M. Salehi. Scientific member of Animal Science Research Institute of Iran Department of Animal Science, Faculty of Agriculture, University of Kerman, Kerman, Iran Topic The effect of shearing time on wool Traits in Baluchi sheep. The effect of shearing time on wool Traits in Baluchi sheep.
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The effect of shearing time on wool Traits in Baluchi sheep
M. Salehi and M. Asadi Fozi
Scientific member of Animal Science Research Institute of Iran
Department of Animal Science, Faculty of Agriculture, University of Kerman, Kerman, Iran
There are 2.034277 million tons of wool that produce by more than 1000 million head of sheep with different breeds
classified as follows
Coarse and long wools
A: Improved Carpet wool
B: Unimproved Carpet wool Or Mixed
2 - Diameter (MFD)
3 - Mean fibre length (MFL)
4 - Medullation
5 - Cuticle or scale
The most value belongs to white color but there are a wide range of
Color between Unimproved wool sheep
(60s and finer)
(5 -10 cm)
30 -43 micron
(36 - 50s )
(15 -37 cm)
The other important difference between improved and unimproved wool are ratio and type of medullation in fleece and scale pattern of fibers
Unimproved or native
(18- 40 micron)
of carpet wool
Average fibre diameter (MFD) and its variation (CV) also staple strength (SS) are important raw wool characteristics that greatly influence wool processing properties such as the length of fibres (Hauteur and Barbe).
Staple strength (SS) appears to be related to minimum fibre diameter (FD) along the staple, although there is some evidence that the rate of change in fibre diameter (FD)
may also be involved.
Therefore CV of fibre diameter (FD) is usually used as a criterion for staple strength (SS) in wool sheep breeding program (Safari et al. 2005).
Seasonal wool production appears to be largely responsible for variation in staple strength (SS), mean fibre diameter (MFD) and it's CV.
The lowest wool production tends to occur in autumn and winter growth in almost all sheep that rearing in tropics regions and to be sever with lambing. (Butler and Head, 1992 & Henderson, 1967).
Since the shape of the fibre depends on where it is cut at shearing, one strategy is to aim to shear at weakest point in fibre. There is considerable evidence that shearing ewes just prior to lambing is a useful means in staple strength (Arnold et al. 1984)
According to Summer (1994) report, clean fleece weight of twice shorn was greater than of once – shorn ewes and mean staple length (SL) of the fleece reflected the interval between shearing and seasonal wool growth.
Autumn shearing may be associated with a vegetable matter fault and it could result in a bigger financial loss than that due to reduction in mean fibre length (MFL) due to tenderness (Lock, 1994).
Also once - shorn wool was more discoloured than twice – shorn wool. Average net wool returns were greater for once – shorn than for twice – shorn ewes (Summer, 1994).
Records on 9535 shearing ofBharat Merino sheep indicated that sir, period of shearing, age, season of shearing and period of birth all had significant effects on greasy fleece yield (Tomar, 2000).
The main objective of this study were:
the effect of the number of shearing on the fleece traits in Baluchi sheep.
Iran population sheep's are over 50 millions heads and approximately
65 million kg grease wool or 30 – 33 million kg clean wool have been produced
Baluch sheep breed content 19% of Iran population sheep's
of Iran under
Baluchi sheep have white wool but black patches on face, around the eyes, ears, lower legs and hands
Usually is shorn twice per year; in spring and late summer while some breeders sheared their flocks only once per year.
Abas Abad sheep station which is situated in Khorasan in North of Iran is used for supporting research on Baluchi sheep.
(In this station some economic traits such as bodyweight and fleece are measured annually).
The first group was shorn only once per year in spring while the second group was shorn twice, in spring and late summer.
But fleece samples were taken from the animals in both groups twice per year i.e. in spring when both group were shorn and in late summer when only second group was shorn.
The experiment was implemented for two years.
The fiber samples (20 gram) were taken from right mid-side of 52 Baluchi sheep.
The fibers was prepared and cut for measurement
with the projection microscope
The sub sample was paralleled in fibro liner to determine the Simi rigid length in Almeter (Hauteur and Barbe length items)
A number of fibres so that, a specimen of 15 to 25 mg is available for testing was prepared.
The clamped tuft were placed in the grips of tensile testing machine (Instron) and used 1 N capacity load cell with the pulling clamps moved at 25 cm/m. Breaking tenacity calculated (ASTM.D-1294 ).
The repeated measurement and general liner model (GLM) was used for the analysis using SAS software package (SAS / STAT User’s Guide, 1987).
The spring FW in group 1 was significantly higher than group 2.
But the difference was due to one more shearing in group 2 that was performed in the previous autumn.
Significant difference was found for SL and CV of SL between the two groups.
SL and CV of SL of group 1 was higher than those in group 2
Changing shearing time can change staple strength in some circumstances but in this search didn't show any significant different between major wool performances expect length and their CV.
But it is not doubt that shearing before lambing has been improves wool characteristics, However in Iran it is not occur because cold weather in late winter the time of lambing.
The authors wish to thank
The conference organizer
The farm staff at Abas Abad station
Thanks also to the technical staff of Animal Science Research Institute of Iran