Silage Calculator
Calculate wet silage tonnage, dry matter tons, bunker trench storage volume (cu.ft and m³), shrink loss %, and silage feed valuation ($).
Calculate Corn Silage & Haylage Requirements
Enter head count, daily wet silage per head (lbs), feeding days, silage DM %, shrink loss %, and silage price.
Calculation Results
Calculated using forage fermentation bunker storage standards: \text{Gross Wet Tons} = \frac{\text{Head} \times \text{Daily Wet Lbs} \times \text{Days}}{2,000 \times (1 - \text{Shrink \% / 100})}
Quick Summary
The Silage Calculator evaluates total forage silage tonnage ($\text{Gross Wet Tons} = \frac{\text{Head} \times \text{Daily Wet Lbs} \times \text{Days}}{2,000 (1 - \text{Shrink})}$), bunker silo storage volume ($ft^3$ and $m^3$), dry matter tons, and feed costs.
Formula Explanation
\text{Net Wet Silage (lbs)} = \text{Head Count} \times \text{Daily Wet Silage (lbs/head)} \times \text{Days}
\text{Gross Wet Silage (lbs)} = \frac{\text{Net Wet Silage (lbs)}}{1 - (\text{Shrink \% / 100})}
\text{Bunker Storage Volume (cu.ft)} = \frac{\text{Gross Wet Silage (lbs)}}{45 \text{ lbs/cu.ft packing density}}How It Works
Corn silage and haylage undergo anaerobic lactic acid fermentation. The Silage Calculator accounts for bunker silo fermentation shrink loss (10%–15%), converting daily herd intake into total wet silage tonnage, dry matter tonnage, and bunker storage volume requirements.
Step-by-Step Worked Example
Practical Problem: A dairy herd of 100 cows consumes 55 lbs of wet corn silage daily (35% DM) for 180 days. Bunker storage shrink loss is 10%. Silage value is $55/wet ton. Calculate gross wet tons, dry matter tons, bunker volume, and total feed value.
- Step 1: Calculate net wet silage required: $100\text{ cows} \times 55\text{ lbs} \times 180\text{ days} = \mathbf{990,000\text{ lbs net silage}}$.
- Step 2: Account for 10% bunker shrink loss: $990,000 / (1 - 0.10) = 990,000 / 0.90 = \mathbf{1,100,000\text{ lbs gross silage}}$.
- Step 3: Calculate gross wet tons: $1,100,000 / 2,000 = \mathbf{550\text{ gross wet tons}}$.
- Step 4: Calculate dry matter tons (35% DM): $550 \times 0.35 = \mathbf{192.5\text{ dry matter (DM) tons}}$.
- Step 5: Calculate bunker volume & cost ($55/ton): $1,100,000 / 45\text{ lbs/cu.ft} = \mathbf{24,444\text{ cu.ft}}$ ($\$30,250\text{ total silage value}$).
Real-World Calculation Examples
Scenario 1: 100 Dairy Cows (180-Day Winter)
Parameters: 100 cows, 55 lbs wet silage/day, 35% DM, 10% shrink
Result: 550 wet tons (192.5 DM tons, 24,444 cu.ft bunker volume).
Scenario 2: 200 Feedlot Backgrounder Steers (150 Days)
Parameters: 200 steers, 30 lbs wet silage/day, 35% DM, 10% shrink
Result: 500 wet tons (175 DM tons, 22,222 cu.ft volume).
Scenario 3: Alfalfa Haylage (45% DM High Dry Matter)
Parameters: 100 cows, 40 lbs wet haylage/day, 45% DM
Result: 400 wet tons (180 DM tons, high protein forage).
Scenario 4: High Oxygen Bunker Shrink Loss (20%)
Parameters: Uncovered bunker silo, 20% shrink loss
Result: 618 wet tons needed (68 extra wet tons lost to spoilage!).
Key Benefits of Using This Calculator
Bunker Silo Sizing ($ft^3$ & $m^3$)
Calculates required bunker, trench, or bag silo storage volume at 45 lbs/cu.ft packing density.
Fermentation Shrink Loss Factor
Incorporates 10% to 20% bunker oxygen spoilage shrink loss into harvest tonnage targets.
Wet Weight vs Dry Matter Tons
Separates wet scale weight from actual dry matter (DM) nutrient tonnage.
100% Free & Client-Side
Executes locally in your browser with zero latency or web server transmission.
Frequently Asked Questions (FAQ)
What is ideal harvest moisture for corn silage?
Ideal whole-plant moisture for corn silage is 62% to 68% moisture (32% to 38% dry matter) for proper packing and anaerobic fermentation.
What is ideal packing density in a bunker silo?
Target packing density is at least 45 lbs of wet silage (or 15 lbs of dry matter) per cubic foot to eliminate oxygen pockets.
Why is plastic tarp oxygen barrier sealing important?
Covering bunker silos with oxygen-barrier plastic tarps and weighted tires reduces top surface spoilage shrink loss from 20% down to 8%–10%.
What is minimum daily bunker face removal rate?
Remove at least 6 inches of silage daily from the bunker face in winter, and 12 inches daily in summer to prevent aerobic heating and mold spoilage.
What is pH of fully fermented corn silage?
Properly fermented corn silage achieves an acidic pH of 3.8 to 4.2 within 21 days of ensiling.
How do I value corn silage based on corn grain price?
Rule of thumb: 1 wet ton of corn silage is valued at 7.5 to 8.5 times the price of 1 bushel of corn grain ($6.00/bu corn = $45–$50/ton silage).
What is silage inoculant?
Silage inoculants add homofermentative lactic acid bacteria (e.g. Lactobacillus plantarum) to accelerate pH drop and reduce dry matter fermentation losses by 2% to 4%.
What is kernel processing in corn silage?
Kernel processors on forage harvesters crush 95%+ of corn kernels, increasing ruminal starch digestibility by 5% to 10%.
What is difference between corn silage and haylage?
Corn silage is whole-plant corn harvested at 35% DM; haylage is wilted alfalfa or grass forage chopped at 45% to 55% DM.
How do I convert cubic feet of bunker storage to tons?
Multiply cubic feet by 45 lbs/cu.ft and divide by 2,000 ($\text{Wet Tons} = \text{cu.ft} \times 45 / 2,000$).