Krishna Himself worships the cows

“Krishna said at that time that the cows are worshiped even by the demigods, and he practically demonstrated how to protect the cows. At least people who are in Krishna consciousness should follow in His footsteps and give all protection to the cows. Cows are worshiped not only by the demigods. Krishna Himself worshiped the cows on several occasions, especially on the days of gopāṣṭamī and Govardhana-pūjā.”
–A.C.Bhaktivedanta Swami Prabhupada