This Hadith lays emphasis on taking care of animals. Because if they are hungry or you overload them, they will not be able to speak out their suffering to you in human language. You are, therefore, supposed to take care of their food and other requirements by yourself. In case you fail in your duty to them, Allah will take you to task. Moreover, eating the flesh of sick and lean animals is unhygienic and can endanger health. Whereas, the flesh of a healthy and robust animal gives energy and strength to human body.