Intérêt d’un outil de médecine de précision pour l’aide à la décision en santé mammaire et l’évaluation de l’état inflammatoire chez la vache laitière

Le logiciel Herd Navigator™ est un outil d’élevage de précision effectuant à intervalles réguliers des mesures de l’activité de la LDH dans le lait. L’objectif de cette étude était de déterminer l’exactitude des alarmes mammite déclenchées par ce logiciel. Au sein d’un élevage, les 295 vaches ayant déclenché cette alarme ou dont l’activité de la LDH dépassait 40 U/L ont fait l’objet de deux examens cliniques à quelques jours d’intervalle (CMT, température rectale, examen vaginal, score de boiterie). L’alarme mammite présente ainsi une valeur prédictive positive de 82.35% dès le premier examen. Plus de la moitié des mammites (55,4%) sont subcliniques. De plus, une activité de la LDH supérieure à 40 U/L, même en-dehors d’une situation d’alarme, est révélatrice d’une mammite dans 63.75% des cas (100% des cas si activité supérieure à 100 U/L). L’éleveur doit donc examiner et si besoin traiter les vaches en alarme ou ayant une activité de LDH élevée

The Influence of Low Intensities of Light Pollution on Bat Communities in a Semi-Natural Context

International audienceAnthropogenic light pollution is an increasingly significant issue worldwide. Over the past century, the use of artificial lighting has increased in association with human activity. Artificial lights are suspected to have substantial effects on the ecology of many species, e.g., by producing discontinuities in the territories of nocturnal animals. We analyzed the potential influence of the intensity and type of artificial light on bat activity in a semi-natural landscape in France. We used a species approach, followed by a trait-based approach, to light sensitivity. We also investigated whether the effect of light could be related to foraging traits. We performed acoustic surveys at sites located along a gradient of light intensities to assess the activity of 15 species of bats. We identified 2 functional response groups of species: one group that was light-tolerant and one group that was light-intolerant. Among the species in the latter group that appear to be disadvantaged by lighting conditions, many are rare and threatened in Europe, whereas the species from the former group are better able to thrive in disturbed habitats such as lighted areas and may actually benefit from artificial lighting. Finally, several methods of controlling light pollution are suggested for the conservation of bat communities. Recommendations for light management and the creation of dim-light corridors are proposed; these strategies may play an important role in protecting against the impact of light pollution on nocturnal animals

Influence of light type on the activity of each bat species.

<p>Because the type of light is a categorical variable, the given estimate is the average estimate of bat activity for each type (white or orange) compared with the absence of light. Thus, the p-value provides information about the significance of the difference between an absence of light <i>vs.</i> the artificial light type (white or orange). Back-transformed estimate effects represent the average estimate of bat activity for each color type on the original scale.</p><p>Influence of light type on the activity of each bat species.</p

Observed species and their abundances.

<p>The percentages are calculated based on the number of stations at which at least one bat species call was recorded relative to the total number of sampling stations. The mean number of calls per minute was calculated only for the sampling stations at which at least one call was recorded. For <i>Myotis</i> and <i>Plecotus</i> spp., the counts are given at the genus level.</p><p>* <i>Myotis bechsteinii</i>, <i>Myotis daubentonii</i>, <i>Myotis myotis</i>, <i>Myotis mystacinus</i>, <i>Myotis nattereri</i>.</p><p>**<i>Plecotus austriacus</i> and <i>Plecotus auritus</i>.</p><p>Observed species and their abundances.</p

Effects of different factors on the light intensity at the sampling stations.

<p>Results of the GLM. SS is the sum of squares, F is the mean of squares for the factor/mean of squares for the error, and Pr is the probability value associated with the test (p-value of Anova).</p><p>Effects of different factors on the light intensity at the sampling stations.</p

Influence of light intensity on the activity of each bat species.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103042#pone.0103042-Dietz1" target="_blank">[3]</a> Dietz C., Helversen O. von, Nill D.(2009) L'encyclopédie des chauves-souris d'Europe et d'Afrique du Nord: Biologie, caractéristiques, protection. Delachaux et Niestlé, Paris. 400 p.</p><p>Influence of light intensity on the activity of each bat species.</p

Landscape composition drives the impacts of artificial light at night on insectivorous bats

International audienceAmong the most prevalent sources of biodiversity declines, Artificial Light At Night (ALAN) is an emerging threat to global biodiversity. Much knowledge has already been gained to reduce impacts. However, the spatial variation of ALAN effects on biodiversity in interaction with landscape composition remains little studied, though it is of the utmost importance to identify lightscapes most in need of action. Several studies have shown that, at local scale, tree cover can intensify positive or negative effects of ALAN on biodiversity, but none haveat landscape scalestudied a wider range of landscape compositions around lit sites. We hypothesized that the magnitude of ALAN effects will depend on landscape composition and species' tolerance to light. Taking the case of insectivorous bats because of their varying sensitivity to ALAN, we investigated the species-specific activity response to ALAN. Bat activity was recorded along a gradient of light radiance. We ensured a large variability in landscape composition around 253 sampling sites. Among the 13 bat taxa studied, radiance decreased the activity of two groups of the slow-flying gleaner guild (Myotis and Plecotus spp.) and one species of the aerialhawking guild (Pipistrellus pipistrellus), and increased the activity of two species of the aerial-hawking guild (Pipistrellus kuhlii and Pipistrellus pygmaeus). Among these five effects, the magnitude of four of them was driven by landscape composition. For five other species, ALAN effects were only detectable in particular landscape compositions, making the main effect of radiance undetectable without account for interactions with landscape. Specifically, effects were strongest in non-urban habitats, for both guilds. Results highlight the importance to prioritize ALAN reduction efforts in non-urban habitats, and how important is to account for landscape composition when studying ALAN effects on bats to avoid missing effects

Comparison between models using light intensity or light type as explanatory variables.

<p>. AIC values are given for each model. (GLMP) indicates a Poisson distribution, (GLMNB) a negative binomial distribution, (ZAP) a zero inflated model with a Poisson distribution and (ZANB) Zero inflated model with negative binomial distribution. (*) indicates that as the best model did not converge for both effect (light intensity and light type), we compared the two models using a Poisson error distribution. The models retained based on the smallest AIC value are shown in bold <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103042#pone.0103042-Burnham1" target="_blank">[45]</a>.</p><p>Comparison between models using light intensity or light type as explanatory variables.</p