Nutrition 4 - Fiber 3/3/16

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1 NDF Digestibility in Dairy Rations Fast Start Mod #4 Realistic view of plant cells from microbial viewpoint Steve Massie, MS, PAS. Renaissance Nutrition, Inc. Breaking cells open by processing and chewing Thickness of cell wall maturity & hybrid Plant Carbohydrates Cell Wall Anatomy & Lignification Organic Mono+Oligosaccharides Acids Cell Contents Starches Fructans Dextrins NDSC / NFC Cell Wall Pectic Hemicelluloses Cellulose Substances Galactans -glucans ADF NDSF NDF Non-Starch Polysaccharides MB Hall, 2000 Lignin highest in primary wall & moves into secondary wall as plant matures Primary cell wall often indigestible (for fiber particles) Bacterial digestion proceeds from lumen outward Cell must be ruptured! Realistic view of plant cells from microbial viewpoint Plant Intrinsic Factors that Influence NDF Digestion Cellulose crystallinity Enzyme accessible space Plant cell anatomy Toxic/inhibitory compounds Phenolic compounds Lignin!! Breaking cells open by processing and chewing Thickness of cell wall maturity & hybrid 1/9

2 Ferulate Cross-Bridges Structure of Lignin Ferulate cross-links with xylans and lignin which strengthens cell wall and reduces digestibility (Ralph, 1996) Lignin and Cell Wall Digestion Ester & ether linkages to hemicellulose Ester bonds can be cleaved; ether cannot Steric hindrance microbes can t attach to fiber! [Lignin] not always related to NDFd Why? Not sure; may be due to amount and type of crosslinking (ester vs ether) esterases in rumen, but no etherases Bacterial Digestion of Lignified Cell Wall Digestion Surface of Cell Wall Colonization Active Digestion Extent of Digestion Chesson (1993) Chesson (1993) 2/9

3 Understanding NDFd It is what the Rumen Bugs can digest in a given time period It is drives VFA production (Acetic = BF%) VFA s produce milk NDFud produce manure Factors Affecting NDFd Variety and Maturity of the Plant Particle Size & Clean Cuts Stress Load on the Plant Rumen ph and overall Rumen Health DMI and Rate of Passage Storage Time Moisture What Do We Do with NDF Digestion Measurements? Benchmarking Inventory/allocation decisions Ration formulation rate of NDF digestion: CNCPS/CPM-Dairy Assigning a more accurate energy value to forage Calculate RFQ The value of NDF digestion Washington State Survey Why a Cow produces 100 lbs of milk 53 lbs Cow Comfort 12 lbs Good Nutrition 8 lbs Genetics 4 lbs Unaccounted for Literature Summary 1 unit increase in NDF digestion = lb DM intake/d lb milk/d 23 lbs Forage Quality Wilson 2007 Oba and Allen, /9

4 F. Owens, 2008 NIRSC/ NFTA/ FeedAC Joint Annual Meeting Effect of the NDF-D of Corn Silage on Milk Production 43 Corn silage NDFD = 65.5% Corn silage NDFD = 58.7% Milk, kg/d -3 lb milk/day difference Milk Weeks on Study Kung, Teller, Schmidt, 2003 Unpublished, Univ. of Delaware 28 DMI, kg/d 26 Effect of the NDF-D of Corn Silage on DM Intake 32 Corn silage NDFD = 58.7%Corn silage NDFD = 65.5% Weeks on Study DMI Kung, Teller, Schmidt, 2003 Unpublished, Univ. of Delaware Milk yield, lb./d NDFD vs. Potential Milk Yield 100 Milk Potential Forage NDFD, % NDF Shaver, /9

5 Symptoms of Poor Forage Fiber Digestibility High cows: lower dry matter intake (and milk production) Low cows: higher dry matter intake (and possibly more weight gain) Lower peak milk yield The value of NDF digestion Literature Summary 1 unit increase in NDF digestion = lb DM intake/d lb milk/d Oba and Allen, 1999 Forages Big Picture Comments- Fermentable Fiber Huge amount of normal variation in forage NDF digestibility Lab values are not precise, but hopefully get you in the ballpark Know your crops and time points Forage Comparison Hr NDFd Straw Alf Hay Alf Hlg Grass Hy Grs Hylg All CSil Dairy One Data 09 Among Corn Silage Hr NDFd Grain Type Silage Type BMR CSil CVAL Data 09 5/9

