Efficacy of monensin against bovine coccidiosis in young Holstein-Friesian calves


Fitzgerald, P.R.; Mansfield, M.E.

Journal of Protozoology 20(1): 121-126

1973


Monensin, an anticoccidial antibiotic, was incorporated into pelleted feed and given to 10-week-old Holstein-Friesian calves at 0.25 mg/kg, 1.0 mg/kg, or 2.0 mg/kg of body weight. Inoculated calves were inoculated by drenching with 500,000 sporulated oocysts of Eimeria bovis. Other calves served as inoculated or uninoculated controls. Observations were recorded on oocyst discharge in the feces, clinical signs, weight gain, food consumption, hemoglobin, packed cell volume, total serum protein, sodium and potassium content of the serum, and differential white cell counts. Calves in the inoculated control group developed severe infections, discharged large numbers of oocysts, developed clinical signs and 1 of 5 died. Uninoculated, untreated control calves were essentially free of coccidia. A few calves in the groups which received monensin developed light infections but none of them had clinical signs of coccidiosis. Calves which received the highest and the lowest dosages of monensin gained weight less rapidly than did the uninoculated controls or the animals which received monensin at 1.0 mg/kg of body weight. Inoculated control calves with severe infections had reduced food intake and a significant reduction in weight which was not regained during the experimental period. The only other significant change in any of the parameters measured was a reduction in the total serum protein of inoculated, nonmedicated control calves. The level returned to normal 5 weeks after clinical signs first appeared.

MONENSIN
AGAINST
BOVINE
COCCIDIOSIS
121
8.
Calderin,
C.
1937.
El
Blastocystis
hominis
como
parasito
patogeno
del
hombre.
Rev.
Med.
Trop.
Parasit.
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Clin.
Lab.
3,
207-13.
9.
Ciferri,
R.
&
P.
Redaelli.
1938.
A
new
hypothesis
on
the
nature
of
Blastocystis.
Mycopathologia
1,
3-6.
10.
Hungate,
R.
E.
1966.
The
Rumen
and
Its
Microbes.
Academic
Press,
New
York.
11.
Knowles,
R.
&
B.
M.
Das
Gupta.
1924.
On
the
nature
of
Blastocystis
hominis.
Ind.
J.
Med.
Res.
12,
31-8.
12.
Lynch,
K.
M.
1922.
Blastocystis
Species
in
Culture.
Am.
J.
Trop.
Med.
2,
215-21.
J.
PROTOZOOL.
20(1),
121-126
(1973).
13.
Panayotatou,
A.
1928.
Sur
la
blastocystose.
Trois
cas
d'enterite
a
Blastocystis
hominis.
Bull.
Soc.
Path.
Exot.
21,
755-
60.
14.
Prowazek,
S.
1904.
Untersuchungen
uber
einige
para-
sitische
Flagellaten.
Arb.
K.
Gesundh.
21,
1-41.
15.
Silberstern,
E.
1929.
Ein
Fall
von
akuter
Enteritis
mit
auffallender
Vermehrung
von
Blastocystis
hominis
im
Stuhle.
Klin.
Wochschr.
8,
553-4.
16.
Zierdt,
C.
H.,
W.
S.
Rude
&
B.
S.
Bull.
1967.
Protozoan
characteristics
of
Blastocystis
hominis.
Am.
J.
Clin.
Path.
48,
495-
501.
Efficacy
of
Monensin
Against
Bovine
Coccidiosis
in
Young
Holstein
-Friesian
Calves*
PAUL
R.
FITZGERALD
and
M.
E.
MANSFIELD
College
of
Veterinary
Medicine,
University
of
Illinois,
Urbana,
Illinois
61801
SYNOPSIS.
Monensin,
an
anticoccidial
antibiotic,
was
incorporated
into
pelleted
feed
and
given
to
10
-week-old
Holstein
-
Friesian
calves
at
0.25
mg/kg,
1.0
mg/kg,
or
2.0
mg/kg
of
body
weight.
