Evaluation of mohair quality in Angora goats from the Northern dry lands of Tajikistan

Published Date
June 01, 2017
Type
Journal Article
Evaluation of mohair quality in Angora goats from the Northern dry lands of Tajikistan
Authors:
Farkhod F. Kosimov
Matazim A. Kosimov, Barbara Rischkowsky, Joaquin Pablo Mueller

Mohair quality of Angora goats in the Sogd Province of Tajikistan was assessed in spring
and autumn 2007 and 2008 by inspecting and sampling a total of 797 goats of both sexes,
different ages and several coat colors from 15 randomly selected flocks. Fiber fineness was
assessed visually on the Bradford scale, staple length was measured with a ruler. Midside
fleece samples were analyzed with an OFDA instrument to determine average fiber diameter,
standard deviation, coefficient of variation (CVFD), comfort factor, fiber curvature and
fiber length. On a subset of 153 goats, kemp and med fiber percentage were determined
inspecting 300 fibers of each goat with a projection microscope. Mixed model procedures
were used to analyze the data. Residuals of the model were used to calculate correlations.
The random flock effect was significant for all traits and the fixed sex, age, and color
effects were significant for most traits. In spring shearing data, fiber diameter of males was
2.7 m coarser than females and increased with age: 27.3 m (1 year old), 31.3 m (2 years
old), 34.6 m (3–5 years old) and 37.0 m (6 years and older). Mohair fiber length ranged
137.3–174.7 mm between ages. Six-month-old kid mohair (autumn shearing) was finest
(24.4 m) and shortest (95.1 mm). White mohair was approximately 3 m coarser than
brown and gray mohair. CVFD was not affected by sex and age but related to color with
white mohair having a lower CVFD. Comfort factor and visual Bradford count decreased
with age. Average med and kemp percentages were 0.88 and 0.34. Almost 20% of goats had
2% or more medullated fibers. The phenotypic correlation between fiber diameter and med
percentage was 0.40 and between fiber diameter and kemp percentage
−0.08. On average,
visual Bradford count underestimated fiber diameter by about 4.1 m. The correlation
between fiber diameter and Bradford count was
−0.28. Thus, visual assessment of fiber
diameter is imprecise and reduction of fiber diameter through selection would therefore
require analysis of fleece samples. The correlation between staple length and fiber length
was 0.78. Thus, ruler determination of staple length measured on the live animals is a good
estimator of fiber length measured on the fleece sample. In comparison with South African
mohair, Tajik mohair is not only white, has long fibers, is rather coarse and medullated.
Given the high variation between and within flocks in fiber diameter and medullation there
is room for culling inferior animals and improve current mohair quality

Citation:
Farkhod F. Kosimov, Matazim A. Kosimov, Barbara Rischkowsky, Joaquin Pablo Mueller. (1/6/2017). Evaluation of mohair quality in Angora goats from the Northern dry lands of Tajikistan. Small Ruminant Research, 113 (1), pp. 73-79.
Keywords:
kemp
fiber
medullation
correlation
fiber diameter
selection