Study Shows Effects of Early Diet Options in Beef X Dairy Calves

By Garland Dahlke and Sherry Hoyer

Results from a recent study on how early nutrition can affect finished beef health, performance and carcass quality in beef x dairy calves provided some clarity and some surprises for Iowa State University researchers. Iowa Beef Center research scientist Garland Dahlke shared information from the project with attendees at the 2025 Feedlot Forum in northwest Iowa. He said the study focused on short and longer-term effects of different diets in the first five months of life.

“We primarily looked at calf starter and the level of nonstructural carbohydrate concentration and the effect this may have on the rest of the calf’s life and subsequent carcass composition,” he said. “Three groups of Angus x Holstein steer calves were followed during the two-year project.”

For the first stage, from birth to weaning at approximately 2 months of age, the calves were divided into two calf starter treatments: one fed a higher NSC (30%) and one fed a moderate level (17%). From age 2 through 5 months, calves from each of the initial two groups were split into a similar pelleted diet to the initial 30% NSC diet vs a total mixed ration. All calves in this stage were in group housing at the ISU Dairy and then at the ISU Beef Nutrition farm near Ames.

After completing the wean-to-grower phase at approximately 850 pounds, calves were moved to the ISU Armstrong Research Farm near Lewis. All received the same ration from 5 months of age until finish.

Dahlke said these early diet treatments had a significant impact on the incidence of liver abscess. Those calves receiving the moderate NSC starter followed by a fairly energy-and-protein-dense total mixed ration had a significantly lower incidence of both liver abscesses as well rumen/GI lesions when compared to calves on the higher NSC level and maintained on this NSC level beyond the calf starter phase, or even those moved to the TMR after the calf starter phase.

“Feedlot performance and carcass results were not significant between treatments when calves were fed to 1,450 pounds of final live weight,” he said. “There was a trend beginning to appear where those animals receiving the moderate NSC and transitioned to the TMR were performing better later in life and some significance may appear if these calves were fed until 1,600 pounds.

“The young age of these calves would tend to indicate that rumen development is rudimentary and may be enhanced by the diet composition,” Dahlke said. “Based on these results and the impact early nutrition has over the long run, a next logical step would be to focus attention on composition of the initial calf starter, intentionally including more digestible fiber sources and better profile of amino acids.”