Corn Silage Hybrid Selection

Transcription

1 F o r a g e U p d a t e Corn Silage Hybrid Selection Bill Mahanna, Ph.D. Nutritional Sciences Manager Pioneer HiBred International

2 Decisions made in the fall on hybrids to plant next spring will impact you for the entire year Bill Mahanna, Ph.D., Dipl ACAN Nutritional Sciences Manager Pioneer, A DuPont Business bill.mahanna@pioneer.com Various University and Seed Company Plots Prove Genetic Differences Certainly Exist But you have to interpret the plot data using valid statistics Measured Silage Yield Difference Number of Environments/Plots 2.0 T/A 1.0 T/A 0.5 T/A 1 60% 52% 51% 10 90% 75% 65% 30 95% 90% 75% % 95% 93% When hybrids are statistically different, then apply biological relevancy to the differences. For example, comparing the nutritional value of 1% unit difference in NDFD (~50-60% digestible) versus 1% point differences in starch content (>90% digestible). After hybrids have been screened for agronomic and technology traits, the UW Consortium recommends these corn silage selection priorities: 1 st Grain Yield 2 nd Whole Plant DM Yield 3 rd Standability (in case want to take for HMC or even dry corn) 4 th Relative Maturity 5 th Quality (e.g. fiber digestibility) Source: 1

3 .Because University data shows there are minimal genetic differences (4-5% units) between conventional hybrids for fiber digestibility and small differences in starch content quickly overwhelm the increased energy from NDFD Factors Impacting Corn Grain Yield Rank 1 2 Factor Weather Nitrogen Dr. Fred Below University of Illinois, Urbana-Champaign The huge impact of growing environment explains why hybrids can perform so differently from location-to-location and from year-to-year. This applies to corn grain and corn silage Hybrid Previous Crop Plant Population Tillage Growth Regulators Source: Total = Value bu/acre % bu 100% Assumes key prerequisites of weed control and soil fertility are met Lets now look at the impact of growing environment on silage hybrid data. growing conditions, harvest timing, chop height, fermentation quality feed-out management Heritability of NDFD is high but the range (variation) among commercial, high yielding germplasm is low...and remember, it doesn t help to apply selection pressure to a trait with minimal genetic variation Which silage hybrid would you choose? growing conditions, harvest timing, chop height, fermentation quality feed-out management A B C D E F G H I J K L M N Source: Dann Bolinger, M.S. Pioneer Dairy Specialist, Michigan 2

4 Surprise.they are all the.they are all the same hybrid (34A89) but grown in different locations in Michigan in 2009 Hybrids will respond differently for starch yield in different growing environments 2009 plots with common hybrid entries 1st 2nd 4th Last Clare Caseville Fowler Saranac Elsie Alto % Starch Source: Dann Bolinger, M.S. Pioneer Dairy Specialist, Michigan Source: Dann Bolinger, M.S. Pioneer Dairy Specialist, Michigan Hybrids will respond differently for tonnage yield in different growing environments 2009 plots with common hybrid entries 2nd 1st Which is why 20+ comparisons across multiple growing years is essential to compare hybrids Last Last Saranac Alto Last Clare Fowler Elsie Caseville 3rd V6 Begins rapid growth stages Begin to determine yield potential Poor time to stress crop due to lack of water Ear Girth and number of kernels around the ear is determined VT (Tassel) Water & fertility requirements are significant Next stage is Reproductive Ear size/length and number of kernels per row is determined 16 around 20 around Source: Dann Bolinger, M.S. Pioneer Dairy Specialist, Michigan Starch Influencers Yield is roughly 50% grain % Starch is ratio of grain to fodder Early vegetative growth w/ mid to late season grain fill harvest Prior to black layer, starch is still being produced Hybrids within a plot should be reasonably close in maturity look at harvest moisture as an indicator Note the date when your corn silked: Tasseling / silking corn plants have ~900 GDUs to reach silage maturity Count ahead six weeks and that s about when you should get serious about checking maturity status. You might have read that corn will reach silage maturity days after silking, but usually that s 30% DM and because of avoiding effluent and increased starch deposition, it is advisable to wait until the corn is a few percentage points dryer than 30%. Most of the difference between hybrids of different relative maturities is between emergence and silking, not from silking to the 32-35% dry matter that s ideal for corn silage. Stage of Approx days to Maturity ½ Milkline Silking Blister Late Milk Early Dent 5-15 It is not unusual for silage to dry down points of moisture per day, depending upon drying conditions. It is also not unusual for corn silage to lay down points of starch per day until kernel reaches physiological maturity at blacklayer (starch deposition significantly contributes to reducing moisture in whole plant samples as the plant matures) Source: Pioneer Research and Ev Thomas, August 2007 Miner Farm Report 3

