses montrent que le délai de reprise de cyclicité est associé à la note d’état corporel (NEC) au vêlage. Cette relation est quadratique et indique qu’une NEC au vêlage proche de 3 points (sur l’échelle 0-5) est associée à un délai de reprise de cyclicité raccourci (23 j). Aucun lien entre le délai de reprise de cyclicité et le niveau de production laitière n’a été détecté dans ces analyses. Bien que le délai de reprise de cyclicité conditionne en partie l’intervalle entre le vêlage et l’apparition des premières chaleurs (IVCHAL1), aucun lien avec la NEC n’a été observé dans cette étude. Pour chaque kilogramme de lait supplémentaire au pic de lactation, l’IVCHAL1 est retardé de plus d’une journée. La probabilité de réussite à la première insémination (TRIA1) est réduite de 2 % pour chaque kilogramme de lait supplémentaire au pic de lactation. Le TRIA1 est amélioré de 22 % pour chaque point de NEC supplémentaire (entre 1,50 et 3,00), au moment où l’embonpoint est au plus bas. La probabilité de gestation est augmentée de 43 % pour chaque point de NEC supplémentaire au vêlage (sur une plage variant de 2,50 à 3,50) et de 17 % pour chaque point de NEC supplémentaire au minimum (sur une plage variant de 1,50 à 3,00). Aucune relation entre la probabilité de gestation et la production laitière n’a été mise en évidence dans cette étude. En conclusion, cette méta-analyse a démontré que le délai de reprise de cyclicité des vaches laitières serait d’abord lié à la NEC au vêlage, alors que l’expression des chaleurs serait en premier lieu associée au niveau de production laitière, et que la fertilité pourrait dépendre à la fois du niveau de production laitière et de la gestion des réserves corporelles. Les stratégies de conduite d’élevage visant une NEC proche de 3 points au vêlage, et qui limitent à la fois l’amaigrissement et le pic de production laitière pourraient permettre d’améliorer les performances de reproduction des vaches laitières., The present study aimed to investigate the relationships between each step of the reproductive process (cyclicity, estrus, and fertility) and both milk production and body reserves management. The database included 102 studies and 300 treatments collected on electronic databases (ISI Web of Knowledge and Google Scholar). Coding for each type of experimental factor enabled within and between experiment variation to be distinguished, and to select subsets of experiments with common objectives in order to avoid inappropriate aggregation of results across studies with very different objectives. The meta-analysis showed that the resumption of ovarian activity was related to body condition score (BCS) at calving. This relationship was quadratic, stressing an optimal BCS at calving around 3 (on a 0-5 scale) for a resumption of luteal activity 23 days postpartum. No relationship was observed between milk yield and the resumption of luteal activity. No relationship was observed between BCS and the calving to first estrous interval, although this reproductive performance is influenced by the resumption of luteal activity. The calving to first estrous interval was delayed about more than one day for each additional one kilogram of milk produced at lactation peak. The conception rate was reduced by 2% for each additional kilogram of milk produced at lactation peak. The conception rate was improved by 22% for each additional point of BCS at nadir (between 1.50 and 3.00). The pregnancy rate was improved by 43% for each additional point of BCS at calving (between 2.50 and 3.50) and by 17% at nadir (between 1.50 and 3.00). No relationship was observed between milk yield and the pregnancy rate in the data. This meta-analysis showed that postpartum cyclicity of dairy cows was mainly associated with BCS at calving, whereas estrus expression was mainly associated with milk yield and fertility with both BCS and milk yield. Genetic and nutritional strategies that target a BCS of 3.00 and limit both BCS loss and peak milk yield could be an effective way to improve reproduction.

International audience; Residual feed intake, which is usually used to estimate individual variation of feed efficiency, requires frequent and accurate measurements of individual feed intake to be carried out. Developing a breeding scheme based on residual feed intake in dairy cows is therefore complicated, especially because feed intake is not measurable for a large population. Another solution could be to focus on biological determinants of feed efficiency, which could potentially be directly and broadband measurable on farm. Several phenotypes have been identified in literature as being associated with differences in feed efficiency. The present study therefore aims to identify which biological mechanisms are associated with residual energy intake (REI) differences among dairy cows. Several candidate phenotypes were recorded frequently and simultaneously throughout the first 238 d in milk for 60 Holstein cows fed on a constant diet based on maize silage. A multiple linear regression of the 238 d in milk average of net energy intake was fitted on the 238 d in milk averages for milk energy output, metabolic body weight, the sum over the 238 d in milk of both, body condition score loss and gain, and the residuals were defined as REI. A partial least square regression was fitted over all biological traits to explain REI variability. Linear multiple regression explained 93.6% of net energy intake phenotypic variation, with 65.5% associated with lactation requirement, 23.2% with maintenance, and 4.9% with body reserves change; the 6.4% residuals represented REI. Overall, measured biological traits contributed to 58.9% of REI phenotypic variability, which were mainly explained by activity (26.5%) and feeding behavior (21.3%). However, apparent confounding was observed between behavior, activity, digestibility, and rumen-temperature variables. Drawing a conclusion on biological traits that explain feed efficiency differences among dairy cows was not possible due to this apparent confounding between the measured variables. Further investigation is needed to validate these results and to characterize the causal relationship of feed efficiency with feeding behavior, digestibility, body reserves change, activity, and rumen temperature.

