In ancient India, killing cows (gohatya) was considered a big sin. The sinner would have to drink barley water for a month, and he would live in a cowshed wearing the dead cow’s skin. For two months he would abstain from sexual activity and bathe in cow urine. He should take care of the needs of cows and donate ten cows and a bull after maintaining a vrat, failing which he would have to donate all his wealth to brahmins. If a cow is stopped for killing it, the person stopping it would have to do one fourth of the above. Tying it up would mean doing half and finding a weapon for killing the cow would mean doing three fourth as per Agnipurana Chapter 156.