NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
RELATIONSHIP OF CLEAN WOOL YIELD WITH BODY
WEIGHT AND BODY SIZE IN BIKANER EWES *
By S. JAYARAMAN and GURBAX SINGH MAHAL, Government Livestock Farm, Hissar
(Received for publication on 14 August 1953)
S HEEP are maintained all over the world for mutton or wool or for both. It
is always the aim of the sheep breeder to increase the productivity of his flock.
In the selection of ewes for breeding purposes it is essential that the characters of
greatest economic importance be given the necessary emphasis. In order to effect
improvement in fleece weight, most of the breeders lay special emphasis on the
size and body weight as a basis for selection. How far this concept helps the breeder
has not so far been well established. A study of the relationship of clean wool
yield with the body weight and body size respectively will, therefore, be of great
importance and interest to the breeder who has to rely on these factors as a means
of improving wool production. With a view to solve this problem a study was
accordingly conducted on the Bikaner sheep at the Government Livestock Farm,
Hissar.
The present study is an attempt to work out the relationship between the fleece
weight on clean yield basis and the body weight and body size respectively, in
Bikaner ewes.
REVIEW OF LITERATURE
Spencer, el al. [1928] were able to find a fairly positive relation between body
weights taken after shearing at the age of one year and unscoured fleece weights.
Studies by Joseph [1931] relating to size of grade fine wool ewes on their produc-
tion showed progressive increase in weight of average lamb crops and fleece weights
with increase in the weights of ewes.
Hunt [1935] in his studies on the effect of size and type of ewe on efficiency of
production concluded that the data and analysis presented in his work lend support
in favour of size of the ewe.
Brody and Campbell [1938] from their studies of the relationship between body
weight and amount of wool showed that body weight is correlated positively to wool
production to a fairly high degree though some of the evidence indicated that this
was not entirely linear. Under certain conditions the largest ewes were poorer wool
producers than medium size ewes. This was related to the optimum size of the ewe
for range conditions where the amount of feed was such as to limit the production of
larger animals.
Gartner and Sternberg [1938] during their statistical studies made at the
Animal Institute, Jena, from flock books and records of performance of the large
*This paper is based on the report of the research problem conducted by S. Jayaraman in partial
fulfilment of the requirements for the Post-Graduate Diploma Course in Sheep Husbandry and Wool
Production jointly sponsored by the Indian Council of Agricultural Research and the Government of
Punjab at the Government Livestock Farm, Hissar.
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144 RELATIONSHIP OF CLEAN WOOL YIELD WITH BODY WEIGHT [Vol. XXIV, Part III,
mutton Merino flock of the Bendleben estate, noted that body weight at one year
was found to be significantly correlated to wool yield.
The relationship of body weight in the selection of yearling range ewes and their
later production of lambs and wool was shown by Terrill and Stoehr [1942] in a
study of 758 Rambouillet, Columbia and Corriedale ewes. Regardless of breed, the
larger ewes excelled in the amount of products obtained.
Jones, et al. [1944] in their studies on the influence of age, type and fertility in
Rambouillet ewes on fineness of fibre, fleece weight, staple length and body weight,
reported that the correlation of clean fleece weight and body weight was highly
significant.
Terrill [1939] found a correlation of 0.59 between yearling fleece weights and
lifetime yields.
Burns [1942] states that greasy fleece weight does not always tell the true
story of wool improvement.
Burns [1948] in a study of greasy and clean weights of Wyoming Range fleeces
reported wide variations in fleece production among individual sheep within flocks
and between different flocks. He further remarks that it supports the view that
culling and breeding programmes can accomplish a great deal even in flocks with
an already high fleece weight average, to bring all animals to a uniformly high
production and to increase the wool income per head,
MATERIAL AND METHODS
Material used in the study
Three hundred and forty one ewes in the flock of Bikaner ewes at the Govern-
ment Livestock Farm, Hissar, were used for the study. The group included 136
yearlings (known as ' female lambs '), 55 two-year old ewes, 44 three-year old ewes,
52 four-year old ewes, 14 five-year old ewes, 30 six-year old ewes and 10 seven-year
old ewes.
Representative fleece samples were obtained from all the selected ewes at the
time of October shearing in 1952 and were scoured in the wool analysis laboratory
attached to the Farm.
Methods employed in the study
Wool, as it comes from the body of the sheep, contains varying amounts of
grease, dirt, sand, etc. consequent to which the grease fleece weight is not a true
guide of the clean wool content of the fleece. Although higher fleece weight is of
great importance to the breeder, the actual value is to be given only to the clean
wool content which is obtained after scouring and deducting the shrinkage. It is
thus obvious that the amount of clean wool in each fleece is to be estimated in
considering the productivity of sheep. In the present study, therefore, it was
necessary to work out the clean weights of the individual fleeces of all the 341 ewes.
The only reliable and accurate method of arriving at the clean yield of a fleece
is to scour the entire fleece in a standard scouring solution and weigh the fleece after
thorough drying. Facilities for the individual scouring of all the entire fleeces being
146 RELATIONSHIP OF CLEAN WOOL YIELD WITH BODY WEIGHT [Vol. XXIV, Part III,
The carded samples were then divided into four batches of about 85 each for
the purpose of scouring as the scouring and drying facilities could not permit scour-
ing of more than 100 samples at a time.
