Not only is the cow with her calf beautiful to look at, but the calf also gives satisfaction to the cow, and so she happily delivers as much milk as possible. But in the Kali-yuga, the calves are separated from the cows as early as possible for purposes which may not be mentioned in these pages of Srimad-Bhagavatam. The cow stands with tears in her eyes, the sudra milkman draws milk from the cow artificially, and when there is no milk the cow is sent to be slaughtered. These greatly sinful acts are responsible for all the troubles in present society. People do not know what they are doing in the name of economic development. The influence of Kali will keep them in the darkness of ignorance. Despite all endeavors for peace and prosperity, they must try to see the cows and the bulls happy in all respects. Foolish people do not know how one earns happiness by making the cows and bulls happy, but it is a fact by the law of nature. Let us take it from the authority of Srimad-Bhagavatam and adopt the principles for the total happiness of humanity.

From Srila Prabhupada's purport to SB 1.17.3