NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
E. J. BRUEN 201
7. Miscellaneous notes in the study of wool quality
Monthly growth of wool in two extreme types of Deccan sheep.—In the
Deccan, shearing is done twice a year. The shepherd believes that the wool
breaks off if left over to grow for the whole year. As stated in the previous
studies the fleeces of the Deccan sheep are in general of the ' C ' grade type
segregated on the farm. The difference in wool quality from the point of
growth will easily be seen by comparing figs. 1 and 2 on Plate XVII.
It is of great importance to study the problem of breakage of wool in the
selection of the stud stock. The continuous growth of wool mainly depends
upon the breed and the feed and to some extent on climate. This year a test
experiment was carried out on the shoulder wool of the two types of Deccan
sheep to study the monthly growth. The ewes were kept without shearing
till the end of the year. Samples were taken from the month of July when
it was possible to clip the wool properly. It must be noted here that the
reading of length for a particular month denotes the growth of the staple
of the previous month.
The whole tuft taken as a sample was analysed on the basis of the fibre
type as mentioned previously, and every type of fibre was measured for length.
A hundred readings for length of each type of fibres were recorded and the
mean, standard deviation and coefficients of variation were calculated.
These statistical constants are given in Tables XI and XII.
TABLE XI
Table of constants for monthly growth of length of fibres (non-breaking type ♀ No.4)
Months
July
August
September
October
November
December
January
Fine fibres
Mean
2.41
2.56
3.38
4.06
4.03
4.75
4.55
S.D.
0.83
0.34
0.40
0.47
0.41
0.53
0.64
C.V.
34.44
13.28
11.84
11.58
10.17
11.16
14.07
Strong fibres
Mean
3.17
3.68
4.61
5.22
5.28
6.04
5.79
S.D.
0.36
0.35
0.34
0.50
0.61
0.70
0.73
C.V.
11.36
9.51
7.38
9.58
11.55
11.59
12.61
Heterotypes
Mean
2.51
2.31
3.17
3.33
2.86
2.94
4.09
S.D.
0.55
0.61
0.91
1.04
1.31
1.22
0.86
C.V.
21.92
26.40
28.70
31.23
45.81
41.51
21.27
Kemps
Mean
1.68
1.25
1.54
1.96
1.73
1.82
1.78
S.D.
0.42
0.31
0.59
0.25
0.44
0.43
0.51
C.V.
25.00
24.80
38.32
12.76
25.44
23.62
28.65
TABLE XII
Table of constants for monthly growth of length of fibres (breaking type D ♀ No. 44)
Months
July
August
September
October
November
December
January
Fine wool fibres
Mean
1.42
1.62
1.81
2.20
1.56
1.40
2.07
S.D
0.16
0.18
0.18
0.27
0.34
0.28
0.39
c.v.
11.19
11.11
9.95
12.27
21.80
20.15
18.84
Hairy fibres
Mean
1.07
1.03
1.22
1.05
1.06
0.85
1.12
S.D.
0.20
0.21
0.20
0.27
0.15
, 0.40
0.45
C.V.
18.69
20.39
16.39
25.71
14.16
47.07
40.18
Kemps
Mean
0.99
1.14
1.13
1.10
0.89
0.97
0.94
S.D.
0.27
0.30
0.26
0.28
0.22
0.17
0.32
C.V.
27.28
26.31
22.82
26.46
25.00
17.52
34.18
Remarks
Month of maximum
growth. Month in which shedding
takes place.
202
Wool Quality as the Basis of Individual Selection
Fig. 6. Monthly growth of fibres of different types in the ' A ' grade Deccan sheep.
The above diagrams will clearly show that the ' C ' grade wool breaks off
in October while in the ' A ' grade the growth is slightly retarded. The maxi-
mum growth attained in the ' C ' grade is 2.22 in. in August, but the staple
suddenly breaks in the month of September. It recoups its length only in
January, while the fine fibre drops in length from 2.20-1.56-in. in October
and then makes a sudden growth to 2.07 in. in December. These results
show that the ' C ' grade wool breaks off definitely once in a year, while the
' A ' grade wool has a distinct tendency of developing into a non-breaking type,
E. J. BRUEN 203
Fig. 7. Monthly growth of fibres of different types in ' C ' grade Deccan sheep.
