NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
A. VISWANATHA IYER AND N. KRISHNA AYYAR 49
TABLE V.—(contd.)
Weeks
14th September 1935 .
21st September 1935
.
28th September 1935 .
5th October 1935 .
12th October 1935 .
Weeks.
19th October 1935 .
26th October 1935 .
2nd November 1935 .
9th November 1935 .
16th November 1935 .
23rd November 1935 .
30th November 1935 .
Final weight . .
Average for group .
2nd Period
Calf No
1
542
2
494
3
359
4
373
With Minerals.
11.1
20.1
14.3
19.5
15.2
10.0
26.0
13.8
13.5
13.3
14.9
19.6
21.4
13.1
7.8
26.9
26.1
20.4
...
14.6
Average
442
15.7
22.9
17.5
20.0
12.7
GROUP A No.Minerals
Calf No.
1
...
28.1
6.9
13.6
16.8
1.8
28.0
625
2
13.1
11.1
7.4
12.8
12.6
3.7
14.1
574
3
23.1
5.0
15.0
27.0
16.8
2.4
23.5
436
16.3
4
24.0
21.2
13.9
13.7
20.2
11.0
32.6
475
Average
20.1
16.4
10.8
16.8
16.6
4.7
24.6
528
Calf No.
5
494
6
448
7
446
8
292
No Minerals
24.3
25.8
13.5
16.5
11.3
26.8
26.1
17.0
13.5
14.3
20.2
6.6
17.5
16.7
12.9
27.4
26.7
13.0
6.5
31.9
Group B With Minerals
Average
420
24.7
21.3
15.2
6.5
17.6
Calf No.
5
...
14.9
7.4
18.1
5.3
1.9
26.6
580
6
16.2
32.9
20.6
16.1
19.9
7.8
30.9
535
7
16.9
4.1
12.4
12.5
22.1
24.0
29.7
520
16.26
8
12.4
3.1
9.1
9.0
23.9
8.8
20.2
353
Average
15.2
13.7
12.4
13.9
17.8
5.6
26.9
497
Initial
weight.
Remarks
The addition of a mineral supplement to the ration has not produced any
significant effect on the live-weight increase of the calves of the two groups.
H
50
Mineral Assimilation of Growing Calves
TABLE
Mineral Balance
Experiment I
Calf 1 .
Calf 2 .
Calf 3 .
Calf 4
.
Calf
5
.
Calf 6 .
Calf 7 .
Calf 8 .
Average . .
Experiment II
No mineral
Calf 1 .
Calf 2 .
Calf 3 .
Calf 4 .
Average
With mineral
Calf 5 .
Calf 6 .
Calf 7 .
Calf 8 .
Average . .
Expe r
i
me nt III
with mineral
Calf
1
.
Calf 2 .
Calf 3 .
Calf 4 .
Average .
No-mineral Calf 5 .
Calf 6 .
Calf 7.
Calf 8 .
Average . .
P 2 O 5
Intake
22.11
20.24
15.88
15.05
20.15
19.02
19.64
13.12
18.15
23.54
22.53
18.96
19.32
21.14
34.77
33.43
33.60
28.52
32.58
35.03
34.67
32.18
33.31
33.80
24.91
21.81
22.35
18.30
21.84
Out go
Fæces
14.99
13.56
10.47
13.53
16.37
12.57
12.59
9.53
...
16.13
14.91
12.94
13.12
...
26.99
24.87
25.02
22.75
...
22.95
19.93
16.17
19.60
...
14.59
13.92
13.84
11.70
...
Urine
0.11
0.10
0.14
0.08
0.11
0.10
0.17
0.06
...
0.11
0.14
0.13
0.05
...
0.13
0.17
0.15
0.07
...
0.14
0.15
0.17
0.16
...
0.13
0.10
0.16
0.05
...
Balance
7.01
6.58
5.27
4.44
3.67
6.35
6.88
3.53
5.09
7.30
7.48
5.89
6.35
6.76
8.25
8.39
8.43
5.70
7.69
11.94
11.59
13.84
13.55
13.98
10.19
7.79
8.35
6.55
3.22
CaO
Intake.
41.35
34.52
26.92
22.02
31.15
29.64
34.89
23.96
30.56
34.69
32.05
25.56
29.30
30.40
42.18
37.97
40.37
34.89
38.93
17.23
14.18
37.68
13.14
43.43
38.09
30.64
33.46
27.65
32.46
Out go
Fæces
32.19
27.44
19.73
15.00
26.84
24.47
7.31
16.42
...
