Corn Silage Evaluation: MILK2000 Challenges &

Opportunities With MILK2006

Professor Randy Shaver

Department of Dairy ScienceUniversity of Wisconsin - MadisonUniversity of Wisconsin - Extension

80 to 98% starch digestibility•Kernel maturity •Kernel particle size•Endosperm properties

40 to 70% NDFD• lignin/NDF

Grain ~40-45% of WPDM Stover= ~55-60% of WPDMLeaves = 15% of DMStem = 20-25% of DMCob+Shank+Husk=

20% of DM

Whole-Plant Corn Silage

•Avg. 28% starch in WPDM•Variable grain:stover

Adapted from Joe Lauer, UW Agronomy

NRC (2001) Dairy TDN

TDN 1-X =tdCP + (tdFA x 2.25) + tdNDF + tdNFC -7

Why measure NDFD in vitro vs. calculating via lignin?

Lignin wet chem assay difficult & its calibration with NIRS has been poorLignin to NDFD equation is theoretically basedLignin explains only about half of the in vitroNDFD variation

Stover NDF & lignin contents & NDFD with maturity, while WP NDF & lignin contents are constant or as grain% increases

0 5 10 15 20 25

AlfalfaR2 = 0.56

CornSilageR2 = 0.54

In v

itro

ND

F di

gest

ibili

ty, %

, 30h 70

60

50

40

30

20

Lignin, % of NDF

Corn silage:3-9%

Alfalfa:11-20 %

Relationship between lignified NDF and in vitro NDFD for corn & alfalfa forages

Allen, 2003

30-h NDFD (adapted from Allen, 2003) vs. NDF digestibility calculated using NRC-01 lignin equation

535762

Calculated NDFD

304.2453.1602.1

30-h NDFDWhole-PlantLignin, % DM

Measured NDFD or Estimated from Lignin?

56

57

57

5756

Calc. NDFD46.03.5245.0

67.33.4345.0

55.03.1845.1

54.43.3245.0

48.43.2645.0

30-h NDFDLignin, %NDF, %

Corn silage data set from Van Amburgh (2004)Similar relationships from 36.5 to 51.8% NDF

Adapted from: Rick Grant, NRAES Silage Conf., 2006

The incubation time-point debate

48-hr.Reflects maintenance intake for use in NRC summative equation

Less influenced by lag & rate, so possibly lower COV

30- or 24-hr.30-h more closely related to ruminalretention time30-h was used in most cow trialsFaster lab turn-aroundBetter lab efficiency at 24-h?

The incubation time-point debate

MILK200048-h

MILK200648-h default, with 30-h or 24-h User Defined Option

Lab average NDFD requiredNDFD DMIadjustment = (avg. NDFD – NDFD) * 0.26

NDFD adjustment for summative TDN1x equation

0

100

200

300

400

500

600

0 10 20 30 40 50 60 70 80 90 100

Time (hours)

ND

F R

esid

ue (g

kg-1

)

F657 bm3

P33A14

TMF113

WQS C0

WQS C1

WQS C2

TMF113 Predicted

F657 bm3 Predicted

WQS C2 Predicted

P33A14 Predicted

WQS C0 Predicted

WQS C1 Predicted

Adapted from Coors (data from Justen, 2004).

Variation in “normal “ corn silage NDF digestibility calculated using NRC-01 lignin equation and table data

564.2 (2stdev)

563.4 (1 stdev)

592.6 (avg.)

611.8 (1stdev)

651.0 (2stdev)

Calculated NDFD

Whole-PlantLignin, % DM

NDFD -- MILK2000 vs. MILK2006MILK2000

A 1%-unit change in NDFD from lab average NDFD changes DMI 0.37 lb (Oba and Allen, 1999, JDS)Double counting of TDN & DMI changes related to changes in NDFD

Tine et al. (2001, JDS) and Oba and Allen (1999, JDS)At production levels of intake, NDFD has minimal impact on NELcontent but does impact NEL intake primarily thru its impact on DMI

Calculation of NEL-3x from TDN1x as per NRC (1989)

MILK2006A 1%-unit change in NDFD from lab average NDFD changes DMI 0.26 lb (Jung, 2004, MN Nutr. Conf.; Oba and Allen, 2005, Tri-State Nutr. Conf.)NDFD used for calculating NEL-3x adjusted for impact of NDFD on DMI (Oba and Allen, JDS, 1999) Calculation of NEL-3x from TDN1x via DE and ME as per NRC (2001)

