“Phase feeding” – feeding multiple diets in the early stages of life – is widely employed in swine and poultry production systems.
The same practice has the potential to significantly benefit lifetime health and performance attributes for preweaned dairy calves as well, according to University of Guelph calf researcher Michael Steele.
Steele shared data with the audience of the 2022 Dairy Calf and Heifer Association Annual Conference that supported the practice of feeding transition milk – or a simulation of it – through the first few days of life.
In a study at the University of Alberta, newborn calves all were fed colostrum in the first day of life, then switched to either whole milk; a 50/50 blend of colostrum and milk (to simulate transition milk); or straight colostrum for days 2 and 3.
The calves then were euthanized and their digestive tracts were dissected. The researchers found that the intestinal villi showed greater development in both of the groups that had received some colostrum.
“These microscopic findings are huge with regard to overall intestinal villi development,” said Steele. “You want to maximize the amount of nutrient absorption, especially if you’re feeding a lot of nutrients early in life.”
Blood samples from the same study showed that circulating IgG persistence was significantly better for the two colostrum groups, versus the group that was abruptly switched to whole milk.
“It appears that we are wasting less IgG going back into the lumen of the gut by continuing to feed it,” noted Steele.
He shared a second study that examined the performance of calves that were fed a diet of milk replacer supplemented with colostrum replacer from days 2-14 of life, compared to a control group that received milk replacer only.
Results of that study showed the boost of colostrum replacer resulted in calves with greater bodyweight and average daily gain (ADG), and lower mortality risk and respiratory disease.
Steele said that idea of supplementing a standard diet with a dose of colostrum replacer is a good example of phase feeding that could be practically applied in commercial production. By targeting nutrients for calves within specific weeks or even days of life, he sees tremendous potential in improving lifelong outcomes for dairy animals.