25.29
22.21
17.23
21.87
...
32.11
29.08
27.19
26.60
...
39.95
31.09
38.30
31.14
...
33.56
27.91
29.12
23.11
...
Urine
2.36
2.37
1.52
2.57
2.33
1.96
1.59
2.03
...
3.15
2.54
1.98
0.88
...
2.99
1.38
1.91
2.40
...
2.19
2.94
1.75
2.29
...
1.08
1.56
1.07
1.98
...
Balance
6.80
4.71
5.67
4.45
1.98
3.21
5.99
5.51
4.79
6.25
7.30
6.35
6.55
6.61
7.38
9.51
11.27
5.89
8.51
5.09
10.45
7.63
9.71
8.22
3.50
1.17
3.27
2.56
2.63
A. VISWANATHA IYER AND N. KRISHNA AYYAR 51
VI
(Grm. per day)
Intake
23.69
20.25
15.79
12.50
19.06
17.90
20.21
13.77
17.90
25.99
28.85
18.99
21.83
22.67
24.56
21.63
23.08
18.64
21.98
26.64
25.16
20.92
24.06
24.20
26.67
22.62
24.20
19.92
23.35
MgO
Out go
Fæces
11.19
10.40
6.61
5.71
11.84
7.87
9.06
5.89
...
12.52
13.23
9.14
13.47
...
15.10
12.21
11.38
9.19
...
15.70
14.43
12.01
14.50
...
17.52
13.72
14.61
12.29
...
Urine
8.39
6.43
5.40
4.92
5.19
5.58
5.49
4.01
...
10.74
9.90
7.70
3.73
...
8.42
8.46
7.95
6.81
...
12.08
9.87
8.60
9.72
...
9.35
8.63
8.63
7.49
...
Balance
4.11
3.42
3.78
1.87
2.03
4.45
5.66
3.87
3.65
2.73
0.72
2.15
4.63
2.56
1.04
0.96
3.75
2.64
2.10
—1.14
0.86
0.31
—0.16
—0.03
0.20
0.27
0.96
0.14
0.29
Intake.
35.51
32.84
28.89
25.99
31.98
31.30
33.08
27.70
30.91
34.96
33.46
30.09
31.95
32.62
33.91
31.89
32.92
29.65
32.09
37.19
36.24
33.42
35.57
35.61
37.21
34.51
35.62
32.91
35.06
Na 2 O
Out go
Fæces
10.80
12.13
10.26
10.32
13.55
12.61
14.42
10.00
...
15.52
11.33
11.65
14.80
...
14.01
12.89
13.99
11.83
...
13.42
10.23
7.80
9.81
...
13.13
9.95
10.22
8.13
...
Urine
3.52
4.64
6.73
4.44
6.66
3.53
4.68
6.58
...
0.48
2.33
2.58
0.77
...
1.82
0.51
0.86
2.61
...
0.87
1.83
2.69
0.88
...
1.96
1.15
1.03
1.29
...
Balance
21.19
16.07
11.90
11.18
11.77
15.16
13.98
11.12
14.05
18.96
19.80
15.86
16.38
17.75
18.08
18.49
18.07
15.21
17.46
22.90
24.18
22.93
24.88
23.72
22.12
23.41
24.37
23.49
23.55
Intake
46.59
41.35
33.42
20.87
39.30
37.73
39.29
29.35
36.74
47.76
44.67
37.25
40.82
42.63
46.10
41.47
43.38
35.47
41.61
54.07
51.87
44.21
49.72
49.97
54.00
47.83
50.23
41.66
48.43
K 2 O
Out go
Fæces
7.88
6.89
3.99
3.57
5.59
3.57
2.83
2.76
...
12.51
14.19
8.04
8.29
...
11.34
12.64
11.00
12.80
...
18.62
14.19
9.66
13.62
...
9.95
9.81
12.19
14.69
...
Urine
37.39
30.59
25.78
21.25
33.04
28.32
32.86
22.37
...
26.91
24.08
21.25
25.35
...
28.04
20.82
24.93
14.49
...
33.71
28.37
30.59
24.01
...
39.94
32.01
35.33
25.80
...
