regulation in working llamas - phase two
Part one of this study was
conducted in 1991, and a preliminary report was published in
the June 1992 issue of The Backcountry Llama.
Our 1996 study was structured primarily to
assess the relative effectiveness of partial shearing and full
body shearing. Although we had limited access to llamas with
certain fiber characteristics, we were fortunate that variations
in the llamas selected allowed at least two llamas representing
any given pertinent feature to be compared with at least two
dissimilar llamas. As a result, we could compare the effects
of wool density on both shorn and unshorn llamas.
We selected six llamas: Llamas A and C both
had coarser fiber with lower density and open chest, and llamas
B and D had finer fiber with higher density and wool closure
over the chest. Control llamas E and F both had coarser fiber
with lower density and open chest area and were selected because
of previously proven successful thermal regulation. Llamas A,
B, and E were moderately overweight. Llamas C, D, and F were
in good condition. All llamas had been completely combed out
the previous year.
- 8 years
- gelded male
- white with <5% orange
- 4.5" wool fiber length, moderate density,
open; 32.0 microns average with 16.1 microns SD
- 45"/344 lb
- 5 years
- gelded male
- black with est 25% white
- 5" wool fiber length, high density,
full wool closure; 25.4 microns average with 10.1 microns SD
- 45"/352 lb
- est 6 years
- gelded male
- orange with <20% white
- 5.5" wool fiber length, low-moderate
density, open; 32.3 microns with 16.7 microns SD
- 42.5"/237 lb
- 10 years
- gelded male
- white with <5% black
- 4.5" wool fiber length, high density,
moderate wool closure; 24.7 microns with 9.1 microns SD
- 43.5"/309 lb
Llama E (control):
- 12 years
- intact male
- 4" wool fiber length, low-moderate fiber
density, open; 29.2 microns average with 12.9 microns SD
- 43.5"/318 lb
Llama F (control):
- 8 years
- intact male
- grey with <20% white
- 6" wool fiber length, low fiber density,
open; 36.5 microns average with 18.4 microns SD
- 44.5"/282 lb
was first estimated by hand (subjective comparison of relative
force necessary to compress the living fleece). Total fiber from
the four shorn llamas was later weighed, raw data corrected for
total fiber length, and amount of fiber removed, and a figure
was derived allowing direct comparison of density between fleeces.
The subjective hand estimation correlated in all cases with the
mathematically derived figures.
were submitted to Yokom-McColl testing laboratories for determination
of average fiber diameter and standard deviation.
measured with the llamas standing on concrete and using a four-foot
leveling device. This method yields repeatable data accurate
to within .125".
recorded at the end of the study using a digital electronic scale.
Weights were rounded to the nearest pound and were not corrected
for probable feed and water intake fluctuations.
All six llamas first contributed at-rest baseline
data in the morning before rising and in the hottest part of
the afternoon. Ambient temperature, location, position (standing
or kushed), and activity level were noted. Humidity measurements
were unavailable, but relative assessments were recorded.
Following accumulation of baseline data, overweight
llamas A and B were shorn over approximately 50% of their bodies
to an average length of 1.5-2". Densely-fibered llama B
was shorn in a "barrel cut" pattern (a current fad);
moderately-fibered llama A was shorn with the reverse: a "muscle
cut." After further at-rest data collection, the remaining
fleece from both llamas A and B was removed, and final data were
Above: Llama B with full body cut plus belly shave
Llamas C and D participated in postexertion
temperature recovery studies. Following initial body temperature
readings, each llama ran with a handler for one mile. Both llamas
were run consectutively by the same handler to eliminate data
contamination by different running speeds and weather conditions.
Llama temperatures were then recorded every five minutes for
one hour postexertion. One run was conducted in the evening (with
cooling conditions), and two runs were conducted mid-day.
Llamas C and D were then shorn in the same
patterns as llamas A and B, but to an average length of 1.25."
This time, moderately-fibered llama C received the "barrel
cut" and densely fibered llama D received the "muscle
cut." Again, pasture data were collected, followed by postexertion
data collection conducted in the same manner as when llamas C
and D were in full fleece.
Above left: Llama C with "barrel cut"; Above
right: Llama D with "muscle cut"
After pattern-shorn postexertion data collection,
llamas C and D were fully shorn. At-rest and postexertion data
collection were again repeated in the same manner.
To complete the study, densely-woolled, "closed,"
and "hot" llamas B and D's undersides were shaved to
the skin and at-rest data recorded. Then, "hot" llama
D and control llama E were combed out and final at-rest temperature
data on all six llamas were recorded.
At-rest body temperatures
Initial data were taken in moderate weather
with an average ambient morning temperature of 48° and an
average ambient afternoon temperature of 68°. Initial results
showed that llamas B and D (whose only common features are dense
wool and wool closure) were consistently hotter by an average
of 1° in the morning and .5° in the afternoon.
After barrel cuts and data taken at comparable
ambient temperatures, llamas B and C were still hotter by an
average of .5° in the morning, but both were insignificantly
different from the controls in the afternoons (although dense-wooled
llama B was in fact consistently hotter than llama C). However,
both of the controls were markedly more active and were often
in the sun; llamas B and C were more often standing in the shade.
