NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
K. S. NAIR, R. KRISHNAMURTI & G. S. KALYANASUNDARAM 317
TABLE VIII
To determine the effect of using varying doses of dried goat spleen vaccine, in
buffalo-calves
Serial
No.
1
1
2
3
4
Dose
2
gm.
0.01 . . .
0.005 . .
0.00125 . .
0 .000625 . .
Reaction
to
vaccination
3
1. Mild .
2. Mild .
1. Mild .
2. Mild .
1. Nil .
2. Severe
(late).
1. Nil .
2. Nil .
Reaction
after
retest
4
Nil . .
Nil . .
Nil . .
Nil . .
Nil . .
Severe and
died.
Severe and
died.
Nil .
Interval
between
vaccination
and
retest
5
Days
18
18
18
25
17
45
8
17
Remarks
6
Vaccine kept in
cold storage for
25 days, was used.
Do.
Do.
Do.
Vaccine kept in
cold storage for 26
days, was used.
Do.
Do.
Do.
Note.—Two calves were used for each serial number.
SOME FACTORS AFFECTING THE INTERNAL QUALITY
OF HEN EGGS
BY
A. J. MACDONALD, B.Sc., B.Sc.(AGRI.), N. D. A.
AND
T. S. KRISHNAN, B.A., M.Sc., A. I. C.
Poultry Research Section, Imperial Veterinary Research Institute, Izatnagar
(Received for publication on 24 October 1941)
With one text-figure)
'QUALITY
' in eggs is a term not easily defined. A good quality egg should
have a normal shape and a clean, smooth, sound shell; the internal con-
tents should be free from faults, e.g. ' meat spots ', ' blood spots ' and, when
examined under a candling lamp, the air space should be small, the yolk central-
ly placed and only dimly visible. On breaking the egg, the yolk should have a
uniform colour and stand up well in the centre of a compact layer of firm al-
bumen. The latter should have a good height and small area with an even
outline and oval shape. The contents should show no signs of embryo develop-
ment and be free from any objectionable odour or foreign matter. Most new-
laid eggs are of first class quality but do not necessarily remain so for any length
of time. The amount of deterioration that occurs depends on the length and
conditions of storage ; high temperature, low humidity and insanitary sur-
roundings all accelerate the process. All eggs, however, are not of the same
high quality when new-laid and, except for major defects such as blood spots
and meat spots, it is impossible to judge the quality of the albumen with any
degree of accuracy by means of the candling lamp, though this is the only prac-
tical method of judging quality in the unbroken egg.
The edible portion of the egg consists of albumen and yolk. The former
is composed of two fractions, a thick, jelly-like portion generally called the
' thick ' or' firm ' white and a thin, viscous liquid portion termed' thin ' white.
Eggs containing a high proportion of thick white are generally considered to
be of better quality than those with much thin white, but there is little inform-
ation regarding the relative biological values of thick and thin white. Guerrant
and Rudy [1939], however, found no difference in the nutritive values of these
two fractions, when fed to rats.
Literature
A considerable volume of literature exists on various aspects of egg quality
and critical reviews have been published by Wilcke [1938], Wilhelm [1939]
and the Canadian Poultry Review [1940]. The quality of the white is affected
by numerous factors such as the individuality of the bird, the season of pro-
duction, the age of the egg and the method of storage. Holst and Almquist
[1931] showed that there were wide variations in the thick white percentage
318
320 Some Factors Affecting the Internal Quality of Hen Eggs
It is generally accepted in trade circles that eggs from well-bred fowls are
of poorer quality than those from unselected stock. It is also widely believed
in countries where poultry keeping is often highly specialized, that there has
been a marked deterioration in egg quality during the last 20-30 years. Though
there are no figures to support these beliefs, many people in the ' trade ' have
had very long experience in, and have little to learn about, the practical
estimation of egg quality. It is impossible to determine the cause or causes
of this so-called deterioration in egg quality because, in recent years, western
countries have revolutionized their methods of breeding, feeding, housing and
managing birds for egg production. If breeding for high egg production has
been responsible for a lowering of egg quality, it would appear probable that
the desi fowls in this country should produce eggs of a better quality than
those from imported utility, fowls, for the desi birds have never been selected
for egg production, whereas the imported birds have been selected for many
generations for high egg production. As eggs from desi, White Leghorn and
Rhode Island Red fowls were all produced under similar conditions in the
Institute flock, it was decided to test the quality of the eggs from each breed,
as judged by the percentage of thick white. Further, as there was no inform-
ation available in regard to factors affecting egg quality under Indian condi-
tions, it was decided to investigate some of the factors concerned.