Inoculated
calves
were
inoculated
by
drenching
with
500,000
sporulated
oocysts
of
Eimeria
bovis.
Other
calves
served
as
inoculated
or
uninoculated
controls.
Observations
were
recorded
on
oocyst
discharge
in
the
feces,
clinical
signs,
weight
gain,
food
consumption,
hemoglobin,
packed
cell
volume,
total
serum
protein,
sodium
and
potassium
content
of
the
serum,
and
differential
white
cell
counts.
Calves
in
the
inoculated
control
group
developed
severe
infections,
discharged
large
numbers
of
oocysts,
developed
clinical
signs
and
1
of
5
died.
Uninoculated,
untreated
control
calves
were
essentially
free
of
coccidia.
A
few
calves
in
the
groups
which
received
monensin
developed
light
infections
but
none
of
them
had
clinical
signs
of
coccidiosis.
Calves
which
received
the
highest
and
the
lowest
dosages
of
monensin
gained
weight
less
rapidly
than
did
the
uninoculated
controls
or
the
animals
which
received
monensin
at
1.0
mg/kg
of
body
weight.
Inoculated
control
calves
with
severe
infections
had
reduced
food
intake
and
a
significant
reduction
in
weight
which
was
not
regained
during
the
experimental
period.
The
only
other
significant
change
in
any
of
the
parameters
measured
was
a
reduction
in
the
total
serum
protein
of
in-
oculated,
nonmedicated
control
calves.
The
level
returned
to
normal
5
weeks
after
clinical
signs
first
appeared.
Index
Key
Words:
Eimeria
bovis;
coccidiosis
in
Holstein
-Friesian
calves;
antibiotic
monensin;
prevention
of
coccidiosis
by.
A
NTICOCCIDIAL
feed
additives
generally
have
not
been
used
for
the
treatment
or
prevention
of
coccidiosis
in
cattle.
Medication
has
usually
been
on
an
individual
basis
with
drugs
being
given
in
drinking
water,
by
dose
syringe,
or,
more
rarely,
by
sprinkling
the
drug
on
loose
feed.
Several
compounds
have
been
used
in
different
ways
for
the
control
of
bovine
coccidiosis
(3,
5-7).
A
newcomer
among
the
anticoccidial
drugs
is
monensin,
an
antibiotic
now
being
used
to
control
poultry
coccidia
(8,
9).
The
antibiotic
is
also
effective
against
hepatic
coccidia
of
rabbits
(4).
The
present
report
describes
the
effectiveness
of
monensin
against
Eimeria
bovis
of
cattle
when
incorporated
in
feed.
MATERIALS
AND
METHODS
Twenty-five
1
to
5
-day
-old
Holstein
-Friesian
calves
were
obtained
and
separated
randomly
into
5
groups
of
5
each
until
they
were
adjusted
to
the
new
environment
and
feed.
After
6
weeks,
the
groups
of
calves
were
re-examined
and
adjusted
to
make
the
groups
as
nearly
equal
in
weight,
size,
conformity,
etc.,
as
possible.
Each
calf
in
4
of
the
5
groups
was
inoculated
by
drenching
with
500,000
sporulated
oocysts;
the
5th
group
was
held
as
an
uninoculated
control
group.
The
inoculum
consisted
of
E.
bovis
*
This
study
supported
in
part
by
a
grant
from
Eli
Lilly
Com-
pany,
Greenfield,
Illinois.
(99%)
and
Eimeria
ellipsoidalis
(1%)
in
water.
Calves
in
group
1,
in
addition
to
the
oocysts,
were
given
monensin
in
pelleted
feed
(0.0015%)
so
that
a
dosage
of
0.25
mg/kg
of
body
weight
was
fed
in
the
morning
and
evening
for
33
days.
