4 reasons why cow is regarded as god/mother in Hinduism

1. Once a mother stops breastfeeding her child, the child starts drinking cow's milk. So, cow is second mother. 

2. In agrarian society, cow has a very special value. Oxen are used to plough land and cow dung is used as manure. So, cow is the basis of productivity, source of wealth and therefore regarded as Goddess Laxmi. 

3. It is a scientific fact that cow urine (gaumutra) has medicinal values. Cow dung is not only used as manure but it is also used to clean houses since it repels harmful ultraviolet rays and harmful bacteria. How pious an animal is whose defecation even have medicinal value? 

4. Cow has a tendency not to harm someone who is helpless or who is in trouble. A cow will never steps into someone who is laying on the ground. So, crawling babies or babies laying in the floor are always safe the cows.