SCOURING OF THE SAMPLES
The samples were all scoured by the emulsion process to determine the clean
yields. The method of scouring used was as suggested by Johnston [1934] with
slight modification suiting the nature of conditions. The percentage of soda was
reduced since the Bikaner wool is a carpet type wool and contains far less amount
of grease than fine wool for which the method was originally adopted by
Johnston [1934].
The scouring equipment consisted of three tubs. The first tub contained the
scouring solution while the second contained the rinsing solution and the third
mere soft water.
The scouring and rinsing solutions kept in the first and the second tub contained
the following:
TUB NO. 1.—Scouring solution
Scouring soap (' Lux' flakes)
Textile washing soda
Soft water
TUB NO. 2.—Rinsing solution
Textile washing soda
Soft water
8 ounces
4 ounces
10 gallons
4 ounces
10 gallons
The temperature of the solutions during scouring was kept between 120 and
125°F. The samples were washed in bags made out of mosquito curtain cloth.
They were thoroughly opened out before putting in the bags and each bag was put
in and immersed in the scouring solution and gently agitated, the action simulating
that employed in commercial mill practice. Each sample was thoroughly washed
by agitation in the scouring solution and the rinsing solutions respectively. In the
absence of a mechanical squeezer, the samples were squeezed by hand after taking
them from each tub. The temperature of the solutions was maintained steady
throughout. The concentration of soap and soda was also maintained steady by
renewing the solutions whenever necessary.
The scoured samples were then dried in the sun for two or three days in trays
care being taken to place an identity slip under each sample in the tray. After
thorough drying they were put inside the laboratory and each of them weighed once
daily until the weights on two consecutive days were constant. The final weight
thus recorded was taken as the weight after scouring and drying the sample. This
represented the clean yield of the sample.
The greasy fleece weights of all the entire fleeces were then reduced to clean
fleece weights by taking into account the shrinkage percentage of the concerned
hand sample of each fleece and calculating accordingly. The clean fleece weights
were all expressed in ounces.
September, 1954] S. JAYARAMAN AND G. S. MAHAL 147
Statistical analysis of the entire data was carried out on the lines suggested by
Amble [1953].
RESULTS
The correlation coefficients of the body weight with clean wool yield and of the
body size with clean wool yield were first worked out separately for the yearlings
and for each 'lambed' and 'not-lambed' group within each age group for the adult
stock. The results are given in Table I.
TABLE I
Correlation coefficients of body size and body weight with clean wool
Age
(nearest birthday in years)
1
2
3
4
5
6
2
3
4
5
6
7
Number
of
ewes
Correlation
coefficient
of body weight
and clean
wool yield
Yearlings
136
0.5868*
Adults (Not lambed)
24
15
20
5
13
0.3967
—0.2474
0.4288
0.2647
0.1837
Adults (Lambed)
31
29
32
9
17
10
0.3305
0.2770
0.0839
00122
0.5576†
0.1193
Correlation
coefficient
of body size
and clean
wool yield
0.2010†
0.4347†
0.0642
—0.0164
0.2438
0.2924
0.3139
0.1847
0.1347
0.1808
0.2603
0.3767
* Significant at 1 per cent level.
† Significant at 5 per cent level.
The estimated value of the correlation coefficients of the body weight and
clean wool yield for different age groups under the non-lambed group were tested
for homogeneity and as they were found to be homogeneous they were pooled.
Likewise, the value of the correlation coefficients of the body weight and clean
yield for the different age groups under the lambed group on testing proved homo-
geneous and were hence pooled.
148 RELATIONSHIP OF CLEAN WOOL YIELD WITH BODY WEIGHT [Vol. XXIV, Part III,
Similar results in the corresponding groups with regard to the body size and
clean wool yield were observed on testing for homogeneity and so the values of the
concerned correlation coefficients of each group were also pooled.
The pooled correlation coefficients in the order of the groups is given in Table II.
TABLE II
Pooled correlation coefficients in adult ewes
Sub-group
Not lambed
Lambed
Number
of
ewes
77
128
Correlation
coefficient
of body weight
and clean
wool yield
0.252*
0.260†
Correlation
coefficient
of body size
and clean
wool yield
0.221
0.228*
* Significant at 5 per cent level.
† Significant at 1 per cent level.
Subsequently the respective pooled correlation coefficient for the lambed and
not-lambed groups were tested for homogeneity. The pooled value of the correla-
tion coefficients for each group, viz. lambed and not-lambed, in respect of body
weight with the clean wool yield were not significantly different and. hence they
were also pooled.
Similar results were obtained in respect of the not-lambed and lambed groups
with regard to their respective values of the pooled correlation coefficients of body
size and clean wool yield. They too were then pooled.
The finally pooled correlation coefficients are given in Table III.
