Winter - Classical Mileend Alpacas

Fibre Curvature
fi neness being the most universally
accepted valuation of animal fi bre), in
the international market is based on
1999 prices. Figure 10:22 (see title page)
will have more signifi cance later in this
article.
IS CURVATURE THE SAME AS CRIMP
OR CRINKLE OR IS IT SOMETHING
ELSE?
Are crimp and curvature synonymous
terms? To many alpaca owners crimp is
the easily visible, attractive, uniform,
corrugated look they may see when
they part a huacaya’s fl eece. This is a
commonly accepted defi nition in the
United States, Australia and England. It is
a common alpaca fl eece characteristic and
was often present in entire populations
of alpacas that I screened in the Andes. If
someone handling an alpaca and parting
its fl eece looks closely they will see that
the uniform undulations in one animal’s
fl eece are often slightly (or markedly)
different from the next. Crimp may appear
in high frequency (many undulations
per centimeter) or in low frequency
(fewer undulations per centimeter) and
it may appear in different amplitudes.
Deep crimp has high amplitude (deeper
undulations), and shallow crimp has
low amplitude (lower undulations). The
curvature measurements for different
types of crimp can range greatly.
Crinkle is a term used to describe a
type of crimp. When an alpaca’s fl eece
is parted not all of them have the crimpy
corrugated look, some possess fl eeces
characterized by a soft cotton-like look.
These crinkly fl eeces may have a great
deal of fl uffi ness and curvature in the
individual fi bres while other crinkly
fl eeces are fl at, coarse and undesirable. It
is well documented that as fi bre coarsens
Chaku is a two-year-old
alpaca with a good overall 3 histogram. In this histogram
we see the usual measurements:
mean fi ber diameter (MFD),
standard deviation (SD),
coeffi cient of variation (CV),
and fi bers greater than 30. For
Chaku all of these measurements
add up to a pretty nice fl eece.
A thanks to Yocom-McColl
Testing Laboratories, which has
expanded its testing capability
this histogram also includes
information on a wide range of
other useful measurements to the breeder. There are two fi ber diameter profi les. The fi rst one is the mean
fi ber diameter (MFD) the second one (darker) identifi es medullation in the sample. Medullation can only be
assessed in light fl eeces. In general medullation studies show alpacas have more medullation (hollow core, or
partially hollow core) than other animals of comparable micron ranges. Medulla (hollowness) in alpacas can
occur in fi bers as low as 18 microns. Chaku has an impressive spin fi neness of 20.3 microns. His curvature of
32.7 deg/mm is at the mean range for alpacas. Chaku’s fl eece appearance shows a uniform waviness known
commonly as crimp, in this case low frequency and fairly low amplitude. His curvature/micron relationship
does not coincide with Table 1 in the Case for Crimp article cited in the text.
48 Alpaca World Magazine Winter 2004/05
it loses curvature. Loss of curvature is the
usual consequence of aging, even when
coarsening is not pronounced. Huacayas
with the cotton-candy look fl eece type are
often said to have crinkle instead of crimp.
Another defi nition of crimp does not
distinguish between crinkle and crimp.
This defi nition views all curvature of
any kind regardless if it has uniform
undulations or not. Many fi bre scientists
refer to all curvature as crimp while many
breeders distinguish between crimp
and crinkle. In The Complete Alpaca
Book examples of several types of crimp
and crinkle are presented in close up
photographs mentioned earlier and
in places medullation and density are
discussed. Vicuña falls into the crinkly
category because its fl eece doesn’t
appear to have uniform undulations
common to many alpacas. Many alpacas
also have crinkly fl eeces. The results may
4
surprise you when you test your fl eeces
for curvature (a test that can be added to
ahistogram with some testing labs).
Taking two-millimetre snippets and
measuring the angle (or degrees) per
millimetre determines average Fibre
Curvature (AFC). The greater the frequency
of degrees (or angle) per millimetre the
fi ner the crimp (defi ned as any type of
curvature i.e., crimp or crinkle). There
is a complicated formula that converts
degrees to millimeter (deg/mm) to crimps
per linear measurement. With most
animal fi bre the fi ner the fl eece the more
crimps, but this is not always true.
HIGH CURVATURE FLEECES MAY NOT
ALL LOOK THE SAME
The argument for crimp style goes
something like this: open the fl eece and if
it has a certain look it will guarantee all
other things: density, fi neness, length etc.
Chiki is a two-year old
alpaca with a generally
impressive standard
histogram, represented in the
mean diameter (MFD), standard
deviation (SD), coeffi cient of
variation (CV), and spin fi neness
(SP). Medullated Fibers (MF)
make up a small portion of
the fl eece but the medullated
profi le probably indicates
this animal’s fl eece will
coarsen with time (dark profi le
shows micron range where
medullation currently occurs).
This animal’s deg/mm is marginally above the mean for alpacas. Chiki’s fl eece appearance shows bundling
and fairly high frequency with medium amplitude crimp.