Calves
in
groups
2
and
3
also
were
inoculated
with
the
oocysts
but
were
given
monensin
in
feed
at
concentrations
of
0.006%
or
0.024%
to
supply
dosages
of
1.0
mg/kg
or
4.0
mg/kg
body
weight.
Two
days
after
starting
the
calves
on
the
medicated
feed
it
was
found
that
those
in
group
3
refused
the
pelleted
feed
that
contained
the
highest
concentration
of
monensin
(0.024%).
Because
of
this
the
medicated
feed
was
mixed
with
an
equal
quantity
of
unmedicated
feed
so
that
the
new
mixture
had
a
concentration
of
0.012%
monensin
and
was
fed
to
obtain
a
dosage
of
2.0
mg/kg
twice
daily
starting
on
the
day
of
inocula-
tion.
The
calves
in
group
4
were
nontreated
inoculated
controls.
Feed
was
prepared
by
incorporating
monensin
in
a
highly
palatable,
complete
feed,
the
mixture
containing
0.0015%,
0.006%,
or
0.012%
monensin.
Pellets
were
prepared
and
given
to
calves
in
quantities
to
meet
dosage
requirements.
Pellets
with-
out
monensin
were
prepared
for
the
controls.
Calves
in
groups
1,
2,
and
3
were
started
on
medicated
feed
3
days
before
inoculation
and
continued
for
30
postinoculation
days.
As
the
calves
gained
in
weight,
the
food
intake
was
adjusted
so
that
they
ate
sufficient
feed
each
day
to
maintain
the
proper
level
of
medication
throughout
the
experimental
period.
Observations
made
on
calves
during
the
experiment
included
122
MONENSIN
AGAINST
BOVINE
COCCIDIOSIS
GROUP
5
(uninoc.
control)
GROUP
4
(
inoc.
control)
GROUP
3
(4.0/2.0
mg/K)
GROUP
2
(
I
mg/K)
GROUP
I
(0.25
mg/K)
I
m
••
I
1
1 1 1
I I
I I I
/
,
14
.
Ai
t
yq
i
-
P.
t
a
I
X
3
a
i
I I I
I
I
I I
i
,
i
i
i
1 ,
I I
i
COCYST
DISCHARGE
AND
CLINICAL
SIGNS
2
V
0
0g0
50,000
!
..
,,,
1400
SLIGHT
DIARRHEA
t_
10,000-25,000
1,1!)%
1
3,000
nt-m
N
N
10
'D
7
DATE
VV
KEY:
DIARRHEA
J
DIARRHEA,
BLOOD
It
-DIARRHEA,
BLOOD
TISSUE,
TENESMUS
Fig.
1.
The
level
of
oocyst
discharge
in
feces
and
clinical
signs
in
Holstein
-Friesian
calves
inoculated
with
E.
bovis
and
treated
with
monensin
incorporated
in
pelleted
feed.
In
all
figures,
group
1-0.25
mg/kg;
group
2-1.0
mg/kg;
group
3-4.0/2.0
mg/kg;
group
4
—inoculated,
nonmedicated
controls;
group
5
—unin-
fected,
nonmedicated
controls.
the
following:
fecal
examinations
for
the
presence
of
oocysts;
observation
of
clinical
signs
(diarrhea,
blood,
tissue,
tenesmus);
feed
consumption;
weights;
blood
hemoglobin
and
packed
cell
volume;
differential
blood
cells;
total
serum
protein;
and
serum
Na
and
K
levels.
295
WEEKLY
WEIGHTS
-
MONENSIN
275—
255—
235—
215—
195—
(
7
)
0
.4
2
175-
155-
135
1
I
1l
I
92
g,
co
in
E
N
Of
I
DATE
Fig.
2.
Rate
of
weight
gain
of
Holstein
-Friesian
calves
in-
oculated
with
E.
bovis
and
treated
with
monensin
in
pelleted
feed.
In
Figs.