Excessive negative energy balance (EB) has been associated with decreased reproductive performance and increased risk of lameness and metabolic diseases. On-farm, automated EB estimates for individual cows would enable dairy farmers to detect excessive negative EB early and act to minimize its extent and duration by altering feeding. Previously, we have shown that EB can be estimated from frequent measurements of body weight (BW) and body condition score (BCS) changes, referred to as EBbody. In this study, we investigated the robustness and sensitivity of the EBbody method to assess its genericity and on-farm applicability. We used 5 data sets with BW of lactating cows (name of data set in parenthesis): 65 Holstein cows in a French feeding trial (INRA); 6 Holstein cows in a British feeding trial (Friggens); 31 Holstein cows and 17 Jersey cows in a Danish feeding trial (DCRC); 140 Holstein cows in a British feeding trial (Scotland's Rural College, SRUC); and 1,592 Holstein cows on 9 Danish farms with milking robots (automatic milking system). We used the INRA and Friggens data sets to develop a dynamic formula to correct BW for increasing residual gut-fill (RGF) during early lactation. With the DCRC data, we tested the effect of smoothing parameters and weighing frequency on EBbody. Also, 2 robustness tests were performed using the SRUC data to test the effect of diet change on BW and the automatic milking system data to test the effect of farm on BW variation. Finally, we combined the results into a blueprint describing different ways to calculate EBbody depending on the purpose and on the availability of BCS. The dynamic RGF adjustment resulted in a lower empty BW during early lactation than that obtained with the previously used constant RGF. The double-exponential smoothing method used to correct for meal-related gut-fill was robust to choice of smoothing parameters. Cows should be weighed at least once every 4 d during early lactation to capture the duration of negative EBbody. Our EBbody method proved robust to diet changes. Finally, although cow BW varied significantly between farms, the quantile regression smoothing of BW did not bias the estimation of weight differences between herds. In conclusion, these results validate the applicability of the EBbody method to estimate EB across a range of farm conditions, and we provided a blueprint that enables the estimation of EBbody for individual cows on-farm using only frequent BW, in combination with BCS when available.

Body condition is an indirect estimation of the level of body reserves, and its variation reflects cumulative variation in energy balance. It interacts with reproductive and health performance, which are important to consider in dairy production but not easy to monitor. The commonly used body condition score (BCS) is time consuming, subjective, and not very sensitive. The aim was therefore to develop and validate a method assessing BCS with 3-dimensional (3D) surfaces of the cow's rear. A camera captured 3D shapes 2 m from the floor in a weigh station at the milking parlor exit. The BCS was scored by 3 experts on the same day as 3D imaging. Four anatomical landmarks had to be identified manually on each 3D surface to define a space centered on the cow's rear. A set of 57 3D surfaces from 56 Holstein dairy cows was selected to cover a large BCS range (from 0.5 to 4.75 on a 0 to 5 scale) to calibrate 3D surfaces on BCS. After performing a principal component analysis on this data set, multiple linear regression was fitted on the coordinates of these surfaces in the principal components' space to assess BCS. The validation was performed on 2 external data sets: one with cows used for calibration, but at a different lactation stage, and one with cows not used for calibration. Additionally, 6 cows were scanned once and their surfaces processed 8 times each for repeatability and then these cows were scanned 8 times each the same day for reproducibility. The selected model showed perfect calibration and a good but weaker validation (root mean square error = 0.31 for the data set with cows used for calibration; 0.32 for the data set with cows not used for calibration). Assessing BCS with 3D surfaces was 3 times more repeatable (standard error = 0.075 versus 0.210 for BCS) and 2.8 times more reproducible than manually scored BCS (standard error = 0.103 versus 0.280 for BCS). The prediction error was similar for both validation data sets, indicating that the method is not less efficient for cows not used for calibration. The major part of reproducibility error incorporates repeatability error. An automation of the anatomical landmarks identification is required, first to allow broadband measures of body condition and second to improve repeatability and consequently reproducibility. Assessing BCS using 3D imaging coupled with principal component analysis appears to be a very promising means of improving precision and feasibility of this trait measurement.

Achieving higher feed effi ciency of animals is expected to improve animal production sustainability through reduction of the used resources and of the associated emissions. The traits determining feed effi ciency remain poorly understood. The present project aimed therefore at identifying the biological factors associated with feed effi ciency differences in lactating dairy cows. Feed effi ciency variation was estimated with the traditional residual intake, which was defi ned as the residual variability of net energy intake which is not explained by net energy required for lactation, maintenance and body reserves change. This residual intake includes by defi nition all measurement errors. To reduce these errors, body condition score, which is commonly measured visually, has been automated and several other candidate traits were measured frequently in a steady environment for almost whole lactation. Residual intake variability represented only 8% of intake variability in our study, among which only 58.9% were found to be associated with feed effi ciency variability and not to errors. The repeatability analysis of the residual intake throughout the lactation suggested to avoid the 7 fi rst lactation fortnights, and rather to focus on lactation middle. Among all measured traits, feeding behaviour, rumen temperature, body reserves change and activity explained 58.9% of residual intake variability. Many of these traits seemed confounded with others, which claimed for the need for further work to properly defi ne their causal relationship with feed effi ciency, especially focussing on digestion, body reserves change and activity functions., L’amélioration de l’efficience alimentaire des animaux peut contribuer à un élevage plus durable par la réduction des ressources utilisées et des rejets associés. Les caractères qui déterminent l’efficience alimentaire des vaches laitières restent mal identifiés. Le projet se propose donc d’identifier les facteurs biologiques associés à la variabilité interindividuelle de l’efficience alimentaire des vaches laitières. La variation d’efficience alimentaire a été estimée avec l’ingéré résiduel, classiquement défini comme la variabilité résiduelle de l’énergie nette ingérée corrigée pour l’énergie nette du lait, l’entretien et les variations de réserves corporelles. Cet ingéré résiduel inclut par définition toutes les erreurs de mesure. Pour réduire ces erreurs, la note d’état corporel, qui classiquement se fait par notation visuelle, a été automatisée et de nombreux autres caractères candidats ont été mesurés fréquemment dans un environnement stable sur quasiment toute la lactation. La variabilité de l’ingéré résiduel ne représentait que 8% de la variabilité de l’ingéré mesuré, dont 58,9% étaient associés à de l’efficience et non de l’erreur. L’étude de la répétabilité de cet ingéré résiduel au cours de la lactation suggère d’éviter les 7 premières quinzaines au profit du milieu de lactation. Parmi tous les caractères mesurés, le comportement alimentaire, la température ruminale, la variation des réserves corporelles et l’activité expliquaient 58,9% de la variabilité de l’ingéré résiduel. Les effets de plusieurs de ces caractères semblent confondus. Leur lien de causalité avec l’efficience reste à étudier notamment pour les fonctions de digestion, d’activités et de gestion des réserves corporelles.

