By Kelly Foerder, Research & Development Coordinator and Dr. Dan Schauff, Ph.D., P.A.S.c
Feed costs, especially with higher commodity prices, can be 50% or more of the total cost to produce milk.
According to a 21-farm survey conducted in 2018, forage dry matter (DM) loss ranged from 7 to 18%, dry ingredient DM loss ranged from 1.5 to 7%; and wet by-products DM loss ranged from 12 to 20% (Greene,2018).
Overall DM loss or shrink ranged from 5 to 7% (Greene, 2018). Consequently, a ration cost of $7.00/hd/day at 6% dry matter loss can cost producers $0.42/hd/day.
If dry matter loss could be cut in half, then this could result in a recovery of $0.21/hd/day to the bottom line.
Besides wet by-products, reducing stored fermented forage dry matter loss will likely have the most impact on overall farm dry matter loss or shrink.
Often cited research conducted at Cornell University demonstrated that dry matter loss could be greatly reduced by increasing dry matter density of stored forage (Ruppel, 1992). A prediction equation developed by Ruppel (1992) and modified by Brian Holmes at the University of Wisconsin-Madison (2006) predicted that increasing dry matter density of forage from 10 lbs./ft³ to 20 lbs./ft³ may reduce 180-day dry matter loss from nearly 20% to nearly 10% (see Figure 1).
Through the excellent work by Brian Holmes at the University of Wisconsin and other university extension services such as Penn State and others, dairy producers have greatly improved their bunker and pile filling and covering management to achieve even greater dry matter density in their stored fermented forages.
In the early-mid 2000’s, Penn State extension researchers were recommending 14 lbs. DM/ft³ or greater in silage as a goal based on their field observations (Roth and Craig; updated 2012).
We wanted to observe how much progress producers had made regarding dry matter densities in their stored fermented forage.
As part of Agri-King’s Forage Smart Check program, our area managers have determined the average dry matter densities of 10 bags, 107 bunkers and 54 drive over piles to-date (see Table 1). We conducted three to 9 separate density cores for each forage face in order to calculate the average dry matter density and the coefficient of variation (CV) of density cores within each bag, bunker or pile (Table 1).
We conducted dry matter and nutrient analysis on each core sample to determine DM density. Findings were that bags had the lowest average density and the greatest variability in density within a bag face.
Nevertheless, the average density of bunkers (19.5) and piles (18.2) shown in Table 1 indicate large improvements in forage filling and packing management by producers. Table 2 shows the average density and CV for corn silage, haylage (primarily alfalfa), H.M. corn and earlage.
Corn silage and haylage had similar average densities and CV of density cores within each storage structure (Table 2). Overall, tremendous progress has been made. Over 78% of bags, bunkers and piles recorded average DM densities exceeding 16 lbs./ft³ (See Figure 2).
In addition, it is clearly possible to achieve 24 or more lbs. of dry matter density as evidenced by our survey (Figure 2). Consequently, there is the potential for further improvements.
Since producers have made so much progress in the past couple of decades, we have changed our recommended dry matter density benchmarks to reflect current progress and future potential (See Table 3).
In addition, we found, in some silage faces, a high variability in densities depending on the core location. Some silage faces had acceptable average dry matter density but high variability along the face as evidenced by >15% CV’s. If CV’s exceed 15%, opportunities might exist to improve the uniformity of dry matter density in a bunker or pile.
In conclusion, tremendous progress has been made by producers to improve dry matter density and reduce potential dry matter loss. Contact an Agri-King Area Manager in your area to learn about more opportunities to improve your bunker and pile management via our Forage Smart Check program and improve forage quality and fermentation efficiency with our unique silage additive Silo-King®. AK
Greene, D. 2019. Optimizing Feeding Management. Proceedings of the Western Dairy Management Conference.
Holmes, B.J. 2006. Density in Silage Storage. Proceedings of the Silage for Dairy Farms Conference (NRAES).
Roth, G.W. and P. Craig. Updated 2012. Penn State Corn Silage Bunker Density Study Summary. Penn State Dairy Extension.
Ruppel, K.A. 1992. Effect of bunker silage management on hay crop nutrient management. M.S. Thesis, Cornell University, Ithaca, NY.
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