Dynamique de l’involution utérine et de la croissance folliculaire pendant l’anoestrus postpartum chez le zébu peulh d’Afrique

Les perspectives d’une remise en reproduction apres velage, prennent en compte la duree de l’anoestrus postpartum. Cette duree dependrait du delai d’involution uterine et du fonctionnement de l’axe gonado-hypothalamo-hypophysaire. L’objectif de cette etude a ete d’apprecier les caracteristiques de l’anoestrus postpartum, notamment l’involution uterine complete et la reprise de l’activite ovarienne apres la parturition chez la vache zebu Peuhl. Elle a concerne dix femelles (n = 10) d’âge et de poids moyens compris respectivement dans les intervalles [4 – 13] ans et [190 – 250] kg. Elles ont ete examinees a partir deJ7 jusqu’a J100 postpartum, au moyen d’un echographe portable muni d’une sonde lineaire de 7,5 Mhz. Les cliches les plus representatifs des cornes uterines, du cervix et des organites ovariens ont ete enregistres et analyses. La courbe de resorption uterine a montre une phase de regression rapide entre J7 et J16 suivi d’une phase lente entre J17 et J45.Ledelai moyen pour l’involution uterine a ete 26,6 ± 2,11jours. La reprise de l’activite ovarienne a ete observee dans un delai de 68,5 ± 6,11 jours. Ce delai varie en fonction de la parite (p = 0,04).Mots cles : Involution uterine, activite ovarienne, postpartum, zebu. English Title: Dynamics of uterine involution and follicular growth during anoestrus postpartum in African zebu Peulh   The prospects for rebreeding after calving were strongly influenced by postpartum anestrus duration which depends on the time of complete uterine involution and ovarian activity resumption. The aim of this study was to assess the characteristics of postpartum anestrus, in particular complete uterine involution and resumption of ovarian activity in the Peuhl zebu. It carried out on ten females (n = 10) which mean age and weight were extended between [4 - 13] years and [190 - 250] kg respectively. They were examined from Day 7 to Day 100 after calving by using a portable ultrasound scanner equipped with a 7.5 Mhz linear probe. The most representative images of uterine horns, cervix and ovarian structures have been frozen, recorded and exported for analyzing. The uterine resorption curve showed a rapid regression phase between Day 7 to 16 followed by a slow phase between D17 and D45. The mean time for uterine involution was 26.6 ± 2.11 days. Resumption of ovarian activity was observed within 68.5 ± 6.11 days. This time varies with parity (p = 0.04). Keywords: Uterine involution, ovarian activity, postpartum, Zebu cows