Balance
1.32
3.87
3.65
2.05
0.67
5.84
3.60
4.22
3.15
8.34
6.40
7.96
7.18
7.47
6.72
8.01
7.45
8.18
7.59
1.74
9.31
3.96
12.09
6.78
4.11
6.01
2.71
1.17
3.5
52
Mineral Assimilation of Growing Calves
MINERAL ASSIMILATION
The mineral balance data of the different constituents for the three ex-
periments are presented in detail in Table VI. In the three experiments the
different constituents show a positive balance The actual figures are given
below :—
Summary of mineral balance (grm. per day)
Experiment
No-
mine-
ral
Mine-
ral
I
II
III
II
III
P 2 O 5
5.09
6.76
8.22
7.69
13.98
CaO
4.79
0.61
2.63
8.51
8.22
MgO
3.65
2. 56
0.29
2.10
0.03
Na 2 O
14.05
17.75
23.35
17.46
23.72
K 2 O
3.15
7.47
3.50
7.59
6.78
Ca : P
ratio of the
ration (group
average)
2.76 : 1
2.35 : 1
2.43 : 1
1.96 :1
2.09 : 1
From this it may be observed that, during the first experiment (the figures
are averages for the eight animals) the assimilation of phosphoric acid and
lime is positive as represented by the figures 5.09 and 4.79 respectively, the
Ca : P ratio being 2.76: 1. In experiment II with the no-mineral group,
phosphoric acid and lime is positive, as in experiment I and the retention is
higher, the average figures being 6.76 and 6.61 and the Ca : P ratio 2.35 : 1
and with the mineral group, consequent on the increased intake of phosphoric
acid and lime, the balance for both the constituents is higher than the no-
mineral group in the same experiment, the figures being 7.69 and 8.51 and
the Ca : P ratio 1.96 : 1 and in experiment III, i.e. after the reversal, where
the no-mineral group became the mineral group and vice versa, the mineral
group showed the highest positive balance for both phosphoric acid and lime
and has also retained the largest quantities, the figures being 13.98 and 8.22
and the Ca : P ratio 2.09 : 1. The figures for the no-mineral group in this
experiment are 8.22 and 2.63 and the Ca : P ratio 2.43 : 1.
One other feature which is particularly noticeable is that as the lime
retention increases, the magnesium retention decreases. The retention of
soda has continued to increase progressively but this cannot be said of potash.
In all these experiments the resultant urine is alkaline, the pH figures
being 7.87 and 8.52 for the no-mineral and the mineral group respectively in
experiment II and 8.05 for both the mineral and no-mineral group in experi-
ment III. It has been noticed that with positive phosphoric acid and lime
balances the resultant urine is alkaline, as has been observed in previous
experiments.
A. VISWANATHA IYER AND N. KRISHNA AYYAR 53
In a previous paper by one of us [Viswanatha Iyer 1935] it was shown
that, when other conditions are favourable, certain minimal quantities of both
phosphoric acid and lime are to be present before they yield positive balances.
In these experiments the intake of both these ingredients are well above those
minimal quantities.
While no difference in the appearance and the health of the animals be-
tween the mineral and no-mineral groups was noticeable, the feeding of calcium
phosphate as a supplement to the animals, resulted only in a greater reten-
tion of lime and phosphoric acid in their systems. Perhaps this increased
retention of lime and phosphoric acid is stored in the skeletal tissue as no
additional live-weight increase was noticed corresponding to the increased
mineral retention.
SUMMARY
From this experiment it becomes evident that when the minerals are
sufficient in the feed itself, a supplement of calcium phosphate does not show
any visible effect except for the fact that the animals receiving the supple-
ment retain more calcium and phosphorus in their systems.
REFERENCES
Chaudhari, A. C. (1933). Ind. J. Vet. Sci. & Anim. Husb. 3, 2, 174.
Crichton, J. A. (1930). J. Dairy Res. 2, 1.
Orr, J. B. (1929). Minerals in Pastures, H. K. Lewis, London.
Theiler, A. and Green, H. H. (1932). Nutri. Absts. Rev. 1, 3, 359.
Viswanatha Iyer, A. (1935). Ind. J. Vet. Sci. & Anim. Husb. 5, 2, 129-139.
SELECTED ARTICLE
THE NUTRITIVE VALUE OF RAW AND PASTEURIZED
MILK FOR CALVES
BY
G. S. WILSON, F. C. MINETT AND H. F. CARLING
From the London School of Hygiene and Tropical Medicine, the Research Institute in
Animal Pathology, Royal Veterinary College, and the Berks and
Bucks Joint Sanatorium, Oxon
(With 1 Figure in the Text)
(Reprinted from The Journal of Hygiene, Vol. 37, No. 2, April, 1937, pp. 243-253.)
