LAHAN: The Animal Breeding Office, Lahan, has started producing liquid nitrogen needed for a semen bank established here some 20 years ago. Liquid nitrogen is used to store the semen safely for many years so that it can be used in artificial insemination of animals. Office chief Sumindra Yadav said the office has successfully started producing liquid nitrogen on its own and started collecting and preserving semen in the bank. He said the semen collected and preserved in the ban will be instrumental in animal breed improvement programme as the demand for artificial insemination is on the rise in the eastern region.