TABLE III
Finally pooled correlation coefficient in yearlings and adults
Class of ewes
Yearlings
Adults
Number
of
ewes
136
205
Correlation
coefficient
of body weight
and clean
wool yield
0.587†
0.257†
Correlation
coefficient
of body size
and clean
wool yield
0.201*
0.225†
* Significant at 5 per cent level.
† Significant at 1 per cent level.
September, 1954] S. JAYARAMAN AND G. S. MAHAL 149
DISCUSSION OF RESULTS
The fact that there exists a significant correlation between body weight and
clean wool yield and between body size and clean wool yield among the yearlings
as well as adults indicates that heavier and bigger sheep are likely to produce more
wool, although the correlation is not very high except in the case of yearlings with
respect to the body weight and clean yield. This finding is in conformity with
those of Spencer, et al. (loc. cit.), Joseph (loc. cit.), Hunt (loc. cit.), Brody and Camp-
bell (loc. cit.), Gartner and Strenberg (loc. cit.), Terrill and Stoehr (loc. cit.) and
Jones, et al. (loc. cit).
In the group of yearlings, where no culling had been performed as yet, the value
of the correlation coefficient of body weight and clean wool yield is significant at
one per cent level while that between body size and clean wool yield is significant
at five per cent level. In the adults, the correlation coefficient of body weight with
clean wool yield as well as that of body size with clean yield are both significant at
one per cent level.
The order of correlation between body weight and wool yield and body size
and wool yield, respectively, is more or less the same for different age groups in the
adults ; in other words this correlation does not depend upon age.
The order of correlation for lambed and not-lambed classes are also not signi-
ficantly different.
The body weight and wool yield in the yearlings are correlated to the order of
0.587 which indicates that a proportion of (0.587), 2 i.e. about 34.46 per cent of the
variation in wool yield of different yearlings can be attributed to the variation in
body weight. This correlation is fairly high as compared to that of the adult stock
and is probably due to the fact that the yearlings include all lambs of different
sizes and weights none of them having been culled while the adult stock includes
only the selected animals excluding the under-sized and under-weight ewes which
were culled as yearlings before they were transferred to the adult stock. A fairly
high correlation between body weight and clean wool yield is a good indication for
the selection of high wool producing yearlings as replacement stock based on the
body weight alone.
SUMMARY AND CONCLUSIONS
The problem was designed to find out the relationship between clean wool
yield of Bikaner ewes and their body weight and body size respectively.
Three hundred and forty one ewes were chosen for the problem. The ewes
were from all ages commencing from the yearlings to the age of seven years. For
the purpose of classification, they were divided into separate age groups and the
adults were further subdivided into two groups within each age group according to
whether they had lambed during the season or not. The group also included 136
yearlings.
Representative samples from the fleeces of the ewes were taken, scoured and
the yield worked out for the entire fleeces from the yield percentage of the respective
representative samples. The body length from the point of the shoulder to the
point of the ischium, and the chest girth just behind the point of the elbow were
METHODS OF ANALYSIS OF WOOL FIBRE FOR
DIMENSIONAL ATTRIBUTES
By K. N. RAMCHANDRAN and P. R. YERI, Wool Research Laboratory, Poona
(Received for publication on 17 June 1953)
(With Plates VI to VIII)
A VARIETY of textile materials are processed out of wool depending on its
quality. Quality of wool is the cumulative effect of fineness or diameter,
length, waviness or crimps, hairiness and fibre density or packing of fibres on the body
of sheep. These measurable attributes of wool quality have a direct bearing on
the value of fleeces and guide the sheep breeders for improvement of their flocks
for yielding finer and better fleeces. The wool buyer is also guided by some of
these attributes while buying wools, which will suit manufacturers' requirements
to process for different types of fabrics. The methods of analysis for each of the
characteristics of wool fibres are detailed below.
Sampling of wool
It is necessary to obtain a reliable estimate of wool quality; analysis of all the
fibre populations either on the body of the sheep or for a bulk is not practicable.
Hence the usual procedure is to draw samples of fibres which will be representative
of the original bulk samples. The methods of sampling are :
(i) Sampling from a sheep. From each of the six regions of neck, wither,
shoulder, side, back and britch, wool fibres from an area of 3 in. x 3 in are clipped
from one side of the sheep (because of the bilateral symmetry) and this constitutes
a sample for each region.
(ii) Preparation of the sample. The sample is washed free of grease with benzene
and then in distilled water. This sample is divided into sixteen zones by process of
halving, without disturbing the natural arrangement of fibres. From each zone
a sheaf of about 50 fibres is drawn from the basal end, and sixteen sheafs of fibres
thus drawn are pooled together to form a final sample from a single region for the
assessment of the attribute under study.
(iii) Sampling from a commercial bale. Eight pickings each of approximately
2 oz. are drawn at random from the different portions of the bale. These samples
are well mixed lockwise and divided into 16 zones by successive halving. The
locks from each zone are spread out and superimposed over one another in order
to set the basal portion in a straight line. The spread of the lock shall be six inches
in length at the base. This arrangement of the locks is placed on a black velvet
board against a steel rule and bunches of approximately 50 fibres are drawn at random
from each of the zones. The 16 drawings are pooled together to form the final
sample for the assessment of the attribute under study.
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