Role of alfalfa in dairy diets
Randy ShaverExtension Dairy Nutritionist
Top producing herds in Wisconsin feed more forage than you may think
Survey Herds
5-Herd
Summary-3
3-Herd
Summary-2
6-Herd
Summary-1
No. Milking Cows 85 - 2274 60 - 331 280 - 570
DHI Milk RHA, lb 32k – 37k 30k – 33k 29k – 31k
Forage Program—Milking Cows
5-Herd
Summary-3
3-Herd
Summary-2
6-Herd
Summary-1
Dry Hay 4/5 3/3 3/6
Alfalfa Silage 5/5 3/3 6/6
Corn Silage 5/5 3/3 6/6
Herd or High Group Forage
5-Herd
Summary-3
3-Herd
Summary-2
6-Herd
Summary-1
Forage% of Diet DM
50 - 60 51 - 58 45 - 63
Alfalfa% of Forage DM
33 - 65 40 - 60 32 - 59
Calculated from Survey Summaries
Calculated from Survey Summaries
Maintenance & BWG energy requirements apportioned to forage or concentrate according to diet F:C ratio
Corn Silage vs. Alfalfa Silage
Lactation performance benefit to feeding 1/4th to 1/3rd of forage DM as corn silage
Similar lactation performance for 1/3rd to 2/3rd of forage DM as corn silage
Feeding 3/4ths or more of forage DM as corn silage creates nutritional challenges
High Corn & Low/Moderate SBM prices favor higher corn silage diets
Low Corn & High SBM prices favor higher alfalfa silage diets
Neither forage is favored when Corn & SBM prices are both either high or low
DM yield per acre advantage for corn silage over alfalfa silage the major factor
Comparative Forage CharacteristicsAlfalfa Corn Silage Grass Wheat
NutrientEarly Cut
Late Cut
Conv. Hybrid
BMR Leafy ShredlageEarly Cut
Late Cut
Straw
CP ++ + -- -- -- -- + - ---
RDP ++ + -- -- -- -- + - ---
RUP - - -- -- -- -- - - ---
NDF -- - - - - - + ++ +++
NDFD - -- + ++ + +? ++ + ---
peNDF + ++ - -- - +? + ++ +++
NFC + - + + + ++ - -- ---
Soluble Fiber
++ + - - - - - -- ---
Starch - - + + + ++ - - --
NEL ++ + ++ +++ ++ +++? ++ + -
New Varieties
• Reduced lignin for greater NDFD
• Reduced protein degradability for greater RUP
DMI related to NDF & NDFD
24% forage-NDF
16% forage-NDF
• High Quality Forages• Large Forage Supply• Forages Favorably Priced
• Limited Forage Supply• Use of High-Fiber Byproducts• Forages Expensive• Moderate/Low Quality Forages
Practical forage-NDF range in high-group TMR
i.e. 60% Forage @ 40% NDF
i.e. 35% Forage @ 46% NDF
24% forage-NDF
16% forage-NDF
• NDF, ivNDFD• Fill Limitation of DMI• Reduced Milk Yield
• peNDF• Milk Fat Depression• Cow Health
Nutritional Constraints
Herd Size % Dairies % Cows % Milk
2000+ 1.3% 32.5% 34.6%
1,000-1,999 1.6% 13.7% 15.7%
500-999 2.8% 12.3% 12.6%
Total ≥ 500 5.7% 48.5% 62.9%
Assumptions for calculations: 4000 milking cows; 800 dry cows; no growing heifers 80 lb. Milk/cow/day Total DMI
LC 50 lb./d; DC 30 lb/d
Dietary Forage Content (% of DM) LC 50%; DC 80%; Total 53%
Forage DMI: LC 25 lb/d; DC 24 lb/d
TMR Fed, tons DM
Daily 115
Weekly 808
Monthly 3,233
Annually 38,796
Approx. Annual $ Value
$9,000,000
Approx. Milk $ Value $24,000,000
Forage Needs @ 15% ShrinkTons DM
Acres Needed @ 6 ton DM avg. yield
Daily 72 12
Weekly 506 84
Monthly 2,024 337
Annually 24,288 4,048
Acres Needed Approx. $ Cost
10% Yield Drag +450 $2.5M
15% more forage in LC Diet DM
+1,019 $5.0M
Both +1,577 $7.5M
Dry Matter Loss for Forage Harvest and EnsilingDry Matter Loss
Range Normal(%) (%) .
Mowing/Conditioning Haylage 1-4 2Respiration Haylage 1-7 4Rain (Haylage only) 0-50 variesRaking Haylage 1-20 5Merging Haylage 1-3 1Chopping Haylage 1-8 3Chopping Whole Plant Corn 0-1 0.5 Storage Filling 2-6 ---Ensiling, Storage & Feedout 10-16 12
(bunker)Haylage Total 17-64
Whole Plant Corn Total 12-23
Dry Matter Losses From Different
Levels of Silo Management
Losses From Excellent Average Poor
Respiration < 1% < 2% > 5-10%
Fermentation < 3% 3-5% 10-15%
Seepage 0% < 1% >5%
Storage (aerobic) 3-5% 5-6% >10-30%
Total 8-10% 11-15% 20-40%
Department of Dairy ScienceUW-Madison
Maximum yield of DM
Vegetative
growth
Optimal
stage
Flower or
Head or
Black LayerStage of maturity
Forage yield - quality vs. quantity
indigestible
digestible
Maximum yield of digestible DM
Dry matter yield(tons/acre)
Matching Relative Forage Quality to Animal Needs
120100 140110 130 150
Dairy heifers, 18-24 mo.
Dry beef or dairy cows
Dairy heifers, 12-18 mo.
Beef cows with calf
Dairy cows, last 200 days lactation.
Dairy calves, 3-12 mo.
Beef stocker cows
Dairy, first 100 days of lactation.Calves, first 3 mo
Relative Forage Quality
Wheat Straw
Visit UW Extension Dairy Cattle Nutrition Website
http://www.uwex.edu/ces/dairynutrition/
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