Percentage of clean wool yield.—This factor is not of much importance
in the case of the Deccan sheep which are washed prior to shearing. But
it is necessary to calculate the yield of wool for the Merino and the cross¬
breds which are highly conditioned. A statement of weights of fleeces from
the shearing yard is of little importance in estimating the yield of wool per
animal. Dr V. Bosman, Senior Wool Research Officer of South Africa, was
kind enough to help the authors with the details on this subject. The method
was studied with the help of the apparatus from the Chemistry Research
Laboratory of the Agricultural College, Poona. The following yields of wool
were estimated for the Merino and cross-bred rams.
Breed
Cross-bred No. 1
Cross-bred No. 2
Merino ram
Merino ewes
Yield (per cent)
49.14
65.73
47.63
49.26
204
Wool Quality as the Basis of Individual Selection
Percentage of grease.—The percentage of grease in a fleece is associated
with its quality. Secondly, it has a bearing on the feed and environment.
It is essential to know the details of grease extent in Merino or cross-bred
sheep so that the effect of breeding these in India can be fully gauged. This
point of study has been included in the proposed wool-testing branch. The
following estimation of grease in the three breeds of sheep on the farm was
carried out along with the clean wool yield. These readings are of great in-
terest as a comparison in these breeds on the farm, including the segregated
Deccan types.
Breed
Grade A
Grade B
Grade C
Cross-bred rams
Merino rams
Merino ewes
Grease content
(per cent)
4.30 to 4.96
3.51 to 4.19
2.69 to 2.93
7.11 to 11.48
19.00 to 23.74
9.40 to 13.29
Density of fleece.—The density of fleece is expressed as the number of
fibres per unit area. This has a direct bearing on the fineness and yield of wool.
The details of estimation of density with the help of the 'Wyedena Wool Caliper'
was studied from the information and calipers supplied by Dr V. Bosman.
The following readings for the three breeds on the farm will be interesting as a
comparison.
Breed
Merino ram
Cross-bred ram
Cross-bred ram
Deccan ram
No.
No.
1
2
Density shoulder
wool
(per 4 sq. cm.)
20392
10080
7109
2292
E.
J.
BRUEN
205
Sheep Breeding Scheme, Poona
Individual and progeny record
Parents
Med %
Class
Reg. No.
.
.
Sire
Breed
Re.
No.
Breed
Sire
Dam
Dam
Breed
Re. No.
Med %
Breed
Shearing
Date
Fleece-
weight
Class
Reg.
Wool yield
No.
Sex
Progeny
1st shearing
Med% C. W.
Individual
Ewe
Ram
Med%
Quantity
2nd shearing
Med%| C. W.
Regd No.
3rd shearing
Med% C. W.
Remarks
(Retained....*)
(Disposed....†)
206
Wool Quality as the Basis of Individual Selection
MEDULLATION
Zonal analysis of the Ram/Ewe Regd. No.
NUTRITIONAL EXPERIMENTS WITH CHICKENS
BY
A. J. MACDONALD, B.Sc., B.Sc. (AGRI.), N.D.A.
Poultry Research Section, Imperial Veterinary Research Institute, Izatnagar,
U.P.
(Received for publication on 1 April 1941)
INTRODUCTION
I T is now widely recognized that cereals and their by-products do not alone
supply all the necessary nutrients for normal growth in chickens. The
feeding of cereals without protein and mineral supplements, especially during
the early stages of growth, invariably results in slow and uneven growth,
high mortality and poor food utilization. In western countries, where poultry
keeping is most highly developed and specialized, it is customary to make good
the deficiencies in cereals by supplements of suitable animal or vegetable
proteins and minerals.
