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 Scientific
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2. Colorado CWD cluster (Tables 2 & 3)
Herbage drawn from an 80 mile cross section of the CWD endemic cluster
zone in North central Colorado (Fig. 4) consistently demonstrated
excessive levels of the divalent cation, calcium, at 1.19% total dry
matter. However, the levels of Mn recorded in this specific batch of
herbage/soil samples were low; averaging out at 39.5 mg/kg in herbage
and 9.3 ppm in the soil. These samples were drawn during the drought
conditions of July 1998 following three months of dry weather. (NB. Soil
Mn is rendered considerably less available during drought conditions
(31) whilst the protracted daylight of the mid summer period decreases
levels of Mn in plant tissues (65). However, soil sampling carried out
the previous autumn on 13-25 October 1997 across the CWD cluster zone -
following a period of rain and snow - recorded considerably higher
levels of Mn averaging out at 317 mg/kg from the same test locations. It
is possible that the recent increase in acid rainfall occurring along
the CWD section of the Front Range during the winter rain/snow season is
also assisting an increased uptake of 'available Mn' from the soil into
the herbage. Ca also averaged high concentrations of 2.55% dry matter in
the autumn 1997 tests.
Table 2 Analyses
of herbage samples drawn across the CWD-endemic region of the Colorado
Front Range on 12/7/98 - 16/7/98; readings in mg/kg dry basis, unless
marked % w/w dry basis
Location
|
N%
|
K%
|
Ca%
|
Cu
|
Fe
|
Mo
|
Se
|
P%
|
Mg%
|
Mn
|
Na%
|
Zn
|
B
|
Co
|
CWD
region
|
|
|
1
Horsetooth
|
1.66
|
1.89
|
0.77
|
5.8
|
84.8
|
0.10
|
.080
|
.15
|
.2
|
38
|
.01
|
19.0
|
19.8 |
.090
|
5 Owl Canyon
|
2.63
|
1.46
|
2.04
|
9.1
|
80.7
|
2.03
|
.250
|
.21
|
.40
|
30
|
.01
|
19.2
|
36.6
|
.160
|
6 Poudre Canyon
|
1.54
|
1.67
|
0.76
|
5.0
|
69.7
|
0.16
|
.240
|
.19
|
.18
|
37
|
.00
|
19.7
|
19.6
|
.110
|
7 Teds Place
|
5.03
|
5.81
|
2.05
|
7.1
|
194.8
|
1.68
|
.065
|
.40
|
.40
|
44
|
.01
|
25.9
|
42.9
|
.220
|
9 Black Canyon
|
2.21
|
1.83
|
0.71
|
6.6
|
365.7
|
1.06
|
.064
|
.26
|
.16
|
50
|
.00
|
105.7
|
18.2
|
.040
|
12
H-Bar-G Ranch
|
1.76
|
1.92
|
0.83
|
5.6
|
131.9
|
1.16
|
.270
|
.24
|
.19
|
38
|
.00
|
45.0
|
21.9
|
.050
|
Av CWD
|
2.47
|
2.43
|
1.19
|
6.5
|
154.6
|
1.03
|
.161
|
.24
|
.25
|
40
|
.005
|
39.0
|
26.5
|
.111
|
Category
|
mean
|
mean
|
very
high
|
low
|
mean
|
mean
|
low
|
low
|
low
|
mean
|
very
low
|
low
|
mean
|
mean
|
|
Levels of
Al/S/V/Ni/Cr/F/As/Cd/Pb/Sn were normal at all sites tested.
