11/17/2017. Application of undf in Ration Formulation. Ian Shivas, Renaissance Nutrition UNDF WHAT IS IT?

Transcription

1 Application of undf in Ration Formulation Ian Shivas, Renaissance Nutrition UNDF WHAT IS IT? 1

2 What is undf Some papers call it indf for indigestible NDF Mertens pushed us to call it undf for undigestible NDF Determined at various time points: undf 30hr, undf 120hr, undf 240hr. pdndf = NDF undf (Potentially digestible NDF) undf Determined by in vitro fermentation Forages: 30, 120 and 240 hr with 240 hr representing undf Non forages: 12, 72 and 120 hr with 120 hr representing undf 3 time points are used to calculate the kd (rate of digestion) for NDFd 2

3 Microbial degradation Opening of cells Fraying of fiber structure Size reduction Decrease in buoyancy Bleaching of chloroplasts How Fast Do Bacteria Digest Cell Wall? Rate of digestion = 0.02μm/h 2 o wall thickness = 1-5μm MRT = 30 to 36 h ~20% of CW digested! Wilson and Mertens (1995) 3

4 Digestion Surface of Cell Wall Chesson (1993) 4

5 5

6 What influences undf profile: (NDF digestibility)? Maturity Lignin Cellulose crystallinity Environment Hot vs Cool Wet vs Dry Hot and Wet: Diges bility/ undf Genetics Spoilage: disease, frost 6

7 So do we have this correct? Well, NO we don t pdndf is actually a two pool system 7

8 We end up with this 8

9 9

10 Variation Further Implications undf and intake appear to be highly correlated It appears in Holsteins that the cow can reach a steady state undf rumen level 4 5kg For her to consume more feed, an equal amount of undf must escape the rumen first. UNDF has 0 kd so completely regulated by kp This has huge potential impact on formulation, procurement and manufacturing thinking 10

11 Example Application of undf in ration modeling Both fiber digestibility (pdndf) and indigestibility (undf) are important for assessing forage quality undf is used to calculate pdndf undf with earlier time points can be used to estimate fast and slow pools and their kd 11

12 Application of undf in ration modeling These values in turn can help to explain feeding and ruminating behavior, especially when the chemical compositions (i.e. ADL, NDF, ADF) are similar Chewing response to pendf is related to forage undf Estimates of the slow pool of NDF and its rate of digestion plus the undf are related to DMI and passage from the rumen 12

13 Application of undf in ration modeling Chewing response to pendf is related to forage undf Estimates of the slow pool of NDF and its rate of digestion plus the undf are related to DMI and passage from the rumen 13

14 Application of undf in ration modeling Miner Institute Studies 14

15 Biological Importance of undf Rumen fiber is a combination of: undf, slowly fermenting NDF and undigested fast pool NDF The entire mass of undf in rumen can be better understood as ballast or a baseline of fill which limits the possible NDF flux/turnover It is proposed that for ruminal undf that there is both a minimum (to obtain rumen health) and a maximum (not to limit intake as a measure of fill) suggesting an optimal mass of digestible NDF within the rumen It is believed that undf measured at 240 hr of in vitro fermentation (undf240) is an accurate assessment of the indigestible component of NDF Miner Institute Research undf: Focus on Level and Digestibility of Corn Silage Fiber Objectives: measure the passage rates of pools for diets differing in amount and digestibility of NDF. Corn silage TMR using either conventional or BMR corn silage 15

16 16

17 17

18 18

19 19

20 20

21 21

22 22

23 pendf vs undf pendf or undf or both: factors in moderating rumen ph Current model is insensitive to pendf and undf Miner: undf and stocking density Investigate change in eating/rumination, DMI, rumen ph and milk fatty acid profile in a high starch diet as corn is withdrawn from the diet in fall

