Effect of permanence of intravaginal fluorgestone acetate sponges on initiation and duration of oestrus in goats

Abstract

The objective of the present essay was evaluated 3 differents permanencies of intravaginal sponges impregnated with 40 mg. of fluorgestone acetate (FGA) plus 400 IU of pregnant mare serum gonadotropin (eCG) on estrus initiation and duration in goats. The does used were 15 multiparous lactating Nubian breed divided at random in the following groups: A: 20, B:18 and C:16 days of permanency. 400 IU of eCG was injected at sponge removal. Estrus was detected during 5 days after sponge removal using a vasectomized buck every 6 hours (0600, 1200, 1800 and 2400 hours). Estrus initiation was (mean ± SD): 31,5 ± 5,7, 35,0 ± 13,4 and 30,0 ± 4,2 hours, for treatments A, B and C, respectively. Estrus duration was 24,0 ± 4,9, 23,0 ± 7,9 and 22,8 ± 2,7 hours for the same groups of treatments, respectively. Estrus initiation and estrus duration were not significantly different between groups (P³O.05). It is concluded that estrus initiation and duration were no differents when intravaginal sponges of FGA were left 16, 18 and 20 days plus 400 IU of eCG injected at sponge removal.