The slaughter of nearly 900 cattle that have been stuck on a cargo ship in the Mediterranean for two months has been postponed until Thursday.
Lawyers for the owners of the "Karim Allah" vessel delayed the process by requesting an official document authorizing the cull.
The slaughter was deemed necessary after Spanish veterinarians said the animals were no longer fit for export.
But the owners argued that the cows' ailments are treatable and they should be allowed to be transported to a place they can recover.
Responding to the plight of the cattle, rights groups on Tuesday reiterated their calls for the transport of live animals to come to an end.
Activist Amparo Marín on Tuesday called on the European Union to prohibit "these trips of terror" immediately.
Marín said the case had exposed "all the dirty laundry" about live animal transports not adhering to ruled on animal welfare regulations.
The ship set sail from the Spanish port of Cartagena on 18 December, carrying a total of 895 cattle destined for export to Turkey.
Turkish port authorities, however, refused to let them disembark, reportedly due to suspicions about their health.
After a second failed attempt to unload the cattle in Libya, the boat returned to Cartagena, where Spanish authorities ordered it to dock.
After an official inspection by government veterinarians, Spain's minister of agriculture said animals were to be killed.
Veterinarians judged them to be both unfit either for transport to another country or for their return to Spain.