A total of 507 culled crossbred Holstein x Lai Sind dairy cows aged 8.5 years on average were examined antemortem (age determination by teeth, body condition scoring, vaginal examination via speculum) and postmortem (ultrasound examination of ovaries, examination of uterine content). Nearly half of them (44.4%) had a body condition score lower than 2.5. The prevalences of pneumovagina and urovagina were 33.1 and 14.7%, respectively. The age and body condition score had a significant effect on the prevalence of these diseases. The prevalences of abnormal vaginal discharges and uterine content were 12.1 and 5.4%, respectively. Among the 507 cows examined, 226 (44.6%) were in anestrus. The prevalence of anestrus associated with pregnancy was 4.9%. The prevalences of functional pathological anestrus (types 0, I and II), of anestrus associated with cyst, and with pyometra were 37.3, 2, and 0.4%, respectively. Anestrus types 0 and I have been more often observed in cows with low body condition scores and in those under six years old.

L’aptitude des vaches laitières à assurer chaque étape de la reproduction dépend de leurs caractéristiques génétiques. 23. Rencontres autour des Recherches sur les Ruminants

International audience; Feed deficits can occur in grazing systems due to low spring grass growth. The objective of this experiment was to investigate if different pasture allowances (PA) offered to early lactation grazing dairy cows for varying time durations influenced bodyweight (BW) and body condition score (BCS; 5 point scale). The two-year experiment offered cows one of four PA (60, 80, 100 or 120% of intake capacity), for either 2 or 6-weeks. Once the 2- and 6-week time durations had elapsed, the cows were offered 100% PA. At the end of the first 2 weeks, there was a linear increase in BW with increasing PA (441, 449, 456 and 464 kg, respectively), but there was no effect of PA on BCS (2.99). There was no effect of the interaction between PA and duration on BW at the end of week 6; BW increased linearly with increasing PA (443, 453, 456 and 466 kg; 60, 80, 100 and 120%, respectively), but, there was no effect of PA or duration on BCS at the end of 6-weeks (2.91). After 10-weeks there were no differences in BW or BCS. However, these results cannot be examined in isolation; other variables such as milk production and fertility need to be considered in order to obtain a complete picture of the residual effects of altering PA in early lactation.

International audience; We studied eel population characteristics (size classes, densities and body condition) in the lower Loire River floodplain (France) to evaluate the effects of longitudinal and lateral gradients. A total of 36 sites were electrofished in June 2005. The sites were grouped first into three river segments according to the distance inland corresponding to a longitudinal gradient and secondly into three lateral connectivity categories. Results indicate that small eels, especially those ≤300 mm, were very abundant downstream but density rapidly decreased upstream. In addition, eels ≤150 mm tended to be most abundant in connected waterbodies. Conversely, the distribution of larger eels was quite uniform across both dimensions. Eel condition decreased upstream. In parallel, in downstream river segment, eels had a lower condition in disconnected waterbodies than in connected ones. Eel specialists still have only a longitudinal perception of eel habitat. Our results suggest that lateral gradients should be also taken into consideration

International audience

Body condition is an important trait in dairy cow management, mainly because it reflects the level and the use of body reserves and indirectly reproductive and health performance. Body condition score (BCS), which is done visually or by palpation, is the usual method on farm but is subjective and not very sensitive. The aim was here to develop and to validate 3DBCS which estimates BCS from 3D-shapes of dairy cows rear, the body area commonly used to assess BCS. For the calibration, a set of 57 3D-shapes from 56 Holstein cows with large BCS variability (0.5 to 4.75 on a 0–5 scale) were transformed with a principal component analysis (PCA). A multiple linear regression was fitted on the principal components to assess BCS. Four anatomical landmarks were extracted to normalize the 3D-shapes: the validation results of a manual labeling proved the concept. Then an automated labeling method was developed to extract them. Prior to the PCA, the 3D-shapes were either regularized to fill in the holes or not regularized. External validation was evaluated on 2 sets: one with cows used for calibration, but with a different lactation stage (valididem) and one with cows not used for calibration (validdiff). Repeatability was estimated with 6 cows scanned 8 times each the same day. The automated method performed slightly better than manual method for external validation (RMSE = 0.27 versus 0.34 for validdiff) and both were more repeatable than usual BCS (σ = 0.20 for 3DBCS and 0.28 for BCS). Surprisingly, regularizing the 3D-shapes performed slightly less than without regularization. Nevertheless regularization should be an interesting process before BCS assessing, especially to avoid discarding too many 3D-shapes. The first results of 3D-BCS monitoring in dairy cows with a fully automated method show promising results in terms of phenotyping. The next step will try to reduce scanning time to decrease the number of bad 3D-shapes due to cow’s movement without losing too much resolution.

This study aimed to estimate body weight of two humped Bactrian camels from South Kazakhstan. In addition, the hump weight was estimated. Four Bactrian camels were monitored and their body and hump weights regularly estimated during 6 months. For estimation barymetric measurements were used. The measurements were achieved in corridor on standing animals with a meter-ribbon and reported in cm. Body weight of experimental camels was estimated by four different models and results were compared. For hump the volume of the hump was assessed, then its weight by considering the fat density of the hump. The comparison of the different models showed that the model of Faye (2014) was closer to the true body weight of animals measured on scale. The body length was better predictor of the body weight of Bactrian camel and the heart girth the best predictor for the body condition score. According to this estimation model, the body weight of experimental camels ranged between 513 and 680 kg over the 6 months. The mean weight of animals was 601 kg, but huge individual variations were noted. The hump weights varied widely and ranged between 5.3 kg and 21.5 kg.

