03459naa a2200313 a 450000100080000000500110000800800410001902400550006010000170011524501190013226000090025152025470026065000160280765000170282365000190284065000200285965000120287965000120289165000240290365000200292765300260294765300250297365300190299865300230301765300140304070000160305470000170307077300580308715306182023-08-28       2002    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1016/S0093-691X(02)01084-12DOI1 aMENCHACA, A.  aFollicular recruitment and ovulatory response to FSH treatment initiated on Day 0 or Day 3 postovulation in goats.  c2002  aThe present study evaluates the effect of the presence of a large growing follicle at the onset of superovulatory treatment on follicular recruitment and ovulatory response in dairy goats. The treatment consisted of six equal doses of pFSH given every 12 h (total dose: 200 mg NIH-FSH-P1) which was initiated at Day 0 (Group DO) or Day 3 (Group D3) postovulation. Two haIt-doses of an analogue of prostaglandin F2a (delprostenate, 80 mg each) were administered together with the last two FSH doses to ensure luteolysis. A dose of a GnRH analogue (busereline acetate, 10.5 mg) was administered at the onset of estrus. Ovarian changes were evaluated twice a day by transrectal ultrasonography. Follicles were classified according to follicular diameter as small (3 to &lt4 mm), medium (4 to &lt5 mm) and large follicles (³5 mm). The number of corpora lutea (CL) was recorded after laparotomy perfoned 6 days after estrus. The work was conducted in replicates. ln the first trial, the does were assigned to either the DO (n = 4) or D3 group (n = 4) and in the second replicate, each goat was assigned to the alternate group. No large follicles were recorded and the diameter of the largest follicle was 3.3 + 0.1 mm (mean + S.E.M.) at the initiation of the treatment in DO-treated goats. ln contrast, a growing large follicle was present (6.7 + 0.4 mm, P &lt 0.01) when the treatment was initiated in D3-treated goats. ln these goats, the number of small follicles increased 24 h after ovulation but then declined 48 h later, temporally correlated with the growth of the largest follicle of the first follicular wave. The number of small follicles recruited by the FSH treatment was significantly higher and occurred earlier in DO-than in D3-treated goats (9.0 + 1.3 versus 5.6+ 1.1 follicles; P &lt 0.05; and 24 h versus 48 h from the onset of the treatment, respectively). The number of large follicles at the onset of estrus was higher in DO- than in D3-treated goats (14.4+ 1.9 versus 10.3+1.3; P &lt 0.05). Consequently, the number of CL recorded 6 days after estrus were higher in DO- than in D3-treated goats (13.6+ 1.9 versus 10.4+ 1.9; P &lt 0.05, respectively). These results demonstrate that the presence of a dominant follicle at the time of initiation of super-stimulatory treatment is detrimental to ovulatory response. This study supports the advantages of the so-called Day 0 protocol, e.g. treatment starting soon after ovulation, when the emergence of the first follicular wave takes place and there are no dominant follicles.  aDairy goats  aReproduction  aSuperovulation  aUltrasonography  aCaprino  aPrenhez  aReprodução Animal  aSuperovulação  aDominância folicular  aFollicular dominance  aOvulation rate  aTaxa de ovulação  aUltra-som1 aPINCZAK, A.1 aRUBIANES, E.  tTheriogenologygv. 58, n. 9, p. 1713-1721, Dec. 2002.