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Randy ShaverDairy Science Department, UW Madison

What’s the Latest on Carbohydrates, Starch Digestibility, Shredlage™ andSnaplage for Dairy Cows?

Average #2 yellow corn cash price in Minneapolis, MN at 5 year intervals from Sept. 1975 through Aug. 2012 (USDA ERS, 2012)

25% - ≥ 30% Starch Diets Common ?

USA Corn Price & Starch Content of Lactating Dairy Cow Diets

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Ingredient Starch%

Shelled corn 70Corn:SBM (65:35) 46

Corn Silage 30Soy hulls 5

Corn gluten feed 23Distillers grains 3

Whole cottonseed 1

DIM at Trial

Start-Up

Weeks on Trial

DietaryForage NDF

DietStarch

NS - RS

Partial Corn

Replacers

UW I 51 14 21% 5% SH

UW II 68 12 20% 5% WM, WCS

UW III 114 14 21% 10% SHUW IV 100 16 21% 6% SH

OARDC 74 16 23% vs. 26% 5% CS

Recent Continuous-Lactation Trials With Reduced-Starch Diets

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DMI for normal- & reduced-starch diets

DGSC partially replaced by High-Fiber Byproducts in UW I-IV & Corn Silage in OARDC to formulate RS diets

SCM yield for normal- & reduced-starch diets

DGSC partially replaced by High-Fiber Byproducts in UW I-IV & Corn Silage in OARDC to formulate RS diets

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SCM/DMI for normal- & reduced-starch diets

DGSC partially replaced by High-Fiber Byproducts in UW I-IV & Corn Silage in OARDC to formulate RS diets

UW I2010

UW II2011

UW III2011

UW IV2011

OARDC2011

Item (RS/NS)

Feed Cost

$/lb. DM

$/cow/day0.99

1.08

0.92

0.98

0.99

1.03

0.99

0.99

0.95

0.92

IOFC

$/cow/day1.00 0.93 0.96 0.96 0.93

Revised using August-2012 milk component & feed prices

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• NDF – Greater proportion of acetate

• Starch – Greater proportion of propionate

• Sugar– Greater proportion of butyrate or valerate

• Pectin/Soluble Fiber– Greater proportion of acetate

• Propionate impacts DMI, milk yield & composition, & lactation efficiency

Endproducts of Ruminal CHO Fermentation

• Broderick & Radloff (2004) Dried or Liquid Molasses vs. HMSC

• Broderick et al. (2008) Sucrose vs. Corn Starch

• Quadratic DMI & milk production responses• 5% - 7% Total Sugar (DM basis) TMR optimum 23% - 25% Starch (DM basis) in these trials

What About Sugars?

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Multiple Ration Groups

Important for effectively implementing reduced-starch diets Potential for fill limitation of DMI and thus milk production when corn starch partially replaced by forage NDF in high-group diets

Reduced lactation efficiency when corn starch partially replaced by byproduct NDF in high-group diets

Effects of Rumensin® in lactating cow diets with differing starch contents

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• UW-Madison Arlington free-stall barn• 16 pens of 8 cows each (90 ± 33 DIM)• Treatments NSR = 27% starch with 18 g Rumensin/ton TMR DM NSC = 27% starch without Rumensin RSR = 20% starch with 18 g Rumensin/ton TMR DM RSC = 20% starch without Rumensin

• Completely randomized design with 4-wk covariate on NSR followed by 12-wk of treatment Pen served as experimental unit for stats analysis

Study Methods

0 g/ton 18 g/ton P-value

DMI, lb/d 59.9 59.1 0.33

Milk, lb/d 90.6 93.5 0.01

Milk/DMI 1.52 1.58 <0.01

Impact of Rumensin on DMI, milk yield & Milk/DMI

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0 g/ton 18 g/ton P-value

Fat, %lb/d

3.873.51

3.823.55

0.520.56

Protein, %lb/d

3.222.91

3.172.95

0.020.37

MUN, mg/dL 12.2 12.6 0.06

Impact of Rumensin on milk composition & component yields

Milk Fat %

Starch × Rumensin (P = 0.15)

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0 g/ton 18 g/ton P-value

FCM/DMI 1.61 1.66 0.04

ECM/DMI 1.59 1.64 0.03

SCM/DMI 1.49 1.53 0.05

Impact of Rumensin on component corrected milk production efficiencies

Lactation efficiency (Milk/DMI)

