Nutrient Planning for Sustainability Backgrounding Cattle Grazing

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Nutrient Planning for Sustainability
Back-grounding Cattle Grazing

• Dann J. Bolinger Lyndon L. Kelley
• Michigan State University Extension

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Basis of Planning

• Maintain economic viability and profitability of
  farm business
• Protect the environment
• Surface water
• Groundwater
• Air quality
• Nutrients of primary concern
• Nitrogen leaching, volatilization
• Phosphorus run-off, leaching

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NP corn uptake vs. manure

• Corn Uptake Manure
• NP 2.5 1.32 (as excreted)
• 0.66 (field applied)
• Overall result if we apply based on crop uptake
  
• of actual field N, we will overapply P.
• Corn 2.5/0.66 3.8X
• Thats a phosphorus excess of about 150 lb/A!

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Raising and Lowering Soil P

• 10 20 lbs of excess P2O5/A
• to raise bray P1 soil test one lb/A.
• 10 20 lbs of crop removal P2O5/A
• to lower bray P1 soil test one lb/A.
• (Most Michigan crop rotations average 50 lb/A
  crop removal,
• so soil test goes down only 5-10 lb/A/year at
  best.)
• Easy and fast to raise, hard slow to lower!

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Fundamental nutrient question
Is my farm concentrating nutrients?
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National Level

• Mass Nutrient Balance

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Manure P vs. crop land P use
lt 25 25 - 50 50 - 100 gt100
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Manure P vs. crop land P use
lt 25 25 - 50 50 - 100 gt100
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Manure P vs. crop land P use
lt 25 25 - 50 50 - 100 gt100
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State and County Level

• Mass Nutrient Balance

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Nutrient Concentration

• National level
• Regional level
• Community level
• Farm level
• Field level

CNMP
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Farm Level Nutrient Balance
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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!

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Animals
Manure
Feed
Manure Nutrients
Crop Nutrients
Nutrient Uptake
Land Application
Farm P Cycle
Soil
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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)

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Manure Nutrient Production Records of manure
production and 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)

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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,
• unknown performance level or nutrition of animals
  in data set)
• New data in progress

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• 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
  (animals size, production, feed types, etc.).

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• Estimating nutrients produced by an operation -
  Dairy
• - Book values for nutrients produced, multiplied
  by animal numbers and days on feed.

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Manure Nutrient Production Mass balance
phosphorus
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Principles of Mass Balance

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

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Animals
Manure
Feed
Manure Nutrients
Crop Nutrients
Nutrient Uptake
Land Application
Farm P Cycle
Soil
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Purchased Animals
Purchased Feeds
Animal Sales
Milk Sales
Manure
Animals
Ration
Leachate Losses
Facility Losses
Grown Feed
Crop Sales
Mortalities
Manure Nutrients
Crop Nutrients
Purchased Fertilizer
Bedding
Nutrient Uptake
Land Application
Farm P Cycle
Soil
Field Runoff
Leaching
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Purchased Animals
Animal Sales
Milk Sales
Animals
Ration
Manure
Facility Losses
X
Mortalities
Animal Mass Balance
Manure Nutrients
Bedding
Ration P Net Product P Manure P
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Manure Nutrient Production Mass Balance

• Pros
• Farm specific
• Nutrient consumption is best predictor of
  excretion
• Cons
• Whole farm mass balance can be difficult and
  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!

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Whole Farm Balance
Manure Nutrients
Crop Nutrients
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GOAL Crop nutrient removal equals or exceeds
manure nutrient production

• Long-term (farm level)
• Crop rotation cycle (field level)

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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 and N Inputs
• Do not exceed animal requirements
• Improve nutrient availability to animals

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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

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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

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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

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Phosphorus Nutrition

• Natural rumen phytase may be inadequate for high
  feed intake cows
• Tend to overfeed phosphorus
• Some excess to offset limited availability
• More excess for unsupported performance claims

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Overfeeding of P

• P is 2nd most expensive nutrient to supplement in
  cattle rations.
• Most nutritionists also sell feed.