2-7,
group
1,
0
0;
group
2,
ID
0;
group
3,
A
A;
group
4,
A
A;
group
5,
•.
RESULTS
It
can
be
seen
in
Fig.
1
that
the
average
discharge
of
oocysts
and
clinical
signs
in
calves
of
groups
1,
2,
and
3
(calves
given
monensin)
was
low
or
nonexistent.
Calves
in
group
4
6—
c
4
0
a_
at
Treatment
Started
0
0
MONENSIN
FOOD
CONSUMPTION
10
ti
N
IT
)
N
vt-
CD
03
0
N
cr
CD
CO
0
GP
0.
0.
E
0
N
Fig.
3.
The
rate
of
food
consumption
of
Holstein
-Friesian
calves
inoculated
with
E.
bovis
and
treated
with
monensin
in
pelleted
feed.
MONENSIN
AGAINST
BOVINE
COCCIDIOSIS
123
Grams
%
14
13
12
11
10
1
Treatment
Started
5
0
4.)
0
I
I
Hg
b
MONENSIN
1
Treatment
Stopped
I
1 1 1
I I I I
COON
(1
)
Nve
;)
Date
Fig.
4.
The
blood
hemoglobin
content
in
Holstein
-Friesian
calves
inoculated
with
E.
bovis
and
treated
with
monensin
in
pelleted
feed.
(nontreated,
inoculated
controls)
became
relatively
severely
infected,
developed
severe
clinical
signs,
and
discharged
a
moder-
ate
number
of
oocysts
for
7-10
days
(1
calf
in
this
group
died
of
coccidiosis).
Two
calves
in
the
nontreated,
uninoculated
con-
trol
group
(group
5)
discharged
a
few
oocysts
in
the
1st
part
of
the
experiment.
The
average
weekly
weights
of
the
calves
during
the
experi-
mental
period
are
shown
in
Fig.
2.
These
results
indicate
a
reduced
rate
of
gain
associated
with
the
presence
of
monensin
in
feed
at
the
lowest
and
at
the
highest
concentrations.
There
was
no
difference
in
the
rate
of
gain
between
the
uninoculated
control
group
and
group
2
(1.0
mg/kg
of
monensin)
calves.
At
the
end
of
the
experimental
period
calves
in
group
4
(the
inoculated
controls)
had
the
smallest
weight
gains,
averaging
25
or
30
lb
less
than
the
uninfected
controls
or
group
2
ani-
mals.
Calves
in
group
3,
which
received
the
highest
level
of
medication,
had
slightly
larger
weight
gains
than
those
of
group
4.
Some
erratic
behavior
in
feed
consumption
was
observed
which
was
associated
with
the
amount
of
monensin
in
the
pellets
(Fig.
3).
Group
3
calves
had
a
marked
decline
in
the
average
consumption
beginning
shortly
after
they
were
started
on
the
pelleted
feed
which
contained
the
high
level
of
monensin
(0.024%).
With
a
subsequent
reduction
of
the
monensin
(0.012%)
concentration,
by
mixing
medicated
with
unmedicated
feed
to
furnish
a
dosage
of
2.0
mg/kg,
the
level
of
feed
con-
sumption
increased,
but
did
not
return
to
the
level
of
the
other
animals
during
the
experimental
period.
Group
4
calves
had
a
marked
reduction
in
feed
consumption
when
clinical
signs
of
coc-
cidiosis
began
to
appear
2
1
/
2
weeks
postinoculation.
The
dif-
ferences
in
rates
of
feed
consumption
between
the
uninoculated
38
37
36
35
34
33
cr
a.
32
31
30
29
28
HEMATOC
RI
T-
MONENSIN
co
---
DATE
i t
N
N N
Fig.
5.
The
packed
blood
cell
volume
in
Holstein
-Friesian
calves
inoculated
with
E.
bovis
and
treated
with
monensin
in
pelleted
feed.
