<Lord Krishna’s Example
To teach by example, the Supreme Lord Sri Krishna and Lord Balaram show us when They descend into this world, how important is to protect, love and serve Cows and Bulls. Krishna is known as Gopala (protector of the Cows) or Govinda (one who gives pleasure to the Cows). Lord Balaram represents plowing the land for agriculture and therefore always carries a plow in His hand, whereas Krishna tends Cows and therefore carries a flute in His hand. Thus the two brothers represent krisi-raksha (protecting Bulls by engaging them in farming) and go-raksha (protecting the Cows). 10.5.20 Purport
“Offering respect to the Cows will help the devotee to diminish the reactions to his past sinful activities” (Skanda Purana)
Vrindavan’s Cows are constant remainders of Krishna’s ecstatic Cow herding lilas (pastimes). By serving the Cows one receives tremendous spiritual benefit. Feeding grains to the Cows, offering puja, or simply a scratch under the neck will please these peaceful personalities and attracts the attention of Supreme Personality of Godhead Sri Govinda. The Gautamiya Tantra says, “One should gently scratch the body of a Cow, offer her a mouthful of green grass and reverentially circumambulate her. If Cows are maintained nicely and comfortably, Lord Gopal will be pleased.”
The Hare Krishna Movement 