This fact sheet has been developed to support the implementation of the Natural Resources Conservation Service Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.
The Natural Resources Conservation Service has adopted a practice standard called Feed Management (592) and is defined as “managing the quantity of available nutrients fed to livestock and poultry for their intended purpose”. The national version of the practice standard can be found in a companion fact sheet entitled “An Introduction to Natural Resources Feed Management Practice Standard 592”. Please check in your own state for a state-specific version of the standard.
Regardless of the size of a dairy operation, producers know problems can occur in every silage program. This fact sheet describes possible causes and solutions for nine potential problems in managing silage in bunker silos, drive-over piles, and bags.
The nine potential problems include:
Dairy producers should discuss these problems and solutions with everyone on their silage team, including their nutritionist and custom operator, as a reminder to implement the best possible silage management practices.
Four Excel spreadsheets to help producers make decisions about bacterial inoculants, packing density, and sealing strategies for bunker silos and drive-over piles are discussed.
Research has not explained why corn silages differ in their susceptibility to aerobic deterioration. Microbes, primarily lactate utilizing yeast, as well as forage and silage management practices contribute to aerobic stability of an individual corn silage. Nevertheless, there are several practical steps dairy producers need to be aware of, which can help minimize feedout problems.
A ‘Facer Cost Analysis’ Excel spreadsheet by Holmes (2003) calculates the breakeven cost of a facer for silage removal compared to a front-end loader.
The breakeven cost of the facer, when converted to an annual cost, equals the sum of improvement in DM recovery value and additional labor, equipment, and fuel use costs. The labor, equipment, and fuel use could actually be savings if the facer operates at a faster rate than the front-end loader. The spreadsheet and a complete discussion of the topic are available on the UW-Extension Team Forage web site.
The bag silo has become a popular storage system on many farms in the USA. While bagged silage requires specialized equipment, bagging machines can be rented or many silage custom operations provide them. Bags are also used to store extra silage when forage yields exceed the capacity of existing silo structures. Nevertheless, bagged silage is not trouble-free. Bolsen and Bolsen (2006a) surveyed 15 nutritionists, dairy producers, and silage contractors and asked, ‘better bagged silage: what is important?’. Selected responses from participants are presented here.
Better bagged silage: what is important?
Consistently protecting workers, livestock, equipment, and property at harvest, filling, and feeding does not occur without thought, preparation, and training (Murphy and Harshman, 2006).
A high DM density in the ensiled forage is important (Holmes, 2006). Why? First, density determines the porosity of the silage, which affects the rate at which air can enter the silage mass during the feedout phase. Second, achieving a higher density increases the storage capacity of a silo.
Thus, a higher DM density typically decreases the annual storage cost per ton of crop by increasing the tons of crop that can be put in a given silo volume and decreasing the ‘forage in’ vs. ‘silage out’ loss that occurs during the fermentation, storage, and feedout periods.
The Holmes-Muck Excel spreadsheet calculations for the average silage density in a drive-over pile of corn silage at a case study dairy are in Table 1. The actual 2003 pile of corn silage had a DM density of 11.5 lbs per ft3 and an estimated silage DM recovery of 77.5% (i.e., a 22.5% ‘shrink’ loss).
The following changes were made for the 2004 corn silage: 1) the maximum pile height was lowered from 16 to 14 feet, 2) the forage delivery rate increased from 75 to 90 tons per hour, 3) the average forage DM content increased from 32 to 34%, 4) a second tractor was added to assist in packing, and 5) the estimated forage layer thickness decreased from 8 to 5 inches. These changes resulted in a predicted silage DM density of 15.8 lbs per ft3. The estimated silage DM recovery was 85.0% (i.e., a 15.0% ‘shrink’ loss) for the 2004 silage, which was based on the data by Ruppel (1992).
