One index of a successful calf enterprise for the milk-feeding phase is to have calves double their weight in the first 60 days (see www.calfandheifer.org Gold Standards I). Depending on when calves are weaned (42, 49, 56, 63 days) their rate of growth at the end of milk feeding will vary.
Earlier weaning = lower rate of gain/day; later weaning = higher rate of gain/day. When on farms where they are successful in doubling birth weights by 60 days I often find that calves finish weaning at 49 days and move to transition housing at 56 days. Their growth that last week on milk (42-49 days) is usually between 1.9 and 2.1 pounds per day. Thus, we are looking for a weaning program that will maintain that rate of growth, 2 pounds per day, in the transition calf housing.
However, weaning calves from a high-volume (8-12 quarts/day) and high-fat liquid diet (e.g., whole milk, greater than 20 percent fat milk replacer) presents special challenges.
Take a look at what works well.
Source: Sam Leadley, Calving Ease, July 2012