The importance of high-quality colostrum as a calf’s first meal is widely known and well documented. Now, newer research and anecdotal evidence shows that the value of colostrum extends past that single meal.

Many farms feed one or two servings of colostrum and then switch calves over to whole milk or milk replacer at 12 hours or 24 hours of age, noted Michael Steele during the December Hoard’s Dairyman webinar. However, the University of Guelph professor said there are reasons to consider a more gradual transition from colostrum to another source of nutrition.

He shared that there are peptides, carbohydrates, and fatty acids unique to colostrum and transition milk compared to whole milk, and these components benefit the calf in different ways. For example, Steele reviewed a study where calves fed a mixture of 50% whole milk and 50% colostrum on Day 2 and Day 3 had greater intestinal development, higher immunoglobulin (IgG) levels, and a lower risk of mortality than calves that received only whole milk.

In another study, calves fed a mixture of 90% milk replacer and 10% colostrum replacer from Days 2 to 14 had higher body weight, greater average daily gain, and a reduced risk of mortality. Studies like this show us that extended colostrum feeding has benefits, Steele noted.

Work at the University of Guelph has also looked at colostrum’s potential as a therapy for diarrhea in preweaned calves. In one study, calves with a fecal score of 2 or 3 (an indication of diarrhea) were enrolled in one of three groups: a control group, a group receiving a mixture of 50% milk replacer and 50% colostrum replacer for two days (four meals), and a group that received 50% milk replacer and 50% colostrum replacer for four days (eight meals). The calves were followed for 56 days after their enrollment in the study.

Steele said the calves that received the colostrum replacer with milk replacer for four days resolved their diarrhea cases sooner than the other calves. These calves also had higher average daily gain and greater body weight at the end of the study period.

If colostrum can be used as a therapy for diarrhea in calves, it may reduce the use of antibiotics for treatment. Steele said this improves both consumer perception and productivity of the calf, since calves treated with antimicrobials during the preweaning phase have been documented to have lower conception rates, extended time to first calving, a greater risk of culling, and reduced milk production in the first lactation.

To learn more about extended colostrum feeding and other calf nutrition topics, watch the December Hoard’s Dairyman webinar, “New developments in calf nutrition: Challenging the dogma.” This webinar was sponsored by Protekta.