24th General Meeting of the European Grassland Federation
FERMENTATION CHARACTERISTICS, ENERGY VALUE
AND CONCENTRATION OF β CAROTENE IN YARROW
(Achillea millefolium L.) SILAGE
LUKAČ B.1, KMECL V.1, VERBIČ J.1, ŽNIDARŠIČ T.1, MEGLIČ V.1, KRAMBERGER B.2
1 Agricultural
2 Faculty
institute of Slovenia, Hacquetova ulica 17, 1000 Ljubljana, Slovenia
of agriculture and life sciences, Pivola 10, 2311 Hoče, Slovenia
Introduction
Permanent grassland in Slovenia:
• Covers 58.1 % of utilized agricultural area
(Statistical Office RS, 2008).
• Contains an considerable share of forbs
with variable feeding values.
• Average NEL value of silages 5.9 MJ NEL.
There are only few reliable data about silage
quality, energy value and β carotene
concentration
of
forbs
in
literature
(Isselstein, Weiβbach…).
The following results are from preliminary
experiment of larger project, where we study
different typs of grass-forbs silage mixtures.
2/12
Yarrow - Achillea millefolium L.
fam. Asteraceae
• A flowering plant.
• In the past grass leys and permanent pastures
contained yarrow.
• Leaves are rich in minerals - prevention of minerals
deficincies in ruminants.
• Persistent plant in strong competitor with desirable
plants on grassland.
• Poor plant species, regarding WSC concentration
More data are needed to draw firm conclusions about fermentation
characteristics at different dry matter levels and enviromental conditions.
The aim of our work was to determine:
- β carotene concentration
- nutritive value
- fermentation characteristic of silage
3/12
Material and methods
• Summer cut on a natural meadow
near the village Murski Črnci (46°37'
N; 16°06' E, 190 m a.s.l. in eastern
Slovenia).
• Material has been cutt at 1.5
cm lenght.
•
Ensiling of the unwilted (UW) and
wilted (W) (8 hours) yarrow at the
flowering stage in small-scale (1L)
laboratory silos.
4/12
Chemical analyses
NEL and ME were assessed on the basis of the in
vitro gas production technicque and chemical
composition using regression equations according
to Menke and Steingass (1987).
Fermentation quality of silages was assesed by
following parameters:
• pH
• Ammonia nitrogen
• Volatile fatty acids
• Lactic acid.
In vitro gas production technique
Acids were analysed by gas cromatography.
ß carotene concentration was determined by
liquid chromatography (EN 12823-2).
Liquid chromatography
5/12
Characteristics of ensiling material
• In both samples dry matter content
were above 200 g kg-1
• Wilted material contained almost
double amount of dry matter as
unwilted material.
600
500
400
300
200
100
0
Dry matter (g kg-1)
278
Unwilted
• β carotene concentration is similar
to values of Lolium multiflorum L.
found in literature, or even higher
from Dactylis glomerata L.
• After 8 hours of wilting beta
carotene was reduced for 18%.
538
Wilted after 8 hours
β-carotene (mg kg-1 DM)
250
200
199.7
163.1
150
100
50
0
Unwilted
Wilted after 8 hours
6/12
Characteristics of ensiling material
• UW yarrow was relatively poor on
WSC.
Concentration of WSC and CP
(g kg-1 DM)
140
136
• After 8 hours of wilting WSC
content increased above 100 g
kg-1 DM.
101.8
Wilted after 8 hours
• CP were about 140 g kg-1 DM.
• NEL and ME were low - most
likely the main reason is maturity
of ensiling material.
• At vegetativ stage yarrow can
reach values even above 6 MJ
NEL kg-1 DM. (our unpublish
data).
Unwilted
69.9
WSC
CP
Concetration of NEL and ME of ensiling material
(MJ kg-1 DM)
9
8
7
6
5
4
3
2
1
0
8.51
7.69
4.42
4.99
Unwilted
Wilted after 8 hours
NEL
ME
7/12
Fermentation quality of silages
• Without signs of detioration.
• Pleasant aromatic smell of
yarrow ant its essential oils in
both silages.
Concentration of Ammonia
nitrogen (g kg-1 total N)
90
80
78.1
70
60
50
40
• In wilted silages concentration
of Ammonia nitrogen were 3.6
times lower.
30
21.4
20
10
0
Unwilted
Wilted after 8 hours
8/12
Concentration of acids in silages
• Concentration of acids was
lower in W than UW silages.
• Absence of butyric acid in W
silage and very low value in
UW silage.
• pH of silages was low enough
to prevent growth of Clostridia.
Concentration of acids in silages
(g kg-1 DM)
• Direct cut grass silages usually
contain 80-120 g lactic acid kg-1
DM.
70
pH = 4.3
60
50
40
30
20
pH = 5.1
10
0
Unwilted
Wilted after 8 hours
butyric acid
0.19
0.00
acetic acid
9.06
1.95
lactic acid
56.61
3.59
• According these parameter W
silage is considered better.
9/12
Nutritive and energy value of silages
• High DM content and lower
activity of lactic acid bacteria are
reasons for higher WSC
concentration in wilted silage.
Concentration of WSC (g kg DM-1)
140
120.1
120
100
69.1
80
• It can be speculated that
relatively high WSC
concentrations were due to the
action of plant hemicellulases
during the ensiling process.
60
40
20
0
Unwilted
Wilted
Concentration of NEL and ME
(MJ kg-1 DM)
10
• Both silages had similarly low
NEL, about 4.6 MJ NEL kg-1
DM.
8.06
8
6
4.64
7.93
4.58
Unwilted silage
Wilted silage
4
2
0
NEL
ME
10/12
Nutritive and energy value of silages
• W silage had 30% lower β
carotene concentration than UW
silage.
• The results are in agreement with
those obtained on ensiling
material.
β carotene concentration in
silages (mg kg-1 DM)
250
237.1
200
166.5
150
• β carotene losses in silages are
higher than in ensiling material.
Probably is the reason relativly
high pH value of wilted silages.
• Carotenoids losses are higher for
legumes than for grasses , when
pH is high.
•
100
50
0
Unwilted silage
Wilted silage
11/12
Conclusions
• Both silages have favorable fermentation. Silage from wilted material
contained more WSC, less acetic acid and ammonia nitrogen. Therefore,
wilted silage is considered better than unwilted silage.
• In terms of β carotene preservation ensiling of unwilted material is much
better. Silage from unwilted yarrow contained almost 30% more β-carotene
then wilted silage.
• Yarrow silages were characterised by relatively low levels of NEL and ME.
The problem of low energy value could possibly be solved by earlier cut of
meadows containing considerable proportions of yarrow. Moreover, base on
these results and relatively low percetage of yarrow in the sward we are not
expecting major impact an silage qulity from permenent grassland.
12/12
Thank you for your attention