Dairy producers, dairy nutritionists, and custom silage operators are sometimes concerned about whether it is economical to use an LAB inoculant when making whole-plant corn silage. Presented in Table 2 is an example from an Excel spreadsheet, which shows the profitability of inoculating whole-plant corn silage with LAB for lactating dairy cows. The dairy herd in this example had an average milk production of 75 lbs per cow per day and a ration DM intake of 52 lbs. The increase in net income with LAB-treated corn silage, calculated on a per cow per day and per cow per year basis, comes from improvements in both forage preservation and silage utilization. The additional ‘cow days’ per ton of crop ensiled from an increased silage recovery (1.5 percentage units) and an in¬creased milk per cow per day (0.25 lbs) gave an added net income of 13.0¢ per cow per day and $39.53 per cow per year. The increase in net return per ton of whole-plant corn ensiled with an LAB inoculant was $5.73. The Excel spreadsheet is on the Kansas State University silage web site.
Presented in Table 3 is an example from an Excel spreadsheet, which shows the profitability of inoculating corn silage with LAB for growing cattle.
The cattle in this example had an average weight of 650 lbs, a DM intake of 2.62% of body weight, a ration DM intake to gain ratio of 7.1, and an average daily gain of 2.39 lbs. The cattle performance responses to LAB-treated corn silage were a 0.06 lb increase in avg. daily gain (2.39 vs. 2.45 lbs) and an improved ration DM to gain ratio of 0.15 (6.95 vs. 7.1). The DM recovery response was 1.5 percentage units for LAB-treated silage compared to the untreated silage (84.0 vs. 82.5). The gain per ton of ‘as-fed’ whole-plant corn ensiled was 92.0 lbs for the LAB-treated vs. 88.45 lbs for untreated corn silage, which was an increase of 3.55 lbs. With a cattle price of $1.20 per lb and a LAB cost of $0.75 per ton of crop ensiled, the net benefit per ton of crop ensiled was $3.51. The Excel spreadsheet is on the Kansas State University silage web site.
An Excel spreadsheet to calculate the profitability of sealing corn silage and alfalfa haylage in bunker silos and drive-over piles was developed from research conducted at Kansas State University between 1990 to 1995 and equations published by Huck et al. (1997). The authors noted that about 75% of the total tons of corn and sorghum silage made in Kansas from 1994 to 1996 were not sealed, and the value of silage lost to surface spoilage was between 7 and 9 million dollars annually.
Presented in Table 4 are examples from the spreadsheet. The profitability of properly sealing bunkers and piles with standard 5- or 6-mil plastic or an improved oxygen barrier film makes it clear that producers should pay close attention to the details of this ‘highly troublesome’ task. Further information about the improved OB film is at http://www.silostop.com.
|Component||Actual: 2003 corn silage||Predicted: 2004 corn silage|
|Bunker silo wall height, ft (0 for drive-over pile)||0||0|
|Bunker silo maximum silage height, ft||16||14|
|Forage delivery rate to the pile, fresh tons/hr||75||90|
|Forage DM content, % (note:decimal)||0.32||0.34|
|Estimated forage packing layer thickness, inches||8||5|
|Tractor #1 weight, lbs3||35,000 (80)||35,000 (80)|
|Tractor #2 weight, lbs3||0||35,000 (95)|
|Estimated average DM density, lbs/ft3||11.5||15.8|
1From B. J. Holmes, UW-Madison, and R. E. Muck, US Dairy Forage Research Center, Madison. Available at: http://www.uwex.edu/ces/crops/uwforage/storage.htm
2Numbers in bold are user inputs.
