Animal Reproduction Science 97 (2007) 47–54 Use of fluorogestone acetate after breeding to reduce the effect of premature luteal regression in dairy goats when superovulation is induced with FSH M.J. Cervantes, M.L. Ju´ arez, V.O. Mej´ ıa, V.J.M. Berruecos, A.H. Vera, J. Valencia ∗ Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Aut´ onoma de M´ exico, M´ exico, 04510 D.F., M´ exico Received 5 May 2005; accepted 17 January 2006 Available online 20 February 2006 Abstract The aim of the present study was to determine the effect of fluorogestone acetate (FGA) administered after mating, on embryo production in the dairy goat subjected to conventional superovulatory and embryo recovery protocols. Adult does, most of them of the French Alpine breed, were randomly assigned after a FSH- superovulatory estrus and fertile matings to a control group (n = 20) or to a treated group (n = 20) in which intravaginal sponges impregnated with FGA were inserted after mating and remove before embryo collection (day 6). Blood samples were collected every 12 h from days 1 to 7 post-estrus and serum progesterone concentrations were determined. The FGA-group had a lesser percentage of does with normal corpora lutea (CL) and a greater percentage of animals with CL in regression or mixed (normal and in regression) when compared with the control group (13.3 and 64.7%, 53.3 and 23.5%, and 33.3 and 11.8%, respectively; P < 0.05). Mean number of normal CL per doe was less and mean number of regressed CL greater in FGA as compared with the control group (4.2 compared with 10.7 and 8.5 compared with 3.6, respectively; P < 0.05). There were no differences (P > 0.05) in recovery rate, total number of CL, total recovered structures, oocytes and transferable and non-transferable embryos between groups. Serum progesterone concentrations from day 5 to 7 post-estrus were lower (P < 0.05) in FGA as compared with the control group. Percentage of does with luteal failure on day 6 post-estrus was greater in FGA as compared with the control group (86.6 compared with 33.3%; P < 0.01). When considering only does with luteal failure on day 6 post-estrus, mean total recovered structures, transferable embryos and percentage of does rendering ≥3 transferable embryos were greater in the FGA compared with the control group (6.3 and 1.3 structures, 4.5 and 1.2 embryos, 67 and 17%, respectively; P < 0.05). In does not having luteal failure, FGA administration did not appear to affect embryo production or embryo survival. These results indicate that FGA administration after mating ∗ Corresponding author. Tel.: +52 56 22 58 60; fax: +52 56 22 59 35/58 93. E-mail address: jjvm@servidor.unam.mx (J. Valencia). 0378-4320/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.anireprosci.2006.01.008