Dr. L. E. Chase
Department of Animal Science
Cornell University

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The dairy cow is a marvel as a biological manufacturing plant
The “average” New York dairy cow produced 20,071 lbs. of milk per lactation in 2009
The “average” New York dairy cow produced 10,885 lbs. of milk per lactation in 1970
This is an 84% increase!

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We have a number of herds in NY with herd average milk production > 30,000 lbs/cow
What is the biological limit to milk production?
How can an individual cow in a herd produce > 200 lbs of milk per day when housed in a group fed a ration balanced for 85 lbs. of milk?

Current World Record -
Holstein
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Ever-Green-View My 1326-ET
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3x, 365 days = 72,170 lbs milk
Average = 198 lbs/day!

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World record – 2007
Mainstream Barkly Jubilee
2x, 365 days = 49,250 lbs. milk
4.6% fat, 3.3% milk true protein
Average of 135 lbs. milk/day!
Was on supplemented rotational grazing for part of the record

8/2004 = 442,690 lbs milk
> 52,000 Gallons!!!!

What Does a Cow Producing
100 lbs. of Milk Excrete/Day?
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Milk -
- 100 lbs (13 lbs of dry matter)
- 4.9 lbs. of lactose (sugar)
- 3.6 lbs of milk fat
- 3.1 lbs. of milk true protein
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Manure -
- 190 lbs of total manure
- 60 – 70 lbs of urine
- 120 -130 lbs fecal material

What Does a Cow producing
100 lbs. of Milk Need to Make
Each Day?
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7 – 8 lbs of glucose (sugar)
3 – 4 lbs. of microbial protein
2 – 2.5 lbs of absorbed amino acids

How Much Does This Cow Eat
& Drink?
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55 – 60 lbs. of feed dry matter intake
- 120 – 130 lbs of wet feed
- Assumes ration is 45% dry matter
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Drinks 30 – 35 gallons of water

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Must be a package size that the cow can be expected to consume
Related directly to potential milk production, feed cost and PROFIT
Essential if rations are formulated on a nutrient density basis
Can’t do problem solving without DMI

Intake
Energy
DM
Low
Ration Energy Content
High

Factors Affecting Dry Matter Intake
Cow Factors
 Milk
 Milk Solids
 Size
 Maturity
 Days in Milk
 Genetics
 Transition Insults
 Mastitis Status
Forage Factors
 Maturity
 Texture/Particle Distribution
 Condition - mold
 Condition - pH
 Condition - fermentation
Environmental Factors
 Air Quality - ventilation
 Ambient Temperature
 Relative Humidity
 Haircoat Condition
 Access to Feed
 Social Overhead
 Access to Stall
 Manger/Bunk Surface
 Stall Comfort
 Lighting
 bST
 Ration Intended vs. Utilized*
People Factors
 Who is responsible for every other factor listed above?!
Concentrate Factors
 Complement with Forage
 Texture
 Condition - mold
 Condition - freshness

17%
6%
10%
22%
45%
Milk
Feed
BCS
BW
Env.

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Do they attain high levels of milk production by increasing ration nutrient density or do they have higher levels of
DMI?

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Use scales that work + moisture tester
Know what is fed, refused, consumed
How many cows are in the group?
Graph intake & milk production
Calculate “actual” versus “predicted” grain disappearance rate

What Nutrients Does A Cow
Need?
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Water
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Protein
Carbohydrates
Lipids/fats
Minerals
Vitamins
Energy???

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Nutrient required in the largest quantity per day
Milk is about 87% water
The cow’s body is about 56 to 81% water
(784 to 1134 lbs. for a 1400 lb. cow)

Predicted Daily Water Intake for
Lactating Cows
Gallons
25
20
15
10
5
0
45
40
35
30
40 60 80 100 120 140
Milk, lbs/day
45 F
85 F
Murphy et. al., 1983

Intakes of Other Animal Groups
Group
Dry cows
Heifers (>5 months)
Calves (< 5 months)
Gallons/day
5 – 10
5 – 10
1 - 5

Is This Clean Water?

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Definition:
◦ A dietary essential for one or more species of animal
All animals do not require the same nutrients
Laboratory analyses determines the nutrients we feed
◦ Fiber vs ADF
Ruminants have simpler dietary nutrient requirements because many are supplied by the rumen bugs

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The first use of any nutrient is meet the maintenance requirement of the animal
This is a fixed cost related to body weight and

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Not a nutrient
Obtained from several sources
◦ Carbohydrates - CHO
◦ Fats - 2.25 times the energy
◦ Proteins – Via deamination

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Energy level in a feed or ration can be expressed in a variety of ways.
TDN – Total digestible nutrients
NFE – Nitrogen free extract
Net Energy Basis
◦ NEM
◦ NEL
◦ NEG
 Expressed as Megacalories of Energy - Mcals

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Protein
Carbohydrates
Lipids/Fats
Minerals
Vitamins
Water

Feedstuff Chemical Analysis Scheme
Water Dry Matter
Inorganic
Minerals Nitrogenous Lipids
Organic
Carbohydrates
Proteins NPN Nonstructural Structural
Sugars Starches Pectins Cellulose Hemicellulose Lignin

1.
2.
3.
4.
Principle component of body tissues
Enhance feed intake and energy use
 Enzymes
Supply N to the rumen microbes
◦ Ammonia, Amino acids, Peptides
Supply amino acids for synthesis of:
◦ Milk protein
◦ Tissue protein
◦ Enzymes, hormones etc.