24 24

25 25

26 26

27 How about chewing 27

28 Summary of Forage Trial Eating time more influenced by diet than ruminating time. Minutes/day Straw influences eating time Non Forage Fiber Sources of undf Previous data confirmed that the relationship between lignin and NDF as a fixed factor used in CNCPS was not appropriate Forage NDF disappears in a varied manner with two digestible pools and undf defined as undf240 hr 28

29 NFFS Does this apply to NFFS? Can same methodology be used? Same time points? In the initial experiment most of the fermentable fiber in NFF feeds was exhausted in 96 hr., Soy Hulls in 120 hr. 29

30 NFFS of undf Plotted results to illustrate fast degrading pool, slow degrading pool and undigestible pool 30

31 NFFS of undf 12, 72 and 120 hr are best time points There options but for commercial lab and modeling purposes we need consistency For some by products lignin factor greatly over estimated the indigestible fraction of NDF, this explains why under certain conditions, more energy is realized from feeding these by product feeds compared to current estimates Summary of Miner and Cornell Data Daily undf intake equals undf output in feces Maximum NDF intake is approximately 10 kg/d (22 lb.) or 1.47% BW (range 1.27 to 1.47) Maximum undf is 0.39% of BW (Miner data) and 0.48% BW (Bologna data alfalfa diet) 31

32 32

33 33

34 Commodity disappearances from Dairyland (through to 10/15/2017) Miner Corn Hybrid Plots 34

35 Hybrid Trial undf30om Hybrid Trial undf240om 35

36 36

37 2015 Corn Silage 30 hr NDFd 2015 Alfalfa Haylage 30 hr NDFd 37

38 Let s get practical 38

39 Benchmarks for formulation Miner: Range in TMR undf240 intake is % of BW Farm Institute for Holsteins 5 to 6 lb. of undf30 from forage 7 lb. of pdndf30 from forage Fiber fractions 39

40 Fiber fractions Fiber fractions 40

41 How about to Rumen Fill undf/ BWT x 100 = 5.68 / 1620 x 100 = 0.35 % BWT Why the Emphasis on Forage Quality? The faster rate of disappearance allows for more nutrient intake Highly fermentable feedstuffs help increase dry matter intakes Increase in the amount of fnfc consumed Impact in more MP from Microbial yield and more VFA undf undf 41

42 Fragility? Does BMR Corn Silage stimulate as much chewing as conventional Corn Silage? Does alfalfa forage stimulate as much chewing as straw? Forage Fragility Adjustments pendfadj pef avgndfd30hr _ x _ samplendfd30hr 94 x % pendf Takes advantage of forage quality Encourages more of the digestible forage into the ration Ensures that there is adequate effective fiber in the rumen for rumen health Improves efficiency 42

43 undf peak intake Min of 7% DMI Min 0.30% BW Min lbs of Max of 12.5% DMI Max 0.40% of BW Max lbs of x 43

44 Let s get practical 44

45 Rumen filling Dry matter intake 45

46 Gut fill? Rumen fill? Eaten Well: This cow has eaten well. Rumen Fill, belly fill and BCS are OK 46

47 Rumen Fill: This cow has not eaten enough today Belly Fill: This cow has not eaten enough this week 47

48 Body Condition Score: This cow has not eaten enough this month Summary NDF formulation NDF Fractions Fast, Slow and indf Metaphors Miner Herd undf intake levels undf 30hr: 5 6 lb. from forage undf 240hr: 3 4 lb. from forage undf 240hr total TMR 0.3 to 0.4 % Bwt TMR vs Forage undf 48

49 Summary of NDF formulation Larry Jones, Farm Institute 5 to 6 lb of undf 30 hr from forage 7 lb of pdndf hr from forage RNI updated NFFS undf values Corn Hybrid: undf profile High FQ: u30 (<15%) u240 hr (<5%) Slide sets References Cotanch CNC 2014 Cotanch CNC 2015 Cotanch CNC 2016 Van Amburgh Advanced Nutrition Conference 2014 Rick Grant Hoard s Dairyman Nov 2017 Rick Grant ADSA Fiber Discovery Conference

50 Questions? 50