Prabhupāda: Yes... They don't say cow. They say better kill one big animal. "So instead of becoming sinful for killing so many animals, you better kill..." And that is also sacrificed in the mosque, and that is called koravāni. Restriction is there.
Tamāla Kṛṣṇa: So there's no... The karma for killing many goats is more severe than killing one cow.
Prabhupāda: No, no. You become responsible for each and every animal.
Tamāla Kṛṣṇa: Irrespective of what kind of animal.
Prabhupāda: Yes. Now if you can serve the purpose by killing one animal, why should you take the risk of killing many animals?
Tamāla Kṛṣṇa: Even if that one animal is a cow.
Prabhupāda: Yes. Animal is animal. And we say protect cow from economic point of view, kṛṣi-go-rakṣya-vāṇijyam (BG 18.44). Without saving cows you cannot get good food, not from the animal point of view. You require milk and milk preparation.