Brantsen: Earlage Moisture and Processing Survey
John Brantsen, a Vita Plus dairy nutritionist, remembers the 2011 harvest season well. In his area of northwest Iowa, the late summer and fall brought high temperatures and a lot of wind. He said harvesters in the area were racing the weather, trying to get corn silage harvested before it got too dry.
“Harvest went way too quickly and guys put up snaplage way too dry,” Brantsen said.
Because snaplage harvest often follows corn silage, the crop had already dropped to low moisture levels before harvesters could get to those fields. Brantsen had a feeling it would affect density, digestibility and aerobic stability; he just wasn’t sure how big the effect would be.
Working with a 12-sample set, Brantsen cored piles to determine packing density, took a composite samples for dry matter content and seven-hour starch content, measured core temperatures 12 inches from the face in the center mass, took infrared images, and evaluated manure samples.
With his earlage samples, Brantsen observed an inverse relationship between moisture and density as well as moisture and core temperature. However, he did not see a high correlation in these measurements.
In contrast, he saw strong correlation between moisture and seven-hour starch digestibility. The higher the moisture, the higher the starch digestibility, even in fresh feed that was in storage for two months at most.
“There’s a lot of dollars worth of feed and energy in these piles and there’s a huge difference in going from 80-percent digestibility down to 50-percent,” Brantsen said. “We’re losing value in that feed when we have to put it up so dry.”
Brantsen said he also observed some correlation between moisture and fecal starch; the wetter the snaplage, the lower the fecal starch content.
“I was very surprised to see starch as high as 25 percent for fecal starch,” Brantsen said. “It’s going straight through the cattle and not adding to gain or performance.”
Across all measurements, Brantsen concluded that the wetter the snaplage, the better the results. Of course, snaplage can reach a point where it is too wet and can spoil or the starch becomes too readily available.
Brantsen pointed out several reasons for snaplage becoming too dry. In addition to waiting for corn silage harvest to end, he said many producers weren’t monitoring corn for snaplage as closely as they should. Instead, they scheduled the harvest on a “get here when you get here” mentality.
He said some also had the perception that drier snaplage was better, especially for those feeding the snaplage in combination with wet byproducts. To them, the ration looked better sitting in the bunk when the snaplage was a little drier even though the actual value of the feed was lower.
Brantsen also recognized that moisture wasn’t the only factor affecting the quality of these feeds. He said he found a lot of heat-damaged feed, moldy feed and spoilage through oxygen infiltration below the plastic. He said that shows harvesters and producers have opportunities for improvement in all areas of harvest and storage.
To demonstrate the economic value of improving snaplage harvest, Brantsen shared the economics of dry matter loss on the top two feet of the bunker. He estimated the value per ton of snaplage as-fed at $164. That means the value of the top 24 inches of an 80- by 200-foot bunker is $96,760. That calculates to $1,000 in lost feed value for every 1 percent drop in dry matter.
“There’s a lot of dollars left on the table every year,” he concluded.
Feed quality and nutrition