||Uniform stands should be established to provide
a minimum of 10 plants/square foot in the year following
|Scheduling of harvests .......
||Dormant entries should be sampled at the first three
harvests of the season; nondorrnants at the second,
fourth and sixth harvest of the season. Fall harvests
which occur during a dormancy reaction period should not
be used for forage quality determination. Harvests should
occur at bud to flower. Visually quantify alfalfa
maturity using a 1-8 scale where l=vegetative (stems have
no buds or flowers); 2=early bud (1 33% ofthe stems have
buds); 3=mid bud (34-65% of the stems have buds); 4=late
bud (66-100% of the stems have buds); 5=early flower
(1-33% of the stems have flowers); 6=mid flower (34-65%
of stems have flowers); 7=late flower (66 100% of stems
have flowers); 8=post flower (stems have pods or seeds).
Do not adjust forage quality data for maturity. Report
data individually for each harvest. Weighted average
values across harvests can also be reported. Weighted
values are calculated by summing the product of yield x (ADF %, NDF % or
RFV) for each sampling before dividing
by the number of samplings.
||Sample from stands in the first or second year
following the seeding year and which have a minimum of 10
plants/square foot. Results from stands in the seeding
year can be used as supporting data but cannot be used to
fulfill minimum test year requirements.
||Data from a minimum of 2 test years (2 tests at
2 locations in the sarne year or 2 tests at 1 location in
||Dry matter yield data for the same plots that are
sampled for quality is not required but can be provided
to augment forage quality data.
||Test soil and apply fertilizer and
lime to promote high yields.
to prevent plant water deficit stress and to promote good
be scouted and insecticides should be applied when
needed. The presence and severity of foliar diseases
should be recorded.
SAMPLE COLLECTION AND PREPARATION
Forage samples should be obtained from non-border areas
of plots. Samples should be taken by hand clipping a
minimum of 3 square feet per plot. If plots are not
uniform, hand grab samples should be taken from multiple
locations within a plot. It is unacceptable to collect
forage samples from a flail-type harvester. Minimum
sample size should be 300 g wet weight. Samples should be
taken to a 5 cm stubble height.
Dry samples at 120 to 140° F in a forced air oven
in less than 48 hr. For drying; cloth, perforated paper
bags, or trays can be used. Grind samples to pass a 1 mm
Quality evaluation is based on deterrnination of
neutral detergent fiber (NDF, for intake), and in vitro
digestible dry matter or acid detergent fiber (ADF, for
digestibility) using wet chemistry or near infrared
reflectance spectroscopy (NlRS). For both wet laboratory
and NIRS procedures, it is assumed that procedures used
have accuracy and precision required for scientific
publication. Relative feed value is calculated using the
and where % DDM
(digestible dry matter)=88.9 - (.779 x ADF %)
% DMI (dry matter intake)
Forage NDF (% of DM)
Crude protein data can be
included in a description of cultivar forage quality, but
should be used only when accompanied by flber and RFV
High quality: WL 322 HQ, Pacesetter, or Cimmaron VR
Low quality: Vernal
In a national test conducted over eight locations,
Pacesetter, Cimmaron VR and WL 322 HQ averaged about 2%
lower NDF and 1% lower ADF than Vernal when harvested at
bud to flower maturity.
High and low quality checks for nondormant alfalfa
cultivars will be described when data become available.
SCIENTISTS WITH EXPERTISE
Name .........Craig C. Sheaffer
Address ..... Dept of Agronomy and Plant Genetics
411 Borlaug Hall
1991 Upper Buford Circle
University of Minnesota
Phone ........ 612-625-7224
Name ........ Michael A. Peterson
Address .....W-L Research Inc.
8701 Hwy. 14
Evansville, WI 53536-9593
Name .........Mark McCaslin
Address ......Forage Genetics
5292 Gills Coulee
West Salem, WI 54669
Relative feed value (RFV) describes
digestible energy intake potential of forages and can be
used for comparison of relative forage quality of alfalfa
cultivars. However, the relationships between intake and
digestibility assumed in RFV calculation may not be
applicable to all types of livestock.
For more accurate and precise
determination of alfalfa maturity,
maturity can be quantified using the mean stage by count
or mean stage by weight methods (2).
1. Goering, H.K., and P.J.
Van Soest. 1970. Forage fiber analyses (apparatus, reagents,
some application). USDA Handbook 379,
U.S. Gov. Print. Office, Washington, DC.
2. Fick, G.W, and S.C.
Mueller. 1989. Alfalfa quality, maturity, and mean stage of
University Iformation Bull. 217.
3. Linn, J.G., and N.P.
Martin. 1989. Forage quality tests and interpretation. Minnesota
4. Mueller, S.C., and G.W.
Fick. 1989. Converting alfalfa development measurements from mean
count to mean stage by weight. Crop.
5. Shenk, J.S., M.O.
Westerhaus, and S.M. Abrams. 1989. Protocol for NIRS calibration:
results and recalibration. p. 104-110. In
G.C. Marten, J.S. Shenk, and F.E. Barton (ed). Near Infrared
Reflectance Spectroscopy (NIRS):
Analysis of forage quality. USDA ARS Handbook 643, U.S. Gov. Print.
Office, Washington, DC.
6. Smith, Dale. 1973.
Influence of drying and storage conditions on nonstructural
carbohydrate analysis of
herbage tissue-A review. J. British
Grassland Soc. 28:129-133.
7. Stucker, R.E., and C.C.
Sheaffer. 1991. Sampling procedures for predicting quality of alfalfa.
p. 190. In
Agronomy Abstracts. ASA, Madison, WI.
8. Undersander, D.J., B.E.
Anderson, and N.P. Martin. 1991. Determining forage quality of alfalfa
p. 191. In Agronomy Abstracts.
ASA, Madison, Wl.
9. Volenec, J.J., J.H.
Cherney, and K.D. Johnson. 1987. Yield components, plant morphology,
quality of alfalfa as influenced by
plant population. Crop Sci. 27:321-326.
10. Windham, W.R., D.R. Mertens, and
F.E. Barton. 1989. Protocol for NIRS calibration: sample selection
and equation development and
validation. p. 96-103. In
G.C. Marten, J.S. Shenk, and F.E. Barton (ed).
Near Infrared Reflectance Spectroscopy
(NIRS): Analysis of forage quality. USDA, ARS Handbook 643,
U.S. Gov. Print. Office, Washington,
11. Wolf, D.D., and T.L. Ellmore. 1975.
Oven drying of small herbage samples. Agron. J. 67:571-574.