L’évaluation in vivo de l’état corporel des animaux s’appuie sur l’estimation des dépôts adipeux sous-cutanés. Pour cela il existe plusieurs méthodes dont les grilles de notation de l’état du dépôt sous-cutané (NEC), ou la mesure de la taille de ses adipocytes (DIAM). La mesure par échographie de ce tissu sous-cutané constitue une troisième méthode d’évaluation. Elle a été testée sur des vaches Charolaises dans un dispositif expérimental répété deux années consécutives dont l’un des objectifs était de comparer ces trois méthodes. Au total des deux années, 42 vaches en début de lactation ont été réparties en deux lots homogènes recevant des niveaux alimentaires contrastés (haut +2 UFL et bas -3 UFL soit respectivement 120 et 70% des besoins) pendant 87 jours afin d’obtenir des dynamiques d’états corporels très différentes. Nous avons mesuré i) les évolutions de poids (+14, -49kg) ii) les évolutions de NEC (+0,12, -0,62) iii) les variations de DIAM (+2, -12 ?m). La teneur en lipides du corps (LIP%PV=11,2%) a légèrement augmenté (H :+0,5%), ou fortement diminué (B :-2%). Des images échographiques ont été réalisées par 2 opérateurs tous les 15 jours au flanc et à la fesse. Sur les images retenues, trois distances ont été mesurées : 1°) au flanc : la peau + tissu adipeux + muscle (CPTAM), 2°) à la fesse, la peau + tissu adipeux (FPTA) et la peau + tissu adipeux + muscle (FPTAM). Une base de 952 mesures pour chaque distance a été constituée. Au final, les corrélations entre NEC, adipocytes et la somme S1 de FPTA et CPTAM sont de 0,82 et 0,80. Lip%PV est linéairement lié à S1 (pente de 1,77%/cm). Cette équation devra être validée, notamment sur d’autres races, pour être utilisée en prévision. Cette méthode échographique pourra être utilisée seule ou en complément des autres, suivant les objectifs poursuivis (élevage ou recherche)., The in vivo assessment of body condition is based on the estimation of subcutaneous adipose tissues. Several methods are used such as body condition scoring (NEC), or measure of the diameter of the adipocytes (DIAM). The ultrasound measurement of the subcutaneous tissue is a thir d method. It was tested on Charolais cows in a repeated trial whose objectives were to compare with the two other me thods. In total, 42 cows in early lactation were divided into two homogeneous groups receiving two feeding levels (high or low respectively -3 +2 UFL/ requirements) for 87days to obtain different body fat. We measured i) changes in weight (+ 14 -49kg) ii) changes in NEC (+0.12, -0.62) iii) changes in DIAM (2, -12 μ m). Initial body fat composition (11. 2 Lip% PV) increase (+0.5% (H) or decrease -2% (B). Ultrasound coastal and rump images were performed by two operators every 15 days. On selected images, 3 distances were measured: 1) coastal: skin + fat + muscle (CPTAM), 2) rump, skin + fat (FPTA) and skin + fat + muscle (FPTAM). A database of 952 data distance was established. Finally correlations between NEC and adipocytes and sum S1 (CPTAM+FPTA) are 0.82 and 0.80. Lip% PV is linearly related to S1 (slope of 1.77% / cm). This equation must be validated, includ ing other breeds, for use in forecasting. This ultrasound method can be used alone or in addition to the other depending on the objectives pursued (breeding or research)

International audience; Background: Partial migration, where one portion of a population conducts seasonal migrations while the other remains on a single range, is common in wild ungulate populations. However the relative costs and benefits associated with the distinct strategies adopted by coexisting migrant and resident individuals have rarely been investigated. Here we compare the body condition of migrants and residents in a partially migratory population of impalas (Aepyceros melampus) in Zimbabwe. The study was conducted during two consecutive years with highly contrasted population densities (16.4 and 8.6 indiv/km(2)) due to harvesting. Results: We first identify a population substructure with a north-south sub-division in two spatial units related to distinct soils and vegetation cover. Impalas in the north range had a consistently higher diet quality and body condition than those in the south range. At the beginning of the dry season about one third of the individuals migrated from the lower (i.e. south) to the higher (i.e. north) diet quality range. This partial migration pattern was consistent between the consecutive years, and most individuals showed constancy to their moving strategy (migrant or resident). In both years, these migrants had a significantly higher body condition at the end of the dry season than the south residents that remained year-round in the lower diet quality range. Diet quality and body condition of impalas were higher in the year of lower density; however we did not detect any evidence for density-dependence in migration propensity, at the individual or population levels, nor in the benefit associated with migration. Conclusions: Our findings provide rare evidence for a significant relationship between body condition and seasonal migration strategy in wild ungulates in relation to a difference in the quality of resources acquired between distinct seasonal ranges. This study also constitutes rare evidence of partial migration in a tropical ungulate population.

The involvement of plasma leptin in the adaptation of dromedary camels to harsh conditions such as food or water shortages was studied through 2 experiments. In experiment 1, fourteen female camels were either fed at 68% of maintenance energy requirements (MER) during 112 d ( n = 4) or overfed at 134% of MER during the first 56 d and then underfed at 17% of MER the next 56 d (OV-UN, n = 5), or underfed and then overfed for the same durations and energy intake levels (UN-OV, n = 5). Weekly plasma samples showed that leptin, glucose and non-esterified fatty acid (NEFA) concentrations were significantly modulated by energy intake level. NEFA increased sharply but transiently in underfed camels of the UN-OV or OV-UN groups, whereas glucose and leptin concentrations decreased with underfeeding and increased with overfeeding with more significant effects in camels that were previously overfed or underfed, respectively. In experiment 2 twelve female camels were either normally watered ( n = 6) or dehydrated ( n = 6) during 23 d and then rehydrated during 4 d. Dehydration specifically increased blood hematocrit, plasma NEFA and glucose whereas leptin decreased slightly. For both experiments, leptinemia was positively related to hump adipocyte volume. Taken together these results provide new data for a better understanding of lipid and energy metabolism in camels.