124
MONENSIN
AGAINST
BOVINE
COCCIDIOSIS
6.0
5.5
4.5
4.4
4
.
I
I
IT
SERUM
PROTEIN
—MONENSIN
a
E
'CI
0
N
I I
I
I
I I
CO
ON
IA
t•-•
co
I
I
01
Date
Fig.
6.
The
serum
total
protein
content
in
Holstein
-Friesian
calves
inoculated
with
E.
bovis
and
treated
with
monensin
in
pelleted
feed.
control
calves
(group
5)
and
those
in
groups
1
and
2,
which
received
lower
concentrations
of
monensin,
were
negligible.
There
was
no
evidence
of
toxic
reaction
in
any
of
the
calves
at
any
time.
Measurements
of
the
hemoglobin
and
packed
cell
volume
from
calves
in
all
of
the
groups
failed
to
reveal
a
consistent
pattern
of
change,
attributable
either
to
coccidiosis
or
to
the
presence
of
the
antibiotic,
in
the
averages
of
any
of
the
groups
(Figs.
4,
5).
Similarly,
there
were
no
consistent
alterations
in
the
generally
erratic
leucocyte
counts
of
any
of
the
calves.
A
reduction
in
the
total
protein
of
the
blood
sera
of
calves
in
the
infected
group
4,
at
the
time
when
they
had
severe
clinical
signs,
is
evident
from
Fig.
6.
There
was
also
a
slight
reduction
in
the
total
serum
protein
of
group
1
calves
(monensin
at
0.25
mg/kg
body
weight).
The
latter
may
have
been
associated
with
low
grade
coccidial
infections
in
these
calves.
This
does
not
seem
likely,
however,
because
changes
in
serum
protein
level
usually
occur
only
in
association
with
severe
clinical
signs.
In
this
group
the
reduction
in
total
protein
was
observed
almost
2
weeks
later
than
in
the
severely
affected
calves
of
group
4.
The
averages
of
the
other
groups
were
similar.
There
were
no
significant
differences
(P
>
95%)
in
the
Na
or
K
levels
of
the
blood
serum
in
calves
given
monensin
at
any
of
the
3
concentrations
or
in
the
uninoculated
or
inoculated
control
animals
(Fig.
7).
DISCUSSION
The
results
of
this
experiment
indicate
that
monensin,
in-
corporated
in
pelleted
feed
at
the
concentrations
used,
protected
Holstein
-Friesian
calves
from
severe
clinical
coccidiosis
caused
by
Eimeria
bovis.
Treatment
of
calves
with
monensin
in
pelleted
feed
at
1.0
mg/kg
gave
somewhat
better
results
than
the
0.25
mg/kg
treatment.
In
the
latter,
all
the
animals
became
lightly
infected
while
only
1
became
lightly
infected
in
the
former
group.
The
response
of
calves
in
group
3
is
less
well
defined
because
these
animals
did
not
feed
readily
on
the
pellets.
Three
of
5
calves
in
this
group
became
lightly
infected
at
various
times
without
any
reference
to
the
time
of
inoculation.
Even
after
concentra-
tion
of
monensin
in
the
feed
was
changed
from
0.024
to
0.012%,
by
mixing
medicated
with
unmedicated
pellets,
the
question
remained
as
to
whether
calves
received
medication
at
the
right
time
and/or
quantity
to
prevent
infections.
Infections
may
have
occurred
on
a
day
the
calves
failed
to
eat
enough
medicated
pellets
to
obtain
the
desired
dosage.
Calves
in
this
group
con-
sumed
the
pelleted
feed
initially
containing
0.024%
of
monensin
reluctantly
and
this
may
have
influenced
their
susceptibility
to
the
coccidia.
All
5
calves
in
the
experimentally
infected,
non
-
medicated
control
group
4
discharged
oocysts,
some
more
than
others,
and
more
severe
clinical
signs
developed
in
some
animals
than
in
others.
