Assessing walking posture with geometric morphometrics: Effects of rearing environment in pigs

International audienceRearing social animals like pigs in isolation from conspecifics can have consequences on behaviour and physiology. The aim of this experiment was to determine whether rearing conditions affect body postures. We adapted a method for quantitative evaluation of postures based on geometric morphometrics, developed in horses, for pigs and applied it in different conditions. Forty eight 75-day old females were reared either alone in 2.25 m2 pens (IH, N = 24 animals and 4 groups) or in groups of four in 4.64 m2 pens (GH, N = 24) for two weeks. They were habituated to human handling (stroking, speaking) and marking on their backs every day, and tested individually once a day for 10 min in a corridor outside the home pen during the two subsequent weeks. We observed their behaviour and posture during the first exposure to the test (novelty), and the fourth and fifth (after habituation). On the sixth and seventh tests, a familiar stockperson was present in the corridor (human presence). Before each test, the animals were marked with seven landmarks along their length, corresponding to anatomical points and easily located. An experimenter took pictures of the animals walking along the corridor, and these pictures were transferred to tps software for analysis. GH animals were more often active in the rearing pen than IH (median (IQ) 15% of observations [12-20%] versus 2% [0-13%]; P < 0.05). All animals except one IH initiated contact with the handler during the last sessions of handling (Fisher's exact test, ns). Principal Component Analyses revealed significant effects of rearing and testing conditions on pigs’ behaviour and posture. Novelty led to fewer vocalisations and more exploration for IH than GH animals (P < 0.05), but there were no differences between treatments after habituation to the testing situation. The backs of IH animals were more rounded than those of GH (P < 0.05; dimension 1 of PCA), independently of the test condition. Human presence had no effect on posture. In conclusion, the method based on geometric morphometrics that we developed to study pig posture detected variations in walking posture in pigs associated with rearing conditions. Postures might reflect affective states in pigs, as shown in other species, but further studies are needed to verify thi

Can we identify back pain in horses? [Plenary talk]

International audienceBack pain and vertebral disorders are more and more pointed out as a primary source of welfare impairment in working horses. If a global consensus exists on the impact of riding techniques and postures at work on the development and prevalence of back pain, the identification of reliable indicators of such disorders is more difficult. Scientific publications on the subject show that in most cases, the prevalence of vertebral disorders is strongly under-estimated by both professionals and owners, highlighting the urgent identification of visible indicators. The expression of back disorders can be at different levels, according to the type of disorder and to the individual affected, and are rarely specific of back pain. Behavioural changes, in the form of chronic modification of the behavioural repertoire (emergence of abnormal behaviours: teeth grinding, groaning...) and time budget (increased restlessness, reduced locomotion), or the modification of interactive behaviours (increased aggressiveness towards both humans and congeners) might reveal the presence of back problems. Immediate behavioural and postural reactions (tail swishing, backing up, head-tossing, nose tilting...) can be observed in response to work constraints/inadapted riders’ actions when ridden. Unwished behaviour when ridden can also result from a chronic state of back pain. Physical changes, such as lameness, abnormal weight distribution, more or less subtle changes in gaits, feet anatomy and orthopedic status can also reveal the presence of back pain. Last but not least, chronic neck and back postural changes may inform on the emergence of back/vertebral disorders. Because these postural alterations are elicited repeatedly, they may lead to chronic postural profiles. Our recent studies using geometric morphometry reveal the potential relationship between the welfare state, working conditions and chronic postural profiles

Testing optimal methods to compare horse postures using geometric morphometrics

International audienceThe study of animal behavior, especially regarding welfare, needs the development of tools to identify, quantify and compare animal postures with interobserver reliability. While most studies subjectively describe animal postures, or quantify only limited parts of the body, the usage of geometric morphometrics has allowed for the description of horses’ and pigs’ upper body outline and the comparison of postures from different populations thanks to robust statistical analysis. We have attempted here to optimize the geometric morphometrics (GM) method already used in horses by introducing the outline analysis with sliding semilandmarks (SSL), by eliminating the balance movement of the neck and by focusing only on parts of the upper line. For this purpose, photographs of 85 horses from 11 riding schools, known for differing in terms of housing and working conditions, were analyzed with previous and new GM methods and these results were compared with each other. Using SSL and eliminating the neck movement appeared to better discriminate the horse populations than the previous GM method. Study of parts of the dorsum proved efficient too. This new methodology should now be used to examine if posture could be an indicator of horse welfare state, and similar studies should be performed in other species in order to validate the same methodology

Could posture reflect welfare state? A study using geometric morphometrics in riding school horses

International audienceDespite the fact that animal posture is known to reflect emotional state, the presence of chronic postures associated with poor welfare has not been investigated with an objective tool for measuring, quantifying and comparing postures. The use of morphometric geomet-rics (GM) to describe horse posture (profile of the dorsum) has shown to be an effective method of distinguishing populations that are known to differ in terms of welfare states. Here we investigated photographs of 85 riding school horses differing in terms of welfare state, in order to determine if a specific posture (modelled by GM) is associated with altered welfare. The welfare state was estimated with the prevalence of stereotypic or abnormal repetitive behaviours, depressed-like posture and the ear positions. ANOVA results show that horses with stereotypic or abnormal behaviour, and to a lesser degree horses with depressed-like postures, tend to have a flatter, or even hollow, dorsal profile, especially at the neck and croup levels. These altered profiles could represent an additional indicator of poor welfare, easy to use in the field or by owners

Oxidation of Zn(Cys)4 zinc finger peptides by O2 and H2O2: products, mechanism and kinetics.

