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).
Creep feeding can add 11-22 kg (25-50 lb.) of weight to a calf at weaning. It takes 7-10 kg (15-22 lb.) of calf starter or creep feed for each additional kilogram (2.2 lb.) of weight gain. Creep feeding is most effective when the calf is 3-4 months old, particularly if the calves are eating poor quality forage.rass-fed cattle grow more slowly than grain-fed cattle, and are often marketed when 2-4 years old. Grain supplements can increase the growth rate, allowing cattle to be marketed earlier. Nevertheless, organic beef producers focus on forage and use grain sparingly.