The
hemoglobin,
packed
cell
volume
and
leucocyte
ratios,
as
well
as
the
Na
and
K
content
of
blood
serum
were
not
significantly
different
(P
>
95%)
in
any
of
the
groups
of
calves
regardless
of
the
treatment
regimen.
No
previous
data
are
avail-
able
that
correlate
such
measurements
in
calves.
It
was
found
previously
that
pronounced
changes
in
serum
Na
or
K
occur
in
calves
moribund
with
severe
coccidiosis
(2).
The
serum
total
pro-
tein
content
was
reduced
in
the
inoculated,
unmedicated
calves
of
group
4
beginning
when
clinical
signs
appeared.
This
is
similar
to
a
typical
change
reported
earlier
(1).
Unfortunately,
it
is
not
evident
from
this
experiment
what
stages
of
Eimeria
bovis
are
affected
by
monensin.
Shumard
&
Callender
(9)
have
shown
that
the
drug
is
effective
against
sporozoites
of
Eimeria
tenella.
In
other
studies
this
antibiotic
has
been
shown
to
be
highly
effective
against
infections
of
Eimeria
stiedai
in
the
livers
of
rabbits
(4),
apparently
affecting
the
sporozoites
as
they
move
into
the
liver.
MONENSIN
AGAINST
BOVINE
COCCIDIOSIS
125
1 1
1 1 1 1 1 111
SODIUM
150
140
I
f
130
E
120-
110
10.5
10.0
9.5
9.0
8.5
8.0-
7
7,5
a.
W
E
7.0
6.5
6.0
5.5
5.0
1.
Fig.
7.
The
Treatment
Started
1
251.4--.
Inoculated
POTASSIUM
Treatment
Stopped
I
I
II
I I
I
IN
I
7
WO
ON.
CD
NI
-
CO
N
C‘l
CV CV
rti
DATE
1
Na
and
K
serum
content
in
calves
inoculated
with
E.
bovis
and
treated
with
monensin
in
pelleted
feed.
I
cv
cv
126
MONENSIN
AGAINST
BOVINE
COCCIDIOSIS
REFERENCES
1.
Fitzgerald,
P.
R.
1964.
Deviations
in
serum
proteins
as-
sociated
with
Eimeria
bovis
infections
in
calves.
J.
Parasit.
50,
42-8.
2.
1967.
Effect
of
bovine
coccidiosis
on
blood
serum
sodium
and
potassium
levels
of
calves.
Am.
I.
Vet.
Res.
28,
667-70.
3.
1970.
Chemotherapy
of
coccidiostats
in
ruminants.
J.
Parasit.
56
(Sect.
II),
101.
4.
1972.
Efficacy
of
monensin
or
amprolium
in
the
prevention
of
hepatic
coccidiosis
in
rabbits.
J.
Protozool.
19,
332-4.
5.
Jolley,
W.
R.,
Hammond,
D.
M.
&
Miner,
M.
L.
1971.
Amprolium
treatment
of
six-
to
twelve
-month
-old
calves
experi-
mentally
infected
with
coccidia.
Proc.
Helm.
Soc.
Wash.
38,
117-22.
6.
Newman,
A.
J.,
MacKellar,
J.
C.
&
Davidson,
J.
B.
1968.
Observations
on
the
use
of
amprolium
in
the
treatment
of
acute
coccidiosis
in
calves.
Irish.
Vet.
J.
22,
142-5.
7.
Peardon,
D.
L.,
Bilkovich,
F.
R.
&
Todd,
A.
C.
1965.
Trials
of
candidate
bovine
coccidiostats:
Efficacy
of
amprolium,
linocomycin,
sulfamethazine,
chloroquine
sulfate,
and
di-phenthane-
70.
Am.
J.
Vet.
Res.
26,
683-7.
8.
Reid,
W.
M.,
Kowalski,
L.
&
Rice,
J.
1972.
