By MICHELE F. MIHALJEVICH
Indiana Correspondent

FORT WAYNE, Ind. — Though use of single total mixed ration (TMR) systems is accelerating, dairy farmers should be sure it’s the best system for their cows, a Michigan State University professor said last week.

Grouping cows by need can increase milk yield and decrease feed costs, said Mike Allen of MSU’s Department of Animal Science. He spoke April 21 on the opening day of the annual Tri-State Dairy Nutrition Conference in downtown Fort Wayne. The conference, in its 18th year, was sponsored by MSU, Purdue University and The Ohio State University.

Lactating cows need a different diet depending on their physiological state, Allen said. “Fresh cows have a low insulin concentration, but early- to mid-lactating cows have a high glucose demand,” he said. “Glucose demands decrease in late lactating cows.”

Adoption of single TMR systems has increased over the last 10 years because of the convenience, labor savings and simplicity, he said. One downside is that single TMR systems limit yield of high-producing cows and there is poor nutrient utilization in late lactating cows, he said.

The goals of diets for fresh, peak lactating and late lactation cows are different, which makes it more difficult for one diet to work effectively during the various stages, he said. For example, diets for fresh cows need to increase plasma glucose and insulin, and decrease plasma nonesterified fatty acid and liver fat content.
Peak lactating cows need highly fermentable diets to maximize energy intake, Allen said. Late lactating cows should avoid highly fermentable diets.

“Energy intake and partitioning response varies with the physiological state of cows,” he said. “Grouping strategies can increase milk yield and efficiency of nutrient utilization, as well as decrease feed costs. One-group TMRs equals a lost opportunity.”

Honoring co-founder

Conference organizers recognized Herb Bucholtz, professor emeritus in the Department of Animal Science at MSU, who is retiring.

Along with Timothy Johnson from Purdue and Maurice Eastridge from OSU, he was one of the conference’s co-founders in the early 1990s.

Before being honored, Bucholtz spoke about the changes he’s seen over his 36-year career.

“Year after year, herd milk production keeps going up,” he said. “How many industries can you see this increasing trend in productivity?”

Despite a slight downturn in the last year or so, he expects the overall trend of increased productivity to continue.

“The industry has had increases over the past 30 years, and I think it will start back up again and keep going.”

In the future, Bucholtz sees dairy nutritionists focusing on monitoring dry matter intake, evaluating the response of a nutritional change and learning new herd management software technology.