Methods
Twelve White Leghorn, 12 Rhode Island Red and 20 desi pullets were
selected for the investigations. All the birds were hatched in February, 1939
and were kept under identical conditions from day-old onwards. The adult
birds were trapnested and the eggs collected 6-7 times daily, stored at ordinary
room temperature and, except when otherwise reported, they were examined
for their quality on the day following production. During the period
1 March, 1940 to 31 July, 1940, 630 White Leghorn, 680 Rhode Island Red
and 849 desi eggs were broken and the thick white percentage (true thick as
defined by Sharp [1934]) determined, using the sieve method of Holst and
Almquist [1931]. The diameter of the sieve used was 4½ inches and it
had 90 holes per sq. inch, each hole having a diameter of approxi-
mately 1/16 inch. The eggs were broken and the white, after separation
from the yolk, was poured on to the sieve placed in a glass funnel, so that the
thin fraction might run through into a measuring cylinder. The thick white
sac was ruptured, the sieve gently rocked and the thin white measured two
minutes later. The thick white was then poured into the measuring cylinder
and the total volume read.
EXPERIMENTAL RESULTS
Individual variations
Table I gives the thick white percentage of seven consecutive eggs from
six birds of each breed taken at random from the daily records. The range in
thick white percentage, from 34-73, gives an indication of the fluctuations that
occur within a normal flock kept under standard conditions of housing, feeding
and management.
A. J. MACDONALD & T. S. KRISHNAN 321
TABLE I
Percentage thick white of seven consecutive eggs from typical birds of each breed—
(April 1940)
Breed
WhiteLeghorn
Rhode Island
Red
Desi
Serial
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Thick white percentage of consecutive eggs
1
44
61
45
55
46
49
48
67
38
48
50
39
56
58
73
46
57
61
2
48
61
46
65
52
48
52
61
34
48
57
42
50
56
69
44
51
67
3
48
52
55
55
53
50
47
54
37
47
56
43
49
50
73
43
53
67
4
47
57
48
57
51
48
50
54
38
46
54
45
52
56
48
44
54
67
5
51
59
48
54
49
50
50
51
38
46
50
42
50
50
60
39
51
57
6
50
57
44
46
46
49
46
52
38
47
53
39
50
45
60
37
54
60
7
46
55
44
53
48
48
49
48
40
47
49
43
52
54
56
39
52
52
Average
48
57
47
55
49
49
49
55
38
47
53
42
51
53
63
42
53
62
During the relatively short period in question, there was a general tendency
for the individual quality of the eggs from any one hen to remain fairly con-
stant, but hen No. 15 was exceptional for she produced two consecutive eggs,
one with 73 per cent thick white and the other 48 per cent thick white.
322 Some Factors Affecting the Internal Quality of Hen Eggs
Table II gives the monthly average percentages of thick white for typical
birds from March to July. Five birds (Nos. 2, 14, 15, 4, 19) were selected as
representatives of those laying eggs with a high proportion of thick white
(58-68 per cent) during the first month of the experiment. Four other birds,
(Nos. 21, 12, 9, 20) were representatives of those which produced eggs with a
comparatively poor quality of white (48-51 per cent) during the same period.
The quality of the white, as judged by actual measurement, declined in both
groups from March to May. In the high quality group, the initial average
figure of 62.8 per cent declined to 52 per cent in May, whilst the corresponding
figures in the low quality group were 48.2 per cent and 38.2 per cent respective
ly. Though the average percentage of thick white in the eggs of all the birds
showed a marked decline from March to May, it is interesting to note that the
decline was no greater in the eggs from the good quality birds than in those
from the low quality ones and that the average thick white percentage of 52 in
the good quality birds for the month of May was higher than that of the low
quality birds for the month of March (48.2). The average thick white percent-
age of both groups rose slightly in June but fell in July to approximately the
same levels as those obtained in May.