Anticoccidial
activity
of
monensin
in
floor
-pen
experiments.
Poult.
Sci.
51,
141-6.
9.
Shumard,
R.
F.
&
Callender,
M.
E.
1967.
Monensin,
a
new
biologically
active
compound.
VI.
Anticoccidial
activity.
Anti-
microb.
Ag.
Chemother.
1967,
369-77.
References
to
the
Use
of
Cultures
of
Algae
and
Protozoa
A
sample
survey
of
the
literature
on
algae
and
protozoa
has
confirmed
the
impression
that
authors
do
not
always
give
ade-
quate
reference
to
the
strains
used
in
work
involving
cultures.
The
sample
used
was
the
1971
issues
of
14
journals
taken
at
this
establishment
which
publish
original
work
on
algae
and
protozoa.
Papers
dealing
with
fossils,
larger
seaweeds,
and
organisms
not
so
far
cultured,
were
excluded.
Minimum
adequate
reference
is
considered
to
be
the
designa-
tion
of
the
culture
together
with,
where
appropriate,
indication
of
the
source
collection
e.g.
CCAP
211/8d
or
Gottingen
11/6.
A
more
complete
reference
would
give
also
the
name
of
the
isolator
and
the
date
of
isolation,
but
this
information
usually
is
available
in
the
List
published
by
the
collection.
It
is
evident
from
the
survey
that
over
3
/
4
(153
out
of
204)
of
the
authors
used
cultures
when
this
was
possible.
It
is
evident
also
that
well
over
half
of
the
users
(89
out
of
153)
gave
inadequate
or
no
reference
to
the
cultures
used.
This
is
most
unsatisfactory,
especially
when
one
considers
the
rigid
insistence
by
authors
and
editors
on
proper
bibliographic
references.
References
to
specific
names
and
a
collection
e.g.
"Chlamy-
domonas
globosa
from
CCAP"
are
not
satisfactory
as
there
may
be
now,
or
in
the
future,
more
than
1
strain
fitting
that
description.
Also,
taxonomic
names
are
liable
to
revision
while
strain
designa-
tion
should
be
immutable.
References
such
as
"Tetrahymena
pyriformis
'W'
Strain"
are
inadequate
without
mention
of
the
source.
It
has
been
shown
recently
by
isozymal
tests
that
strains
of
this
species
from
different
sources
but
with
the
same
designa-
tion,
may
differ,
while
differently
designated
strains
may
be
iden-
tical.
The
cause
of
this
confusion
presumably
lies
in
mislabelling
and
failure
to
record
the
origin
of
stocks
used.
In
1
paper
there
was
a
serious
orthographic
error
in
a
strain
designation.
Among
the
advantages
of
using
properly
documented
strains
are:
(1)
that
the
work
can
be
repeated
or
compared
with
other
work
on
the
same
strain,
and
(2)
the
comparison
of
different
strains
of
a
species
or
of
different
species
of
a
genus
enables
one
to
assess
the
significance
of
the
particular
characters.
Too
often
one
sees
a
general
statement
about
a
species
made
from
evidence
derived
from
only
one
strain.
Wherever
possible,
cultures
of
new
taxa
or
new
strains
used
in
important
research
should
be
deposited
in
at
least
one
major
col-
lection.
It
is
also
of
great
value
to
a
culture
collection
to
receive
reprints
of
work
done
with
its
cultures.
—E.
A.
GEORGE,
Direc-
tor,
The
Culture
Centre
of
Algae
&
Protozoa,
36
Storey's
Way,
Cambridge
CB3
ODT,
England.
Note
from
the
Publisher
The
delay
in
the
publication
of
the
November,
1972
issue,
vol-
ume
19
(4),
was
caused
by
circumstances
beyond
our control
or
that
of
the
editor.
We
wish
to
apologize
to
the
subscribers
and
readers
for
this
delay
which
we
are
certain
will
not
recur
in
the
future.
—Allen
Press.