The Georgia researchers fed Holstein steers a wheat silage-based TMR containing graduated levels of the grocery blend at 0, 20, 40 and 60 percent of dry matter. They saw a nearly direct linear increase in consumption as inclusion levels of the grocery blend went up. In other words, the more fruits and vegetables in the diet, the more they ate. “They love it,” says Froetschel.
An evaluation of digestible energy showed the grocery feed source to have an energy value of 85 percent TDN, which is just below that of corn. But Froetschel also was concerned about the potential variability of the feed source. His team studied 200 samples and found a 23 percent variation in moisture content, but just an 8 percent variability of energy levels on a dry-matter basis.
Froetschel points out that, compared to other co-product feed sources that have the starch and sugar components removed, those elements remain intact in the grocery blend. “The result is a highly fermentable product with excellent rumen digestibility,” he says.
Finally, the research team evaluated the potential of ensiling the product for on-farm storage. “This is a feedstuff that is very high in sugars and organic acids like acetate and lactic acid,” Froetschel explains. “Because it lacks physical form, there is no need to pack it like traditional silage, and we found the pH drops very quickly, stabilizing at around pH 4 even though it is a very high-moisture product.”
While the Georgia researchers confirmed that ensiling is possible, most farms feed it within two to three days of delivery. Froetschel says either way is acceptable, noting that sugars will be higher when it is fed “as delivered,” organic acids will be higher when it is ensiled, but ultimately, its TDN on a DM basis is relatively consistent.
With high levels of soluble carbohydrate (25-45 percent), the product also delivers a moderate amount of fiber (25 percent NDF) and a small amount of protein (12 percent). Froetschel says soy hulls are an excellent choice as an added protein source because their water-binding capacity is highly compatible with the high moisture content of the grocery blend. It also mixes well in silage-based TMRs. “Dairies currently using the product are blending it at about 20 percent of their total TMR on a DM basis,” adds Froetschel.
The Viridiun team was highly enthusiastic about the results of the University of Georgia research, but also recognized that there are other questions that need to be answered to ensure confidence in the product. The biggest one: safety.