EXTENDING THE GRAZING
SEASON TO IMPROVE
PROFITABILITY OF COW-CALF
OPERATIONS
Jim Russell,
Iowa Beef Center
Iowa State University
MAJOR FACTOR LIMITING THE PROFITABILITY
OF BEEF COW-CALF PRODUCTION IN THE
MIDWEST
• Feed costs
– Limited productivity
from summer
pastures
– Excessive stored feed
use and costs
Profitability
Pasture costs
per animal unit
month
Stored feed fed
per cow, lb DM
High ¼ Average Low ¼
$6.47 $9.22 $12.33
3,509
3,722
4,388
PASTURE LAND VALUE IN IOWA
GOALS OF A YEAR-ROUND GRAZING SYSTEM
• Optimize calf production per acre.
• Optimize cow reproduction.
• Maintain long-term productivity and quality of
pastures.
• Minimize the amounts of stored feed fed to cows.
KEY TO YEAR-ROUND GRAZING
• To integrate of summer rotational grazing and
winter grazing of corn crop residues and
stockpiled forages to meet the cattle nutrient
needs.
Energy Requirements of Beef Cows
Calving in Different Months
NE reqt., Mcal/day
25
February calving
April calving
August calving
20
15
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Months
Total forage mass, lb/acre
Forage Production or Availability in
Different Months
3000
2000
1000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Months
Cool season grass
Legumes
Warm season grass
Stockpiled gr-leg (Hay equiv.)
Corn stalks (Hay equiv.)
NE reqt., Mcal/day
25
February calving
April calving
August calving
20
15
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Months
Total forage mass, lb/acre
Matching Forage Production for Grazing and
Cow Nutrient Requirements
3000
2000
1000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Months
Cool season grass
Legumes
Warm season grass
Stockpiled gr-leg (Hay equiv.)
Corn stalks (Hay equiv.)
STRATEGIES TO IMPROVE THE PRODUCTIVITY
OF SUMMER PASTURES IN IOWA
• Incorporate improved species
• Rotational grazing
• Lime and fertilize pastures based on soil
tests
• Early weaning
• Substituting grain-processing co-products
for forage?
ADVANTAGES AND LIMITATIONS OF
INCORPORATING LEGUME SPECIES INTO
PASTURES
• Advantages
– Increases uniformity and
quality of forage production
over season.
– Increases animal production by
as much as 15%.
– Reduce needs for N fertilization.
• Limitations
– Management
• For persistence
– Species
– Rotational grazing
» 35-day rest periods
– Avoid grazing under muddy
conditions
• For bloat
– Adequate grass in mix
– Rotational grazing
» Adequate stocking
rates
– Avoid moving when hungry
– Avoid moving in early
morning
– Have water in each paddock
– Poloxalene
• Against weeds
– Initiate grazing or mowing
early in season
ADVANTAGES OF USING ROTATIONAL
GRAZING FOR BEEF COWS
• Increased animal productivity
by 25 to 33%.
• Improved persistence of
desirable forage species.
•
Improved manure distribution.
•
Reduced soil erosion and
nutrient loss in run-off
0
Rest periods, days
(40-day cycle)
40
KEYS TO MAKING ROTATIONAL GRAZING WORK
1 2 3 4 5 6 7 8 9 10 11 12
Number of paddocks
• An adequate number of
paddocks to allow rest.
• Paddock shape and size.
•
Adjust forage removal rate
with forage growth rate.
•
Water source in every
paddock.