The poultry industry in India is, however, very different from that in
western countries for there is practically no specialization of production, the
birds usually being kept in very small flocks under the most primitive con-
ditions of housing, feeding and management. The chickens are hatched under
hens and are fed limited amounts of small grains during the first few weeks of
their life, but, thereafter, it is not customary to feed any appreciable amounts
of food. From a few weeks of age onwards the birds are allowed to roam freely
in search of their own food and pick up such materials as household scraps,
fallen grains and various forms of small animal life. Such methods of
rearing are very unsatisfactory, for the mortality during rearing is usually
very high (50 per cent is a common figure) and the rate of growth is very much
lower than that obtained under western conditions.
In view of the lack of knowledge regarding chick nutrition under Indian
conditions, a series of experiments were carried out to investigate the growth-
promoting value of various supplements in the diet of chicks fed on a standard
basal diet consisting of locally produced foodstuffs supplemented with green
food and crushed limestone.
In view of the proven value of separated milk in the diet of chicks,
separated milk was chosen as the control supplement in each experiment and
the results obtained were compared with those obtained with the standard
diet only and with the standard diet supplemented with soya bean meal
plus salt. As the cost of a ration is largely determined by the level of its
protein content, an analysis was made of the protein consumptions of all
( 207 )
208
Nutritional Experiments with Chickens
groups during the different stages of growth. Further, as there was little
information available concerning the growth rates of different breeds under
Indian conditions, it was decided to use three breeds for the experiments and
keep separate records of their growth rates.
METHODS
Breeds.—White Leghorn and Rhode Island Red hatching eggs were
purchased from three reputable breeders and desi eggs were purchased in the
local bazar. Though the desi eggs were of unknown origin and age it was
found that the hatching results were satisfactory and that the chickens were
representative of the desi stocks in the neighbourhood.
Brooding and rearing.—The chickens were all wing-banded at day-old
and transferred from the incubator to a brick-built sectional brooder house,
each compartment measuring 10 ft. × 9 ft. The chicks were brooded under
electric brooders measuring 2½ ft. × 2½ ft. The temperature under the
brooders was maintained at approximately 90°F. during the early stages of
brooding but this was gradually reduced by the manipulation of a thermos-
tatic control fitted on each brooder.
The chicks were confined near
the source of heat for the first few days by means of a wire guard, but there-
after they were allowed free access to the whole compartment and at one week
old they were allowed outside in wire enclosed runs. The chicks were kept
under heat for 2-5 weeks according to the prevailing weather conditions but
were kept in the brooder house up to 8 weeks in order to prevent losses from
crows and other predatory animals. Sand was used as litter throughout the
brooding stage.
At 8 weeks of age the chickens were transferred to 6 ft. × 3 ft. rearing
houses constructed from ½ in. angle iron covered with wire (½ in. mesh) on all
four sides and roofed with an asbestos sheet. Further protection from the
rain and sun was provided by means of chuppars made of bamboo and bhurra
grass. Each rearing house was placed centrally in a run measuring 40 ft.
× 40 ft. surrounded by 6 ft. wire netting.
FEEDING
All the birds were fed on mash and grain rations from day-old onward.
The mash was fed ad libitum in suitable containers and the grain was fed in the
litter, morning and evening, according to appetite. Supplementary calcium,
as broken limestone, was fed ad libitum from day-old onward. The birds also
received succulent green food, such as alfalfa or berseem, twice daily.
A basal mash consisting of wheat bran 50 parts, yellow maize meal 30
parts and finely ground oats 20 parts was fed throughout to all the experi-
mental groups. During the first 8 weeks the grain ration consisted of equal
parts of yellow broken maize, jowar and millet (cheena) and from 8 weeks
onwards the grain mixture consisted of equal parts of yellow cracked maize,
wheat and paddy. Table I gives the average composition of the mashes
and grains used in the experiments.