6 Corn Silage Comparison (MSU Data) * Drought Normal Time Points Rule #1: Thou shall know thy time points Rainfall (in) * * DM Yield (T/A) NDF% Lignin, %NDF %NDF dig. Note: Drought year had only 15% more growing degree days Rule #2: Only Compare same time points. Rule #3: See Rule #1. Much Variation by Timepoints NDFd by Timepoints Corn Silage Ave NDFd 6 Hrs Hrs 38.1 Hrs.5 48 Hrs 59.4 % N D F d CS Halg Avg values for DairyOne Forage Lab Hours How do I define good corn silage? Appropriate moisture content and VFA profile Kernel processed to improve starch digestibility while maintaining adequate particle length Moderate starch/grain content EXCELLENT FIBER DIGESTIBILITY What about hay and haylage?? Forages with enhanced NDF digestibility Less filling Allow greater DMI when limited by gut fill Allow higher NDF diets to be fed, stabilizing ruminal fermentation May increase energy partitioned to milk (and/or cow) Where & how to feed? Slide adapted from Dr. G. Varga, PSU 6/9

7 Grass or Alfalfa??? Plant Extrinsic Factors that Influence NDF Digestion Higher NDF digestibility More filling Slow rate of digestion & passage Perennial grass Non-fiber Potentially digestible fiber Indigestible fiber Non-fiber Legume Potentially digestible fiber Indigestible fiber Lower NDF digestibility Less filling Fast rate of digestion & passage Maturity Environmental conditions Temperature Rainfall Sunlight Post-harvest environment? Heating a consideration for some NFFS Rate of NDF Digestion and % Indigestible NDF in Forages at Different Stages of Maturity (Smith et al, 1972) Forage Alfalfa Bromegrass Orchardgrass Maturity Pre-Bloom Early Pod Vegetative Mature Boot Mature Indigestible NDF (%) NDF Digestion Rate (%/hr) Slide courtesy Dr. G. Varga, PSU Allen, 2003 Fiber Particle Digestion: Bottom Line Cell disruption Chewing, processing, chop length? Lignification is major intrinsic factor inhibiting digestion Interaction of rate of digestion (K d ) and rate of passage (K p ) Available NDF pool Goals: Corn Silage- 6%, Alfalfa- 16% What works?? Good to excellent quality forages Harvest, storage, & feeding mgt. Fermentable carbohydrates Balanced carbohydrate and protein fractions Healthy rumens, healthy feet, healthy cows Comfortable cows Successful transitions Maintaining positive momentum What about Pioneer s 11CFT Corn Silage Inoculant?? The product: Introduced in 2006 Contains an L. buchneri bacteria that produces a ferulate esterase enzyme Claims of improved fiber digestibility, feed intake, BCS, and milk production (2-3 lb) Cost is approximately $3.00 per treated ton turns non-bmr corn silage into BMR corn silage The results: Company research suggests up to 7 percentage point improvement in NDFD (3 to 5% increase more common) Most producers report no measurable difference in milk production Product improvements coming?? 7/9

8 11CFT- Just like BMR?? NDFd by Timepoints h In Situ NDF-D, % Uninoculated 11CFT % N D F d CS Halg P33A87 P33J57 BMR Hours Hofherr, et al, 2008 Rate of Fermentation Ruminal Feed Carbohydrate Fermentation Profile Sugars Fast Starches Slow Starches NDF EAT Big Picture Comments- Fermentable Fiber Critical component of sustained high production Grow it or buy it??? Often the toughest nutrient to achieve adequate amounts of Should facilitate: Higher forage, lower starch content rations Healthier cows More milk; more profitable ration formulation (IOFC) Plant Carbohydrates Cell Contents Cell Wall Organic Mono+Oligosaccharides Acids Starches Fructans Dextrins Pectic Hemicelluloses Cellulose Substances Galactans -glucans ADF NDSC / NFC NDSF NDF Non-Starch Polysaccharides MB Hall, /9

9 Non-forage Fiber Sources (NFFS) Feeding BMR Corn Silage (CS) to Transition Cows Soy hulls Beet pulp Citrus pulp Corn gluten feed Distillers grains Brewers grain Wheat midds Whole cottonseed Cottonseed hulls More digestible fiber Less digestible fiber Stone, et al, 2008 Versus conventional corn silage, cows fed BMR CS during the transition period: Higher DMI (1.76 lb more pre-calving and 4.4 lb more post-calving) More milk (+6.6 lb 3.5% FCM/day through 105 DIM) Tendency for less metabolic disease Santos, et al, 2001 Cows fed either conventional or BMR CS both pre- and postcalving Similar DMIs and health events Multiparous cows produced 4.4 lb/day more milk on BMR CS Summary- NDF Digestibility Essential use of NDF digestibility is to estimate energy content of a feed What is best fermentation end-point? Lignin is primary plant intrinsic factor limiting NDF digestion Role of cross-linking between hemicellulose and lignin/phenolics Ester linkages can be broken, ether linkages can t Current Model: lignin related to extent, and linkages related to rate and early digestion of NDF Questions? Slide adapted from R. Grant 9/9