Enquête de terrain sur la pratique du horse-ball de haut niveau en France

Le horse-ball est une discipline équestre relativement récente. Une enquête a été effectuée sur le terrain afin de connaître les opinions des joueurs et de recueillir des informations générales sur le sport, au meilleur niveau de la discipline puisque seules les divisions majeures ont été sondées.NANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF

Etude bibliographique du syndrome surentrainement chez le cheval de course

Après avoir détaillé les effets de l'exercice et de l'entraînement sur les paramètres biologiques du cheval, le syndrome surentraînement est présenté chez l'homme et le cheval. Les marqueurs précoces du syndrome sont décrits dans les deux espèces, montrant que chez le cheval, seuls le poids et le comportement seraient utilisables, même si d'autres paramètres comme la créatine semblent prometteurs. L'étude du surentraînement doit être approfondie mais vétérinaires et entraîneurs doivent dès aujourd'hui en tenir compte.NANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF

Influence d'une supplémentation en vitamine E et sélénium sur la santé de la mamelle de la chèvre

Une expérience de supplémentation orale en vitamine E et sélénium, pendant la période sèche, a été menée dans un élevage caprin laitier, pour vérifier si, comme dans l'espèce bovine, les deux micronutriments antioxydants ont un impact sur la santé de la mamelle des chèvres. Les résultats ont montré que la supplémentation a eu un impact bénéfique significatif sur les numérations cellulaires, mais aucun sur les critères bactériologiques de mammite.NANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF

Calcium, magnésium, cuivre et zinc dans le plasma séminal d'étalon, concentrations chez des chevaux fertiles et relations avec la congélabilité de la semence

On recherche un critère de prédiction de la congélabilité du sperme d'étalon à partir de la qualité de la semence à la récolte. Les concentrations en calcium, magnésium, cuivre et zinc ont été déterminées dans 53 échantillons de 17 étalons fertilesNANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF

La reproduction assistée de l'éléphant d'Afrique (Loxodonta africana)

La population captive d'éléphants d'Afrique est en déclin aux Etats-Unis, et l'importation d'éléphanteaux sauvages n'est plus possible. Cette étude se propose d'effectuer un bilan de la situation démographique de l'espèce et d'expliquer les raisons du recours à la reproduction assistée.NANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF

Interactions entre les performances sportives et la fonction de reproduction chez le cheval

De nos jours, les chevaux de sport exercent souvent en parallèle carrière d'athlète et carrière de reproducteur. Cependant, il existe de nombreuses intéractions entre la fonction de reproduction et les performances sportives, pouvant diminuer les performances dans l'un des deux domaines. Pour remédier à cela, des techniques de reproduction artificielle ont été mises au point, de manière à concilier au mieux ces deux activités.NANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF

Stallion spermatozoa : putative targets for estrogens.

International audienceAmong the mammals, stallion appears as the male producing the largest amount of testicular estrogens (Raeside, 1969). This synthesis occurs mainly in Leydig cells (Almadhidi et al., 1995) and seems to be submitting to a seasonal regulation. Indeed, Lemazurier et al. (2002) demonstrated the presence of higher amounts of estrogens in semen in April-May and June compared to December. To exert their effects estrogens use specific nuclear receptors (ESR1, ESR2), which could exert both genomic and non-genomic actions. Recently, we identified estrogen receptors in ejaculated stallion spermatozoa and in order to determine a putative seasonal response to estrogens a quantification of ESR1 was performed, on semen samples.Semen were obtained monthly between May 2012 and February 2013 from 5 stallions, aged from 10 to 23 years, housed at Jumenterie du Pin (IFCE). Seminal plasma was removed by centrifugation and spermatozoa were washed twice in Tyrode. ESR1 protein expression was studied by Western-blot, confocal analysis and flow cytometry with MC-20 antibody. Results were analyzed by ANOVA followed by Tukey-Kramer multiple comparisons test.Western-blot analysis showed a single 66kDa band corresponding to the wild-type isoform, and then immunofluorescence analysis showed a flagellar staining. We described a high rate of spermatozoa from a sample positive for the detection of ESR1 between May and October then there is a progressive and regular decrease of signal from October to reach a nadir on January, followed by an increase of signal in February. So, we describe for the first time, a seasonal regulation of ESR1 associated to spermatozoa. Further studies will elucidate a putative relation between sperm ability to respond to estrogen and sperm quality

Stallion spermatozoa : putative targets for estrogens.

International audienceAmong the mammals, stallion appears as the male producing the largest amount of testicular estrogens (Raeside, 1969). This synthesis occurs mainly in Leydig cells (Almadhidi et al., 1995) and seems to be submitting to a seasonal regulation. Indeed, Lemazurier et al. (2002) demonstrated the presence of higher amounts of estrogens in semen in April-May and June compared to December. To exert their effects estrogens use specific nuclear receptors (ESR1, ESR2), which could exert both genomic and non-genomic actions. Recently, we identified estrogen receptors in ejaculated stallion spermatozoa and in order to determine a putative seasonal response to estrogens a quantification of ESR1 was performed, on semen samples.Semen were obtained monthly between May 2012 and February 2013 from 5 stallions, aged from 10 to 23 years, housed at Jumenterie du Pin (IFCE). Seminal plasma was removed by centrifugation and spermatozoa were washed twice in Tyrode. ESR1 protein expression was studied by Western-blot, confocal analysis and flow cytometry with MC-20 antibody. Results were analyzed by ANOVA followed by Tukey-Kramer multiple comparisons test.Western-blot analysis showed a single 66kDa band corresponding to the wild-type isoform, and then immunofluorescence analysis showed a flagellar staining. We described a high rate of spermatozoa from a sample positive for the detection of ESR1 between May and October then there is a progressive and regular decrease of signal from October to reach a nadir on January, followed by an increase of signal in February. So, we describe for the first time, a seasonal regulation of ESR1 associated to spermatozoa. Further studies will elucidate a putative relation between sperm ability to respond to estrogen and sperm quality

Implication of the estrogen receptors GPER, ESR1, ESR2 in post-testicular maturations of equine spermatozoa

International audienceEstrogen receptors ESR1, ESR2 and GPER are present on mature ejaculated horse spermatozoa, suggesting these cells as putative targets for estrogens. Indeed, spermatozoa are exposed to high level of estrogens during the transit in the male and female genital tracts but their roles are not investigated. So, we evaluated in vitro the role of 17β-estradiol during post-testicular maturations: regulation of motility, capacitation and acrosome reaction. Moreover according to the pseudo-seasonal breeder status of the stallion, we analyzed the putative seasonal variations in the presence of ESRs in spermatozoa. We showed that ESRs are more present on stallion sperm during the breeding season. We showed that capacitation and acrosome reaction are independent of estradiol action in horse. Estradiol can weakly modulate the motility and this effect is strictly associated with GPER and not with ESR1 and ESR2. The subcellular localization of GPER in the neck on stallion sperm is coherent with this effect. It seems that estrogens are not major regulators of sperm maturations associated to mare genital tract, so they could act during the epididymal maturations

Insémination artificielle équine

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