{"id":2316,"date":"2023-11-29T08:49:40","date_gmt":"2023-11-29T07:49:40","guid":{"rendered":"https:\/\/www.rumexperts.vet\/?post_type=training&#038;p=2316"},"modified":"2024-03-16T08:35:29","modified_gmt":"2024-03-16T07:35:29","slug":"les-ovulations-multiples-chez-la-vache-comprendre-le-mecanisme-hormonal","status":"publish","type":"training","link":"https:\/\/www.rumexperts.vet\/en\/training\/les-ovulations-multiples-chez-la-vache-comprendre-le-mecanisme-hormonal","title":{"rendered":"LES OVULATIONS MULTIPLES CHEZ LA VACHE : COMPRENDRE LE MECANISME HORMONAL"},"content":{"rendered":"<div class=\"fusion-fullwidth fullwidth-box fusion-builder-row-1 fusion-flex-container has-pattern-background has-mask-background nonhundred-percent-fullwidth non-hundred-percent-height-scrolling\" style=\"--awb-border-radius-top-left:0px;--awb-border-radius-top-right:0px;--awb-border-radius-bottom-right:0px;--awb-border-radius-bottom-left:0px;--awb-flex-wrap:wrap;\" ><div class=\"fusion-builder-row fusion-row fusion-flex-align-items-flex-start fusion-flex-content-wrap\" style=\"max-width:1248px;margin-left: calc(-4% \/ 2 );margin-right: calc(-4% \/ 2 );\"><div class=\"fusion-layout-column fusion_builder_column fusion-builder-column-0 fusion_builder_column_1_1 1_1 fusion-flex-column\" style=\"--awb-bg-size:cover;--awb-width-large:100%;--awb-margin-top-large:0px;--awb-spacing-right-large:1.92%;--awb-margin-bottom-large:20px;--awb-spacing-left-large:1.92%;--awb-width-medium:100%;--awb-order-medium:0;--awb-spacing-right-medium:1.92%;--awb-spacing-left-medium:1.92%;--awb-width-small:100%;--awb-order-small:0;--awb-spacing-right-small:1.92%;--awb-spacing-left-small:1.92%;\"><div class=\"fusion-column-wrapper fusion-column-has-shadow fusion-flex-justify-content-flex-start fusion-content-layout-column\"><div class=\"fusion-text fusion-text-1\"><p>Diff\u00e9rentes \u00e9tudes ont confirm\u00e9 que le risque d\u2019ovulations multiples augmente syst\u00e9matiquement lorsque l\u2019\u00e9mergence d\u2019une vague de croissance folliculaire appara\u00eet dans un environnement progest\u00e9ronique faible qui classiquement s\u2019accompagne de concentrations plus \u00e9lev\u00e9es en FSH et en LH avant et apr\u00e8s le moment de la d\u00e9viation et de concentrations plus \u00e9lev\u00e9es en oestradiol avant et apr\u00e8s cette d\u00e9viation.\u00a0 Ainsi, le risque d\u2019ovulations multiples diminue avec le num\u00e9ro d\u2019ovulation au cours du postpartum (Voir figure). Le nombre de vagues de croissance folliculaire qui n\u2019aboutissent pas \u00e0 une ovulation est plus \u00e9lev\u00e9 avant l\u2019apparition d\u2019une ovulation multiple que simple (Kusaka et al. Theriogenology 2017,91,98). Par ailleurs, la pr\u00e9sence d\u2019une codominance (deux follicules dominants) au cours de la premi\u00e8re vague de croissance folliculaire est plus \u00e9lev\u00e9e que lors de la deuxi\u00e8me et troisi\u00e8me vague en cas d\u2019ovulations multiples (Kulick et al. Biol. Reprod. 2001, 65, 839\u2013846\u00a0; Sartori et al. J. Dairy Sci. 2004, 87, 905\u2013920).<\/p>\n<p>Il semble que le risque d\u2019ovulation multiple soit ind\u00e9pendante de la concentration en inhibine un inhibiteur folliculaire de la FSH (Kulick et al. Biol. Reprod. 2001, 65, 839\u2013846) m\u00eame si une diminution de la concentration en inhibine 30 \u00e0 12 heures avant la d\u00e9viation a \u00e9t\u00e9 observ\u00e9e chez les vaches qui pr\u00e9sentent une ovulation multiple ( Lopez et al. Biol. Reprod. 2005, 72, 788\u2013795).<\/p>\n<p>L\u2019insulin growth factor (IGF) pourrait \u00eatre impliqu\u00e9 sa concentration \u00e9tant plus \u00e9lev\u00e9e chez les vaches avec ovulations multiples lors de la premi\u00e8re ovulation postpartum (Macmillan et al. Can. J. Anim. Sci. 2018). Cet IGF1 contribue \u00e0 l\u2019augmentation de la synth\u00e8se d\u2019oestradiol par les follicules antraux et les pr\u00e9pare \u00e0 la diminution de la FSH et \u00e0 l\u2019augmentation de la LH.