Going “cold turkey” at weaning is stressful on all calves. But it may be particularly hard on early-weaned calves and calves offered milk free-choice, according to a new University of British Columbia study.

All early-weaned calves — those fed milk either free-choice or restricted to 10 percent of their bodyweight — took a hit in growth when their milk was abruptly taken away at four weeks. Calves abruptly weaned from free-choice milk at eight weeks of age also faired poorly after weaning. In fact, average daily gain for all of these calves dropped from about 1.8 pounds per day before weaning to just 0.4 pounds per day during the week after weaning.

In contrast, calves offered milk on a restricted basis and weaned at eight weeks of age actually tended to gain more during the week after weaning than before weaning. These calves gained about 1.6 pounds per day before weaning and about 2.5 pounds per day during the week after weaning.

“These results illustrate the need for alternative weaning practices to accompany new milk-feeding methods (like early-weaning and ad libitum milk consumption),” conclude the researchers.

The research was presented this past summer at the annual meeting of the American Dairy Science Association.

2006 Journal of Dairy Science, Vol. 89, Suppl. 1, Abstract #W14