SUBSTITUTION RATE OF DDGS FOR FORAGE
(lb reduction in forage intake/lb DDGS)
Substitution Rate
Substitution Rate
0.8
0.6
0.4
Mean
0.2
Calculated
0
0
0.5
1
DDG (% BW)
1.5
EFFECT OF DDGS SUPPLEMENTATION
ON PASTURE RENT
Pasture rental with or without DDGS at 1% BW
(Cost = Approx. $18/AUM)
20
18
16
14
$/AUM
12
10
$/AUM
8
Pasture w/DDGS
6
4
2
0
2000
2001
2002
2003
2004
2005
Year
2006
2007
2008
2009
THE KEY TO PROFITABLE
COW-CALF PRODUCTION
RESOURCES TO REDUCE WINTER FEED
COSTS FOR BEEF COWS IN THE MIDWEST
Crop residues
Stockpiled forages
Standing corn
Annual forages
CORN CROP RESIDUES
• Approximately ½ ton
of hay is saved/acre
of corn crop residues
grazed
– Provides 33 cowdays/ac
– @ $90/ton hay = $45
saved/ac
– 13.5 million acres of
corn (Iowa) = winter
feed for 2.25 x the Iowa
beef herd
CONSIDERATIONS FOR GRAZING
CORN CROP RESIDUES
• Allocation
• Perceived effects on soils and subsequent
crop production
• Nutritional supplementation/Risk
management
STRIP GRAZING OF CORN CROP RESIDUES
Advantages
0.75 1.00 1.25 1.50
IVOMD, %
52.5
60.1
61.7
58.0
1.0
2.0
Continuous
.5
Strip
0.5
Selected Dig OM/Available Dig OM
Grazing selectivity of cows grazing
corn crop residues
.5
Stocking rate (ac/cow/mo)
and system
• Controls grazing
selectivity
• Limits trampling of corn
crop residues in the mud
• Control excessive grain
consumption
EFFECTS OF CORN CROP RESIDUE
GRAZING ON SOIL
EFFECTS OF CORN CROP RESIDUE GRAZING
ON SOIL PHYSICAL PROPERTIES AND
SUBSEQUENT CROP PRODUCTION
Perceived by producers
• Soil compaction
• Increased soil surface
roughness
• Decreased soil residue cover
• Decreased crop production in
subsequent growing year
RATIO OF PENETRATION RESISTANCE IN THE UPPER 4
INCHES OF SOIL IN GRAZED AND UNGRAZED AREAS OF
PADDOCKS GRAZED IN DIFFERENT MONTHS AT .67
AC/COW/MO (Atlantic, IA; * P <.05)
1
.
5
0
*
*
*
*
*
1
.
2
5* *
*
1
.
0
0
0
.
7
5
PentraioestancertioGrazed:Ungrazed
0
.
5
0
0
.
2
5
0
.
0
0
1
9
9
9
0
0
2
0
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1
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EFFECTS OF CORN CROP RESIDUE GRAZING ON THE
YIELDS OF SOYBEANS PLANTED WITH DISKING OR NO
TILLAGE IN THE SUBSEQUENT YEAR
(ATLANTIC, IA; * P<.05)
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3
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1
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+
2
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6
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32
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5
5
5
Soybeanilds,bu/ac
5
0
*
4
5
1
9
9
9
0
0
2
0
0
0
0
1
2
0
0
1
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STOCKPILED FORAGES
An alternative or supplement to grazing
crop residues
• Stockpiled forages are forages allowed to grow in late
summer and fall after hay harvest or grazing
• Over 70 to 100 days of stockpiling, yields will be:
– 1 ton/acre for unfertilized grass or grass-legume pastures
– 1 1/2 tons/acre for grass or grass-legume pastures fertilized
with 40 lb N/acre
• Grazing efficiency =
– 70% in late fall
– 55% in late winter
• Hay savings from stockpiled grazing =
– 1100 to 2100 lb hay/acre
KEYS TO STOCKPILED GRAZING
•
•
•
•
•
Forage species
Length of stockpiling period
Nitrogen fertilization
Allocation management
Risk management
COOL SEASON GRASSES FOR STOCKPILED
GRAZING
• Tall fescue
–
–
–
–
–
Good fall growth
Good nutritive value at beginning of winter
Persistent
Low summer forage quality
Endophyte fungus
• Smooth bromegrass
–
–
–
–
–
–
Less fall growth than fescue
More dead forage at beginning of winter than fescue
Lower forage quality at beginning of winter than fescue
Maintains forage quality better than fescue
Higher summer forage yields than fescue
Cattle perform equally to cows winter grazing fescue
• Orchardgrass
– Yields slightly lower than fescue
– Nutritive value equal or greater than fescue
VALUE OF LEGUME FORAGES IN WINTER
GRAZING SYSTEMS
• Benefits
– Increased summer
forage yields and
quality
– N fixation
– High digestibility of
stockpiled forage at
beginning of winter
– Improved animal
performance early in
winter grazing
season
• Limitations
– Rapid loss of
digestibility over winter
– Reduced animal
performance late in
winter grazing season
LENGTH OF STOCKPILING
KEY TO SUCCESSFUL WINTER GRAZING
• Stockpiling for a period
of 70 to 80 days
D M y ie ld , lb /a c
3000
144
87
2500
2000
TF-leg
SB-RC
73
78
78
1500
81
Number of top
of bar refers to
days stockpiled.