3Estimated packing time as a percent of filling time is in parenthesis.
|Corn silage, other forage, and grain/supplement inputs:|
|Ration ingredient||DM intake, lb||DM, %||As-fed, lb/day||$/lb||Feed cost, $/day|
|Corn silage inventory and inoculant cost:|
|Corn silage required/cow/year, ton||7.94|
|LAB cost/ton of crop ensiled, $||0.75|
|1Numbers in bold are user inputs.|
|Component||Untreated corn silage||LAB corn silage|
|Silage recovery, % of crop ensiled2||85.0 (1.5)||86.5|
|Silage recovered/ton of crop ensiled, lb||1,700||1,730|
|Amount of corn silage fed/cow per day, lb||45.0||45.0|
|Cow days/ton of crop ensiled||37.74||38.41|
|Extra cow days/ton of crop ensiled||0.67|
|Milk production/cow/day, lb||75.0|
|Milk gained/ton of crop ensiled, lb||49.9|
|Milk price, $/lb||0.135|
|Increased milk value/ton of crop ensiled, $||6.74|
|Increased milk/cow/day, lb||0.25|
|Increased milk value/ton of crop ensiled, $||1.30|
|Preservation + utilization efficiency:|
|Extra milk value/ton of crop ensiled, $||8.04|
|Increased feed cost/extra cow day, $||3.46|
|Increased feed cost/ton of crop ensiled, $||2.31|
|Increased net return/ton of crop ensiled, $||5.73|
|Added cost of LAB:per cow/day, $||0.02|
|Added cost of LAB:per cow/year, $||5.96|
|Added income as milk:per cow/day, $||0.15|
|Added income as milk:per cow/year, $||45.53|
|Net benefit with LAB:per cow/day, $||0.13|
|Net benefit with LAB:per cow/year, $||39.53|
1Numbers in bold are user inputs.
2Shown in parenthesis is the response to LAB inoculant expressed in percentage units.
|Ration ingredients||DM basis||Untreated ration||LAB ration||Untreated ration||LAB response2||LAB ration|
|%||DM, %||DM, %||lb/day||lb/day|
|Grain or supplement||12.5||0.90||0.90||2.12||2.12|
|Avg. cattle wt., lb||650|
|Cattle price, $/lb||1.20|
|Avg. daily gain, lb||2.39||2.45|
|DM intake, lb/day||17.0||17.0|
|Ration DM/lb of gain, lb||7.1||-0.15||6.95|
|Silage/lb of gain, lb as-fed||18.7||18.3|
|DM recovery, % of the ensiled crop||82.5||+1.5||84.0|
|Gain/ton of as-fed crop ensiled, lb||88.45||92.0|
|Increased gain/ton of as-fed crop ensiled, lb||---||3.55|
|Value of the extra gain/ton of crop ensiled, $||---||4.26|
|Cost of LAB/ton of crop ensiled, $||---||0.75|
|Net benefit/ton of LAB-treated crop ensiled, $||---||3.51|
1Numbers in bold are user inputs.
2From Bolsen et al. (1992).
|Inputs and calculations||Bunker 1 corn standard||Bunker 2 corn OB film||Bunker 3 alfalfa standard||Bunker 4 alfalfa OB film||Pile 1 alfalfa OB film|
|Silage value, $/as-fed ton||32.50||32.50||60.00||60.00||60.00|
|Density in the top 3 ft, lb as-fed, ft3||39||39||35||35||40|
|Silo width, ft||40||40||40||40||100|
|Silo length, ft||120||120||120||120||250|
|Silage lost in the original top 3 feet:|
|unsealed, % of the crop ensiled||50||50||50||50||50|
|sealed, % of the crop ensiled||22.5a||12.5a||20a||10a||10a|
|Cost of covering sheet, ¢/square ft||4.0||10.0||4.0||10.0||10.0|
|Silage in the original top 3 ft, ton||280||280||250||250||1,500|
|Value of silage in original top 3 ft, $||9,125||9,125||15,120||15,120||90,000|
|Value of silage lost if unsealed, $||4,565||4,565||7,560||7,560||45,000|
|Value of silage lost if sealed, $||2,055||1,140||3,025||1,510||9,000|
|Sealing cost, $||670||960||670||960||5,900|
|Net value of silage saved by sealing, $||1,840||2,460||3,860||5,090||30,100|
1Numbers in bold are user inputs.
aAdapted from Bolsen and Bolsen (2006b).
