Improving Forage Quality: Dreams vs. Reality - Penn State University

Improving Forage
Quality: Dreams vs.
Reality
Ev Thomas
William H. Miner Agricultural Research Institute
Chazy, NY
Factors influencing a farmer’s farmer s
corn hybrid purchases
Performance on his farm, local and regional trial data.
Particular needs of the farm—BMR, farm BMR, RR, Bt, other traits.
Who stops by first for a seed order, early order
discounts.
Past relationships—”I’ve relationships ve always bought seed corn from
Joe.” Joe.
Caps, jackets, etc.
Dairy nutrition consultants’ consultants dream:
One hybrid, one silage quality
Reality: Reality:
The normal range of planting dates, soil types
and field conditions from field to field will result in corn
silage that’s that s not nearly uniform, even in only one hybrid
is used. used
Planting more than one hybrid spreads the risk if a
particular hybrid turns out to be highly susceptible to
foliar disease, drought, cold soils, etc.
If corn planting is spread over several weeks, planting
the same hybrid from first field to last may result in
unacceptable differences in silage dry matter.
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3
5
Corn silage:
A “minor minor” crop?
Only about 7% of corn in the U.S. is harvested for silage.
Of this, some is planted for grain but harvested for
silage.
Therefore, the real market for corn planted for silage is a
bit less than 7%.
Historically, this has limited most seed companies’
companies
interest in silage-only silage only hybrids.
How many hybrids to plant for silage?
Obviously, depends on corn acreage. 100 acres of
corn—at corn at least 2 hybrids, 4 or 5 isn’t isn t too many. But 1000
acres for silage doesn’t doesn t mean 20 or 30 hybrids!
If planting and harvest can each be completed in a week
or so, fewer hybrids are needed, of similar relative
maturity—i.e. maturity i.e. all 100-105 100 105 RM.
If planting takes several weeks and a custom operator
harvests the entire crop in several days, use hybrids with
a greater range of relative maturity—i.e. maturity i.e. 95-105 95 105 RM.
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Corn silage quality
One silo, one hybrid.
Nov. Dec. Jan. April June
DM, % Starch, % NDF, %
2
4
6
1

Corn hybrid selection
Leafy hybrids
Most leafy hybrids are “silage silage only” only hybrids, but a few
are promoted as dual-purpose
dual purpose—for for grain or silage.
Leafy hybrids have up to twice as many leaves
above the ear. (I’ve (I ve seen as many as 12.)
However, leaves don’t don t add to forage quality, only
represent 10-12% 10 12% of whole plant yield.
(20% more leaves x 10% = 10 + 2 = 12%)
Therefore, there’s there s often less than meets the eye.
However, leafy hybrids are hot!
Why are leafy hybrids hot?
Seed price and yield
similar to non-leafy non leafy
hybrids.
The extra leaves are at
eye level, where
farmers can see them. them
Leafies simply look
great in the field.
Leafies got sex appeal!
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In vitro true digestibility (%)
80
75
70
65
Whole plant
y = 0.83x + 73
R 2 = 0.88
Stover
1900-1929 1930-1944 1945-1959 1960-1974 1975-1989 1990-present
Relationship between corn forage in vitro true digestibility and era of
release for whole-plant and stover.
8 leaves
above the ear
Leafy corn
Normal corn
5 leaves above
the ear
Brown midrib (BMR) corn hybrids
Silage-only Silage only hybrids sold by Mycogen Seeds. Still a
tiny portion of the silage market, but increasing.
A naturally-occurring naturally occurring mutation causes incomplete
lignin formation, resulting in high stover digestibility.
Problems: Lower yield, poor standability, lousy
drought and disease tolerance, very high seed price.
Much of the benefit is from improved dry matter
intake; especially good in high corn silage diets and
for high-producing high producing cows.
cows
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12
2

Normal corn
BMR corn
13
BMR planted May 1
Leafy corn BMR corn
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17
BMR planted May 1
“Your Your grandfather’s grandfather s corn” corn
The BMR gene was discovered many years ago, but
BMR corn wasn’t wasn t commercialized until the 1990s.
BMR is therefore competing with hybrids that are the
result of 70 years of selection and improvement since
corn was hybridized in the 1930s.
BMR yield and stress tolerance aren’t aren t good
compared to today’s today s best hybrids, more like corn
grown 25 years ago.
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3

BMR vs. non-BMR non BMR corn silage
105
100
95
90
Average of 18 field and lactation trials
Yield ADF NDF Milk/Ton Milk/Acre
BMR Non-BMR
Corn hybrid selection: Summary
Don’t Don t assume that the newest hybrids have better NDF
digestibility. Rely on university corn silage trials.
Leafies are a good option if they have superior
digestibility. Some do, some, don’t. don t.
BMR: Not for all farms, not for all cows on a farm. Should
be stored in a separate silo. Requires a strong stomach
and a pioneering spirit. (As opposed to a Pioneer-ing
Pioneer ing
spirit.)
Penn State chop height research
Chop
height
6”
18” 18
Centre County, 2004
Tons/A @
35%DM
26.4
24.6
48 hr
NDF-D NDF
54.9
58.0
Milk/ton
3129
3406
29,169
29,473
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21
Milk/acre
23
120
115
110
105
100
95
90
85
80
New BMR hybrid =
improved performance?
Two Cornell University silage trials, 2005
Yield Milk/t Milk/A Yield Milk/T Milk/A
BMR Trial Ave.
Corn silage chop height height
“Normal Normal” chop height is generally considered to be
6-8”. . In recent years there’s there s been interest (and a lot
of research) on chopping at 12” 12 to 18”, 18 , with some
research at 30” 30 chop height .
High chop corn is a trade-off trade off between reduced yield
and increased silage quality. Yield reduced ~300#
lbs. per inch above 6-8”. 6 .
3-4% 4% higher milk production per ton, but lower fat%.
Chop height realities
Many farmers already chop higher than 6-8” 6 because of
uneven fields and wide chopper heads. 10” 10 not unusual.
Custom harvest operators often chop 10”+, 10 +, especially on
farms where stones are a problem and where the farmer
hasn’t hasn t done a good job of stone picking.
Chop height: “Just Just above the height of the biggest stone
in the field.”
field.
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4

Processed corn silage
Chop height: 17”
(continued)
Alfalfa mowing height:
How low should we go?
Yield of alfalfa-grass alfalfa grass hand harvested
at 2” 2 and 4” 4 cutting heights
First
Second
Third
Total
Tons DM/A
2”
2.0
0.8
1.4
4.2
Tons DM/A
4”
1.7
0.7
1.3
3.7
P
0.001

Forage quality of alfalfa-grass alfalfa grass mowed
with disk mower at 3.1” 3.1 and 4.3” 4.3
CP, %
NDF, %
Ash, %
NDF-d, NDF d, 24 hr
Milk2000/T Milk2000/T
3.1” 3.1
17.4
49.4
8.6
49.4
2615
4.3” 4.3
17.9
48.7
8.3
53.8
2813
But how about milk per acre?
P
0.144
0.020
0.06