A. J. MACDONALD 209
TABLE I
Food composition (percentages) on dry matter basis
Feeding stuff
Basal mash—
Wheat bran
Yellow maize
Ground oats
Soya bean mash—
Basal mash
Soya bean
Salt
Chicks' grain—
Yellow maize
Cheena
Jowar
Grower's grain—
Yellow maize
Paddy
Wheat
Parts
50
30
20
Parts
81.5
18
0.5
Parts
1
1
1
Parts
1
1
1
Fibre
12.5
11.3
5.8
4.6
Crude
protein
11.4
15.9
9.9
9.7
Ether
extract
5.9
7.7
4.2
3.1
Nitrogen-
free
extract
63.5
58.2
77.4
79.5
Ash
6.7
6.9
2.7
3.1
210
Nutritional Experiments with Chickens
Experiment 1. To investigate the value of separated milk supplements to cereal
rations
Stock—A total of 84 day-old chicks, hatched in January, 1939, were
wing-banded and weighed individually at hatching and divided into two
comparable groups as follows :—
Breed
White Leghorn
Rhode Island Red
Total
Group 1
No. of chicks
28
14
42
Group 2
No. of chicks
28
14
42
Feeding.—Both the groups were fed on the standard basal rations des-
cribed above. Group 1 received the basal ration plus separated milk only
to drink from day-old to 10 weeks. From 10-24 weeks separated milk and
water in separate containers were fed. Group 2 was fed water only to drink
from 0.6 weeks, separated milk only from 6-8 weeks, water only from 8.12
weeks and separated milk and water from 12.24 weeks. Originally it was
proposed to keep Group 2 on water only to drink throughout the whole experi-
mental period but the condition of the chicks necessitated the alterations
described above.
Rate of growth.—The chickens were weighed individually at each weigh-
ing and the average weights of the cockerels and pullets in each group are given
in Table II. For purposes of convenience Group 1, fed on separated milk
from day-old, is hereafter known as ' the milk-fed group ' and Group 2 as
' the water-fed group '. The cockerels were removed from the experiment
at 14 weeks.
TABLE II
Average weights in ounces for each breed
Breed
Group
Sex
Day old
1 week
2 weeks
White Leghorn
Male
1.48
2.4
4.2
1
Female
1.46
2.2
3.9
Male
1.47
1.7
2.2
2
Female
1.47
1.8
2.2
Rhode Island Red
Male
1.42
2.3
4.2
1
Female
1.44
2.2
4.1
Male
1.48
1.8
2.1
2
Female
1.41
1.7
2.1
A. J. MACDONALD 211
Breed
Group
Sex
3 weeks
4 „
5
„
6 „
7 „
8
„
9 .,
10 „
12 „
14 „
16 „
18 „
20 „
22 „
24 „
White Leghorn
1
Male
6.1
9.4
13.3
15.8
21.5
26.1
30.7
37.0
46.0
52.0
Female
5.7
8.5
12.6
14 .8
20.5
24.6
28.8
34.6
40.8
47.5
52.4
55.7
57.1
61.0
63.6
2
Male
2.5
3.0
3.1
3.1
5.6
8.0
9.5
10.2
13.1
21.7
Female
2.6
3.0
3.3
3.8
5.9
8.5
9.6
10.2
13.9
22.0
30.4
35.6
36.8
41.2
46.0
Rhode Island Red
1
Male
6.1
9.1
13.4
16.6
22.4
27.9
33.5
41.3
49.5
59.2
Female
5.8
8.9
13.1
16.3
21.1
25.2
28.2
34.5
41.2
49.2
56.2
60.2
57.5.
60.5
65.5
2
Male
2.6
2.7
2.7
3.0
5.0
7.2
8.6
9.4
14.5
23.3
Female
2.7
3.0
3.4
3.9
6.4
9.1
10.3
11.2
10.6
25.0
32.0
38.7
41.3
43.3
48.0
Table II shows very clearly the marked difference in the rate of growth
obtained from the birds on the two rations under experiment. The birds on
the milk ration made satisfactory gains throughout, whilst the birds on the
water ration were considerably lower in weight at each weighing from one
week onward. At 6 weeks the average weights of the White Leghorn cockerels
and pullets on the milk diet were 15.8 oz. and 14. 8 oz. respectively, whereas the
corresponding figures for the birds on the water diet were 3.1 oz. and 3.8 oz.
The corresponding figures for the Rhode Island Reds on the milk and water
rations were 16.6 oz., 16.3 oz., 3.0 oz., and 3.9 oz. respectively. The gains
made by the birds of both breeds on the milk ration compare very favourably
with data published by Card and Kirkpatrick [1918], Charles and Knandal
[1928] and Kempster and Parker [1936] but the rate of growth of the water-
fed group is decidedly sub-normal, especially during the period 4.6 weeks.