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Intake Protein
◦ IP - What the cow eats
Crude Protein
◦ Calculated from Nitrogen content of feed
◦ Proteins are 16% N
◦ Multiply N content of feed by 6.25 (100/16)
◦ Measure of the total protein in a feed
 Both true and NPN
◦ Measured as a % of the dry matter

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Rumen Degradable Protein
◦ Broken down in rumen and used by the rumen bugs
( RDP)
◦ Soluble Protein (SIP) is the portion of the RDP that is rapidly broken down in the rumen
Rumen Undegradable Protein
◦ Not broken down in rumen
◦ Also referred to as bypass protein
( RUP)

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Microbial Protein
◦ Refers to protein produced by the bugs in the rumen
◦ Microbial protein is important because it supplies ~50% of cow’s total protein requirement
◦ Microbial protein is much higher quality protein than the feed components from which it was produced
◦ As a result you don't have to worry too much about the amino acid (AA) content of the diet or providing the essential AA in diet.
◦ Rumen microbes use protein and degradable energy sources for the production of microbial protein

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Essential and Nonessential
◦ Nonessential - synthesized by body
◦ Essential - 10 Essential AA’s
 Necessary for the animal
 Must come from diet
Not a concern in most ruminant diets because essential AA’s are synthesized by rumen bugs as microbial protein is produced
However in higher producing animals we see a response to adding certain essential AA’s such as lysine or methionine

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Major source of energy for cattle
Makes up more than 65% of DM in feeds
Broken down in rumen to VFA’s, methane, carbon dioxide and water
Two types
◦ Structural and Nonstructural
Tremendous differences in the speed with which structural and nonstructural breakdown in the rumen.
◦ Structural Slow; Nonstructural - Rapid
Compatible combination important for good rumen digestion

(Hall, 2003)

Carbohydrates
NFC Sugars, starch, pectin
NDFiber
Effective NDF
Highly Ruminally
Available
Microbial
Digestion
Digestible
NDF
Physical NDF
Stimulates
Chewing
Acid Production from VFAs
Saliva secretion :
80 gal/d 7 lb Na bicarb
3 lb phosphate buffers
Buffering agents:
NH3, forage, protein

Carbohydrate Digestion
Dynamics
(sugars)
, starch

Physical & Chemical Fiber
Recommendations
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Chemical NDF
◦ 28-32% of ration DM
◦ Minimum ~25% (NRC,
2001)
◦ 1.2% of body weight as total
NDF intake
 1350-lb BW x 0.012 = 16.2 lb
NDF intake/d
 Realistic upper limit on NDF intake/day
 Fermentability of NDF
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Physical NDF
◦ 550-600 min of rumination/day
◦ ~60% of resting cows should be ruminating
◦ Rumen pH >5.8
◦ ~5-8% >19 mm
 Penn State PS
◦ peNDF >21% of DM

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Also known as Ether Extract
Highest energy per lb
Chemical structure
◦ Fatty acids - Hydrocarbon chains
◦ Glycerol
Majority absorbed in small intestines
◦ Few converted to VFA’s
Too much fat in the diet inhibits rumen digestion of cellulose
◦ Fatty Acids inhibit bacteria
◦ Coats fiber to prevent breakdown

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Fat is 225% the energy of CHO or protein
◦ Good way to boost the NEL of a diet
◦ When physically can’t get anymore energy into the diet with grains and by products
Low heat increment so it is good to add in hot weather
Inhibits fiber digestion
Fats provide energy for the dairy cow but not the rumen bugs (rumen bugs need carbohydrate energy)

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Mineral required by dairy cattle
◦ Calcium for milk production
◦ Mineral supplements usually nearly 100 % DM
◦ Minerals, vitamins and other additives take up space or DM in the ration
 Provide little or none of the major nutrients.
◦ When balancing rations leave about 1 – 2 lb of space for these supplements.
 i.e. If DMI is estimated to be 50lb/day, balance the ration to meet the NEL, CP, ADF, NDF, and NSC in 49 lb of DM leaving one pound for all the minerals and vitamins etc. that need to be added

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Grams/cow/day
Calcium
Phosphorus
Potassium
Magnesium
Sulfur
Sodium
Chloride

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Milligrams/cow/day
Iron
Zinc
Manganese
Copper
Cobalt
Iodine
Selenium

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Water soluble - B's & C
Fat soluble - A,D,E & K
Bugs in the rumen
◦ No requirement for any of the water soluble vitamins.
◦ The bugs manufacture their own B vitamins.
◦ Only supplement the A, D, & E
◦ However as milk production increases we balance the ration for more feed to bypass digestion. We are finding that supplementation of niacin (B3) and others may have a positive affect on animal performance.