Compared with data taken in full fleece, dense wooled llama B
was cooler (.3° average), but llama C was not significantly
After muscle cuts and data taken at comparable
ambient temperatures, llamas A and D had average morning temperatures
identical to the controls; however, both were hotter than the
controls in the afternoon by an average of .4°. Compared
with data taken in full fleece, dense-wooled llama D averaged
a full degree cooler than before, but llama A showed no significant
All partially shorn llamas either posted their
coolest temperature or initially moved to a substantially warmer
location the morning after shearing. Also, all partially shorn
llamas began to seek shelter during rainstorms after shearing.
Although we anticipated such behavior based on previous results
(1991), the change was abrupt and unexpected given the moderate
rainfall amounts. Llama B, densely wooled and with the greatest
amount of fleece remaining (2 inches) proved least likely to
seek shelter by several days postshearing.
After full body cuts, morning and afternoon
temperatures for the shorn group did not differ significantly
from those taken when partially shorn, either as averages or
when compared individually. This is significant in light of the
markedly hotter weather (average ambient morning temperature
55°; average ambient afternoon temperature 96°). The
shorn group was slightly hotter than control llama F (control
llama E's data had to be discarded because he was markedly more
active in the pasture than the rest of the group). Despite the
heat, llama C began to preferentially spend afternoons in the
sun rather than the shade after being fully shorn, which is also
a significant behavioral change.
After belly shaves, llamas B and D posted
their lowest individual morning temperatures up to that time,
but with no change in afternoon temperatures. Unlike postshearing,
both llamas B and D did not have lower temperatures initially,
but they showed a steady decrease over the course of several
days. This implies that wool closure affects the ability of a
llama to disperse heat during the night and thus has a cumulative
effect in increasing body temperature.
After combing (llama D and control llama E
only), the group as a whole had very similar temperatures for
both morning and evening except for uncombed, dense-wooled llama
B, whose average morning temperature was still .7° above
the group average and .5° above the next highest of the group
(llama D). Llama B's afternoon temperatures were comparable,
but he was less active. Combed-out llama D became markedly more
active at this time and also spent more time in the sun.
In summary, it is apparent that densely-wooled
llamas benefit significantly from shearing, but that llamas with
moderate to low-density fleeces do not benefit significantly
at rest. Any shearing -- partial or full -- did result in habit
changes and obvious discomfort during inclement weather. Full-body
shearing proved superior to partial shearing for heat dispersal
at rest. Finally, fiber length did not prove to be an important
factor in heat retention (the coolest llama of the group also
had the longest fiber), but fiber fineness still appears to play
a contributing role in that fine fiber is necessary to maximize
Postexertion temperature increase and recovery
Initially, llamas C and D were run in full
fleece at an average ambient temperature of 92°. Dense-wooled
llama D began hotter than llama C and also proved to be comparatively
inferior in postexertion heat dispersal. After one markedly humid
run, llama D's temperature continued to climb rapidly to reach
a potentially dangerous level, and so he was cooled and data
were discarded from that run.
Llama C then received a barrel cut and llama
D received a muscle cut. Three days postshearing elapsed before
running to allow body temperatures to stabilize. The average
ambient temperature was cooler (75°), and so data were directly
comparable only between llamas and not with data taken in full
fleece. Despite the unfortunate difference in ambient temperatures,
it was clear that llama D benefited more from his muscle cut
than did llama C from his barrel cut during exertion. However,
the muscle cut was markedly inferior to the barrel cut for postexertion
Both llamas C and D were then fully shorn
to 1.25" of fiber. Again, three days postshearing elapsed
before running to allow body temperatures to stabilize. The average
ambient temperature was 84°.
With identical sheared areas, dense-wooled
llama D's statistics were once again contoured similarly to llama
C's, but the overall average temperatures were as proportionately
inferior as when both llamas were in full fleece, with one exception:
llama D now dispersed significantly more heat (1.1° compared
with .5°) postexertion with his full body cut. Overall, llama
C gained little by being fully shorn and did not benefit as much
as did llamas who were combed out (including llama D) in the
1991 study. Llama D did not benefit as much from shearing as
from combing but did benefit significantly when fully shorn.
The 1996 data clearly showed that a llama
who is cooler when at pasture will also be cooler after exertion.
As in the 1991 study, individually considered and averaged data
again fully support that wool fineness and density -- not fiber
length -- play the primary roles in heat retention. Llamas with
lower fiber density (natural or acquired) and coarser fiber consistently
managed heat better. Those llamas also benefited comparatively
little from shearing; dense, fine-fibered llamas benefited most
from a combination of shearing and combing.
The 1996 data also showed conclusively that
when dense-wooled llamas are shorn with the objective of attaining
adequate heat dispersal both during and after exertion in warm
to hot weather, the entire body should be shorn (1-1.5"
remaining), the belly shaved to the skin, and the remaining fleece
should be combed out as well. Observation of the study llamas'
behavior as well as data taken in mildly inclement weather during
the 1996 study indicates that provisions should be made to adequately
shelter and protect shorn llamas from the elements.
This report originally appeared in The
Backcountry Llama, April 1997, and appears here with the
permission of the author. Reproduction in any form is prohibited
without the express written consent of the author. Address permission
requests to: email@example.com
Copyright © 1997 by Gwen Ingram. All
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