At 6 weeks the birds in the water-fed group were all very weak and, as it was
apparent that they would not live much longer on the ration, it was decided
to supplement their diet with separated milk. From 6.8 weeks the condition
of the birds in Group 2 improved and the gains in weight were significantly
higher than during the previous periods. From 8-12 weeks water was again
fed in place of milk to Group 2 and, as again there was a falling off in
results, it was decided to feed milk and water to this group for the remainder
of the experiment. The rate of growth in Group 2, when fed on milk from 12
weeks onward, improved very considerably and the average gain made
from 12.24 weeks was even greater than the corresponding figure in Group
1, which was fed on milk from day-old. The average final weights of the
White Leghorn pullets at 24 weeks were 63.6 oz. in the milk-feel group and
212
Nutritional Experiments with Chickens
46.0 oz. in the water-fed group. The corresponding figures for the Rhode
Island Reds were 65. 5 oz. and 48.0 oz. respectively.
Food consumption.—Table III gives the average food consumption per
bird in pounds for each group for each period of 4 weeks and the food consump-
tion in pounds per pound of live weight gain.
TABLE III
Food consumption
1. 0-4 weeks
2. 4-8 „
3. 8-12 „
4. 12-16 „
5. 16-20 „
6. 20-24 „
Average food
comsumption per
bird (lb.)
Group 1
1.71
4.44
5.53
4.77
4.61
5. 32
Group 2
1.15
1.40
3.24
4.01
4.21
4.90
Food consumption
in lb. per pound live
weight gain
Group 1
3.70
3.74
5.05
8.22
26.50
8.75
Group 2
22.20
6.32
12.38
5. 32
6.99
9.50
NOTE.—The food consumption figures include the separated milk reckoned on a
dry matter basis of 9 per cent.
The average food consumption per bird was greater during each periods
for the milk-fed group than the water-fed group. During the first three
periods the milk-fed group made much better utilization of their food, as shown
by the food consumed per unit of live weight gain. During period 1 the food
consumptions per unit of gain were 3.7 and 22.2 for Groups 1 and 2 respec-
tively. During period 2 the corresponding figures for Groups 1 and 2 were
3.74 and 6.32. The improved food utilization by Group 2 during period 2
was solely due to the addition of the milk during the second half of the period.
In period 3 Group 1 consumed 5.05 lb. of food per lb. of live weight gain whereas
the figure for Group 2, which was again on water during the whole period,
was 12.3. During periods 4 and 5 Group 2 made better utilization of the
food consumed than Group 1 but during these periods both groups were fed
similar diets. The high food consumptions per unit of gain for Group 1
during these periods is quite normal for birds which have received adequate
rations during the early stages of growth. At 12 weeks of age the birds
of Group 1 were well grown for their age and the efficiency of food utiliza-
tion as regards growth normally decreases very materially during the latter
stages of growth. The birds in Group 2 at 12 weeks of age were, however
A. J. MACDONALD 213
very much sub-normal in weight and it is quite normal for animals to make
better utilization of their food when fed on a good diet after being fed on a
deficient one. The exceptionally high food consumption per unit of live
weight gain made by Group 1 in period 5 is most probably due to the
birds being well grown for their age at 16 weeks and a subsequent check in the
rate of growth from 16-20 weeks due to a spell of hot weather. On the other
hand the birds in Group 2 were undersized at 16 weeks and made relatively
better gains in weight despite the rise in temperature.
Milk consumption.—Table IV gives details of the milk and water consum-
ed by bo h groups during the different stages of the experiment. In Group
1 the milk and water consumption was measured throughout all stages but
in Group 2 the milk and water was only measured during the periods that the
birds were given supplements of milk.
