The aim of this work was to evaluate the efficiency of different concentrations of a commercial FSH-p on the nuclear maturation of Bos indicus oocytes, cleavage and in vitro development of embryos until blastocyst stages. The oocytes were selected and transferred to the maturation medium (TCM 199/25 mM HEPES) supplemented with different concentrations of FSH-p (T1 = 10mg/m<img border=0 width=32 height=32 id="_x0000_i1032" src="../../../../img/revistas/cr/v31n4/a14img01.gif"> ; T2 - 20mg/m<img border=0 width=32 height=32 id="_x0000_i1033" src="../../../../img/revistas/cr/v31n4/a14img01.gif"> ; T3 - 40mg/m<img border=0 width=32 height=32 id="_x0000_i1034" src="../../../../img/revistas/cr/v31n4/a14img01.gif">) and after 24 hours of incubation, at 39ºC in a moist 5% CO2 atmosphere. Some of the oocytes were removed and submitted to the analysis of nuclear maturation and the others were placed in the fertilization medium (mDM). After 18 hours of incubation, at the same atmosfhere condition mentioned above, the presumptive zygotes were transferred to the culture medium (KSOM) with a granulosa cells monolayer. The metaphase II, cleavage and blastocyst percentages were, respectively, 81.8/62.0/17.6% (T1), 55.6/64.0/19.5% (T2) and 50.0/65.0/16.3% (T3). The statistic analysis showed that a lower percentage of oocyte (P £ 0.05) treated with 20mg/m<img border=0 width=32 height=32 id="_x0000_i1035" src="../../../../img/revistas/cr/v31n4/a14img01.gif"> and 40mg/m<img border=0 width=32 height=32 id="_x0000_i1036" src="../../../../img/revistas/cr/v31n4/a14img01.gif"> of FSH-p reached the metaphase II stage and that the cleavage and blastocyst rate do not differ among treatments (P ³ 0.05). The results allow to conclude that the addition of 20mg/m<img border=0 width=32 height=32 id="_x0000_i1037" src="../../../../img/revistas/cr/v31n4/a14img01.gif"> and 40mg/m<img border=0 width=32 height=32 id="_x0000_i1038" src="../../../../img/revistas/cr/v31n4/a14img01.gif"> of FSH-p to the culture medium interfere in the nuclear maturation process, however all tested concentrations may be used without apparent damage to the cleavage and subsequent embryonic development.
maturation; cleavage; blastocyst; FSH-p