5 ½ ML Harvesting too premature will cost you starch yields ¾ ML Starch Germ ity, % NDF Digestibili NDFD vs Grain yield (Wisconsin Silage Tests) <90 d d d 106+ d NDF R 2 = R 2 = R 2 = R 2 = Grain yield, bushel/acre 120 Composition and Digestion Changes with Silage DM Value, % of DM or of Nutrient Starch Digestibility (Processed) With the cost of grain today, increased starch content of silage compensates for relatively small decreases in NDF digestibility (and dilutes NDF) Source: Dr. Fred Owens, Pioneer Senior Research Scientist. Journal of Animal Science and Journal of Dairy Science literature review summary NDF Digestibility NDF Content Starch Content Sugar + Organic acid Content Silage Dry Matter, % acre NDF yield, ton/a NDF yield vs Grain yield (Wisconsin Silage Tests) <90 d d d 106+ d R 2 = R 2 = R 2 = Grain yield, bushel/acre When selecting a silage hybrid, don t get hung up on marketing hype or labels such as: dual-purpose.. silage-specific. specific. grain hybrids. Rather, rely on multi-year data for important traits such as yield and starch content, just like you rely on bull proof date, not the name of the bulls you are using in your herd. To be a good silage hybrid, it must start out as a good grain hybrid because you can not overcome lack of starch (>90% digestible) with small increases in fiber digestibility (60-70% digestible) BUT not every grain hybrid makes a good silage hybrid because they may be too short and not deliver the desired stover yields 4

6 NDFD Influencers Greatest during vegetative growth (pre-tassel) Early moisture stress = improved NDFD Moisture availability More water typically y lower NDFD Less water typically higher NDFD Heat Units More heat, less NDFD Less heat, more NDFD Impact of Growing Environment on NDFD Shown by the Drought-Stress Effect of the Same Hybrids Grown in 2006 (wet year) vs (drought year) Source: Dann Bolinger, Pioneer Dairy Specialist - Michigan What is one point of forage NDFD worth? The weather before and after silking (R1) appears to affect final corn silage nutritive value Before silking, weather affects corn plant height (and yield) and fiber quality Dry conditions => higher NDFD Wet conditions => lower NDFD but not as much if heat units are lagging behind normal After silking weather affects corn grain yield, NDS:NDF ratios and total DM digestibility R1 - Silking Oba and Allen, MSU For CS (at least 40% of the diet), the results showed a.25lb increase in DMI and a.3lb increase in milk Meta-analysis of published studies with a variety of forages and a large range of NDFD (24-87%) showed a.37lb increase in DMI and a.55lb increase in milk Source: Mertens, 2002 Cornell Nutrition Conference Source: Jung, H.G., M, Raeth Knight and J.G. Linn Forage fiber digestibility: measurement, variability and impact. Proceedings Minnesota Nutrition Conference Hybrids will respond differently for NDFD in different growing environments Growing environment during stalk - Moisture development and heat effected (June NDFD 1 thru July of all 15) hybrids, but moisture had a greater influence. -Some hybrids were more susceptible to environmental influences (blue hybrid) Plots grouped by 2009 growing environment during stalk development - June 1 to July 15 Wet with moderate heat wet with high heat dry with mod heat dry with low heat Source: Dann Bolinger, M.S. Pioneer Dairy Specialist, Michigan Source: Mertens, D.R. and P. Berzaghi. 2009b. Silage quality and dairy production. Proceedings 15th International Silage Conference. Monona Center, Madison, WI. July 27-29, p

