The impact of forages and their quality on the efficiency of dairy production. Randy Shaver, Ph.D., PAS, ACAN Dairy Science Department

Transcription

1 The impact of forages and their quality on the efficiency of dairy production Randy Shaver, Ph.D., PAS, ACAN Dairy Science Department

2 Production Efficiency 2016 average for USA exceeded 10,000 kg milk per cow (USDA-NASS) For WI in 2016, 5% of dairy herds on DHIA test exceeded 13,500 kg milk per cow with 3 herds >17,000 kg milk per cow (R.D. Shaver survey) Projected that average for USA to exceed 13,500 kg milk cow within 20 years (J.H. Britt, 2016)

3 Milk from Forage Calculated from ration surveys of selected WI herds producing 13,500 kg milk per cow (R.D. Shaver) Averaged 63% or approximately 27 kg per cow/d

4 Calculated from Ration Survey of WI Herds at 13,500 kg Milk per Cow 90 % of Dietary Nutrient Provided By Forage NDF pendf CP Starch NFC Energy

5 Milk from Forage Calculated from ration survey of WI herd producing 20,000 kg milk per cow (R.D. Shaver) 60% or 38 kg per cow/d

6 Calculated from Ration Survey of WI Herd at 20,000 kg Milk per Cow 90 % of Dietary Nutrient Provided By Forage NDF pendf CP Starch NFC Energy

7 Corn Silage Quality Indicators for High-Producing Dairy Herds Parameter NDF Lignin undf 240 NDFD 30 Starch Milk per ton Indicates Better Quality Primary Reason Rumen Fill Limitation of DMI Potential for production response or feeding of higher-forage diets Energy Density Potential for production response or feeding less corn grain Quality Index for Ranking

8 Corn Silage Quality Indicators for High-Producing Dairy Herds Parameter Indicates Better Quality n Average ± 1 STDEV NDF (% DM) 384, Lignin (% DM) 344, undf 240 (% NDF) 81, NDFD 30 (% NDF) 170, Starch (% DM) 347, Milk per ton (kg) 136, Summary of combined multi-year, multi-lab (CVAS, DairyOne, RRL, DLL) data

9 Whole-Plant Corn Silage Grain ~40-45% of WPDM Avg. 32% starch in WPDM Variable grain:stover Stover= ~55-60% of WPDM Avg. 41% NDF in WPDM Variable stover:grain 80 to 98% StarchD Processing, particle size Fermentation Maturity Endosperm properties Additives (exp.) Adapted from Joe Lauer, UW Madison Agronomy Dept. 40 to 70% IVNDFD Lignin/NDF Hybrid Type E nvironment; G E M aturity Cutting height Additives (exp.) Variable pendf as per chop length

10 Corn Silage Starch (or NDF) % Hybrid impacts grain yield potential, possibly grain:stover ratio, & thus the potential starch % But actual starch % largely uncontrolled since varies depending on: Crop growing conditions (i.e. rainfall amounts & timing) Harvest timing relative to kernel maturity Risk management issue relative to StarchD primarily Cutting height Survey of 4 commercial labs; over 300k samples Normal range was 25% to 39%

11 Corn Silage NDFD Reduced lignin & corresponding greater ivndfd, DMI & milk yield have consistently been reported for bm 3 -type corn silage hybrids in research trials 15-year data summary from UW-Madison Agronomy Dept. hybrid performance trials bm 3 ivndfd 6%- to 11%-units greater than trial averages Milk per ton consistently greater than trial averages Starch % & DM yield per acre trended lower for the bm 3 hybrids included in those trials For conventional-type hybrids, progress in improving ivndfd has been slow & small relative differences among hybrids often observed Due to sampling & assay variation, ivndfd differences between samples of only 3%-units or less may not be statistically different or repeatable Consider magnitude of difference when selecting on ivndfd

12 Corn Silage NDFD Brown midrib mutation 1 st discovered in 1924 at UMN 4 mutants identified; bm1 (1931) bm4 (1947) Reduced lignin & greater digestibility in ruminants reported during 70 s Several positive bm3 production trials by Allen s group at MSU in 90 s Commercialization of bm3 since and recently bm1 WPCS hybrids Some agronomic & yield drag constraints inherent to mutants remain Low-Ferulate corn mutant Published on recently by Hans Jung s group at USDA/UMN Similar lignin % but reduced lignin-arabinoxylan crosslinking by ferulates & greater NDFD, DMI & milk yield (Jung et al., 2011, JDS) Transgenics or CRISPR?