1000
500
0
1992 1993 1994 1995 1996
Years
– optimizes forage quantity
– optimizes forage quality
• Stockpiling for a period
longer than 100 days
– increases forage quantity
– severely reduces forage
quality
– increases susceptibility to
fescue toxicity
• Fescue alkaloids decrease
over winter
FERTILIZATION CONSIDERATIONS IN A
STOCKPILED GRAZING SYSTEM
• Potential response
– 40 lb N/ac may increase
stockpiled forage yields of
grass pastures by 50%
– 40 lb N/ac may increase
stockpiled forage yields of
grass-legume pastures by
15 to 25%
– N fertilization increases
digestibility and crude
protein content of stockpiled
forages
• Factors limiting response
– Forage species
– Late application
– Drought
ALLOCATION CONSIDERATIONS IN A
STOCKPILED GRAZING SYSTEM
• Problems
– Cows selectively graze
most nutritious plants and
plant parts first
– Nutrient requirements of
spring-calving cows
increase as winter
progresses
– Spring mud
• Management
– Strip-grazing
– Strip-grazing
– Sacrifice paddock
FACTORS AFFECTING NUTRITIONAL
SUPPLEMENTATION OF BEEF COWS
• Production goals for cattle
• Nutritional value of grazed forage
• Cost and availability of the supplements
PRODUCTION GOALS FOR BEEF CATTLE
AFFECTING WINTER SUPPLEMENTATION
Body condition score or
Body condition score or
weight maintenance
weight gain
• Pregnant spring-calving
• Pregnant cows with body
cows with body conditions
conditions < 5
>5
• Replacement heifers
• Lactating fall-calving cows • Stocker cattle
with body condition
scores > 4
BODY WEIGHTS AND CONDITION SCORES OF
SPRING- AND FALL-CALVING COWS
SUPPLEMENTED TO MAINTAIN CONDITION
SCORE 5 OR 4 DURING WINTER, RESPECTIVELY
(3-year average)
630
610
b
c
570
c
550
c
c
c
b
b
530
c
b
c
b
590
c
c
c
6.5
c
c
c
Month
Au
gu
st
Se
pt
em
be
r
Oc
tob
er
Ju
ly
Ju
ne
M
ay
Ap
ri l
ch
M
ar
nu
ary
Ja
tob
er
Year-round fallcalving
Year-round
spring-calving
Minimal land
spring-calving
Year-round
fall-calving
6.0
Year-round
spring-calvi
5.5
Minimal land
spring-calvi
5.0
4.5
510
Oc
Body weight, kg
d
7.0
b
Body condition score
b
4.0
MG PreC
C
PoC PreB
B
PoB
Production stage
LL
W
PoW
CRUDE PROTEIN CONCENTRATION OF
DIFFERENT FORAGES
18
16
14
12
10
CP reqd
Range diet
ar
M
Fe
b
Ja
n
D
ec
N
ov
ct
O
Au
g
Se
pt
Ju
ly
8
6
4
2
0
Ap
r
M
ay
Ju
ne
Crude protein, %DM
650 kg Beef Cow calving in April
Cool-season grass-legume
Corn crop residues
November
March
Forage/Month
16
14
12
10
8
6
4
2
0
November
March
Forage/Month
Bromegras
s-red
clover
Tall fescuered clover
Hay
Corn stalks
Available
Selected
Hay
Bromegras
s-red
clover
Tall fescuered clover
Hay
Corn stalks
Available
Selected
CP, %
90
80
70
60
50
40
30
20
10
0
Hay
Dig., %
SELECTIVITY OF BEEF COWS GRAZING CORN
STALKS OR STOCKPILED FORAGES DURING
WINTER
CRUDE PROTEIN CONCENTRATION OF
DIFFERENT CORN CROP RESIDUES
12
CP, % DM
10
8
6
4
2
0
Stalk
Leaf
Husk
Cob
Stover fraction
Grain
HAY FEEDING AS A RISK MANAGEMENT TOOL
$.75 - $1.50/Cow/Day
• Harvest losses
– 15-50%
• Storage losses
– 12-33%
• Feeding losses
– 12-35%
COSTS OF DIFFERENT RATIONS FOR
1300 lb ANGUS X SIMMENTAL COWS IN MIDGESTATION DURING WINTER
• 27 lb Alfalfa hay, $90/ton
• 23 lb Brome hay, $80/ton
+ 4 lb Corn, $4.50/bu
• 21 lb Corn stalks, $55/ton
+6 lb Corn gluten feed, $113/ton
+6.5 lb Distillers dried grains, $135/ton
+5.5 lb Soybean meal, $295/ton
+6 lb Wheat mids, $135/ton
+6 lb Corn grain, $4.50/bu
• 17 lb Corn gluten feed, $109/ton
- $1.22/day
- $1.24/day
-$.92/day
-$1.02/day
-$1.39/day
-$.98/day
-$1.22/day
-$.92/day