0.75

0.69

0.81

0.69

0.66

0.73

0.640.660.68

0.70.720.740.760.78

0.80.82

46 50 54 58 62 66 70 46 50 54 58 62 66 70NDFD%

Mca

l/lb

.Corn Silage NDFD% vs. NEL3x

Calculated assuming corn silage with 35% DM proc., 27% starch, 45% NDF, and 58% avg. NDFD

MILK2006

MILK2000

3579

3237

4065

3074

2936

3530

2900

3200

3500

3800

4100

46 50 54 58 62 66 70 46 50 54 58 62 66 70

NDFD%

lb. M

ilk/t

on C

s D

MCorn Silage NDFD% vs. Milk per Ton

Calculated assuming corn silage with 35% DM proc., 27% starch, 45% NDF, and 58% avg. NDFD

MILK2006

MILK2000

NRC (2001) Dairy TDN

TDN 1-X =tdCP + (tdFA x 2.25) + tdNDF + tdNFC -7

NRC (2001) Dairy TDN

tdNFC = NFC% x 0.98 x PAF

PAFCorn grain, ground dry 1.00Corn grain, ground high moisture 1.04Corn silage, normal 0.94Corn silage, mature 0.87

Schwab-Shaver Energy Equation

TDN1-x =

DIGCP + DIGFA + DIGStarch + DIGNSTNFC + DIGNDF – 7

Predicted Starch Digestibility

65

70

75

80

85

90

95

30 32 34 36 38 40 42 44 46 48

Whole plant DM (%)

Sta

rch

dige

stib

ility

(%)

Unprocessed

Processed

Adapted from Schwab et al., 2003.

Differences in calculation of tdNFC

34363940

Unprocessed

Schwab et al., 2003tdStarch&NSTNFC%

38394040

Processed

35353840

NRC-01 tdNFC%

45403530

WPDM %

Based on corn silage with 41% NFC & 28% starch

636465666768697071

30 35 40 45 30 35 40 45WP DM%

TDN

%Corn Silage WP DM% vs. TDN1x

Calculated assuming corn silage with 27% starch, 45% NDF, and 58% NDFD

Unprocessed Processed

MILK2006

2600

2700

2800

2900

3000

3100

3200

3300

30 35 40 45 30 35 40 45WP DM%

lb. M

ilk/t

on C

S D

MCorn Silage WP DM% vs. Milk per Ton

Calculated assuming corn silage with 27% starch, 45% NDF, and 58% NDFD

Unprocessed Processed

MILK2006

Evaluating Starch Digestion in Ruminants…………

In Vivo…… Total Tract Collections & Digesta MarkersCannulae (Rumen, Duodenum, Ileum)

Macro In Situ…. Rumen cannulaeIncubation time?Starch-Feeds cannot be fine groundPost-Ruminal Enzymatic?

In Vitro…. Rumen fluidIncubation time ?Starch-Feeds cannot be fine groundPost-Ruminal Enzymatic?

Corn Silage Processing ScoreMertens, USDFRC & Dairyland Labs, Arcadia, WI

Ro-Tap Shaker9 sieves (0.6 thru 19 mm) and panAnalyze for starch on 4.75 mm & greater sieves

% of starch passing4.75 mm sieve CSPS>70%70% to 50%< 50%

OptimumAveragePoor

Kernels and Large Fragments Were Retained on > 4.75-mm Sieves

US Dairy Forage Research CenterUSDA-ARS

65.566

66.567

67.568

68.569

69.5

45 55 65 75

KPS %

TDN

%Corn Silage KPS vs. TDN1x

Calculated assuming corn silage with 40% DM 27% starch, 45% NDF, and 58% NDFD

MILK2006

Degree of Starch Access (DSA)Blasel, Hoffman and Shaver, JAFST, 2006

Adaptation of food industry assay “Degree of Starch Gelatinization”Detects particle size, moisture, and vitreousnessdifferences in corn samplesAppears to offer better characterization of processed corn silage samples than KPSDSA can be related to total tract starch digestion

