1. 1 Nutrient Planning for Sustainability - Dairy Dann J. Bolinger, M.S. Michigan State University Extension Dairy Agent

2. 2 Basis of Planning Maintain economic viability & profitability of farm business Protect the environment –Surface water –Ground water –Air quality Nutrients of primary concern –Nitrogen: leaching, volatilization –Phosphorus: run-off, leaching

3. 3 N:P – Corn Uptake vs. Manure Corn UptakeManure N:P2.51.32 (as excreted) 0.66 (field applied) Overall result: if we apply based on crop uptake of actual field N, we will overapply P. Corn2.5/0.66 = 3.8X That’s a phosphorus excess of about 150 lb/A!

4. 4 Raising & Lowering Soil P  10 – 20 lbs of excess P 2 O 5 /A to raise Bray P 1 soil test one lb/A.  10 – 20 lbs of crop removal P 2 O 5 /A to lower Bray P 1 soil test one lb/A. (Most MI crop rotations average ~50 lb/A crop removal, so soil test goes down only ~5-10 lb/A/year – at best.) Easy & fast to raise, hard & slow to lower!

5. 5 Fundamental nutrient question: Is my farm concentrating nutrients?

6. 6 National Level Mass Nutrient Balance

7. Manure P vs. crop land P use < 25% 25 - 50% 50 - 100% >100%

8. Manure P vs. crop land P use < 25% 25 - 50% 50 - 100% >100%

9. Manure P vs. crop land P use < 25% 25 - 50% 50 - 100% >100%

10. 10 State and County Level Mass Nutrient Balance

13. 13 Nutrient Concentration… National level Regional level Community level Farm level Field level

14. 14 Farm Level Nutrient Balance

15. 15 Indicators of Nutrient Imbalance Animals per acre thumb rules Less than one acre per animal unit Soil P increasing with time High soil P levels Majority of feed protein and P comes from off-farm sources These are neither exact nor reliable!

16. Feed Manure Animals Manure Nutrients Crop Nutrients Soil Land Application Nutrient Uptake

17. 17 Estimating Nutrient Balance Estimate crop nutrient removal –Based on crop specific removal rate and yield Estimate manure nutrient production –Records of manure production and analysis –Book excretion values (MWPS-18, table 6) –Mass balance (inputs vs. outputs)

18. 18 Manure Nutrient Production Records of manure production & analysis Pros: –farm specific Cons: –Inadequate records before CNMP implementation –Difficult to get truly representative manure analysis –Weather variables impact volumes and analysis Frequently inaccurate! (Manure GAAMP says do not use)

19. 19 Manure Nutrient Production Book excretion values (MWPS-18, table 6) Pros: –Simple to calculate (no records required) –Constant values Cons: –Not farm specific –Book values not always representative (+/- 30%, don’t know performance level or nutrition of animals in data set) New data in progress

20. 20 Estimating nutrients produced by an operation. - Book values for nutrients produced, multiplied by animal numbers. Several sources of values exist: “Midwest Plan Service Book - 18” is most commonly referenced. Referenced data needs to match or be adjusted to an account for difference between the operation and the description of the values referenced (animal size, production, feed types, etc.).

21. 21 Estimating nutrients produced by an operation - Dairy - Book values for nutrients produced, multiplied by animal numbers and days on feed. Animal descriptionNumberlbs P 2 O 5 per daylbs P 2 O 5 per year 1,400 lbs milking cow 100.4215,330 1,400 lbs dry cow 25.201,825 750 lbs dairy heifer 25.07639 250 lbs dairy calves 40.02292 Total18,086

22. 22 Manure Nutrient Production Mass balance: phosphorus

23. 23 Principles of Mass Balance 1.Elements are neither created nor destroyed. 2.Elements which enter a system either exit the system or are stored (soil or dead space of storage). 3.The composition of animal products – meat, milk, eggs, etc. – are relatively constant regardless of diet. (Diet can affect flavor, odor, etc.)

