Immunization of sheep against GnRH early in life: effects on reproductive function and hormones in ewes

blood brebis ciclo estral ciclo vital cycle oestral desarrollo embrionario embryonic development ewes fsh gnrh gonadotropin releasing hormone hfs hormona liberadora de gonadotropina hormonas hormone hormones immunisation immunization lh life cycle oestrous cycle ovaire ovaries ovarios oveja ovin ovinos sang sangre sheep