1. Matt Akins, Luiz Ferraretto, Shane Fredin & Randy Shaver Dairy Science Department, UW Madison

2. 24% forage-NDF 16% forage-NDF High Quality Forages Large Forage Supply Forages Favorably Priced Limited Forage Supply 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

3. 24% forage-NDF 16% forage-NDF Fill Limitation of DMI Reduced Milk Yield peNDF Milk Fat Depression Cow Health Nutritional Constraints

4. 24% forage-NDF 16% forage-NDF Dairy NRC Min. forage NDF & Max. NFC Dietary Guidelines 44% NFC 38% NFC High Fiber Byproducts Starchy Grains

5. Varying proportions of Starch Sugar Pectin/Soluble Fiber Organic Acids Analytical Errors CP, NDF, Fat, Ash Variable ruminal & total tract digestibility of starch

6. NDF Greater proportion of acetate Starch Greater proportion of propionate Sugar Greater proportion of butyrate or valerate Pectin/Soluble Fiber Greater proportion of acetate Impacts DMI, milk yield & composition, & feed conversions

7. 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) Optimum in TMR With 23% - 25% Starch (DM basis) in these trials

8. Average #2 yellow corn cash price in Minneapolis, MN at 5 year intervals from Sept. 1975 - Aug. 1976 through Sept. 2010 - July. 2011 (USDA ERS, 2011) 25% - ≥ 30% Starch Diets Common ? Dietary Starch Content

10. IngredientStarch% Shelled corn70 Corn:SBM (65:35)46 Corn Silage30 Soy hulls5 Corn gluten feed23 Distillers grains3 Whole cottonseed1

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

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

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

18. Matt Akins & Randy Shaver Dairy Science Department, UW Madison Kelly Perfield & Howard Green Elanco Animal Health

19. Rumensin Increase milk-production efficiency (Milk/DMI) Reduce DMI These responses greater on reduced-starch diets

20. UW-Madison Arlington free-stall barn 16 pens of 8 cows (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 treatment period Pen served as experimental unit for stats analysis

22. Normal StarchReduced Starch - - - - - - - - - - - - - - % of DM - - - - - - - - - - - - - - Corn silage25 Alfalfa silage25 Dry ground corn23.915.0 Soyhulls5.515.5 SBM-4811.310.2 DDGS4.5 Mins-Vits-Adds3.9 Control or Rumensin Premix 0.9 Rumensin concentration 0 or 18 g/ton within NS & RS TMR

23. Normal StarchReduced Starch - - - - - - - - - - - - - - % of DM - - - - - - - - - - - - - - CP18.318.1 NDF28.534.9 Forage NDF19.5 Starch26.920.4 Ether Extract5.9 TDN 1x 74.568.9

24. NSRSP-value DMI, lb/d59.859.30.53 Milk, lb/d93.790.40.01 Milk/DMI1.561.540.11

25. Starch × week (P < 0.01) * * * * †

26. 0 g/ton18 g/tonP-value DMI, lb/d59.959.10.33 Milk, lb/d90.693.50.01 Milk/DMI1.521.58<0.01

27. * * * Rumensin × week (P < 0.01)

28. NSRSP-value Fat, % lb/d 3.81 3.55 3.88 3.52 0.36 0.85 Protein, % lb/d 3.22 3.00 3.17 2.87 0.01 <0.01 MUN, mg/dL12.112.7<0.01

29. * * * * Starch × week (P < 0.01)

30. 0 g/ton18 g/tonP-value Fat, % lb/d 3.87 3.51 3.82 3.55 0.52 0.56 Protein, % lb/d 3.22 2.91 3.17 2.95 0.02 0.37 MUN, mg/dL12.212.60.06

31. NSRSP-value SCM, lb/d90.688.90.28 SCM/DMI1.521.500.54

32. 0 g/ton18 g/tonP-value 3.5% FCM, lb/d96.197.90.30 ECM, lb/d95.096.80.29 SCM, lb/d88.990.60.31

33. 0 g/ton18 g/tonP-value FCM/DMI1.611.660.04 ECM/DMI1.591.640.03 SCM/DMI1.491.530.05

34. Starch × Rumensin (P < 0.08)

35. 0 g/ton18 g/tonP-value Body Weight, lb152715370.52 Condition Score3.053.040.65 Body Weight Change, lb/d 1.031.140.53

36. NSRSP-value Body Weight, lb154515200.12 Condition Score3.063.030.48 Body Weight Change, lb/d 1.151.020.45

37. NSRSP-value TT StarchD, %96.898.1<0.01 NE L, Mcal/lb DM0.74 0.69

38. 0 g/ton18 g/tonP-value TT StarchD, %97.597.30.29 NE L, Mcal/lb DM0.730.750.01

39. Reduced starch diet: Similar DMI and SCM yield Reduced milk and protein yields 18 g Rumensin/ton DM: Increased milk yield Reduced DMI as trial progressed Increased milk-production efficiency by 4% Similar milk fat and protein yields Few interactions between dietary starch content & Rumensin supplementation were detected Results support use of Rumensin in normal & reduced starch diets

40. The digestibility of starch from corn in dairy cows? Pat Hoffman & Randy Shaver Dairy Science Department University of Wisconsin - Madison

41. Primary Factors: Influencing Starch Digestibility in Feed Grains Processing i.e. Particle size; Steam Treatment Harvest/Storage i.e. Dry vs. HMC DM of HM/Maturity; Fermentation Time Endosperm Type i.e. Prolamin; Prolamin-starch matrix; Hardness

42. FeedGrainV2.0 Integrates Primary Factors: Influencing Starch Digestibility in Feed Grains Processing Particle size Harvest/Storage Dry vs. HMC DM of HMC/Maturity Silo Fermentation Time Endosperm Type Starch-Protein Matrix Hardness Vitreousness MPS Ammonia Prolamin

43. FeedGrainV2.0

48. Snaplage HMC Ammonia = 6.0% of CP Kernel MPS = 1456 µ Ammonia = 1.8% of CP MPS = 1335 µ

49. Snaplage HMC kd = 26%/hr RSD = 69% TTSD = 97% kd = 19%/hr RSD = 62% TTSD = 95% Kd, RSD & TTSD estimated from Ammonia & MPS with FeedGrainv2.0 - Hoffman et al. 2012

50. HMSCSnaplage Snaplage + 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/dL11.4 b 14.0 a 10.3 c <0.001

51. a b a a ab b Week × Treatment interaction (P < 0.05)

53. Visit UW Extension Dairy Cattle Nutrition Website http://www.uwex.edu/ces/dairynutrition /