By Dr. Dan Schauff, Ph.D., P.A.S.; Dave Spangler; and Lucas Krueger
The cost of milk production has increased dramatically in the past year due to various factors such as money supply in excess of economic expansion, higher energy costs, supply chain disruptions, and uncertainty in world wheat/grain markets due to the war in Ukraine. On many farms, ration costs have increased by $2/head/day on similar rations compared to a year ago. Record milk prices have helped to offset some of the higher production costs. However, getting the most out of every pound of homegrown and purchased grain, forages, and commodities is extremely important. That makes digestibility key.
One of the ways we can evaluate whether there is room for improvement in grain and starch digestion efficiency is by assaying representative fecal samples from dairy herds for starch content. Agri-King developed a starch digestion prediction equation using fecal starch that compares well to other peer-reviewed published equations. (Owens et al, 2016.) In order to look at the potential for improvements in grain/starch digestion on farms, we evaluated 743 fecal starch sample results from dairy herds across the United States. The distribution of fecal starch and predicted starch digestion are shown in Figures 1 and 2.
There was a wide range in both fecal starch and starch digestion, but the vast majority of the fecal samples range from 0.2 to 6% fecal starch, which translates to 93-99% predicted starch digestion. We consider a fecal starch content of nil to 1.1% as ideal. Levels of 1.1 to 3.1% are acceptable but show room for improvement, and >3.1% needs improvement (See Table 1).
From our analysis of fecal samples, one-third of the dairy herds have a definite opportunity for improvement in starch digestion. A little over one-half of the samples were acceptable, but still have room for improvement in starch digestion. Meanwhile, only 15.8% were ideal starch digestion (See Figures 1 & 2). The vast majority of dairy herds across the U.S. have at least some opportunity for improvement in starch utilization. This is in spite of much improved practices on most farms such as optimal kernel processing of grains in corn silage, earlage, and high moisture corn, and fine grinding of dry/unfermented grains (600-700 microns or less).
Other ways to improve starch digestibility in corn silage and grains are the use of forage and feed additives that contain direct-fed microbial and enzyme ingredients that help to optimize corn silage and high moisture grain fermentation and starch digestibility, while also reducing dry matter loss during fermentation and storage.
We conducted a corn silage fermentation trial using mini-silos. We used either no additive (control) or adding Silo-King® (Agri-King’s forage additive product) to the silage at harvest. The addition of Silo-King® resulted in higher levels of lactic acid being produced. The study also showed greater dry matter retention (See Figure 3) after 18 days of ensiling. The increased lactic acid and enzymatic action from Silo-King® treatment helped to solubilize the prolamin proteins that encapsulate starch granules in the corn kernel endosperm. As a result, 12-hour in vitro starch digestibility of Silo-King® treated corn silage increased compared to the non-treated control (Figure 3).
Agri-King recently introduced a new, enhanced version of Zy-Mend®. Zy-Mend is a feed additive formulated with direct-fed microbial and fiber and starch digestive enzyme activities. In particular, amylase, (starch-digesting enzymes) components were enhanced. Our research and development lab evaluated 24-hour in vitro dry matter digestibility (IVDMD) of numerous dairy client TMR samples already using the previous Zy-Mend® formulation. They observed an approximately 2% unit increase in digestibility after adding the new Zy-Mend® to the TMR samples. (See Figure 4.) We are observing in many cases improvements in energy-corrected milk on similar dry matter intakes and lower fecal starch contents. Furthermore, on some farms, corn and protected fat ingredients were able to be reduced in the milk cow rations.
In summary, during these times of both increased production and ration costs, it is even more economically vital for your cows to get the absolute most out of each pound of forage and grain that they consume. Contact your local Agri-King area manager to find out how you could further improve the fermentation efficiency of your fermented forages and grains and increase feed efficiency in your herd. AK