More animal validation data needed

Pilot study of assay across labs in progress

0

20

40

60

80

100

370 500 640 1100 3140 > 4000Mean Particle Size, u m

Deg

ree

of S

tarc

h A

cces

s, %

of s

tarc

h

Particle Size P<0.0001

Blazel et al., 2005

r2 = 0.76

40.0

50.0

60.0

70.0

80.0

90.0

100.0

62.0 67.0 72.0 77.0 82.0 87.0 92.0Corn Dry Matter, %

Deg

ree

of S

tarc

h A

cces

s, %

of s

tarc

h

Dry Matter P<0.0001

Blazel et al., 2005

DSA vs. Total Tract Starch Digestibility from Literature Sources

y = 0.198x + 76.9R2 = 0.73

65

70

75

80

85

90

95

100

0 10 20 30 40 50 60 70 80 90 100

Estimated DSA %

Tota

l Tra

ct S

tarc

h Di

g. %

Difference worth 3 lb. milk

63646566676869707172

80 85 90 95 100

DSA %

TDN

%Corn Silage DSA vs. TDN1x

Calculated assuming corn silage with 27% starch, 45% NDF, &58% NDFD

MILK2006

MILK2006: Starch DigestionUser Defined Options

DefaultWP DM & Kernel Processing Regressions

KPS

DSA

Ruminal in situ plus post-ruminal in vitro

79.9

57.3

76.3

56.2

53

56

59

62

65

68

71

74

77

80

TDN

%TDN1x Simulation -- Input Extremes

LQ 45% DM unproc., 20% starch, 54% NDF, and 46% NDFD

HQ 30% DM proc., 34% starch, 36% NDF, and 70% NDFD

MILK2000MILK2006

4256

2418

3617

2242

2000

2400

2800

3200

3600

4000

4400

lb. M

ilk/t

on C

S D

MMilk per Ton Simulation -- Input Extremes

LQ 45% DM unproc., 20% starch, 54% NDF, and 46% NDFD

HQ 30% DM proc., 34% starch, 36% NDF, and 70% NDFD

MILK2000

MILK2006

3000

3100

3200

3300

3400

3500

3600

3700

3800

LF HF LF HF

lb. M

ilk/t

on C

S D

MMilk per Ton -- High NDF, NDFD vs. Low NDF, NDFD

Ivan et al., JDS, 2005

LF 26% starch, 49% NDF, 58% NDFD

HF 22% starch, 53% NDF, 67% NDFD

MILK2000

MILK2006

168

132

297

100

150

200

250

300

HF - LF HF - LF HF - LF

lb. M

ilk/t

on C

S D

MMilk per Ton -- High NDF, NDFD vs. Low NDF, NDFD

Ivan et al., JDS, 2005

LF 26% starch, 49% NDF, 58% NDFD

HF 22% starch, 53% NDF, 67% NDFD

MILK2000

MILK2006

Calculated fromanimal data

Treatment differences for model-predicted milk per ton versus milk per ton from in vivo data

-150

-100

-50

0

50

100

150

200

250

300

MILK2006

MILK2000

Calculated from 10 JDS papers with 13 comparisons

Treatment differences for model-predicted milk per day versus milk per day in vivo data

-2.0-1.5-1.0-0.50.00.51.01.52.02.53.03.5

MILK2006

MILK2000

Calculated from 10 JDS papers with 13 comparisons

UW Correlationsn = 3727 treatment means

0.740.750.440.48Starch

-0.100.160.700.49NDFD

-0.27-0.250.210.30StarchD

-0.99-0.94-0.40-0.46NDF

Milk per Ton DM1991

Milk per Ton DM1995

Milk per Ton DM2000

Milk per Ton DM2006

r-values

UW Correlationsn = 3727 treatment means

0.610.520.200.23Milk per Ton DM

0.850.880.970.97DM Yieldtons/acre

Milk per Acre1991

Milk per Acre1995

Milk per Acre2000

Milk per Acre2006

r-values

Milk per Ton (lb/T)3200 3300 3400 3500 3600 3700

Milk

per

Acr

e (lb

/A)

22000

24000

26000

28000

30000

32000

34000

36000

38000

RX601RRYG

RX664

RX730RRYG

B3195

B3203

S6408Bt

F657

CX1020Bt

CX1080AD2660

DST10419

HiDF3300

HiDF3600

DKC4446RRYGCB

DKC5073

DKC5334RRYGCB

DKC5824

DKC5878YGCBDKC6009

DKC6017

DKC6019RRYGCB

DKC6411

56K44

24X

8523IT

8590IT

G8779

GS1061

H2387

H6775Bt

H8250FS4042Bt

FS4481

7625RRBt HC350

JC7

JC8

JS5450

K8105LFRRLC4531

LC7415

6068Bt

LG2488

LG2499

LGX52001

G7366

F377

F407

N48V8

N51Z7

N59Q9

6406Y

33B51

34B23

34M95

P35D45

35R58

RK668 S9617

T6900

T7012

T7095

Highyield

High yieldand quality

Highquality

Relationship between milk per acre and milk per ton of corn hybrids in South Central WI during 2002.

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