Satellite 3R; absent

L'évaluation des réserves corporelles est un outil utile aux zootechniciens et aux éleveurs pour gérer l'état nutritionnel d'animaux soumis à de fortes contraintes alimentaires saisonnées. Plusieurs outils se présentent pour appuyer une gestion raisonnée et une évaluation du statut nutritionnel énergétique du dromadaire et pour lesquels on dispose de quelques références récentes. Quatre méthodes sont développées dans le présent document de synthèse : (i) la notation des réserves corporelles à partir d'une grille visuelle adaptable en fonction des phénotypes de dromadaire et qui permet d'apprécier l'état corporel global ; (ii) l'estimation du poids de la bosse, principale réserve adipeuse et organe assez unique dans le monde animal, qui permet d'avoir une idée de l'adiposité du dromadaire ; (iii) la mesure des adipocytes qui relève d'approches analytiques plus pointues à visée de recherche ; et enfin (iv) le dosage de métabolites indicateurs du niveau énergétique tels que la leptine, l'hormone de l'engraissement.

Ce travail est une étude expérimentale ayant pour but d’évaluer le statut thyroïdien (FT4, TT3, TSH) de chiens sains et d’étudier l’influence de facteurs épidémiologiques sur ce dernier. La population étudiée comprend 179 chiens sains, et est représentative de la population canine française. Chez ces individus un dosage ponctuel des concentrations plasmatiques de TT3, FT4, TSH, triglycérides et cholestérol a été réalisé, et quatre indices de régulation de l’axe thyréotrope ont été calculés (TSH x FT4, TSH/FT4, IBL et IQL). Dans ce travail, il apparaît que l’âge s’accompagne d’une certaine anergie de la glande thyroïde, que l’axe thyréotrope est peu sollicité en cas d’effort physique intense, que les chiens de petite taille semblent présenter une relative hyporéactivité de la thyroïde et que la réactivité de la glande thyroïde à l’égard de la stimulation hypophysaire varie en fonction de la race considérée et qu’elle serait relativement importante chez les Cockers Anglais. De plus, l’analyse des variations simultanées des concentrations circulantes des hormones de l’axe thyréotrope (TT3, FT4 et TSH) et des 4 indices de régulation a conduit à l’établissement de plusieurs profils thyroïdiens particuliers. Devant l’absence de relation entre l’obésité et le statut lipidique avec le statut thyroïdien, il serait intéressant de réaliser le même type de travail sur un nombre plus important de chiens obèses.

Diplôme : BTSA

L’objectif de cette etude a ete de determiner les effets saisonniers sur l’evolution du poids et de la note d’etat corporel (NEC) des zebus arabes du Tchad. Durant les cinq saisons liees au calendrier fourrager, des mensurations et des notations d’etat corporel ont ete effectuees sur des bovins mâles et femelles. Les mesures barymetriques ont concerne le perimetre thoracique. La NEC a ete determinee par palpation de la region lombaire de l’animal. L’alternance saisonniere a provoque de grandes variations de poids et de l’etat corporel des animaux qui ont ete notees selon le sexe et l’âge. La variabilite des performances ponderales (2,2 ± 16 kg a 64 ±24 kg) et d’etat corporel des animaux, obtenue a partir des facteurs individuels (sexe ou âge) et saisonniers (disponibilite fourragere), a montre que ce sont les animaux d’âge superieur a 6 ans qui ont perdu plus de poids en saison seche. Les femelles de 3-6 ans (64 ± 44,8 kg) et les mâles de 2-3 ans (54 ± 43 kg) ont montre les fluctuations ponderales les plus significatives en saison des pluies. Afin de minimiser les risques et maximiser la production en elevage extensif, des ameliorations dans la conduite des animaux ont ete proposees. Mots cles : Variations fourrageres - Poids - Etat corporel - Zebu arabe - Tchad