7 High-chopping corn silage allows producers the option of dialing in desired fiber digestibility for transition & high string rations There appears to be a significant Genetic x Growing Season Interaction cubation NDFD - 24 hour in Pioneer Chopping Height Field Trial Year 1 (New York, 2000) Chop Height Influence on NDFD 16% increase 18 cut 9 cut 39.7% 34.2% 34B23 27 cut 51.7% Source: Review of 11 Scientific and Popular Press articles on high-chopping by Wu and Roth at Penn State Concentrated more starch 3.4% unit increase There appears to be a significant Genetic x Growing Season Interaction Pioneer Chopping Height Field Trial Year 2 (New York, 2001) NDFD - 24 hour inc cubation Cutting Height Influence on NDFD 67% increase 27 cut This season only a 5% 5% increase 50.1% 9 cut 29.9% 9% 18 cut 31.7% 34B You Do Give Up Some Yield When High-Chopping For each 4 inches (10 cm) of increased cutting height expect yields to be reduced by 1 as fed silage ton (909kg, 30%DM) per acre But what you leave in the field are stalks, not high-starch corn silage You Can Vary Silage Chop Height Depending upon the Silage Growing Season and the Quality of the Haylage Already in Storage.. Hand-chop representative plants and analyze NDFD before chopping Then alter chop height based on desired d NDFD and NDFD of other forages in storage (e.g. hay haylage) The growing season influence on NDFD requires pre-testing the crop to determine the exact NDFD impact from high chopping 6

8 Field example of monitoring the growing season effect and influence of high-chopping 5 representative plants hand-cut by sales rep Tom Hemesath on Data from Pioneer lab reported back M M P P62 22 Average Values % Moisture % starch % Sugar % Str + Su ?? % NDF % NDFD (24 hrs) % CP % ash Note the hybrid (and/or sampling) effect in that 33P62 did not show a very big improvement in NDFD with high chopping Pioneer has received official Canadian government approval to make the following claims for 11CFT: Registration received January 5, Improved dry matter intake 2. Improved NDF digestibility 3. Improved gain/tonne of silage fed 4. Improved feed efficiency 5. Reduced heating at feeding 6. Reduced dry matter loss at feeding Inoculation: another approach to improving NDFD. PLUS Improves consistency Reduces shrink (DM loss) CFT breaks this ester bond with an enzyme produced in the bunker by our L. buchneri strain, allowing rumen bacteria to digest the cell wall much faster because it is separated from the lignin. Fiber and Lignin are similar to Concrete and Rebar 4 th generation product to vastly improve NDFD After CFT Before CFT 7

9 CNCPS V6.1 CPM Fast Kd s We use to think the B 3 pool was the only one changed in CFT-silage Portion of NDF that CFT frees up Slow Kd s 1. Assume slightly higher intakes (hence more starch intake) 2. Be sure ration has adequate effective fiber (pendf, scratch) 3. Increase the energy density of CFT-silage by assuming a 4-percentage point increase in NDFD Independent Research Substantiating Pioneer s CFT Data These are all still valid, but #3 did not provide adequate direction for consulting nutritionists If nutritionists use Net Energy (NE-L), changing NDFD 4-points results in very minor changes in NE-L estimates. We do not think NE-L will be sensitive enough to the digestion rate changes we see with CFT. Some nutritionists use the increase in NDFD to adjust NDF (B 3 ) digestion rates (Kd s) with a Cornell spreadsheet CNCPS V6.1 CPM Dr. Mike VanAmburgh s NDFD Kd calculator available from Cornell University or Pioneer 4 points of NDFD only increased NE-L.01 Mcals In this corn silage, a 4-point increase in NDFD translates to a 15% higher Kd Lets see how this approach works in a real ration 8

