It's just that keeping your heart rate in the target range during regular aerobic exercise has been shown to be safe and effective for increasing your aerobic fitness. Exercising above this range can be very uncomfortable and may increase your risk of injury.
Typical daily weight gains for feedlot animals ranges between 0.5kg to 2.5kg per day, while grass fed animals are somewhat lower than this. The following data was collected from a small beef cattle company in Dallarnil in Queensland (approximately 300km north of Brisbane).
After only a few days a Moose Calf is capable of outrunning a human. Moose gain weight at an incredible rate in the first year of life. A calf will gain more than 1 pound a day in the spring and later will have weight gain of over 4 pounds a day. When born calves are dark brown in color, almost black.