TABLE IV
Average consumption (in lb.) per chick of milk and water
Period
1. 0-4 weeks
2A. 4-6 „
2B. 6-8 „
3A. 8-10
„
3B. 10-12
„
4. 12-16 „
5. 16-20 „
6. 20-24 „
Group 1
Average
milk
consump-
tion
per chick
2.48
2.21
2.48
3.29
1.01
2.31
6.06
7.84
Average
water
consump¬
tion
per chick
Nil
Nil
Nil
Nil
3.70
9.42
17.20
14.49
Group 2
Average
milk
consump-
tion
per chick
Nil
Nil
0.97
Nil
Nil
3.82
6.71
6.56.
Average
water
consump-
tion
per chick
Unrecorded
Do.
Nil
Unrecorded
Do.
4.51
15.00
17.97
The average milk consumption per chick in Group 1 from 0-10 weeks
whilst receiving milk only to drink, was 10.46 lb. From 10-12 weeks, whilst
fed on milk and water, the average consumptions of milk and water
were 1.01 lb. and 3.70 lb. respectively. During period 4 the proportion of
milk to water consumed was even less but during periods 5 and 6 the propor¬
ions of milk to water consumed were greater than in periods 3B and 4. The
214
Nutritional Experiments with Chickens
total milk consumption from 0-24 weeks was 27.68 lb. Group 2, during
period 4, consumed 3.82 lb. of milk and 4.51 lb. of water. The proportions
of milk to water consumed during periods 5 and 6 decreased.
Protein consumption.—Table V gives details of the total protein percent-
ages contained in the food consumed during the different periods of the experi-
ment. The milk was brought to a dry matter basis and included along with
the mash and grain figures.
TABLE V
Protein consumption
Period
1. 0-4 weeks
2A. 4-6 „
2B. 0-8 „
3A. 8-10
„
3B. 10-12
„
4. 12-10 „
5. 10-20 „
6. 20-24
„
Group 1
Supplement
Milk only
Do.
Do.
Do.
Milk & water
Do.
Do.
Do.
Percentage
of
protein
15.6
13.2
13. 3
13.4
11.0
11.9
13. 3
14.3
Group 2
Supplement
Water
Do.
Milk only
Water
Do.
Milk & water
Do.
Do.
Percentage
of
protein
11.1
11.0
13.3
10.8
10.8
13.0
14.3
13.6
In Group 1, the percentage of protein in the food consumed was at its
maximum (15.6) during period 1. From 4-10 weeks the percentage of
protein consumed was comparatively steady, ranging from 13.2 for period
2A to 13.4 for period 3A. The percentage of protein consumed during period
3B was only 11.6 but thereafter the consumption rose each period to give a
figure of 14.3 for period 6. The percentages of protein in the food consumed
in Group 2 were 11.1 and 11.0 for periods 1 and 2A. The protein consump-
tion rose to 13.3 per cent during period 2B, whilst the birds received milk
only to drink, but fell to 10.8 per cent during periods 3A and 3B when given
water only to drink. During period 4 the percentage of protein consumed
rose to 13.0 but after rising to 14.3 in period 5 there was a fall to 13.6 in
period 6.
A. J. MACDONALD 215
Mortality.—The value of separated milk in the diet of the chick is very-
well illustrated in Table VI which gives a summary of the number of deaths
which occurred in each group at different stages of the experiment.
TABLE VI
Mortality (0-24 weeks)
Period
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
0-1 week
1-2 weeks
2-3 „
3-4 „
4-5 „
5-6 „
6-7 „
7-8 „
8-11 „
11-12 „
12-13 „
13-14 „
14-24 „
Tolal mortality
Percentage mortality
Number of deaths
Group 1
1
..
1
..
..
..
..
..
..
..
..
..
..
2
4.8
Group 2
2
3
2
4
4
5
1
1
..
2
1
1
..
26
61.9
Group 1, fed on milk, had an excellent health record throughout. The
birds always handled well, had good tight feathers and were always ready for
their grain. The total mortality of 2, representing 4.8 per cent of the chicks
used in the experiment, may be considered very .satisfactory.
Group 2,
however, had a very poor health record ; the chicks were excessively thin
until very late in the experiment, had ruffled feathers and abnormal appetite.
From a few days onward the chicks showed little interest in their food
and spent most of the day scratching feverishly in their runs. The birds