Transcript Dairy Cattle Nutrition * The Basics

Dairy Cattle Nutrition –
The Basics
Dr. L. E. Chase
Department of Animal Science
Cornell University
Today’s Dairy Cow
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!

Today’s Dairy Cow - 2
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
Ever-Green-View My 1326-ET
 3x, 365 days = 72,170 lbs milk
 Average = 198 lbs/day!

What About Jersey’s?
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

World Lifetime Milk
Production Record Cow
8/2004 = 442,690 lbs milk
> 52,000 Gallons!!!!
What Does a Cow Producing
100 lbs. of Milk Excrete/Day?
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
 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?
-
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?
55 – 60 lbs. of feed dry matter intake
- 120 – 130 lbs of wet feed
- Assumes ration is 45% dry matter
 Drinks 30 – 35 gallons of water

Why is DMI Important?
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

What Controls DMI?
Energy
DM
Intake
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
Concentrate Factors
Complement with Forage
Texture
Condition - mold
Condition - freshness
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?!
Factors Which Influence DMI
10%
17%
45%
6%
22%
Milk
Feed
BCS
BW
Env.
High Producing Dairy Herds

Do they attain high levels of milk
production by increasing ration nutrient
density or do they have higher levels of
DMI?
Monitoring DMI
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?
Water
 Protein
 Carbohydrates
 Lipids/fats
 Minerals
 Vitamins
 Energy???

Water
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
45
40
35
30
25
Gallons
20
15
10
5
0
45 F
85 F
40
60
80
100
120
140
Milk, lbs/day
Murphy et. al., 1983
Intakes of Other Animal Groups
Group
Gallons/day
Dry cows
5 – 10
Heifers (>5 months)
5 – 10
Calves (< 5 months)
1-5
Is This Clean Water?
Would
You
Drink
this
Water?
Would You Drink this Water?
Nutrient

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
Nutrient Use and Efficiency
The first use of any nutrient is meet the
maintenance requirement of the animal
 This is a fixed cost related to body weight
and

Energy
Not a nutrient
 Obtained from several sources

◦ Carbohydrates - CHO
◦ Fats - 2.25 times the energy
◦ Proteins – Via deamination
Net Energy Measures
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
Nutrient Categories
Protein
 Carbohydrates
 Lipids/Fats
 Minerals
 Vitamins
 Water

Feedstuff
Water
Chemical Analysis Scheme
Dry Matter
Inorganic
Minerals
Organic
Nitrogenous
Proteins
Lipids
Carbohydrates
NPN
Nonstructural
Sugars
Starches
Structural
Pectins
Cellulose
Hemicellulose
Lignin
Protein is Required to:
Principle component of body tissues
Enhance feed intake and energy use
1.
2.

Enzymes
Supply N to the rumen microbes
3.
◦
Ammonia, Amino acids, Peptides
Supply amino acids for synthesis of:
4.
◦
◦
◦
Milk protein
Tissue protein
Enzymes, hormones etc.
Protein Terminology

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
Protein Terminology

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)
Protein Terminology

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
Amino Acids

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

Carbohydrates
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
Plant Carbohydrate Fractions
(Hall, 2003)
Carbohydrates
NDFiber
NFC Sugars, starch, pectin
Highly Ruminally
Available
Microbial
Digestion
Effective
Digestible
NDF
NDF
Physical NDF
Stimulates
Chewing
Saliva secretion:
Acid Production
from VFAs
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

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

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
Fats
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
Feeding Fat

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)

Minerals

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
Macro Minerals
Grams/cow/day
 Calcium
 Phosphorus
 Potassium
 Magnesium
 Sulfur
 Sodium
 Chloride

Micro (trace) minerals
Milligrams/cow/day
 Iron
 Zinc
 Manganese
 Copper
 Cobalt
 Iodine
 Selenium

Vitamins
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.
Summary