It is foretold in the Twelfth Canto of the Bhāgavatam that in this age of Kali married life will be accepted on the consideration of sex only; when the boy and girl are pleased in sex, they get married, and when there is deficiency in sex, they separate. That is not actual marriage, but a combination of men and women like cats and dogs. Therefore, the children produced in the modern age are not exactly human beings. Human beings must be twice-born. A child is first born of a good father and mother, and then he is born again of the spiritual master and the Vedas. The first mother and father bring about his birth into the world; then the spiritual master and the Vedas become his second father and mother. According to the Vedic system of marriage for producing children, every man and woman was enlightened in spiritual knowledge, and at the time of their combination to produce a child, everything was
(Srimad Bhagavatam-------3:24:15--------purport).

A father always remains in anxiety until he can hand over his grownup daughter to a suitable boy. A father and mother's responsibility for children continues until they marry them to suitable spouses; when the father is able to perform that duty, he is relieved of his responsibility.
(Srimad Bhagavatam-------3:22:24--------purport).

A materialistic father and mother want to engage their sons in begetting children, striving for improved economic conditions and rotting in materialistic life. They are not unhappy when their children become spoiled, useless citizens, but they lament when they join the Kṛṣṇa consciousness movement to achieve the ultimate goal of life. This animosity between parents and the Kṛṣṇa consciousness movement has existed since time immemorial. Even Nārada Muni was condemned, not to speak of others. Nevertheless, Nārada Muni never gives up his mission. To deliver as many fallen souls as possible, he continues playing his musical instrument and vibrating the transcendental sound Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare.
(Srimad Bhagavatam-------6:5:23--------purport).

According to smṛti regulation, the cow is the mother and the bull the father of the human being. The cow is the mother because just as one sucks the breast of one's mother, human society takes cow's milk. Similarly, the bull is the father of human society because the father earns for the children just as the bull tills the ground to produce food grains. Human society will kill its spirit of life by killing the father and the mother. It is mentioned herein that the beautiful cows and bulls were of various checkered colors—red, black, green, yellow, ash, etc. And because of their colors and healthy smiling features, the atmosphere was enlivening.
(Srimad Bhagavatam-------3:2:29--------purport).

The cow is the most important animal for developing the human body to perfection. The body can be maintained by any kind of foodstuff, but cow's milk is particularly essential for developing the finer tissues of the human brain so that one can understand the intricacies of transcendental knowledge. A civilized man is expected to live on foodstuffs comprising fruits, vegetables, grains, sugar and milk. The bull helps in the agricultural process of producing grain, etc., and thus in one sense the bull is the father of humankind, whereas the cow is the mother, for she supplies milk to human society. A civilized man is therefore expected to give all protection to the bulls and cows.
(Srimad Bhagavatam-------3:5:7--------purport).