THE value of pasteurization in destroying pathogenic bacteria in milk and so
safeguarding the health of the human population is beyond question. While
admitting this, certain workers have hesitated to give their unreserved support
to pasteurization on the ground that it may have some deleterious action on the
nutritive value of the milk which will more than counteract the beneficial effect
resulting from the destruction of harmful micro-organisms.
A number of papers have been published in recent years describing attempts
that have been made—chiefly on rats and children—to determine whether in
fact pasteurized milk is in any way inferior in its nutritive qualities to raw milk.
The literature on this subject has been reviewed by Stirling and Blackwood [1933]
and M'Candlish and Black [1935]. Many of the results are ambiguous, and none
of them, in our view, definitely answers the main question at issue. The fact
that in several experiments no statistically significant difference was found be-
tween the two classes of milk is not sufficient to give us the assurance we need,
for the numbers of animals or children under observation were sometimes so
small as to allow a possible real difference to be obscured by the inevitable accom-
panying error of sampling. Moreover, the interpretation of the results is rendered
difficult by the circumstance that in all these experiments the subjects under test
were being fed with milk from a heterologous animal source.
It seemed to us that if a clear answer was to be obtained to our main question
it was desirable to make a direct comparison of the two types of milk on the
homologous animal species, namely the calf. Comparatively few experiments
on this animal are on record, and those that have been described have suffered
( 55 )
56
Nutritive Value of Raw and Pasteurized Milk
(1) from being carried out on too small a number of animals to enable a satisfac-
tory result to be obtained, and (2) from being complicated by the occurrence of
disease in the experimental animals which may have entirely falsified the outcome
of the investigation.
In planning an experiment to be carried out on calves, we determined as far
as possible to avoid the sources of these errors. Since for financial and other
reasons an experiment on really large numbers of animals presented formidable
difficulties, it seemed of special importance to make our observations on absolutely
healthy animals so that the results might not be influenced in any way by the
occurrence of latent or overt disease.
DESCRIPTION OF EXPERIMENT
With the kind consent of the Committee of the Berks and Bucks Joint
Sanatorium, permission was obtained to carry out an experiment on the herd
attached to the Sanatorium. The general plan of the experiment, which lasted
from July 1934 to September 1936, was to feed alternate calves, as they were born,
on raw or pasteurized milk for eight weeks, and to compare their rate of growth.
The relevant details may best be considered under separate headings. It may
be pointed out at this stage that the management of the herd and the day-to-day
control of the experiment was under the personal control of one of the authors
(H. F. C.).
The Peppard herd.—This contains about twenty Shorthorn cows which calve
down regularly throughout the year so as to maintain a more or less constant
supply of milk for the Sanatorium. Except for two pedigree bulls, which have
been bought in, the herd has been self-contained since 1932. The animals are
kept out at pasture during both summer and winter, and are never stalled except
for the actual purpose of milking, which is done by hand morning and evening.
Calving takes place in the open field. Bull calves are sold at about one week
old ; heifer calves are mostly kept for replacements.
Since March 1925 the herd has been tested at six-monthly intervals with
tuberculin ; all positively reacting animals have been sold off. The last occasion
on which positive reactors were found was in June 1932, when two animals had
to be removed from the herd. During the whole course of the feeding experiment
the herd remained completely free from tuberculosis. Moreover, at a herd test
carried out a month after the conclusion of the experiment, all animals passed
satisfactorily.
With regard to contagious abortion, the history of the herd has been pecu-
liarly satisfactory. Two cows aborted in January 1928 and were found to give
a positive blood agglutination reaction to Brucella abortus. The herd was
G. S. WILSON, F. C. MINETT AND H. F. CARLING 57
vaccinated the same month with a living vaccine, since when there has not been a
single case of abortion. At a herd test carried out some time before the com-
mencement of this experiment, no animals showed the presence of specific agglu-
tinins in the blood.
Johne's disease has seldom occurred; the last animal to be affected with it
was in September 1929.
The herd has always been relatively free from udder troubles. In October
1936, at the conclusion of the feeding experiment, the milk of each cow was exa-
mined culturally by plating in ox-blood agar, with the result that of the eighteen
animals present three were found to be affected with streptococcal mastitis in a
subclinical form.
