The following case study was handled by Barry Dye, senior dairy consultant with Purina Animal Nutrition, LLC.  

A North Carolina mixed breed herd ― part Jersey, part Holstein and part Jersey-Holstein cross ― expanded from approximately 300 cows in the milking herd to 840.

Even though the expansion involved a new free-stall barn, the owners felt that given the size of the holding pen and other potential bottlenecks, it was best to switch from three-times-a-day milking to 2X.

The switch from 3X to 2X occurred in November 2012. Anytime a switch like that occurs, the farm risks losing some milk production ― and, in this case, it wasn’t the outcome the owners wanted. They felt there was still untapped milk production potential in the herd, despite the switch to 2X milking.

So, they challenged nutritional consultant Barry Dye to look at the rations and see if there were some opportunities. Is there more milk in these cows? they asked.

Dye reviewed the rations and they looked OK on paper. Dry matter intake didn’t appear to be a problem, either. 

It would require closer inspection.

Dye turned to a forage diagnostic system known as Calibrate. And, the first set of results certainly got his attention. The rumen undegradable NDF score ― a measure of undegraded NDF mass in the rumen ― was higher than 100 in a couple of the key feeding groups.

That told him two things:

  • Dry matter intake may be limited by undegraded feed/rumen fill.   
  • More degradable starch is needed in the diet.

“When that score is greater than 100,” it indicates that ”if we increase the NDF digestibility or decrease the amount of NDF in the diet, there is a likelihood we can increase dry matter intakes,” Dye says.  

More and more evidence came in. Another component of the Calibrate test turned up rumen degradable starch scores that were lower than Dye wanted to see.

Since the farm was already targeting its better forage to the high-producing cows, there wasn’t a lot of opportunity to feed more digestible NDF from the current feed supply. So, Dye cut back some of the forage, which lowered the amount of NDF in the diets.

”It worked out pretty neat, because some of room that was left in the diet gave us more room to increase the amount of fine-ground corn we were feeding, and that let us raise our ruminally degraded starch scores,” he said.

There was an immediate response. Within a three-week period, the herd average moved from 62 pounds of milk per day to 68. Even with 6 extra pounds of milk, the components remained constant ― butterfat at 4.1 percent and protein at 3.15 percent.

Meanwhile, the farm owners “have been extremely satisfied,” Dye says.

And, it turned out that the owners’ intuition was right ― the cows did have more milk in them that needed to be utilized.

Bottom line: Calibrate gave Dye a powerful tool to dig deeper and peer into what was going on in the feed and the rumen