The Christian contribution to this whole debate is patchy to say the least. Christianity became established under the Roman Empire, and the RE, which was founded and extended by wars of conquest, generally prized the military virtues, which left little room for such sentiments as sympathy for the weak. As we know, there was a time when Christians were thrown to the lions at the so-called games, and the slaughter of humans and other animals was looked upon as an exciting form of entertainment. Later, when they were not themselves persecuted, Christians were forbidden to attend the games, on pain of excommunication, and the gladiator, who survived by killing his opponent, was regarded by the Church as a murderer. Soon after the conversion of Constantine to Christianity, gladiatorial combat came to an end altogether, but killing and torturing non-humans was permitted and apparently only declined with the empire itself as wild animals became more difficult, because too expensive, to obtain. The bullfight is perhaps the last vestige of this kind of entertainment.
Only a very few Romans had objected publicly to the use of sentient creatures for human pleasure, be it pleasure at the table or in the arena, and we have to wait nearly 1600 years before a Christian writer attacks cruelty to animals as wrong in itself.
The New Testament contains no injunctions against cruelty to animals, nor any exhortation to consider their interests. However we interpret the account of Jesus inducing a herd of swine to hurl themselves into the sea, we cannot avoid the impression that he was at best indifferent to their fate. After all, they were swine, and he was a Jew. Augustine used this incident to argue that our behaviour towards animals should not be governed by the same moral rules as our behaviour towards one another, and St Paul asks, Does God care for oxen?, in a context that clearly invites the answer 'No'.