As shown in Table I, the thick white percentage is an individual charac-
teristic which ordinarily tends to remain fairly constant for seven consecutive
eggs but, in certain individuals, considerable fluctuations occurred even in the
day to day percentage of thick white, thus making it impossible to place much
reliance on an estimation of egg quality for any individual based on the exa-
mination of a single egg.
TABLE II
Monthly average percentages of thick white of eggs laid by some typical birds
Bird No.
2
14
15
4
19
Average . .
21
12
9
20
Average . .
March
No. of
eggs
laid
15
9
7
21
17
13.8
11
19
25
20
18.7
Av.
thick
white
percent-
age
68
65
64
59
58
62.8
51
49
47
46
48.2
April
No. of
eggs
laid
16
8
14
13
5
11.2
9
11
22
17
14.7
Av.
thick
white
precent-
age
58
52
58
54
52
55.6
48
41
39
43
42.7
May
No. of
eggs
laid
2
10
4
1
11
5.6
6
9
19
13
11.7
Av.
thick
white
percent-
age
59
52
47
51
51
52.0
43
41
32
37
38.2
June
No. of
eggs
laid
18
15
8
2
15
11.6
2
2
2
8
4.0
Av.
thick
white
prcente-
age
54
53
55
56
53
54.2
48
39
41
41
42.2
July
No. of
eggs
laid
10
5
9
12
22
11.6
11
6
12
...
7.2
Av.
thick
white
percent-
age
55
48
54
53
52
52.4
44
38
34
...
38.7
A. J. MACDONALD & T. S. KRISHNAN 323
Table III gives the average percentage of thick white of all the eggs laid
by six typical birds for a period of one month (April) and the averages of six
consecutive eggs from each bird collected at the beginning of the month, from
the 11th of the month, and the last six eggs laid during the month. In all
cases, the average thick white percentage for the first six eggs laid was higher
than the average for the whole month but in four of the six cases the differ-
ence was only 2 per cent or less. In the other two cases, the differences of
3 . 9 per cent and 7 per cent are somewhat large and are partly due to fairly wide
fluctuations in the day-to-day figures but the main cause was the large decline
in egg quality among these particular birds during the month. In the case of
the last six eggs laid during the month, the figures for the thick white percent-
ages are somewhat lower than the corresponding figures for the whole month.
The thick white percentages for six consecutive eggs laid from the 11th onward
are in five of the cases within 2 per cent or less of the average for the whole month
but in bird No. 1080 there was a difference of 2.7 per cent. As these figures are
typical of those obtained during other months, it may be concluded that,
during a period of rising temperature, the average thick white percentage of
six consecutive eggs laid at the beginning of the month will be somewhat higher
than that of all the eggs laid during the month and that the average for the last
six eggs will be somewhat lower than the average for the month. However,
the average of six consecutive eggs laid during the middle of the month is a
fairly close approximation to that obtained for all the eggs laid during the
month.
TABLE III
Comparison of a monthly average thick white percentage with the average of six
consecutive eggs laid at the beginning of the month, the middle of
the month and the end of the month
Bird No.