\u00a0 La concentration de l\u2019IGF1 augmente lors de la distribution d\u2019une ration riche en \u00e9nergie (Silva et al. Theriogenology 2009, 71, 1193\u20131208) et notamment en amidon (Subramaniam et al. J. Dairy Sci. 2016, 99, 2762\u20132774).<\/p>\n<\/div><div class=\"fusion-image-element \" style=\"--awb-caption-title-font-family:var(--h2_typography-font-family);--awb-caption-title-font-weight:var(--h2_typography-font-weight);--awb-caption-title-font-style:var(--h2_typography-font-style);--awb-caption-title-size:var(--h2_typography-font-size);--awb-caption-title-transform:var(--h2_typography-text-transform);--awb-caption-title-line-height:var(--h2_typography-line-height);--awb-caption-title-letter-spacing:var(--h2_typography-letter-spacing);\"><span class=\" fusion-imageframe imageframe-none imageframe-1 hover-type-none\"><img decoding=\"async\" width=\"800\" height=\"534\" title=\"MacMillan 2018 frequence ovulations multiples PP par num\u00e9ro ovulation\" src=\"https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2023\/11\/MacMillan-2018-frequence-ovulations-multiples-PP-par-numero-ovulation.png\" data-orig-src=\"https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2023\/11\/MacMillan-2018-frequence-ovulations-multiples-PP-par-numero-ovulation-800x534.png\" alt class=\"lazyload img-responsive wp-image-2318\" srcset=\"data:image\/svg+xml,%3Csvg%20xmlns%3D%27http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%27%20width%3D%27821%27%20height%3D%27548%27%20viewBox%3D%270%200%20821%20548%27%3E%3Crect%20width%3D%27821%27%20height%3D%27548%27%20fill-opacity%3D%220%22%2F%3E%3C%2Fsvg%3E\" data-srcset=\"https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2023\/11\/MacMillan-2018-frequence-ovulations-multiples-PP-par-numero-ovulation-200x133.png 200w, https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2023\/11\/MacMillan-2018-frequence-ovulations-multiples-PP-par-numero-ovulation-400x267.png 400w, https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2023\/11\/MacMillan-2018-frequence-ovulations-multiples-PP-par-numero-ovulation-600x400.png 600w, https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2023\/11\/MacMillan-2018-frequence-ovulations-multiples-PP-par-numero-ovulation-800x534.png 800w, https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2023\/11\/MacMillan-2018-frequence-ovulations-multiples-PP-par-numero-ovulation.png 821w\" data-sizes=\"auto\" data-orig-sizes=\"(max-width: 640px) 100vw, 800px\" \/><\/span><\/div><\/div><\/div><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":20,"featured_media":2317,"template":"","keyword":[],"theme":[59],"class_list":["post-2316","training","type-training","status-publish","has-post-thumbnail","hentry","theme-reproduction-en"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/training\/2316","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/training"}],"about":[{"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/types\/training"}],"author":[{"embeddable":true,"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/users\/20"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/media\/2317"}],"wp:attachment":[{"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/media?parent=2316"}],"wp:term":[{"taxonomy":"keyword","embeddable":true,"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/keyword?post=2316"},{"taxonomy":"theme","embeddable":true,"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/theme?post=2316"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}