1.4

1.45

1.5

1.55

1.6

1.65

RSC NSC RSR NSR

Treatment

lb m

ilk/lb

DM

I

Starch × Rumensin (P < 0.08)

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Corn

Shr

edlage

™

Corn

Shr

edlage

™Shredlage

KP

30 mm TLOC2.5 mm roll gap

19 mm TLOC2.5 mm roll gap

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Penn State Separator Box (as-fed basis)

Screen, mm Shredlage KP

19 31.5% 5.6%

8 41.5% 75.6%

1.18 26.2% 18.4%

Pan 0.8% 0.4%

Samples obtained during feed-out from the silo bags

Kernel Processing Score

Shredlage KP

% Starch Passing 4.75 mm Sieve 75.0% ± 3.3 60.3% ± 3.9

Samples obtained during feed-out from the silo bags

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Experimental Diets (DM basis)

Shredlage KPShredlage 50% ---

KP Silage --- 50%

Alfalfa Silage 10% 10%

Ground Dry Shelled Corn 10.3% 10.3%

Corn Gluten Feed 7.4% 7.4%

SBM 48%, solvent 6.9% 6.9%

SBM, expeller 9.3% 9.3%

Rumen-Inert Fat 1.9% 1.9%

Min/Vits 4.2% 4.2%

Penn State Separator Box (as-fed basis)

Screen, mm Shredlage KP19 15.6% 3.5%

8 38.2% 52.9%

1.18 38.9% 35.8%

Pan 7.3% 7.8%

TMR Samples

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3.5% FCM Yield by Week

*

***

* P < 0.10

** P < 0.01

Week × Treatment Interaction (P < 0.03)

Total Tract Starch Digestibility

TreatmentP < 0.001

WeekP < 0.03

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HMC Silo Fermentation Increases Starch Digestibility

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Prior to Ensiling Ensiled 240 d

Hoffman et al., 2011, JDS

Hoffman et al., 2011, JDS

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FeedGrainV2.0 IntegratesPrimary Factors Influencing Starch Digestibility

in High Moisture Corn

ProcessingParticle size

Harvest/StorageDry vs. HMC

DM of HMC/MaturitySilo Fermentation Time

MPSAmmonia

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Snaplage HMCAmmonia = 6.0% of CPKernel MPS = 1456 µ

Ammonia = 1.8% of CPMPS = 1335 µ

Feeding trial conducted during months 8 -10 in storage

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Snaplage HMCkd = 26%/hrRSD = 69%TTSD = 97%

kd = 19%/hrRSD = 62%TTSD = 95%

Kd, RSD & TTSD estimated from Ammonia & MPS with FeedGrainv2.0 - Hoffman et al. 2012

HMSC SnaplageSnaplage + Dry Corn

P <

Fat % 3.67%a 3.40%b 3.52%ab 0.05

Protein % 2.97% 2.93% 2.94% 0.89

MUN, mg/dL 11.4b 14.0a 10.3c <0.001

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a

b

a a

ab

b

Week × Treatment interaction (P < 0.05)

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Corn Silage Fermentation Increases Starch Digestibility

Corn Silage Fermentation & Starch Digestibility

Ruminal in situ starch & CP degradabilities for WPCS with longer ensiling (Newbold et al., 2006)

Ruminal in vitro starch digestibility for WPCS with longer ensiling (Hallada et al., 2008 & Der Bedrosian et al., 2010)

WPCS ammonia-N & ruminal in vitro starch digestibility with protease addition & longer ensiling (Young et al., 2011)

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Corn Silage Ammonia-N

Lab Years n Average Normal Range- - - - - % of N - - - - -

Dairy One 2000-2011 12,000 7.1 3.0 – 11.1

Dairyland* 2008 - 2011 1,900 5.7 2.7 – 10.7

CVAS* 2007-2012 44,000 9.6 7.8 – 11.4

*Almost none of variation in ammonia content explained by DM content in either corn silage dataset

0

50

100

150

200

250

# of samples 

51% Adequately Processed42% Inadequately Processed

7% Optimally Processed 

Corn Silage Processing Score, 1131 Samples, CVAS 2010 - 2011

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Corn Silage Fermentation & Starch Digestibility

Can ammonia-N & some measure of particle size, i.e. KPS or % starch passing 4.75 mm screen (Ferriera & Mertens, 2005), be used to predict corn silage digestibility during feed-out?

http://www.uwex.edu/ces/dairynutrition/

Visit UW Extension Dairy Cattle Nutrition Website