13 High vs. Normal Cut Corn Silage 11 trial average summarized by Wu & Roth, 2003 Item 17 cm Ht. 49 cm Ht. DM, % NDF, % IVNDFD, % of NDF Starch, % Tons DM/ha Milk per Ton, kg 1 1,508 1,582 Milk, kg per ha 1 23,548 23,121 1 Calculated by Ferraretto et al., 2017

14 High vs. Normal Cut Corn Silage Neylon & Kung, JDS, 2003 Item Normal Cut High Cut DMI, kg/d Milk, kg/d 45.2 b 46.7 a Feed Efficiency 1.67 b 1.72 a

15 Corn Silage StarchD Hybrid selection for kernel endosperm properties to improve StarchD very slow to evolve Genetic effects on StarchD tempered in corn silage Harvest should be completed pre-blacklayer Kernel processed during harvest Prolonged silo storage increases StarchD No standardized agreed upon method for assessing differences in StarchD among samples Test Sample/Assay Sample particle size a challenging confounder Ruminal vs. post-ruminal starch digestion StarchD has not been incorporated into university-extension hybrid performance trials Altering kernel endosperm properties in WPCS mainly experimental & cannot ignore potential changes in Starch (NDF) %, NDFD or agronomics

16 Corn Silage StarchD Genetic or transgenic modifications studied Comparisons of Flint, Dent, Reduced-Vitreousness Dent, Floury, Opaque, Waxy Endosperm in Conventional Hybrids (numerous citations but few feeding trials) Floury-Leafy Hybrid (Ferraretto et al., 2015, JDS; Morrison et al., 2014, JDS abstr) Floury-BMR Hybrid (Morrison et al., 2016 JDS abstr) α-amylase expressed in kernel (Hu et al., 2010, JDS; trials in progress)

17 Kernel Vitreousness (%) Relationship between kernel DM% & vitreousness Johnson et al. (2002) - exp. 1 Johnson et al. (2002) - exp. 2a Johnson et al. (2002) - exp. 2b Philippeau and Michalet-Doreau (1997) - dent Philippeau and Michalet-Doreau (1997) - flint Correa et al. (2002) Ferraretto et al. (2015) - bm3 Ferraretto et al. (2015) - leafy-floury Ferraretto et al. (2015) - dual-purpose Kernel DM concentration (% of as fed) Ferraretto et al., 2017

18 Ensiling time effects on StarchD & N fractions NH3-N (% N) Sol-CP (%CP) ivstarchd (% Starch) % (P = 0.001) Ensiling time (d) Ferraretto et al., 2015, PAS

19 ivstarchd (% starch) Hybrid type ensiling time vs StarchD BMR DP FL-LFY Time effect (P < 0.001) Hybrid effect (P = 0.02) Hybrid Time (P > 0.10) Ensiling time (d) Ferraretto et al., 2015, JDS

20 Hybrid type ensiling time vs NDFD Ferraretto et al., 2015, PAS

21 Processing Maturity vs StarchD Ferraretto & Shaver, PAS 2012

22 Processing TLOC vs StarchD Ferraretto & Shaver, PAS 2012

23 WPCS Particle Size vs TLOC & Processing % WPCS as fed on PSU Top Screen trial treatment comparisons with >TLOC in processed WPCS 18 trial treatment comparisons with =TLOC in processed WPCS TLOC-Avg 13 mm UN TLOC-Avg 22 mm PROC TLOC-Avg 17 mm UN TLOC-Avg 17mm PROC ( mm TLOC) (19-32 mm TLOC) (6-40 mm TLOC) (6-40 mm TLOC) Ferraretto et al., 2017

24 Corn Silage Harvesting Conventional Processors mm TLOC 20% Roll speed differential 1-2 mm Roll Gap Contemporary Processors mm TLOC 40-50% Roll speed differential 1-3 mm Roll Gap Alternative processor type Cross-grooved rolls Intermeshing discs

