- Goats, roosters and pigs are given as sacrifice to gods.
- There are also many other animals and birds living but they are not Sacrificed.
- Why certain animals like Goat, roosters, pigs are given as animal sacrifice and others NOT ?
There are many more animals other than the ones mentioned in the question, that can be sacrificed. Sacrificing animals for both Gods and Manes is prescribed in scriptures.
The Manu Smriti mentions the following animals that can be offered to manes:
3.266. I will now fully declare what kind of sacrificial food, given to the manes according to the rule, will serve for a long time or for eternity.
3.267. The ancestors of men are satisfied for one month with sesamum grains, rice, barley, masha beans, water, roots, and fruits, which have been given according to the prescribed rule,
3.268. Two months with fish, three months with the meat of gazelles, four with mutton, and five indeed with the flesh of birds,
3.270. Ten months they are satisfied with the meat of boars and buffaloes, but eleven months indeed with that of hares and tortoises,
And what kind of meat can be offered to Gods is mentioned in the following verse of the KulArnava Tantram:
MAmsantu Tribidham Proktam Kha-Bhu-Jalacharam Priye | YathAsambhavampekyam TarpanArtham Prakalpayeth ||
The meat is of three kinds ; obtained from animals that fly , that walk on earth and that live in water. For the gratification of deity anyone of them has to be arranged.
KulArnava Tantram 5-44.
However, i need to reiterate here that killing is only allowed for the sake of Devas and Pitrus. If its done without sacrifice and for our own gratification then that is a sin as stated in the following verse:
Pitridevatayajneshu VaidhahimsA Vidhiyathe | ATmArtham PrAninAm HimsA KadAchinnoditA Priye ||
Killing is legal in sacrifices for manes and gods. Priye, but no scriptures ever allow doing the same for one's own pleasure.
KulArnava Tantram 5-45.