24. Feed Manure Animals Manure Nutrients Crop Nutrients Soil Land Application Nutrient Uptake

25. Purchased Fertilizer Grown Feed Manure Animals Manure Nutrients Crop Nutrients Soil Land Application Leaching Purchased Feeds Nutrient Uptake Crop Sales Animal Sales Field Runoff Bedding Mortalities Ration Milk Sales Purchased Animals Facility Losses Leachate Losses

26. Animals Manure Nutrients Animal Sales Bedding Mortalities Ration Milk Sales Ration P – Net Product P = Manure P Animal Mass Balance Purchased Animals Facility Losses Manure

27. 27 Manure Nutrient Production Mass Balance Pros: –Farm specific –Nutrient consumption is best predictor of excretion Cons: –Whole farm mass balance can be difficult & complicated –Ration on paper not always what is actually fed –Rations corresponding animal group sizes, and animal performance change over time Useful when book values are not representative!

28. 28 Whole Farm Balance Crop Nutrients Manure Nutrients

29. 29 GOAL: Crop nutrient removal equals or exceeds manure nutrient production 1.Long-term (farm level) 2.Crop rotation cycle (field level)

30. 30 Whole Farm Balance Strategies for Sustainability Credit manure nutrients –Minimize purchased fertilizers –Apply manure where needed Increase available land for spreading –Easement, rental, purchase of more acres Move nutrients off farm – sell, give-away Optimize Feed P & N Inputs –Do not exceed animal requirements –Improve nutrient availability to animals

31. 31 Optimizing Feed P Inputs High excretion P (two primary reasons) –P fed in excess of nutrient requirement of animal –Limited availability of P to animal Common P form in grains has low availability Over feed P to compensate

32. 32 Phosphorus Essential for skeletal system development Generally low availability –Phytate is not available to animals –Feedstuffs: 60-75% of P is phytate Corn grain – 12% available Soybean meal – 23-30% available Wheat – 50% available Dicalcium phosphate – 100% available –Unavailable and unabsorbed P is excreted

33. 33 Phytase Enzyme that makes phytate P available –Also may improve availability of other minerals and improve utilization of protein and energy Animals do not produce their own phytase –Ruminants (cattle, sheep) get phytase produced by symbiotic bacteria in rumen –Monogastrics (swine, poultry) have no natural source of phytase

34. 34 Dairy Phosphorus Nutrition Natural rumen phytase may still be inadequate for high producing (high feed intake) cows Tend to overfeed phosphorus –Some excess for to offset limited availability –More excess for unsupported performance claims

35. 35 Dairy P: Reqs. vs. Recs. Dietary requirements in grams/cow/day –P requirement same regardless of feed intake –Thumb rule: 1 gram of ration P for each 1 lb of milk in each management group (24 minimum) Diets mixed on dry matter ratio basis –Recommendations based on % ration P (% P of total ration dry matter)

36. 36 P Feeding Recommendations (NRC, 2001) MY, lb/day Ration P, % of DM Ration P, % of DM 0 (dry cow)0.24 400.29 600.33 800.35 1000.36 120 0.38 (max)!

37. 37 Dairy: Overfeeding of P Surveys: >50% of herds in WI, PA, and FL were fed rations with more P than needed to meet requirements Similar results with informal survey in MI P is second most expensive nutrient to supplement in dairy rations. Most nutritionists also sell feed.

38. 38 Three types of information that maybe available on the farm and used for phosphorus balance for the livestock operation. 1.Daily ration fed multiplied by the number of animals fed and the number of days fed. 2.Total pounds of each ration fed over a noted time period. 3.Disappearance or annual totals of inputs used. Each livestock operations record need to be reviewed to decide the best input side record to use for the calculation.

