forage macro-minerals (ca, p, k, mg, na, cl, s) and dairy cow requirements
DESCRIPTION
Forage Macro-Minerals (Ca, P, K, Mg, Na, Cl, S) and Dairy Cow Requirements. Jim Linn, PhD Professor Emeritus – University of Minnesota Milk Specialties Global Waconia Farm Supply. Importance of Minerals. Animal Health Production/Reproduction Ration cost. Close-Up Dry Cow - PowerPoint PPT PresentationTRANSCRIPT
Forage Macro-Minerals (Ca, P, K, Mg, Na, Cl, S)
and Dairy Cow Requirements
Jim Linn, PhDProfessor Emeritus – University of Minnesota
Milk Specialties GlobalWaconia Farm Supply
Importance of Minerals
AnimalHealthProduction/ReproductionRation cost
Lactating Cow8 to 10% of total
$/cow/day0.75 - 1.00
Close-Up Dry Cow18 – 22% of total
$/cow/day0.75 - 1.00
Nutrient Composition (% DM) of Dairy Rations
Lactating Cow Close-up Dry Cow0
102030405060708090
100
44 39
28 36
17 145.5 7.05.5 3.5
FatMineralsProteinNDFNonFiber CHO
Forage Minerals
Forage mineralsContribute to animal requirementVariability – species, maturity, soils, fertilizationAnimal – Plant Imbalances
Forage Mineral Analysis
NIRS or Wet Chemistry?– NIRS doesn’t measure minerals only C,N,O bonds– Are the minerals reported on NIRS forage tests
accurate?– At the end of the day, when nutritionists have
several rations to formulate, can NIRS predicted forage minerals be used?
NIR Prediction of MineralsHaylage Calibration Data
Mineral Mean SEC RSQ SECV
Ca 1.12 .15 .86 .16
P .34 .04 .61 .04
Mg .32 .05 .69 .05
K 2.66 .32 .81 .32
S .26 .04 .75 .04
Source – Dairyland Labs, Arcadia WI
SEC – Std Error Calibration – lower better (±1 SEC – 67% of values)RSQ – R2 1 = perfect prediction SECV – Prediction validation – lower the better
NIR mineral validity depends on good reference wet chemistry methods and equation(s) development
NIRS Analysis – Forage Minerals
Macro Minerals – – Lactation rations
• Acceptable estimator – Ca, P, K, Mg and S
• Rationale – Most rations over formulated and
supplemented– Small range in P, Mg and S within species– Salt meets Na and Cl req’t
– Dry cow • NIRS not recommended for mineral analysis• Forages are large proportion of diet• Accuracy needed for DCAD and requirements
Trace minerals – NIRS not recommended
Forage Macro MineralsSGS Forage Summary - 2012
Mineral LegumeHaylage
GrassHaylage
Grass 2+Haylage
MixedHaylage
Mix-LegHaylage
Corn Silage
------------------------------- Mean / SD ---------------------------------------------
Ca 1.13 0.67 0.75 1.05 1.33 0.22SD 0.37 0.26 0.25 0.39 0.34 0.07
P 0.29 0.31 0.32 0.29 0.30 0.21SD 0.07 0.08 0.07 .07 0.06 0.03
K 2.46 2.57 2.65 2.45 2.41 0.88SD 0.54 0.78 0.58 0.63 0.54 0.24
Mg 0.27 0.25 0.30 0.26 0.31 0.18SD 0.08 0.08 0.06 0.08 0.07 0.06
Mineral
Mineral bioavailability (%) estimate of forages
NRC 2001
Ca 30 – 35
P 60 – 65
K >85
Mg 15 – 20
S 85 – 90
Na >85
Cl >85
Minerals in Rations of Lactating Dairy Cows
Feed DM (lb) – 85 lb Milk
Haylag
e
Corn Sil
CornBlood
SoyP
assDDGS
Soy-4
6%Ca c
arb
Mono CalMgO
xSa
ltBica
rbK-53%
K-Mg-S
0123456789
101112131415161718
Lb
Feed
DM
52 lb DM17% CP1.18 Mcal ME/lb32% NDF25.5% Starch61 % Forage DM
Macro Minerals for Lactating CowsRequirements vs. Ration Formulation
Mineral 2001 NRC Updated NRC Weiss1
Formulated
------------------------------- % of DM ----------------------------------
Calcium 0.6 – 0.75 0.70 - 0.86 0.9 – 1.0
Phosphorus 0.32 – 0.40 0.38 – 0.48 >0.42