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

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• 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 P2O5 Elemental
phosphorus (P) 0.44 P2O5
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• Estimating nutrients produced by a operation.
• -Phosphorus Input /Output Balance

Mr. Smith Back-grounds 100 head of holstein each
fall through early spring. In addition to Grazing
corn stalks, cover crops he fed 45,000 lbs of
corn , 40 ton grass hay and 8.5 ton calf
supplement.
489/.44 1,111 lbs. P2O5
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Nutrients retained by animals

• 100 calves with a end wt. 1,000 lbs
• start wt. of 500 lbs
• 50,000 lbs gain
• 50,000 lbs X 0.007 350 lbs P
• 350 lbs P/.44 795 lbs P2O5

Source MWPS-18 LPES Guide
Nutrient Requirements
of Dairy Cattle, NRC 2001
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• Calculating Nutrient Applied

100 head holstein calves affect on phosphorus
levels.
Total P2O5 fed - total P2O5 in weight sold
total lbs P2O5 in manure 1,111 lbs
P2O5. - 795 lbs P2O5 316 lbs P2O5
total lbs P2O5 in manure / Gazed on 500 acre
Net lbs P2O5 acres supplied 316 lbs P2O5 /500
acre .63 lbs P2O5 /acres
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• Calculating Average Crop Removal

Total lbs of purchased P fed pasture P content

P removal By calf sales
-
P build up pasture P removal
1,111 lbs P2O5 Fed
795 lbs P2O5 Sold
316 Net lbs P2O5

-
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• Calculating Average Crop Removal

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• Calculating Average Crop Removal

Corn 310 acres 130 Bu. 0.35 lbs P2O5 / Bu.
14,105 lbs P2O5 Soys 190 acres 60 Bu. 0.88
lbs P2O5 / Bu. 10,032 lbs P2O5 28,210 20,064
24,137 lbs of P2O5 removal 24,137 lbs P2O5 /
500 acres 48 lbs/acre of P2O5
(average
P2O5 removal)
P2O5 removal rates from MSU Bulletin
E-550a
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Animal Mass Balance

• Horse Example

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• Estimating nutrients produced by a operation.
• -Phosphorus balance horse example

Horse example- Mr. Randel pastures three horses
on a five, one acre paddocks. He spreads the
winter accumulation of manure from the barn and
from around the feeders back onto the pasture.
In addition to the pasture production Mr.
Randels feed annually 1,100 lbs of
manufactured horse feed, with a P content of
.003 9,000 lbs grass/alfalfa hay, with a P
content of .0023
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• Estimating nutrients produced by a operation.
• -Phosphorus Input /Output Balance

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Nutrients retained by animals

• Animals with no weight increase,
• provide no P removal
• Animals that never leave the farm
• provide no P removal
• A 800 lb yearling foal sold each year will
  remove 5.6 lbs P annually
• (800 lbs X .007 5.6 lbs P )

Source MWPS-18 LPES Guide
Nutrient Requirements
of Dairy Cattle, NRC 2001
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• Calculating Average Crop Removal
• (One acre pasture lot)

Total lbs of purchased P fed pasture P content

P Net applied pasture P removal

47 lbs P2O5 Net applied
47 lbs P2O5 fed
Assuming a 10/1 soil P test build-up ratio , bray
1 P soil test level will increase about 5 lb/year.
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Nutrient Planning for SustainabilitySummary

• Determine total 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 spread able acre to crop base
  needed.
• -If youre short on land base, start
  making adjustments.

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Nutrient Planning for Summary (continued)

• Compare your actual spread-able acre to crop base
  needed.
• -If youre short on land base, start
  making adjustments.
• Increase yields
• Increase spread-able acre. Rent, trade acre,
  spreading agreements
• Lower phosphorus inputs feed less P
• Move phases of production heifer or dry cow to
  another farm