39. 39 Estimating nutrients produced by an operation. -Phosphorus balance for the livestock operation or whole farm. Not all phosphorus is the same. Elemental phosphorus (P) / 0.44 = P 2 O 5 Elemental phosphorus (P) = 0.44 * P 2 O 5

40. 40 Dairy cattle: Why is P overfed? Safety marginNot needed Increased milk yieldDoesn’t work HypophosphatemiaDoesn’t help Improves reproductionData ??? P in feed unknownNo excuse NRC, 2001; Beede & Davidson, 1999

41. 41 Animal Mass Balance Dairy Example

42. 42 Animal mass balance: dairy Feed intake phosphorus –Dry matter intake (DMI); actual or expected –Ration P concentration from ration sheets –Average cow & heifer group sizes are generally known Milk Sold –Track milk shipped vs. cows milked for 30 days (not DHIA) –Average number of cows lactating (DHIA) Animals Left –Records of animals sold and mortalities left farm (DHIA) –Herd turnover rate and average herd size (DHIA)

43. 43 Lotta P Dairy Farm Information Collected P Intake –Ration sheets for all groups fed a TMR –Animal group number report, edited for “average” annual numbers P Export - milk –30-day average milk shipped: 88.7 lbs/cow/day –annual average of 345 lactating cows P Export - animals –Cows left: 131 (32%) @ 1,300 lbs BW –Bulls calves sold: 210 @ 100 lbs BW –Heifers sold: 3 @ 1,100 lbs BW

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45. 45 Nutrients retained by animals AnimalNPK Beef0.0160.00700.002 Dairy0.0120.00700.002 Pork0.0230.00720.002 Layers0.0220.00600.002 Broilers0.0260.00600.002 Turkeys0.0210.00600.002 Milk0.00500.0009* Eggs0.01660.0021 Source: MWPS-18; LPES Guide * Nutrient Requirements of Dairy Cattle, NRC 2001

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49. 49 Total Manure P 2 0 5 55,621 lbs

50. 50 Calculating Average Crop Removal Year (1000 acre) Shelled Corn acres corn yield (bu.) Silage corn acres Silage yield ( tons) Soybean acres Soybean yield (bu.) Hay Acres Hay yield (tons) 199870012015018300551504.2 199970013515020300671506.0 200070013015019300601504.7 200150012515017500531504.5 200250014015020.5500651506.3 5 yr.ave.62013015018.938060 bu.150 5.1 Ton P 2 0 5 / unit.353.6.8810 Total P 2 0 5 (lbs) 28,21010,20620,0647,650 MSU Bulletin 550-a, table 1 66,130 Lbs. P 2 0 5 1,000 acres = 66 lbs/acre Average P 2 0 5 Removal

51. 51 Estimating land-base need based on nutrients produced. Total lbs. of phosphorus generated or purchased by farm. Average crop removal for the rotation. = Acres need to spread manure (without changing P levels). 66 lbs/acre Average Crop P 2 0 5 Removal = Total Manure P 2 0 5 55,621 lbs 843 acres

52. 52 Impact & Influence of Rations Lotta P Dairy –72,338 lbs P 2 O 5 –1,315 Acres (3.2 /cow) (55 lbs/A crop removal) Book Values –63,423 lbs P 2 O 5 –1,153 Acres (2.8/cow) NRC levels of P –55,621 lbs P 2 O 5 –1,011 Acres (2.5/cow) Animal Mass Balance –Works both ways. –Ration corrections can be almost immediate. 3/4 Acre/cow

53. 53 Nutrient Planning for Sustainability Summary Determine t otal nutrients produced -P is most often the limiting factor Determine your average crop removal Determine the crop base needed to utilize nutrient produced -Divide total nutrients produced by average crop removal Compare your actual spreadable acre to crop base needed. -If you’re short on land base start making adjustments.

54. 54 Nutrient Planning for Sustainability Summary ( continued ) Compare your actual spreadable acre to crop base needed. -If you’re short on land base start making adjustments. Increase yields Increase spreadable acre. Rent, trade acre, spreading agreements Lower phosphorus inputs – feed less P – Move phases of production – heifer or dry cow to another farm