385
391
1048
1080
1106
1488
No. of eggs
laid during
month
18
20
21
22
20
20
Average
thick white
percentage
of all eggs
48.3
46.7
47.5
40.1
47.1
56.2
Range
42.5-55.2
40.0-50.9
43.4-52.6
31.6-50.0
42.1-52.9
46.7-66.7
Average thick white percentage of six
consecutive eggs
1st period
48.7
47.6
49.5
44.0
49.8
63.2
2nd period
48.9
47.5
45.8
37.4
46.3
54.6
3rd period
47.3
45.8
45.8
35.5
44.4
52.3
Breed characteristics
The weekly average thick white percentages of the eggs for each, of the
three breeds for the whole experimental period are given in Table IV. The
averages range from 43 to 58 per cent in the White Leghorns, 37 to 54 per cent
324 Some Factors Affecting the Internal Quality of Hen Eggs
TABLE IV
Weekly average thick white percentages of eggs from the different breeds for the
entire experimental period
Week ending
7 March 1940 . . . . .
14 March 1940. . . . .
21 March 1940. . . . .
28 March 1940. . . . .
4 April 1940 . . . . .
11 April 1940 . . . . .
18 April 1940 . . . . .
25 April 1940 . . . . .
2 May 1940 . . . . .
9 May 1940 . . . . .
16 May 1940 . . . . .
23 May 1940 . . . . .
30 May 1940 . . . . .
6 June 1940 . . . . .
13 June 1940 . . . . .
20 June 1940 . . . . .
27 June 1940 . . . . .
4 July 1940 . . . . .
11 July 1940 . . . . .
18 July 1940 . . . . .
25 July 1940 . . . . .
31 July 1940 . . . . .
Average percentages of thick white
White
Leghorn
56
58
55
56
52
50
49
48
45
48
44
43
52
44
50
54
52
46
50
50
45
46
Rhode Island
Red
53
54
52
54
49
48
46
47
44
40
37
40
44
39
40
48
49
44
45
40
43
38
Desi
57
59
56
57
54
52
50
49
46
46
43
48
46
46
50
51
56
48
47
44
47
44
A. J. MACDONALD & T. S. KRISHNAN 325
in the Rhode Island Reds and 43 to 59 per cent in the desis. The monthly
averages of thick white percentage and the averages for the whole period
together with the temperatures and probable errors are given in Table V. In
every single weekly period (Table IV), the average thick white percentage
of the Rhode Island Reds is lower than that of the White Leghorns and
desis for the same period. The figures obtained for the desis and the
Leghorns are, however, very similar for most weeks and the monthly
averages bear a very close resemblance to one another.
TABLE V
Fluctuations in thick white percentages and maximum temperatures during the
experimental period
Breed
White Leghorn . . .
Rhode Island Red. . .
Desi . . . . .
Mean Max. Temperature, °F .
Mean thick white, percentage
March
56±0.47
53±0.28
56±0.36
83±0.70
April
49±0.42
47±0.38
50±0.39
97±0.74
May
47±0.65
40±0.57
46±0.46
105±0.44
June
51±0.38
45±0.62
50±0.47
100±0.93
July
48±0.48
43±0.77
46±0.47
91±0.43
Entire
experimental
period
50±0.63
45±0.74
50±0.69
100±l.46
With the limited number of birds used in these observations, it is impossible
to draw any sweeping conclusion with regard to the relative thick white per-
centages in the three breeds used but the data available regarding the slight
superiority of quality in the White Leghorns over the Rhode Island Reds sup-
port the findings of Knox and Godfrey [1934]. The similarity in the average
thick white percentages found, as the result of analysing 542 and 750 individual
eggs from the Leghorns and desis respectively, is of considerable interest in that
it leads one to question, if it does not actually disprove, the general belief in
trade circles that eggs from birds specially bred to lay, such as Leghorns, are
poorer in internal quality than those from nondescript fowls such as desis.
Influence of egg size
In order to throw more light on the relationship between egg size and
thick white percentage, a total of 1,120 eggs collected during the months of
March and April were divided into three groups according to their size (Table
VI). The figures show that there are very wide variations in the thick white
present in each of the weight groups. The ranges of variations for each
group are, however, fairly comparable and the group averages of 51, 53 and
53 per cent for the large, medium and small eggs respectively, as well as the
standard deviations show that the size of egg has little influence on egg
quality as judged by thick white percentage. Somewhat similar conclusions
were arrived at by Knox and Godfrey [1938] and Gordon [1940].
E
326 Some Factors Affecting the Internal Quality of Hen Eggs
TABLE VI
Influence of size of egg on thick white percentage
Weight (oz.)
No. of eggs examined
Max. thick white per cent
Min. thick white per cent
Average thick white per cent
....
