Editor’s note: Carl Old, independent dairy nutritionist from Le Grand, Calif., handled the following case.

A dairyman in eastern New Mexico had been buying milo from one of the local grain elevators. He bought it whole rather than steam-flaked because he had a grinder at his farm, and by grinding his own he was able to save in the neighborhood of $20 per ton.  

But one day the grinder broke, and it was going to take a considerable amount of time to get replacement parts. So, the dairyman went to a feed mill, bought steam-flaked milo and fed it to his cows instead of whole milo.

Fairly quickly, milk production in the herd went up by 4 pounds per cow per day. At that rate, after subtracting out the higher feed cost, he was coming out ahead by 40 cents per cow per day.  

The herd’s nutritionist, Carl Old, was glad to hear that the cows were producing more, but he wanted verification.

“As a nutritionist, you have to look at it and ask how do I account for this difference?” he says.

With milk yield up by 4 pounds, on average, it meant higher component yields even if the milkfat and protein percentages stayed the same.  

To achieve higher protein yield, the cows needed to increase microbial protein synthesis in the rumen.

“The primary driver of microbial growth is carbohydrate availability,” Old says. And, in order for the cows to increase milk production by 4 pounds, he figured they would need to ferment about 2 pounds more carbohydrates in the rumen to account for that level of microbial protein synthesis.

Steam-flaking the milo made the carbohydrate more available to the cows than was the case with ground milo.

“What you have in milo is a starch that is very different when compared to other starches (from other feed ingredients),” Old says. “The starch in milo is very resistant to rumen degradation,” he adds. “It responds best to steam-flaking.”

“I could account for the vast majority of the change by accounting for shifts in the extent and site of starch degradation,” he said.

In this case, Old was able to verify that the changes in milk yield were indeed real and tied specifically to the steam-flaked milo.  

“If you have one plus one, you’d better hope it comes up two,” he says. “If it doesn’t, you’d better find out why.”