Putting the least in least cost rations

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Putting the least in least cost rations

• Lou Armentano
• UW-Dairy Sciece

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Armentanos first law

• Animals require nutrients, not feeds
• Are you (did you hire) a nutritionist or a
  feedist?

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Basis of Least Cost Balancing

• minimum requirements for nutrients
• note does not optimize ration
• if adding feed to bring nutrient from 95 to 100
  of requirement costs more than milk yield
  response tough luck, you will go there and pay
  for it
• amino acids may be a good example
• usually manage risk of variation in feed (low) or
  requirement (high) by over specifying requirement
• maximum amount of nutrient (or toxin)
• NFC, Sugar, Ether extract, free oil, RDP, P
• These are OK!

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In a perfect world with no variance
economic optimum for cheap nutrients
Milk
true requirement
economic optimum for expensive nutrients
Nutrient amount
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Economics in perfect world
optimum for invariant feed
Milk
Nutrient amount
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In real world with tight feed
optimum for invariant feed
loss cost of nutrient
Milk
loss milk loss nutrient savings
loss cost of nutrient extra Milk
Nutrient amount
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In real world with loose feed
optimum for invariant feed
loss cost of nutrient
Milk
loss milk loss nutrient savings
loss cost of nutrient extra Milk
Nutrient amount
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Feeds with large nutrient variation

• must increase requirement in least cost program
  to optimize returns (minimize losses)
• can never get as optimum a return as with tight
  feed
• ergo loose feeds have less value than tight feeds
  with same average composition
• but realize you probably only pay for guaranteed
  minimum nutrient which should be further below
  mean for loose feeds
• for maximum tolerable levels (fat?) guaranteed
  minimum doesnt help (need guaranteed maximum!)

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How we limit least cost programs

• force in feeds
• forages to use inventories (justified short term)
• pet feeds Cottonseed in WI
• because home grown feeds are free, right?
• note this forces in nutrients, forcing out feeds
  when nutrient caps or ratios are included
• limit feeds
• thumb rules
• minimize risk associated with variability, toxins
• not including a feed in available feeds list
  limits it to 0!
• takes effort to add updated feed nutrient and
  price info
• suggest programs like feedval or sesame to
  scout feeds
• one of the best things a professional
  nutritionist brings to farm

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A feedval example pre- and post- ethanol boom
Enter actual price of standard feeds
Resulting nutrient values in
What changed? Cost of energy (TDN)! No surprise
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Apply nutrient values to forages
/100 lbs DM
At this price forages cost same to feed as
standard concentrates would pick
forageconcentrate ratio that gave maximum
performance/health
If costs you less than this to make forages then
your forage enterprise is profitable
If your forage production costs (-LDP for corn
silage) were same in Jan 04 as today, that
enterprise has become more profitable
Note corn silage has little value other than
energy, hence its larger relative increase in
value With high TDN value and same energy
values, corn silage much closer in value to
haylage
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Apply nutrient values to other concentrates
Low A/FV bargain feed! Feeds with A/FV lt 1
should definitely be available in least cost
program Let them compete with all feeds
(including forages based on forage true
cost) Must include a forage NDF or peNDF
requirement Note feed with A/FV over 1 may still
least cost in feedval assumes you need ALL the
nutrients in a feed (often not true) least cost
balancing uses this information (values only
nutrients required)
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Nutrient Ratios

• Ca/P (not all that relevant in lactation)
• Metabolizable Lysine/metabolizable essential
  amino acids
• Lysine/Methionine
• Almost always nutrient/DM
• animal needs mg, g, kg, Mcal etc.
• if diet allows greater of lesser intake this is a
  problem
• real issue with non-forage vs. forage fiber
  sources
• fat sources that reduce intake
• remember to consider cost/cow/day not per kg DM
  intake
• balancing Carbohydrate is more complicated
• at low intake could probably stand hotter diet
  (lower NDF/DM)
• but lower forage NDF/DM decreases intake

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Terrible ratios

• RUP/CP
• with high quality legumes we will be feeding
  excess RDP
• RUP/DM, RDP/DM and let CP float is ok
• RUP/CP of max CP could force out legumes
• especially a problem if you lock in legume, or
  lock in forage and corn silagelegume ratio
• Forage NDF/Total NDF
• in a lower forage diet, adding high fiber (fine)
  byproducts is good
• setting a minimum (75 NDF from forage) prevents
  this!
• saying fine byproducts are some forage (or
  peNDF) may fix this but its not true!

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Even Nutrients can be misused

• Correlated nutrients
• balance for NEL and NDF with oil cap?
• balancing for RUP/CP or forage NDF/NDF?
• minimum NDF and minimum NFC
• More nutrients
• difficult to understand what program is doing

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Ingredients vs. NutrientsNot always so clear

• I consider physically effective fiber a nutrient
• Physically effective fiber comes (mostly) from
  forages
• Forage-NDF is not an unreasonable thing to
  consider as a nutrient but is it really an
  ingredo-nutrient?
• Certainly forage is an ingredient so forage NDF
  (21 Forage NDF) constraints are preferable to a
  forage restraint (50 Forage)
• Physically effective NDF (once well defined) is a
  truer nutrient
• NDF above some minimum particle length or
  adjusted for mean particle size
• similar toavailable P

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Least cost ration balancing a process

• Start with few feed limits to get true minimum
  price
• is ingredient mix fairly standard? if so ok
• is ingredient mix out of box? if so
• are you sure? maybe thumb rules not so good.
• if sure it is bad (or cautious) then add
  constraints
• Priority
• try to specify a nutrient requirement, maximum,
  range or ratio to get something closer to comfort
  zone
• if this doesnt work add in loosest feed
  constraints possible

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The road not taken

• The perfect is the enemy of the very good
• Alternative diets to the optimal solution may
  be attractive (and less risky) for many reasons
  NOT specified in the model and may be only
  slightly (insignificantly) more expensive
• a diverse set of feeds has inherent advantages in
  reducing risk
• feeds you are familiar with also have an
  advantage
• For feeds included in available feed library but
  not used in the solution
• Shadow Price the price for a feed at which it
  would be used in solution
• Shadow price actual price marginal price
  change
• If feed hits its max or min inclusion rate need
  to explore the benefits of changing feed
  constraint

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Risk reduction

• Using multiple ingredients with similar nutrient
  profiles reduces potential diet nutrient
  variation
• Simple example
• imagine 2 feeds each with 12 oil and a standard
  deviation of 1 units
• six sigma rule says range of 9 to 15 99 of
  feeds
• if feed one feed,6.8 chance that it is 13.5 oil
  or more
• if feed 5050 mix, chance of exceeding 13.5 oil
  is only 1.7

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Monte Carlo Simulation
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Summary

• We do not have enough nutrition knowledge to
  completely ignore feeds
• Use as much nutrition knowledge as possible
• Be a feedist as last resort
• Approach out of box rations slowly
• limit feeds, listen to cows
• edge up if all good
• back off when needed
• depends on trust and communication between
  producer and nutritionist
• be aware of normal fluctuations in herd
• more work, more risk to obtain economic optimum

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Last Thoughts

• Know what your existing constraints are costing
• Nutrient constrains
• explore marginal changes in nutrient requirements
• Feed ingredient constraints
• Know what introducing a new constraint will cost
• may be a much more traditional diet at similar
  cost