The invention concerns a bag (1) for packaging liquid substances for animal artificial insemination, consisting of two thermoplastic sheets soldered by a weld run (2) defining a pouch (3), along a closed generally rectangular marking defining two short sides (x) and (x') and two long sides (z) and (z') when the bag is empty, and whereof one of the short sides (x) has a break, the weld run constituting starting from said break a filling passage (4) defining in said thermoplastic sheets a filling portion (17), the other of the short sides (x') has a break, the weld run (2) constituting starting from said break a drawing passage (9), defining in said thermoplastic sheets a drawing portion (11) Preferably, at least one of said thermoplastic sheets has in the drawing portion a peel-off zone (12).
