Bhopal, Aug. 27: Madhya Pradesh is pinning its hopes on vasectomy to curb the threat that nilgai pose to crops, after methods such as Boma (catch and relocate), fladry, fencing, scarecrows and fire failed or proved too expensive.

Culling, as demanded by agitating farmers from Neemuch two years ago, is legal but is unpalatable to chief minister Shivraj Singh Chouhan - apparently because of his personal beliefs and the possible political fallout, sources said.

This despite his government last year renaming the animal as rojad - a colloquial word for antelopes in general - to rid it of the sacred-sounding-gai (cow) suffix that has generally deterred culling.

Last month, a team of five vets teamed up in Bhopal's Van Vihar National Park to perform vasectomy on 12 male nilgai, brought from across the state. A.B. Srivastava, V.P. Chandpuria, Kajal Jadav, R.S. Chouhan and Amol Rokde performed the "pinhole" surgery after tranquilising the nilgai.

Government sources said this was an experiment and that wildlife officials would now watch how the operation affects the antelopes' breeding patterns to assess its success.

The promiscuous and fast-multiplying nilgai, whose females are ready to mate at 25 months while living for 12-13 years, causes extensive crop damages, particularly in Ratlam, Mandsaur and Neemuch districts that grow opium under state supervision.

Forest officials say the nilgai, also known as the blue bull, have developed a taste for poppy and a single animal is capable of eating up to 300 dodas (the opium fruit) in one night. Whatever fruits they cannot eat, the animals trample while running amok in the fields.

Fencing the fields with tall thorny trees or fladry -coloured strips of cloth suspended from a rope mounted along the top of a fence - have proved inadequate deterrents.

The Boma proved too costly. This South African technique involves chasing the animals into a temporary enclosure and relocating them.

According to Madhya Pradesh Assembly records, the government spent Rs 41.6 lakh to catch and relocate 27 nilgai last December - an average of Rs 1.5 lakh per animal - using the Boma technique in Mandsaur. The captured nilgai were relocated to the forests of the Gandhi Sagar Sanctuary in the same district.

State forest minister Gauri Shankar Shejwar has said over 150 forest officials, 70 villagers and 30 horses were used in the exercise, and a private helicopter had to be hired to guide the operation from above.

Under state laws, the nilgai is a protected animal. Eating its meat is banned, and its carcasses have to be handed over to the forest department for cremation.

Despite the suffix- gai, the antelope is more horse-like: it has a long neck with a short and upright mane, a narrow head, a barrel-like chest, strong legs and high withers sloping back to the croup. During the Mughal period, it was called a nil ghora (blue horse).

Section 11 of the Wildlife Protection Act, 1972, empowers the state's chief wildlife warden to allow culling if he is satisfied that a particular animal has become dangerous to human life or property.

In March 2014, some opium growers in Mandsaur had urged Chouhan to set free two leopards that had been caught and relocated, claiming that their absence had made the nilgai, which usually move in herds of 40-50, more daring.