National audience

Photoperiod, metabolism and reproduction : advantage of the equine model. Equidae are born in the spring. This is due to the fact that mares go through a period of anovulation from October to the end of April. For breeders, bringing forward the first ovulation presents an enormous advantage, as it increases the number of usable cycles in the mare and increases the actual age of the offspring at the time of sports performance or slaughter. In mares under our latitudes, the first ovulation can be moved to its earliest by using 14.5 h of daily light for 35 days, beginning around the winter solstice. This treatment is robust, as repeated accidents do not affect its outcome. The administration of melatonin to pony mares during winter ovarian inactivity, either daily in the evening or with a subcutaneous implant, suppresses the photostimulating effect of long days (LD). On the other hand, the use of this implant around the summer solstice brings forward the first ovulation, as in photostimulated mares, thereby confirming the existence of an annual endogenous rhythm. These implants inserted under the same conditions in non-pregnant mares do not induced ovarian inactivity. Therefore, the role of melatonin seems limited to the timing of winter inactivity. In thin but healthy mares subjected to the natural photoperiod, winter inactivity is systematic and long lasting. This inhibition, induced by the feed restriction, masks the effect of the photostimulation. On the other hand, 60% of fat mares have cycles all year long, and in the remaining 40%, the period of inactivity is very short, missing only one or two cycles. Increasing the feed in thin mares in autumn or winter seems to have no effect on the date of the first annual ovulation. Nutrition is the main cause of ovarian inactivity in winter, but it does not play a role in the resumption of activity in the spring. The mechanism inhibiting the cycles in autumn results from an interaction between short days and a negative energy balance. This nutrition-photoperiod interaction seems to be applicable to numerous species in temperate areas., Chez les Équidés, les mises-bas ont lieu au printemps, conséquence d'une période sans ovulation commençant vers octobre pour s'achever fin avril. Pour les éleveurs, une avance de la première ovulation est capitale car elle augmente d'une part, le nombre de cycles utilisables et d'autre part, l'âge réel au moment de l'épreuve sportive ou de l'abattage. Chez les juments, l'avance maximale de la date de la première ovulation annuelle, sous nos latitudes, est obtenue avec un éclairement quotidien de 14h30, commençant vers le solstice d'hiver et pouvant être interrompu au bout de 35 jours longs (JL). Ce traitement est robuste : des accidents répétés n'altèrent pas son effet. L'administration de mélatonine à des ponettes en inactivité hivernale, chaque soir ou sous forme d'implants sous-cutanés, supprime l'effet photostimulant des JL. Par contre, la pose des implants, aux alentours du solstice d'été, avance la première ovulation de l’année suivante comme chez des juments photostimulées, démontrant ainsi l'existence d'un rythme endogène annuel. Ces implants posés dans les mêmes conditions chez des juments non gravides n'induisent pas l'inactivité. Le rôle de la mélatonine semble donc limité au centrage du moment de la phase d'inactivité. Chez des animaux maigres, en bonne santé, sous photopériode naturelle, l'inactivité est systématique et durable. Cette inhibition, liée à la sous-alimentation masque l'effet de la photostimulation. Par contre, 60 % des juments grasses cyclent toute l'année, les 40 % restants présentent une inactivité très courte correspondant à l'absence d’un ou deux cycles. Une réalimentation automnale ou hivernale des juments amaigries ne semble pas avoir d’effet sur la date de la première ovulation annuelle. La nutrition est la principale cause de l'arrêt hivernal de la cyclicité mais n'intervient pas sur sa reprise printanière. Le mécanisme qui induit à l'automne l’arrêt de la cyclicité est dû à l'interaction entre des jours courts et une balance énergétique négative. Cette interaction nutrition-photopériode est semble-t-il généralisable à de nombreuses espèces des zones tempérées., Guillaume Daniel, Salazar-Ortiz Juan, Menassol Jean-Baptiste, Malpaux Benoît, Chemineau Philippe. Photopériode, métabolisme et reproduction : intérêt du modèle équin. In: Bulletin de l'Académie Vétérinaire de France tome 163 n°1, 2010. pp. 5-18.

Diplôme : Dr. d'Université; We assumed that a systemic approach would allow us to better understand on farm nutritional and health factors associated with infertility in Holstein dairy cows observed on a 2 years survey in 21 herds in Reunion Island. Reproductive efficiency was assessed by first service conception risk (FSCR) and intervals from calving to 1st service (CS1) or to conception (CC). Statistical modelling of these reproductive parameters with body condition score, milk yield, blood parameters (glucose, insulin, cholesterol, NEFA, β-OH, urea, albumin, GLDH, GGT, Ca, P, Mg) and the timing of diseases occurrence was done. For both biological and statistical reasons, we analysed the influence of the factors cited above within three distinct physiological stages i.e. before calving, within the first 30 d postpartum and after 30 d in milk, during the breeding period. We established that high body condition losses (> 1.5 points) during the 1st month postpartum, negative prepartum energy balances in high yielding cows, diets with nitrogen deficit or excess pre- and postpartum, liver disorders at time of first service or health disorders, were associated with a higher risk of decrease in FSCR and/or an increase in CS1 or CC. Most of nutritional imbalances that were identified seemed to exert a carry-over detrimental effect on the onset of 1st service or conception. This delay is in agreement with reported alteration of the first stages of postpartum follicle development. We identify some risk practices like insufficient feeding of dry cows, poor quality silage, inappropriate supplementation of tropical forages, and absence of group-feeding practices. Our thesis support that such a global approach allows a classification of reproductive risk factors, previously isolated in factorial design, in on farm dairy herds. In the present case, we show that reproductive performances are mostly explained by nutritional factors and to a lesser extend by health troubles. We established relationships that may be useful both for integrative knowledge on links between nutrition and reproduction and implementation of advices for farmers.; Nous avons entrepris une analyse globale, de type écopathologique, sur les facteurs de risque de l'infertilité chez les vaches laitières de l'île de la Réunion. Vingt et un troupeaux ont été suivis pendant 2 années (1153 lactations de vaches multipares de race Holstein) afin d'identifier les principaux facteurs nutritionnels et sanitaires associés à une faible réussite de l'insémination première (I1) et à la durée des intervalles vêlage – insémination première (VI1) et vêlage – insémination fécondante (VIf). La modélisation statistique de ces paramètres de reproduction s'est appuyée sur les mesures d'état corporel, de production laitière et de paramètres biochimiques sanguins (glucose, insuline, cholestérol, AGNE, β-OH, urée, albumine, GLDH, GGT, Ca, P et Mg) et sur les fréquences des troubles sanitaires. Les points de vue biologique et statistique nous ont conduit à distinguer l'influence respective de ces facteurs à trois stades physiologiques distincts :avant vêlage, au cours des 30 premiers jours de lactation et lors de la période de reproduction. Ainsi, une mobilisation intense (> 1,5 points) des réserves corporelles au cours du 1er mois postpartum, un déficit énergétique antepartum chez les vaches fortes productrices, des déséquilibres azotés (déficits ou excès) observés avant vêlage ou en début de lactation, une atteinte hépatique au moment de l'I1 et certains troubles sanitaires survenus en tout début de lactation sont associés à une diminution de la réussite de l'I1 et/ou à l'allongement des intervalles VI1 et VIf. Nous avons mis en évidence que la plupart des déséquilibres nutritionnels exercent un effet différé de plusieurs semaines sur la survenue de l'I1 ou de l'If. Ceci coïncide avec des atteintes des premiers stades des cycles de maturation folliculaire qui surviennent en tout début de lactation. Nous avons également mis en évidence que certaines pratiques d'alimentation comportent des risques : sous-alimentation des vaches taries, médiocre qualité de conservation des ensilages d'herbe, complémentation azotée inadaptée aux fourrages tropicaux, absence d'allotement des animaux selon leurs exigences alimentaires. Nous soutenons la thèse que ce type d'approche permet de hiérarchiser efficacement, sur des troupeaux en production, les facteurs de risques qui ont été auparavant isolés dans des expérimentations analytiques factorielles. Dans le cas présent, nous montrons la primauté des déséquilibres nutritionnels sur les troubles sanitaires dans l'atteinte des paramètres de reproduction. Nous avons établi des relations d'association entre ces facteurs et la reproduction des vaches qui pourront être utiles à des démarches intégratives d'appréhension des relations nutrition – reproduction et à des démarches d'appui au développement.