International audienceThe reactivity of a series of Zn(Cys)(4) zinc finger model peptides towards H(2)O(2) and O(2) has been investigated. The oxidation products were identified by HPLC and ESI-MS analysis. At pH<7.5, the zinc complexes and the free peptides are oxidised to bis-disulfide-containing peptides. Above pH 7.5, the oxidation of the zinc complexes by H(2)O(2) also yields sulfinate- and sulfonate-containing overoxidised peptides. At pH 7.0, monitoring of the reactions between the zinc complexes and H(2)O(2) by HPLC revealed the sequential formation of two disulfides. Several techniques for the determination of the rate constant for the first oxidation step corresponding to the attack of H(2)O(2) by the Zn(Cys)(4) site have been compared. This rate constant can be reliably determined by monitoring the oxidation by HPLC, fluorescence, circular dichroism or absorption spectroscopy in the presence of excess ethyleneglycol bis(2-aminoethyl ether)tetraacetic acid. In contrast, monitoring of the release of zinc with 4-(2-pyridylazo)resorcinol or of the thiol content with 5,5'-dithiobis(2-nitrobenzoate) did not yield reliable values of this rate constant for the case in which the formation of the second disulfide is slower than the formation of the first. The kinetic measurements clearly evidence a protective effect of zinc on the oxidation of the cysteines by both H(2)O(2) and O(2), which points to the fact that zinc binding diminishes the nucleophilicity of the thiolates. In addition, the reaction between the zinc finger and H(2)O(2) is too slow to consider zinc fingers as potential sensors for H(2)O(2) in cells

Morphométrie et comportement : leçons de la systématique

National audienceno abstrac

Cyclic peptides bearing a side-chain tail: a tool to model the structure and reactivity of protein zinc sites.

International audienc

Effectiveness of the first French psychoeducational program on unipolar depression: study protocol for a randomized controlled trial

International audienceAbstractBackgroundMajor Depressive Disorder (MDD) is highly prevalent and was associated with greater morbidity, mortality (including suicide), and healthcare costs. By 2030, MDD will become the leading cause of disability in high-income countries. Notably, among patients with a previous experience of a major depressive episode, it was indeed estimated that up to 85 % of those patients will suffer from relapse. Two main factors were associated with a significantly higher risk of relapse: poor medication adherence and low self-efficacy in disease management. Interestingly, these issues could become the targets of psychoeducational programs for chronic diseases. Indded psychoeducational program for depression are recommended in international guidelines, but have not yet been proposed in France.Methods/DesignWe propose to evaluate the first French psychoeducational program for depression “ENVIE” in a multicenter randomized controlled trial. The group intervention will include 9 weekly sessions. Its aim is to educate patients on the latest knowledge on depression and effective treatments through didactic and interactive sessions. Patients will experiment the latest innovating psychological skills (from acceptance and commitment therapy) to cope with depressive symptoms and maintain motivation in behavioral activation. In total, 332 unipolar non-chronic (<2 years) outpatients with moderate to severe depression, without psychotic features, will be randomly allocated to the add-on ENVIE program (N = 166) or to a waiting list (N = 166). The follow-up will last 15 months and include 5 assessment visits.The primary endpoint will be the remission rate of the index episode at 15 months post-inclusion, defined by a Montgomery and Asberg Depression Rating Scale (MADRS) score ≤ 12 over an 8-week period, and without relapse during follow-up. We will also assess the response rate and relapse at 15 months post-inclusion, hospitalization rate and adherence to treatment during the follow-up period, quality of life and global functioning upon inclusion and at 9 and 15 months post inclusion.DiscussionIf the proposed trial shows the effectiveness of the intervention, but also an increased remission rate in depressed outpatients at 15-months post-inclusion, in addition to improved treatment adherence in patients, it will further promotes arguments in favor of a wide dissemination of psychoeducational programs for depression.Trial registrationThis trial is registered under number 2015-A00249-40 (PURE clinical trial: NCT02501226) (June 30th, 2015)

Geometric morphometrics as a tool for improving the comparative study of behavioural postures

International audienceDescribing postures has always been a central concern when studying behaviour. However, attempts to compare postures objectively at phylogenetical, populational, inter- or intra-individual levels generally either rely upon a few key elements or remain highly subjective. Here, we propose a novel approach, based on well-established geometric morphometrics, to describe and to analyse postures globally (i.e. considering the animal's body posture in its entirety rather than focusing only on a few salient elements, such as head or tail position). Geometric morphometrics is concerned with describing and comparing variation and changes in the form (size and shape) of organisms using the coordinates of a series of homologous landmarks (i.e. positioned in relation to skeletal or muscular cues that are the same for different species for every variety of form and function and that have derived from a common ancestor, i.e. they have a common evolutionary ancestry, e.g. neck, wings, flipper/hand). We applied this approach to horses, using global postures (1) to characterise behaviours that correspond to different arousal levels, (2) to test potential impact of environmental changes on postures. Our application of geometric morphometrics to horse postures showed that this method can be used to characterise behavioural categories, to evaluate the impact of environmental factors (here human actions) and to compare individuals and groups. Beyond its application to horses, this promising approach could be applied to all questions involving the analysis of postures (evolution of displays, expression of emotions, stress and welfare, behavioural repertoiresaEuro broken vertical bar) and could lead to a whole new line of research