10 Using the example lactating ration (and feed library corn silage) that comes loaded in CNCPS (Feed library corn silage parameters are 35%DM, 35.5% STR, 41% NDF, 2.87% lignin, 3.4%/hr B3, 30%/hr B1, 30%/hr B2) Milk predicted from the metabolizable energy (ME) or metabolizable protein (MP) in the ration Same ration with CS modified to account for CFT by changing B3 rate using VanAmburgh calculator (4 pts NDFD) from 3.4% to 3.9%/hr Using CPM ration software to compare control vs. CFT in 7 side-by-side field trials with vacuum packed silage for which gas-production data was generated. BUT NOW CFT increased the predicted ME milk by.87 lbs and MP milk by 1.1 lbs Kd rates based on average gas data for NDF(B 3 ) by 35% B 1 by 50% and B 2 by 30% % Kd/Hr or Hours to Max Kd s on all the pools (B 1, B 2 and B 3 ) were modified based on the averages of the gas data shown below. C F T c o n t r o l Faster is better for high producing cows with rapid rumen turnover rates C F T Less time to reach maximum digestion rates is preferred for high producing cows with rapid rumen turnover rates c o C n F t T r o l Pool Kd %/h Fast Pool Pool Kd %/h Slow Pool Fast Pool Kd, %/hr Kd, %/hr time to max, Max, hr hr Slow Pool Pool time to to max, Max, hr hr 11CFT Competition To produce the same ME and MP milk as the non-cft silage ration, you can remove.37 lbs of corn meal when feeding CFT-silage With $3.50/bu corn this resulted in a savings of 2.3 cents/c/d Kept grain at 5.2 lbs versus 5.57 lbs in the original ration CFT-silage now predicted to increase ME by 1 lb (.45 kg) and MP by 4.3 lb (1.9 kg) compared to control CS Compared to ME milk.87 lb (.39 kg) and MP by 1.1 lb (.5 kg) when adjusting B 3 rates alone Biological reality is probably somewhere in the middle! 9

11 What about protein? Protein savings, from more rumen microbial growth on CFTsilage, contributes more to decreasing ration costs than the effect of reducing corn meal in the ration. Fate of Proteins in Ruminants In this ration, soybean meal was reduced from 2.33 lbs to 1.70 lbs (did not change anything else, so DM intake will be lowered accordingly). Now the predicted ME and MP milk is similar to what was predicted with the original base ration (90.12 and 96.51). Reducing soybean meal by.63 = 11cents/c/d savings. Note this reduced the CP level to 15.9%. Note that even when removing.63 lbs of soybean meal, the production of microbial protein is still 86 grams better than the original base ration Back to the Base Ration using Feeds From the CNCPS Feed Library (35%DM, 35.5% STR, 41% NDF, 2.87% lignin, 3.4%/hr B3, 30%/hr B1, 30%/hr B2) Notice relatively low CP level of this ration predicted to generate kg of MP milk.this is consistent with where Cornell is recommending nutritionists alance protein remember, this is the example ration that comes loaded with the CNCPS program Milk predicted from the metabolizable energy (ME) or metabolizable protein (MP) in the ration Note the production of microbial protein from this base ration is 1326 grams A 4% point increase in 48-hour NDFD (over baseline estimates) is a reasonable starting point to factor in the effect of CFT. Changes in digestion rates (Kd) of the B 3 pool (available NDF) resulting from the improvement in NDFD can be made in formulation models, such as CPM or CNCPS, by employing the VanAmburgh Rate Calculator (VARC) available from Cornell professor, Dr. VanAmburgh (mev1@cornell.edu) or from Pioneer. However, field experience suggests that increasing B 3 rates by %, (which VARC predicts from a 4-point increase in NDFD), will not fully account for the effect of CFT and adjustments will likely be required in the rates of B 1 (starch) and B 2 (soluble fiber) pools to prevent over-feeding of concentrates Key points are that CFT appears to: 1. Increase the rate of B 3 ( slow pool ) digestion by upwards of 35%; causing B 3 nutrients (e.g. hemicellulose) to digest at rates more commonly observed among fast pool (B 2) nutrients (e.g. soluble fiber) 2. Reduce the time required to achieve maximum B 3 (slow pool) digestion rates 3. Increase the digestion rates of both the B 1 and B 2 pools by upwards of 30-50%. 4. Feeding CFT silage typically allows for reduction in fast pool nutrients (e.g. starch). In practice, this means reducing concentrate (grain) in the TMR to offset increased availability of hemicellulose and the shifting of slow pool nutrients into the fast pool. 5. Field experience with herds who experienced milkfat depression problems when starting to feed CFT-silage, were typically borderline for effective fiber and/or acidosis issues and quickly resolved the problem (and lowered feed costs) by reducing grain (especially HM corn), increasing corn silage inclusion rates (and effective fiber) and/or adding coproducts such as soyhulls (additional source of soluble fiber). 6. CFT silage-based rations may require attention to protein formulation; allowing for the reduction of rumen degradable and/or undegradable protein due to increased bacterial protein production and MP milk predicted when CFT-silage digestion rates are modeled in CPM or CNCPS. One Topic Related to Feeding CS Changing starch digestibility over time in fermented storage All ration ingredients kept constant Now with changing the digestion rates of B1, B2 and B3, the production of microbial protein was increased by 93 grams over the basal diet and 76 grams over the CFT ration with only B3 rates increased (from 3.4 to 3.9%/hour) 10