Table 3
Analyses of top soils drawn across the CWDcluster zone of the North
Central Colorado Front Range and a CWD-free zone in Utah on 12-16/7/98
and 20/9/97 respectively
Test
Site
|
pH
|
P
|
K
|
Mg
|
Cu
|
B
|
Na
|
Zn
|
Ca
|
Mo
|
Fe
|
S
|
Se
|
Mn
|
Mn
|
CWD
ZONE COLORADO
|
(1997)
|
1
Horsetooth Mt
|
7.0
|
6.0
|
250
|
309
|
1.4
|
0.7
|
3.3
|
1.0
|
2576
|
0.0
|
14
|
36.7
|
.09
|
6.4
|
333
|
2 Spring Creek
|
6.6
|
3.8
|
115
|
167
|
1.3
|
0.4
|
2.4
|
0.9
|
1541
|
0.1
|
28
|
23.1
|
.18
|
15.0
|
261
|
3 Horsetooth Re
|
6.8
|
4.0
|
101
|
280
|
0.8
|
0.5
|
3.5
|
0.9
|
1635
|
0.1
|
22
|
27.1
|
.24
|
8.0
|
300
|
4 Livermore
|
8.7
|
5.4
|
290
|
72
|
1.0
|
0.8
|
1.4
|
1.1
|
2833
|
0.0
|
2
|
34.4
|
.09
|
2.0
|
373
|
5 Owl Canyon
|
8.6
|
6.0
|
221
|
153
|
0.8
|
0.7
|
5.2
|
0.9
|
3777
|
0.1
|
11
|
32.9
|
.18
|
5.0
|
229
|
6 Poudre Canyon
|
7.4
|
7.4
|
247
|
97
|
2.7
|
0.7
|
2.0
|
2.8
|
1512
|
0.0
|
16
|
24.1
|
.10
|
9.0
|
465
|
7 Teds Corner
|
6.8
|
25.4
|
506
|
99
|
2.5
|
0.8
|
3.9
|
3.0
|
2251
|
0.1
|
37
|
33.2
|
.19
|
18.0
|
320
|
8 Bellvue
|
8.3
|
29.2
|
236
|
248
|
2.1
|
1.0
|
9.9
|
1.7
|
3295
|
0.1
|
9
|
42.9
|
.13
|
3.0
|
99
|
9 Black Canyon
|
6.7
|
29.4
|
395
|
170
|
3.8
|
0.8
|
4.3
|
9.1
|
1418
|
0.3
|
50
|
21.9
|
.16
|
20.0
|
329
|
10
Black Canyon
|
6.4
|
5.6
|
175
|
146
|
0.9
|
0.5
|
3.1
|
1.5
|
1822
|
0.3
|
51
|
19.2
|
.16
|
10.0
|
468
|
11
H-Bar-G Ranch
|
6.6
|
6.6
|
249
|
150
|
1.3
|
0.5
|
1.9
|
0.8
|
1194
|
0.1
|
29
|
17.0
|
.06
|
7.0
|
341
|
12
H-Bar-G Ranch
|
6.5
|
4.8
|
167
|
110
|
1.4
|
0.5
|
3.5
|
2.9
|
1260
|
0.1
|
38
|
18.7
|
.12
|
8.0
|
293
|
| |
Av CWD
|
7.2
|
10.6
|
246
|
166
|
1.6
|
0.6
|
3.7
|
2.2
|
2093
|
0.1
|
25
|
27.6
|
.14
|
9.3
|
317
|
Category
|
high
|
low
|
mean
|
mean
|
very
low
|
low
|
very
low
|
mean
|
mean
|
low
|
high
|
mean
|
low
|
mean
|
very
high
|
| |
CWD-FREE
UTAH
|
Gt
Cottonwood
|
7.6
|
11.4
|
194
|
177
|
10.7
|
0.6
|
275
|
61
|
2056
|
0.2
|
52
|
67.7
|
.26
|
25.0
|
|
Lt
Cottonwood
|
7.2
|
9.4
|
91
|
75
|
5.1
|
x
|
x
|
8
|
x
|
1.3
|
88
|
x
|
x
|
32.0
|
|
Av
CWD-free
|
7.4
|
10.4
|
142
|
126
|
7.9
|
0.6
|
275
|
35
|
2056
|
0.7
|
70
|
67.7
|
.26
|
25.0
|
|
Category
|
mean
|
low
|
low
|
mean
|
high
|
low
|
high
high
|
very
|
mean
|
mean
high
|
very
high
|
very
high
|
mean
|
high
|
|
|
All samples analysed by
National Resources Management Ltd on dry basis. x = insufficient sample
for test
Cu/Zn were as EDTA extractable mg/l.
Na/Ca/K/Mg were as ammonium nitrate extractable mg/l.
Fe/Mn were as DPTA extractable mg/l.
B as hot water soluble Mg/l.
Mo as Tamms extractable mg/l.
S as available phosphate buffer soluble mg/l.
Se as 'total' mg/kg.
P as sodium bicarbonate extractable mg/l
Levels of Sn/Hg/F/I/Cr/Ni/Co/Pb/As/Al/V/Cd were normal at all locations
tested.
However,
soil sampling carried out the previous autumn on 13-25 October
1997 across the CWD cluster zone-following a period of rain and
snow - recorded considerable higher levels of Mn averaging out
at 317 mg/kg from the same test locations. It is possible that
the recent increase in acid rainfall occurring along the CWD
section of the Frong Range during the winter rain/snow season is
also assisting an increased uptake of 'available Mn' from the
soil into the herbage. Ca also averaged high concentrations of
2.55% dry matter in the autumn 1997 tests. Interestingly,
local ranchers in the CWD zone consider that the increased
incidence rate of CWD correlates with the increase in population
density of deer and elk in the 'Rocky Mountain National Park'
region - the epicentre of the CWD cluster. They also report an
increase in the consumption of pine needles by deer/elk in the
overpopulated region, who have progressively switched onto this
abnormal substitute ration since competition for the limited
supplies of normal foods has increased. Pine needles contain
high concentrations of certain cations, particularly in acid
rainbelt districts: Mn being recorded at excessive
concentrations ranging between 214-5810 p.p.m. (67).
Fig.
4 Mapdepicting sample locations of the comparative study
between
the scrapie endemic and scrapie-free valleys near SKURETRI, N.
Iceland.
Sample numbers correspond with the numbered farms of Table 1.
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