Kartik Shukla Ashtami is known as Gopashtami. This festival is dedicated to Lord Krishna and cows. It is famous festival in Mathura, Vrindavan and other Braj regions. There is a tradition of decorating and worshiping cows with their calf on this day. On this day, Shri Krishna's father Nanda Maharaj had given the responsibility of taking care of the cows to Shri Krishna and Shri Krishna took the cows to the forest for grazing.
Nanda Maharaja decided to organize a ceremony for Lord Krishna and Balarama while going for the first time in Vrindavan to graze the cow. Radha, the divine wife of Lord Krishna, wanted to feed the cows, but she was denied having a girl. Therefore, being similar to Subala-sakha, she disguised herself as a boy, put on her dhoti and robe and joined her companions to have fun with Lord Krishna by rearing cows . This festival is celebrated on the Ashtami of Shukla Paksha of Kartik month.
It is also believed that Lord Krishna broke the pride of Lord Indra on this day.
On this day, after bathing the cows in the morning, they perform aarti with the calf with water, akshat, roli, jaggery, jalebi, clothes and incense-lamp. If there is no cow in the house, then one should go to the cowshed and serve the cows etc.
The cows are decorated with clothes and ornaments before the devotees perform special rituals. Special fodder is fed for good health. The ritual of worshiping a cow and a calf is similar to Govatsa Dwadashi in Maharashtra.
On this day, Shree Krishna Puja and Cow Puja is performed along with Pradakshina to seek blessings for a good and happy life. Devotees also have special respect for the usefulness of cows in daily life. Cows provide milk which helps in fulfilling the nutritional requirement of people like a mother. This is the reason why cows are considered sacred and worshiped as mothers in Hinduism. The glory and protection of the cow is discussed by senior devotees. They graze all the cows and take part in the feast near the cowshed.
After returning from the forest of the cows in the evening, after prostrating, tilak should be applied from their feet.