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/

Questions?