Le dromadaire est le seul animal domestique capable de valoriser, par ses productions (lait, viande, poils, travail), les espaces arides et semi-arides de l'Afrique et de l'Asie. Son exceptionnelle capacité à résister à la chaleur et à la privation d'eau a fait de lui un élément capital de la vie socio-économique des populations habitant ces zones à l'environnement hostile. Pour cette étude, 12 chamelles issues du sud marocain ont été utilisées. Deux lots homogènes de 6 dromadaires ont été constitués :un lot témoin, et un lot test dont les animaux ont subi une déshydratation de 23 jours suivie de 5 jours de réhydratation. L'état corporel et le poids vif des animaux ont été affectés par la déshydratation même si la taille de la bosse est inchangée. L'hématocrite, la glycémie, la triglyceridémie et la concentration en acides gras libres ont largement augmenté avec la déshydratation alors que les concentrations sériques en cholestérol et corps cétoniques n'ont pas été influencées. La réhydratation a permis un rétablissement rapide de tous les paramètres.

International audience; This research was aimed at evaluating the respective influence of reproductive rhythm (R), artificial insemination (AI) performed on the 11th or the 25th day after kindling, and age at weaning (W) at 23 or 35 days of lactation, on the evolution of body condition and reproductive performance of rabbit does. Immediately after the initial kindling 12 does were selected for initial slaughter. The 234 primiparous does were assigned at their first parturition to one of four treatments: R11W23, R11W35, R25W23 and R25W35. The does representative of each experimental group were slaughtered at successive stages of the reproduction cycle to evaluate reproductive performance or body condition. When artificial insemination was performed 25 days compared to 11 days after kindling, main dissectible fat weight of the does was lower at insemination (67 g vs. 98 g in R25 and R11 does respectively; P < 0.001). But main dissectible fat weight at second parturition was higher in the R25 than in the R11 group (+27.3%; P < 0.001). From the first kindling to AI, the energy balance of does was positive in the R25 group and negative in the R11 group (+847 kJ·kg−0.75 vs. –729 kJ·kg−0.75 in R25 and R11 does respectively; P < 0.015). Moreover,the R25 does had a higher sexual receptivity at AI (+24 points; P < 0.001), and pregnancy rate (+16 points; P < 0.05) than the R11 does. Additionally, foetal viability (+5.4%; P < 0.05) was higher in the R25 than R11 groups whereas the number of corpora lutea, number of kits born alive and weight of litter at birth were not affected by reproductive rhythm. An early weaning did not affect the reproductive performance of the does but significantly reduced the main dissectible fat mobilisation (–35% vs. –54% in W23 and W35 groups respectively; P < 0.001) and increased live body (+135 g vs. –32 g, P < 0.005), empty body (+78 g vs. –93 g, P < 0.001) and defatted carcass weight gains (+79 g vs. –19 g, P < 0.001) from 1st to 2nd parturition. The present results demonstrate that limiting the nutritional solicitation of females by shortening the duration of lactation or the length of superposition between lactation and pregnancy, reduces the body fat mobilisation of primiparous does. The effects of reproductive rhythm and weaning age on corporal condition add together.

International audience; This research was aimed at evaluating the respective influence of reproductive rhythm (R), artificial insemination (AI) performed on the 11th or the 25th day after kindling, and age at weaning (W) at 23 or 35 days of lactation, on the evolution of body condition and reproductive performance of rabbit does. Immediately after the initial kindling 12 does were selected for initial slaughter. The 234 primiparous does were assigned at their first parturition to one of four treatments: R11W23, R11W35, R25W23 and R25W35. The does representative of each experimental group were slaughtered at successive stages of the reproduction cycle to evaluate reproductive performance or body condition. When artificial insemination was performed 25 days compared to 11 days after kindling, main dissectible fat weight of the does was lower at insemination (67 g vs. 98 g in R25 and R11 does respectively; P < 0.001). But main dissectible fat weight at second parturition was higher in the R25 than in the R11 group (+27.3%; P < 0.001). From the first kindling to AI, the energy balance of does was positive in the R25 group and negative in the R11 group (+847 kJ·kg−0.75 vs. –729 kJ·kg−0.75 in R25 and R11 does respectively; P < 0.015). Moreover,the R25 does had a higher sexual receptivity at AI (+24 points; P < 0.001), and pregnancy rate (+16 points; P < 0.05) than the R11 does. Additionally, foetal viability (+5.4%; P < 0.05) was higher in the R25 than R11 groups whereas the number of corpora lutea, number of kits born alive and weight of litter at birth were not affected by reproductive rhythm. An early weaning did not affect the reproductive performance of the does but significantly reduced the main dissectible fat mobilisation (–35% vs. –54% in W23 and W35 groups respectively; P < 0.001) and increased live body (+135 g vs. –32 g, P < 0.005), empty body (+78 g vs. –93 g, P < 0.001) and defatted carcass weight gains (+79 g vs. –19 g, P < 0.001) from 1st to 2nd parturition. The present results demonstrate that limiting the nutritional solicitation of females by shortening the duration of lactation or the length of superposition between lactation and pregnancy, reduces the body fat mobilisation of primiparous does. The effects of reproductive rhythm and weaning age on corporal condition add together.

