Mixing hay and grain for young calves didn’t help them adapt to a total mixed ration later in life, University of Guelph, Ontario, researchers report.

Starting at birth and continuing for eight weeks, Holstein bull calves were fed chopped hay and concentrate as a mixture or in separate buckets. They also received milk replacer for the first seven weeks. All calves were fed the mixed diet in weeks nine through 11, then were offered a novel TMR in weeks 12 and 13. The TMR contained haylage, corn silage, high-moisture corn and protein supplement.

The two groups had similar average daily gains and weights throughout the study. Feed intakes were similar for those fed mixed and separated feeds. When all calves were offered the mixed diet in week nine, intake remained similar between treatments and stayed that way when they were switched to the TMR.

“These results suggest that dietary selectivity associated with early feed presentation may be transient, without statistically significant effects on longer-term intake or calf growth,” the researchers wrote.