Magnesium 0.20 0.28 0.32 – 0.38
Potassium 1.0 1.15 >1.5
Sodium 0.22 0.25 0.4 – 0.6a
Chloride 0.26 0.30 >0.4b
Sulfur 0.20 0.20 0.25
1 Weiss – Hoards Dairyman Feb 10, 2013a Sodium Buffersb Higher forage concentrations - legume
Calcium Contribution From FeedsLactating cow diet – 0.90% Ca
Haylage
Corn Sil Corn
Blood
SoyP
assDDGS
Soy-4
6%
Ca carb
Mono CalMgO
xSa
lt
Bicarb
K-53%K-M
g-S0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0lb Feed DM
% Ca contribu-tion
lb or %
Phosphorus Contribution From FeedsLactating cow diet – 0.40% P
Haylag
e
Corn Sil
CornBlood
SoyP
assDDGS
Soy-4
6%Ca c
arb
Mono CalMgO
xSa
ltBica
rbK-53%
K-Mg-S
0.0
5.0
10.0
15.0
20.0
25.0
lb or%
lb Feed DM % P contribution
Magnesium Contribution From FeedsLactating cow diet – 0.35% Mg
Haylag
e
Corn Sil
CornBlood
SoyP
assDDGS
Soy-4
6%Ca c
arb
Mono CalMgO
xSa
ltBica
rbK-53%
K-Mg-S
0
5
10
15
20
25
30
35
40lb Feed DM % Mg contribution
lb or%
Potassium
Mineral required in the highest amounts in lactating dairy cows• K balance studies indicate 1.6% K needed in early lactation for positive
balance • Heat stress increases requirement
Forage K >85% available
Potassium Contribution From FeedsLactating cow diet – 1.5% K
Haylag
e
Corn Sil
CornBlood
SoyP
assDDGS
Soy-4
6%Ca c
arb
Mono CalMgO
xSa
ltBica
rbK-53%
K-Mg-S
0
10
20
30
40
50
60% K contribution
lb or%
Sulfur Contribution From FeedsLactating cow diet – 0.28% S
Haylag
e
Corn Sil
CornBlood
SoyP
assDDGS
Soy-4
6%Ca c
arb
Mono CalMgO
xSa
ltBica
rbK-53%
K-Mg-S
0
5
10
15
20
25
30
35% S contribution
lb or%
Sodium and Chloride Contribution From FeedsLactating cow diet – 0.5% Salt
Haylage
Corn Sil Corn
Blood
SoyP
assDDGS
Soy-4
6%
Ca carb
Mono CalMgO
xSa
lt
Bicarb
K-53%K-M
g-S0
10
20
30
40
50
60
lb or%
Ration – 0.5% Na and 0.62% Cl
Minerals in Rations of Close-up Dry Dairy Cows
Close-up Dry Cow Diet28 lb DM/day
lb/cow/day• Grass hay 8.3• Corn silage 13.7• Corn 0.8• Protein 3.8• Macro minerals 1.04• TM/Additives 0.64
Close-up Dry Cow Diet% Macro Mineral from Forage
Calcium
Phosphorus
Magnesu
m
Potassiu
mSu
lfur
Sodium
Chloride
0
10
20
30
40
50
60
70
80 Diet mineral % Ca – 1.60 P – 0.38 Mg – 0.41 S – 0.36 Na – 0.09 Cl – 0.50 DCAD - +0.3
77% Forage diet – 13.7 lb Corn sil + 8.3 lb Grass Hay DM
%
Minerals from Forages in Dry Cow Diets
• Forages can supply 20 to 70% a mineral• Accuracy on mineral concentration in forages
more important – less error tolerance Cation – Anion balance Metabolic problems – greater risk with mineral
imbalance• Wet chemistry analysis recommended for
minerals in dry cow forages
DCAD, mEq/100g = [(%Na 43.5 + %K 25.6) (%Cl 28.2 + %S 62.5)]
LACTATING COWS CLOSE-UP DRY COWS
DCAD, mEq/100g = [(%Na 43.5 + %K 25.6) (%Cl 28.2 + %S
62.5)]
Macro Minerals in Forage Summary
• Forages are an important source of most macro minerals in lactating and dry cow rations.
• Ration formulation needs to consider– Requirements– Sources– Amounts fed – excess as well as deficiencies– Interactions amongst minerals fed in excess
Macro Minerals in Forage Summary
• NIRS acceptable estimator of Ca, P, K, Mg and S in lactating rations.– Formulations usually exceed minimum requirements
• Forages are a greater proportion of dry cow ration and mineral formulation requires accuracy – Wet Chemistry mineral analysis recommended.
• Precision feeding lactation and/or dry cow diets require wet chemistry analysis of minerals.
THANK YOU!