Standard Deviation
Class of eggs
Large
1 7/8 and above
647
80
32
51 ±0.20
7.62
Medium
1 9/16 to 1 13/16
247
73
33
53±0.34
7.83
Small
1½ and below
226
78
35
53±0.36
8.13
Seasonal changes
Fig. 1 shows the weekly fluctuations in the thick white percentages of the
three breeds and the variations in maximum shade temperature for each period
as recorded at the adjacent meteorological station in Bareilly. Table V
gives the mean monthly record of egg quality for each breed as well as the
monthly average maximum temperatures. The figure shows that the thick white
percentages steadily declined from 55 per cent at the commencement of March
to about 42 per cent in the middle of May. During the remainder of the
period the thick white percentage remained around 45, except for a temporary
rise towards the end of June. The temperature curve shows that the maximum
temperature rose from 80°F. at the beginning of March to 109°F. in the middle
of May and after a sharp drop to 103°F., it rose again to 110°F. in the middle
of June. Thereafter the maximum temperature declined and remained
fairly steady around 92°F. during July. The graphs in Fig. 1 in conjunction
with the data in Table V show that the rise in temperature which occurred
between the beginning of March and the end of May was accompanied by a
deterioration in the thick white percentage. In June, the fall in the maximum
temperature was accompanied by a corresponding rise in the thick white per-
centage but in July this percentage again deteriorated despite a further fall
in the maximum temperature. With the exception of the figures obtained in
July, for which no explanation can be offered at present , it can be concluded
that there is a fairly close inverse relationship between the atmospheric tem-
perature and the thick white percentage as measured in day-old eggs.
As the percentage of thick white in the eggs examined might have been
adversely influenced even by one day's storage under room conditions, it was
decided to carry out further investigations in order to find out the percentage of
thick white in new-laid eggs and the influence of storing eggs under cool
conditions upon the percentage of the white. In this investigation, other birds
of the Institute flock kept under standard conditions, as well as the usual ex-
perimental birds, were trapnested hourly and the eggs were examined as
quickly as possible after collection. A dozen eggs of each of the three breeds
were examined daily for seven consecutive days, Table VII gives the figures
A. J. MACDONALD & T. S. KRISHNAN 327
FIG.
1. Fluctuations in temperature and egg qualities during the experimental period
E 2
328 Some Factors Affecting the Internal Quality of Hen Eggs
obtained for day-old eggs for each of the three breeds for one week starting on
11 May, 1940 and similar figures for new-laid eggs (i.e. examined about
one hour after laying) for the week commencing 19 May, 1940. The table
also shows the average maximum shade temperature recorded each day as well
as the average thick white percentage for the eggs of the three breeds for the
week commencing 1 March, 1940. The last line of the table gives the average
thick white percentage of 12 new-laid eggs from each breed placed in a
refrigerator on 28 May, 1940 and stored at a temperature of 55°F. for one
week prior to examination.
TABLE VII
Average daily thick white percentages of fresh-laid, day-old and cold-stored eggs
as well as maximum temperatures during the respective experimental days
Date of experiment
1 March 1940 . . .
2 March 1940 . . .
3 March 1940 . . .
4 March 1940 . . .
5 March 1940 . . .
6 March 1940 . . .
7 March 1940 . . .
Average
....
11 May 1940 . . .
12 May 1940 . . .
13 May 1940 . . .
14 May 1940 . . .
15 May 1940 . . .
16 May 1940 . . .
17 May 1940 . . .
Average
....
19 May 1940 . . .
20 May 1940 . . .
21 May 1940 . . .
22 May 1940 . . .
23 May 1940 . . .
24 May 1940 . . .
25 May 1940 . . .
Average . . . .
28 May 1940 . . .
Max.
temp.
(°F.)
80
77
81
84
77
81
81
80
110
110
109
107
110
107
106
108
102
103
97
101
106
106
106
103
107
Nature
of eggs
examined
Day-old
„
„
„
„
„
„
..
Day old
„
„
„
„
„
„
..
Fresh laid
„
„
„
„
„
„
..
Stored in
refrigerator
for a
week at 55°F.
