Practices of Hindu animal sacrifice are mostly associated with Shaktism, and in currents of folk Hinduism strongly rooted in local tribal traditions. Animal sacrifices were carried out in ancient times in India. Hindu scriptures, including the Gita, and the Puranas forbid animal sacrifice.

A Sanskrit term used for animal sacrifice is bali, in origin meaning “tribute, offering or oblation”. Bali among other things “refers to the blood of an animal” and is sometimes known as Jhatka Bali among Hindus.

Animals are sacrificed by Hindus in all parts of India, mainly at temples of Goddesses such as Bhavani or Kali.

The Rajput of Rajasthan offer a sacrifice of buffalo or goat to the their family Goddess ( Kuldevta) during the festival of Navaratri. The ritual requires slaying of the animal with a single stroke. In the past this ritual was considered a rite of passage for young men. The ritual is directed by a Brahmin priest.

Animal Sacrifice is practiced by people in Southern Indian states of Karnataka, Andhra Pradesh, and Tamil Nadu by local Hindu people. It is most notably done in front of Local Deities or Clan Deities. The ritual involves most caste members of the village with each caste performing different roles. In Karnataka, the Goddess receiving the sacrifice tends to be Renuka. The animal is either a male buffalo or a goat.

The Kathar or Kutadi community of Maharashtra while observing the Pachvi ceremony, after delivery of a child in the family, offer worship to their family deity, Saptashrungi and also offer a sacrifice of a goat. Following this they hold the naming ceremony of the child on the 12th day

The Hindu temples in Assam and West Bengal in India and Nepal where this takes place involves slaying of goats, chickens and sometimes male Water buffalos. These sacrifices are mainly done at temples following the Shakti school of Hinduism where the female nature of Brahman is worshipped in the form of Kali and Durga. A number Tantric Puranas specify the ritual for how the animal should be slayed. In Bengal, a priest recites the Gayatri Mantra in the ear of animal to be sacrificed, in order to free the animal from the cycle of life and death.

Bali Jatra of Sonepur in Orissa, India is also an annual festival celebrated in the month of Aswina (September–October) when animal sacrifice is an integral part of the ritual worship of deities namely Samaleswari, Sureswari and Khambeswari. Bali refers to animal sacrifice and hence this annual festival is called Bali Jatra.

Source: http://en.wikipedia.org/wiki/Animal_sacrifice_in_Hinduism