Berger, L.L. and K.K. Bolsen. 2006. Sealing strategies for bunker silos and drive-over piles. In: Proc. Silage for Dairy Farms: Growing, Harvesting, Storing, and Feeding. NRAES Publ.181. Ithaca. NY.
Bolsen, K. K. 2002. Bunker silo management: four important practices. Pg. 160-164. In: Proc. Tri-State Dairy Nutrition Conference. Ft. Wayne, IN. The Ohio State University, Columbus.
Bolsen, K.K., R.N. Sonon, B. Dalke, R. Pope, J.G. Riley, and A. Laytimi. 1992. Evaluation of inoculant and NPN additives: a summary of 26 trials and 65 farm-scale silages. Kansas Agric. Exp. Sta. Rpt. of Prog. 651:102.
Bolsen, K.K. and R.E. Bolsen. 2006a. Better bagged silage: what is important? Presentation at the Penn State Dairy Nutrition Workshop. http://www.das.psu.edu/research-extension/dairy/nutrition/pdf/bolsen-bag-silageppt.pdf/
Bolsen, K.K. and R.E. Bolsen. 2006b. Common silage pitfalls. Pg. 5-13. In: Proc. of the Penn State Dairy Nutrition Workshop: http://www.das.psu.edu/research-extension/dairy/nutrition/pdf/bolsen-silage-pitfalls.pdf/
Holmes, B.J. 2003. Bunker silo facer: why invest? UW-Extension Team Forage web site: http://www.uwex.edu/ces/crops/uwforage/storage.htm
Holmes, B.J. 2006. Density in silage storage. Pg. 214-238. In: Proc. of Silage for Dairy Farms: Growing, Harvesting, Storing, and Feeding. NRAES Publ. 181. Ithaca, NY.
Huck, G.L., J.E. Turner, M.K. Siefers, M.A. Young, R.V. Pope, B. E. Brent, K.K. Bolsen. 1997. Economics of sealing horizontal silos. Kansas Agric. Exp. Sta. Rpt. of Prog. 783:84.
Jones, C.M., A.J. Heinrichs, G.W. Roth, and V.A. Isher. 2004. From harvest to feed: understanding silage management. Publ. Distribution Center, The Pennsylvania State University, 112 Agric. Admin. Bldg, University Park, PA 16802.
Kung, L., Jr., M.R. Stokes, C.J. Lin. 2003. Silage additives. Pg. 305-360. In: Silage Science and Technology. D. Buxton, R. Muck, and J. Harrison, eds. ASA, CSSA, and SSSA Publ., Madison.
Murphy, D.J. 1994. Silo filling safety. Fact sheet E-22. Agric. and Biol. Engineering Dept, The Pennsylvania State University, University Park, PA.
Murphy, D.J. and W.C. Harshman. 2006. Harvest and storage safety. Pg. 171-187. In: Proc. of Silage for Dairy Farms: Growing, Harvesting, Storing, and Feeding. NRAES Publ. 181. Ithaca, NY.
Ruppel, K.A. 1992. Effect of bunker silo management on hay crop nutrient management. M.S. Thesis, Cornell University, Ithaca, NY.
Visser, B. 2005. Forage density and fermentation variation: a survey of bunker, piles and bags across Minnesota and Wisconsin dairy farms. Four-state Dairy Nutrition and Management Conference. MWPS-4SD18. Ames, IA.
Whitlock, L.A., T. Wistuba, M.K. Siefers, R. Pope, B.E. Brent, and K.K. Bolsen. 2000. Effect of level of surface-spoiled silage on the nutritive value of corn silage-based rations Kansas Agric. Exp. Sta. Rpt. of Prog. 850:22.
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This fact sheet reflects the best available information on the topic as of the publication date. Date 6-20-2007
This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.
This project is affiliated with the LPELC.
Cattle Nutrition and Forage Management
Kansas State University
Associate Professor, Beef Extension Specialist
Kansas State University
Bill Weiss - The Ohio State University
Dwight Roseler - Consulting Nutritionist