12 CS data from France.some of the first published research showing this effect (%) EVOLUTION AMAT = % OF Soluble " AMAT" Protein and " A2" A2 = % Starch Source: Dr. Jacques Eouzan. ESSAI ENSILAGE DE MAÏS 2001/2002- CENTRALYS 65 AMAT y = x R 2 = % 55 increase in Starch 50 A2 y = x Digestibility R 2 = TIME (days) IN STORAGE Nebraska study looking at the rate of in situ (ruminal) DM digestion of HMC of varying moistures and time in storage ISD DMD, % Higher ensiling moistures increases in situ digestibility Dry Rolled (only one point because it never changed over time like fermented corn) 28% 24% 30% 35% 24% moisture HMC is a safe feed but you give up the feed efficiency that can be captured with higher moisture HMC. 280 days ensiled vs. ensiled only 60 days 28% recon 30% higher 30%HMC 8% higher 35% recon 14% higher Ensiling Period (days) Source: J.R. Benton, G.E. Erickson, and T.J. Klopfenstein U of NE, Lincoln. Abstract # ASAS/ADSA Sessions, St. Louis, MO 30% increase in 3-hr STRD in corn silage stored for 2 months vs. 10 months in study reported at 2006 Dairy Science meetings Results from 2005 HMC (27% moisture, processed through tub-grinder with a ¼ screen) analyzed for 12-hr in vitro STRD comparing a (saved-frozen) 60-day (fall) sample against a 200-day (spring) sample (both samples incubated in the same in vitro run) Source: J. Dairy Sci. Vol. 89, Suppl ADSA/ASAS Annual Meeting abstracts. Solublility of High Moisture Corn Protein, % Harvest Year (October through September) If a cow was receiving 10 lbs DM from this HMC, her rumen would theoretically be exposed to: 4.6 lbs of starch (10*.68*.68) in the Fall, increasing to 5.7 lbs by Spring (10*.68*.85) 1.6% units per month increase in 12-hr STRD in corn silage study reported at 2008 Dairy Science meetings A factor contributing to spring acidosis, besides increasing STRD in CS, is the loss of buffering capacity when cows expel CO2 from panting during heat stress, increased drooling which reduces saliva flow to rumen and increased urinary bicarbonate excretions. Hoof trimmers are the busiest in September.the result of acidosis in spring and summer! I factor in a 2% unit increase in corn silage ruminal STRD per month of storage with a starting point of about 70% 11