Daily average thick white per-
centage
White
Leghorn
52
55
58
60
57
58
53
56
44
46
43
42
44
46
41
44
54
52
54
53
51
54
55
53
51
Rhode
Island
Red
53
53
54
54
52
53
57
54
35
37
35
39
39
38
40
38
54
53
54
52
57
53
52
54
51
Desi
58
56
53
57
55
60
59
57
46
42
46
41
44
43
47
44
59
55
59
63
52
53
55
57
51
330 Some Factors Affecting the Internal Quality of Hen Eggs
TABLE VIII
Quality of new-laid eggs at different seasons of the year
Breed of fowls
White Leghorn . . .
Rhode Island Red . .
Desi
All breeds
....
Av. max. temp. °F. during ex-
perimental period
Thick white percentage of new-laid eggs
May
53.2
54.3
56.7
54.7
103
September
58.8
56.1
70.4
61.8
92
December
65.8
65.0
76.1
69.0
69
April
62.0
63.0
70.6
65.2
100
fertile and infertile new-laid eggs were collected and analysed for their thick
white content. Six eggs from each of the fertile and infertile pens of each of
the three breeds were collected and examined each day for a period of one week
and the results obtained have been tabulated in Table IX.
As the figures obtained for the infertile and fertile desi eggs were very
similar and as the slightly higher figure obtained for the fertile eggs from the
White Leghorns were counterbalanced by slightly better quality in the Rhode
Island Red infertile eggs, it may be concluded that there is no appreciable
difference in the thick white percentage of fertile and infertile new.laid eggs.
On 28 May, 1940, six fertile and six infertile eggs from each of the three
breeds were placed in a refrigerator within one hour of production and examined
after being stored for one week at a temperature of 55°F. The results given
in Table IX show that the Rhode Island Red and White Leghorn fertile eggs
had a somewhat lower thick white content than the corresponding infertile
eggs but as the fertile desi eggs had a somewhat better thick white content
than the infertiles, it is evident that there was no appreciable difference in the
rate of deterioration in fertile and infertile eggs stored at 55°F.
Influence of broodiness
Desi birds are characterized by persistent broodiness and under typical
village conditions the birds lay only 10-15 eggs and then go broody for a period
of 2-3 months. On the Institute farm also the desi birds went broody after
laying 10-15 eggs but, by suitable management, the broodiness was quickly
checked and the birds usually came back into production within 10-20 days.
During the course of the investigation, only one White Leghorn and two Rhode
A. J. MACDONALD & T. S. KRISHNAN 331
TABLE IX
Influence of fertility on the thick white percentage of fresh-laid eggs
Date of laying
and examina-
tion of the
eggs
19 May 1940
.
20 May 1940
.
21 May 1940
.
22 May 1940
.
23 May 1940
.
24 May 1940
.
25 May 1940
.
Average .
Collected on 28
May 1940 and
stored for one
week at 55°F.
before analysis
Average thick white percentage
White Leghom
Fertile
55
52
56
56
52
56
57
55
50
Infertile
52
51
53
51
49
53
52
52
53
Rhode Isand Red
Fertile
54
51
52
50
54
51
51
52
49
Infertile
54
54
57
54
59
55
54
55
53
Desi
Fertile
59
54
59
57
53
56
56
56
53
Infertile
60
56
60
69
50
52
53
57
50
TABLE X
Effect of broodiness on the internal quality of eggs
Breed
W.L
R. I. R
"
.
.
.
.
Desi
.....
„.....
„....
Bird
No.
1064
1058
1080
356
358
368
Thick white percentage
Last egg
laid before
broodiness
30.5
45.8
48.9
44.3
60.5
56.6
47.6
55.0
50.0
58.3
48.9
54.5
46.3
First egg
laid after
broodiness
46.3
61.8
56.0
41.3
77.5
56.1
53.8
57.8
63.6
58.3
62.5
70.6
50.0
Increase
+15.8
+16.0
+7.1
—3.0
+17.0
—0.5
+6.2
+2.8
+3.6.
0.0
+13.6
+16.1
+3.7