25 Longer TLOC Corn Silage Ferraretto et al. (2012, PAS); Vanderwerff et al. (2015, JDS) 30 mm TLOC or 26 mm TLOC, respectively, vs. 19 mm TLOC 30-40% Roll speed differential >70% KPS % on PSU top screen increased 3-4 fold, however, % on PSU top-2 screens similar Milkfat content & rumination activity unaffected by TLOC

26 Starch content & KPS in WPCS. WPCS hydrodynamically separated kernel-fraction nutrient content & GMPS. Item Whole-Plant Corn Silage DM, % of as fed Mean SD Min Max Starch, % of DM KPS, % starch passing through 4.75 mm sieve Kernel Fraction NDF, % of DM Starch, % of DM GMPS, µm Dias Jr. et al., 2016,JDS, 99:

27 Haycrop Silage Quality Indicators for High-Producing Dairy Herds Parameter NDF Lignin undf 240 NDFD 30 NFC (includes soluble fiber) CP Ash RFV; RFQ Indicates Better Quality Minimal Soil Contamination Primary Reason Rumen Fill Limitation of DMI Potential for production response or feeding of higher-forage diets Energy Density Potential for production response or feeding less corn grain Supplemental Protein Energy Density Quality Index for Ranking

28 Legume Silage Quality Indicators for High-Producing Dairy Herds Parameter Indicates Better Quality n Average ± 1 STDEV NDF (% DM) 111, Lignin (% DM) 100, undf 240 (% NDF) 25, NDFD 30 (% NDF) 61, NFC (% DM) 94, CP (% DM) 112, Ash (% DM) Minimal Soil 100,888 <13 RFV 100, RFQ 51, Summary of combined multi-year, multi-lab (CVAS, DairyOne, RRL, DLL) data

29 New Alfalfa Varieties Reduced Lignin & Greater ivndfd Varieties from both conventional plant breeding & gene knockout approaches commercialized recently 5-15% reductions in lignin reported (Combs, 2016) Up to 15% increases in ivndfd & RFQ reported for the transgenic over normal-lignin alfalfa (McCaslin et al., 2015)

30 Yield and Quality Curve of Alfalfa Reduced-Lignin Alfalfa Quality Conventional Alfalfa Quality Yield Slide courtesy of Dave Combs, UW Madison

31 BMR + Reduced-Lignin Alfalfa in TMR? Chop Length/peNDF Dietary Forage NDF NDF ROP/ROD

32 Potential New Alfalfa Varieties Reduced proteolysis during ensiling & reduced ruminal protein degradation for greater RUP Condensed tannins or polyphenol oxidase (PPO)/о-quinones via insertion of transgenes (Grabber, 2014)

33 Grass/MMG Silage Quality Indicators for High-Producing Dairy Herds Parameter Indicates Better Quality n Average ± 1 STDEV NDF (% DM) 85, Lignin (% DM) 76, undf 240 (% NDF) 15, NDFD 30 (% NDF) 34, NFC (% DM) 80, CP (% DM) 85, Ash (% DM) Minimal Soil 76,530 <10 RFV 79, RFQ 24, Summary of combined multi-year, multi-lab (CVAS, DairyOne, RRL, DLL) data

34 Modern Grass Varieties Reduced NDF Slower Maturity Decline Closer timing of maturity relative to alfalfa maturity in mixed stands.

35 Winter Annuals Cover Crop? Forage Inventory Contributor? Replacement Heifers Dry Cows (K, DCAD issue?) Lactation Rations Agronomic Challenges

36 Forage yield - quality vs. quantity Dry matter yield (tons/ha) indigestible Maximum yield of DM Maximum yield of digestible DM digestible Vegetative growth Optimal stage Flower or Head or Black Layer UW-Madison Slide courtesy of Michel Wattiaux, UW Madison Department of Dairy Science

37 Practical forage-ndf range in high-group TMR 24% forage-ndf High Quality Forages Large Forage Supply Forages Favorably Priced i.e. 60% 40% NDF 16% forage-ndf Limited Forage Supply Use of High-Fiber Byproducts Forages Expensive Moderate/Low Quality Forages i.e. 35% 46% NDF

38 Nutritional Constraints 24% forage-ndf NDF, ivndfd Fill Limitation of DMI Reduced Milk Yield 16% forage-ndf pendf Milk Fat Depression Cow Health

39 Visit UW Extension Dairy Cattle Nutrition Website