Les signatures biologiques constituent une démarche novatrice pour l'étude des réponses métaboliques des systèmes biologiques à différents stimuli. Elle associe la spectroscopie à résonance magnétique, qui fournit une description exhaustive des métabolites présents dans les liquides biologiques, les cellules ou les tissus, à des méthodes d'analyses statistiques multivariées permettant l'investigation des contrastes biologiques. Ces techniques sont ici appliquées à l'étude de l'évolution du métabolisme général en fonction de l'âge et de l'état corporel chez le chien. Les urines de 95 chiens mâles entiers en bonne santé sont analysées en RMN du proton. Les analyses factorielles discriminantes mettent en évidence une ségrégation significative selon l'âge. L'état d'entretien, évalué par attribution de BCS, ne semble pas affecter le profil métabolique urinaire. En revanche, l'influence d'autres facteurs intrinsèques (race) ou extrinsèques (alimentation et mode de vie) est révélée.

In order to study the effect of underfeeding and overfeeding on the fat deposition in the dromedary camel, 14 camels were divided into three groups: an overfed-underfed group (OV-UN), an underfed-overfed group (UN-OV) and a control group (CTRL). After a 4-wk adaptation, a cross-over design was applied for 16 weeks including two periods of 8 weeks each. The three energy levels in the diet corresponded to 17% (UN), 68% (CTRL) and 134% (OV) of the theoretical maintenance energy requirements. Body weight and barymetric parameters were measured weekly. Hump fat samples were collected monthly for determination of adipocyte size and lipid content. Overfeeding had or tended to have a significant effect on body weight, hump size, hump lipid content and adipocyte volume. Thus, the increase of the hump weight was 71% in the OV-UN group and 19% in the UN-OV group. Hump fat content increased from 52.9 to 63.6% in the OV-UN group and from 54.2 to 64.7% in the UN-OV group. Similarly, trends were observed for the adipocyte volume with an increase from 138 to 253 pL and from 275 to 346 pL in the OV-UN and UN-OV groups, respectively. Underfeeding had reverse effects: the hump weight decreased by 41% in the OV-UN group and 4% in the UN-OV group. Similarly, the hump lipid content decreased significantly in the OV-UN group from 63.6 to 53.0% and not significantly from 58.0 to 54.2% in the UN-OV group. Underfeeding decreased the adipocyte volume from 253 to 167 pL (OV-UN group) and from 292 to 275 pL (UN-OV group). A high significant positive correlation was observed between the hump lipid content and adipocyte volume. Low speed changes in the hump size, volume and lipid content could be linked to the camel adaptation to underfeeding conditions in dry areas., Effet du niveau d'alimentation sur le poids vif, la taille, la teneur en lipides et le volume des adipocytes de la bosse chez le dromadaire. Les effets de la suralimentation et de la sous-alimentation sur les réserves lipidiques chez le dromadaire ont été mesurés chez 14 chamelles divisées en trois lots : un lot suralimenté - sous-alimenté (OV-UN), un lot sous-alimenté - suralimenté (UN-OV) et un lot témoin (CTRL). Après 4 semaines d'adaptation un schéma expérimental croisé a été appliqué pendant 16 semaines comprenant 2 périodes de 8 semaines chacune. L'apport énergétique des 3 niveaux d'alimentation représentait 17, 68 et 134 % des besoins énergétiques théoriques d'entretien respectivement pour le régime sous-alimentation, témoin et suralimentation. Le poids vif et les paramètres barymétriques ont été mesurés chaque semaine. Les biopsies de la bosse pour la détermination de la taille des adipocytes et la teneur en lipides ont été réalisées mensuellement. La suralimentation a un effet significatif sur le poids vif, la taille de la bosse et sa teneur en lipides ainsi que sur le volume des adipocytes. Le poids de la bosse augmente de 71 % pour le lot OV-UN et de 19 % pour le lot UN-OV. La teneur en matière grasse augmente de 52,9 à 63,6 % pour le lot OV-UN et de 54,2 à 64,7 % pour le lot UN-OV. Des évolutions similaires sont observées pour le volume des adipocytes qui augmente de 138 à 253 pL et de 275 à 346 pL pour les lots OV-UN et UN-OV, respectivement. La sous-alimentation a un effet inverse avec une diminution du poids de la bosse de 41 % pour le lot OV-UN et de 4 % pour le lot UN-OV. La teneur en lipides de la bosse diminue également significativement de 63,6 à 53,0 % pour le lot OV-UN et de manière non significative de 58,0 à 54,2 % pour le lot UN-OV. De même, la sous-alimentation diminue significativement le volume des adipocytes de 253 à 167 et de 292 à 275 pL pour les lots OV-UN et UN-OV, respectivement. Une corrélation hautement significative est observée entre le volume des adipocytes de la bosse et sa teneur en lipides. La faible vitesse de variation de la taille de la bosse, de sa teneur en lipides et de la taille de ses adipocytes sont probablement des particularités liées aux mécanismes d'adaptation du dromadaire à la sous alimentation dans les zones arides.

Sept profils d'état corporel ont été identifiés à partir de 428 lactations observées sur des animaux de race Prim' Holstein dans les élevages laitiers à la Réunion. Un tiers des lactations montrent l'existence d'un déficit énergétique post-partum intense et prolongé. Les animaux extériorisant ces profils d'état présentent des performances de reproduction très dégradées: (i) la proportion d'animaux fécondés à 110 jours est inférieure de 15 points par rapport à celle du profil optimal et (ii) entre 30 et 40 jours supplémentaires sont nécessaires pour observer une fécondation chez plus de 50% des animaux. L'effet de l'origine des animaux (génisses élevées dans vs hors de l'exploitation) et du niveau de production laitière des 150 premiers jours de lactation est également significatif sur l'intervalle VIF. Les taux de réussite en 1ère IA restent néanmoins très inférieurs aux objectifs habituellement fixés (entre 22 et 38%, selon les profils). Le faible niveau des performances de reproduction suggère l'existence de facteurs additionnels responsables d'infertilité, comme l'état sanitaire ou les pratiques de détection des chaleurs.