Pasteurizer.—To ensure a supply of adequately pasteurized milk, it was decid-
ed to pasteurize the milk on the premises; A small batch pasteurizer, of 2-gallons
working capacity, fitted for low-pressure steam heating, was specially manufac-
tured for us by Messrs. Brown and Son, Ltd., London, N. 19. It was made of
copper, coated with pure tin, and consisted of an outer steam-heated jacket and
an inner vessel, to hold the milk, which could be lifted out for cleaning and steriliz-
ing purposes. It was provided with an overhead motor-driven agitator and an
auto-thermostatic control. In practice the milk was heated up till the indicator
thermometer, which dipped into the milk itself, registered 145°F. (62.8°C.). The
temperature was maintained at this level for 30 minutes, after which the steam
was turned off. The milk was then cooled, either to 90°F. (32. 2°C.) if it was to be
fed immediately to the calves, or to the temperature of the tap water if it was to
be kept for some hours.
The milk.—The mixed milk of the herd from the morning's milking alone was
used. The required quantity was divided into two parts. One part was pas-
teurized at once at 145°F. (62.8°C.) for 30 minutes ; the other half was left raw.
Part of the raw and part of the pasteurized milk were fed at a temperature of about
90°F. (32.2°C.) to the calves in the morning. The remainder of the raw and pas-
teurized milk was water-cooled and kept in covered pails in a cool dairy till the
evening, when it was warmed to about 90°F. and fed to the calves.
Though this was the routine practice throughout the greater part of the ex-
periment, a misunderstanding occurred at the commencement which was responsi-
ble for some trouble during the first six months. Instead of the milk, immediately
after pasteurization, being divided into two parts, one part being cooled to 90°F.
and fed to the calves in the morning, the other part being cooled to tap-water
temperature and kept for the evening feed, the whole of the pasteurized milk was
cooled only to 90°F., and the part for the evening feed was left to cool down slowly
in the dairy. As a result considerable bacterial multiplication occurred in the
I
58
Nutritive Value of Raw and Pasteurized Milk
pasteurized milk destined for the evening feed, and this appears to have been
responsible for a certain amount of scouring in the calves. As soon as the trouble
was traced to its source, the practice of leaving the pasteurized milk to cool slowly
in the dairy was stopped and the routine described above was enforced. No
further difficulty was experienced from scouring, except in a mild form in occa-
sional calves. It may be noted that the milk was always produced under cleanly
conditions and was of approximately the same standard as Certified milk.
Selection of the calves.—In order to avoid any unconscious bias in the selec-
tion of the calves for the different groups, it was decided to allot alternate calves,
as they were born, to the raw and pasteurized groups respectively* ; no selection
whatsoever was made. Though this would have been an ideal method for a large
experiment, it proved a little unsatisfactory in the present instance. In the first
place it resulted in a very uneven distribution of the sexes, there being far fewer
bull calves allocated to the pasteurized than to the raw group. In the second
place it so happened that two calves, both of which at birth were quite unfit to be
included in the experiment , had to be allocated to the pasteurized group. One
calf, P 1 , was born of a mother which had to be slaughtered a week after parturition
on account of " actinomycosis " of the larynx. Not only was this calf an under-
sized weakling at birth, but it further received a mauling by a horse when it was
one day old from which it never recovered. The other, P 20 , had a very difficult
delivery ; it was unable to stand and had to be held up for feeding. The first of
these animals died in three weeks, the second in a fortnight. In neither instance
could death be in any way attributed to the type of diet that was being given.
These deaths, it may be noted, were the only deaths among calves that occur-
red throughout the course of the experiment. During the previous 15 years there
had been altogether ten deaths among a total of 250 calves born. A loss of two
calves during the experimental period of 27 months might therefore have been
expected on the basis of the mortality rate previously experienced in the herd.
In each group there were four animals which were first calves.
Housing of the calves.—As soon as they were removed from their mothers,
the calves were housed in a wooden shed, opening on one side into a yard about
52 × 36 ft. in area. The shed was divided into three compartments, so that the
calves could be grouped more or less according to their ages. The animals in the
raw and pasteurized groups were run together. Straw was used for bedding.
The diet.—Every calf had its mother's colostrum for the first three and a half
days and was then hand-fed. for eight weeks. At the beginning of the experiment
the calves were given 1 lb. of milk daily per 10 lb. of body weight. This amount,
* For the sake of convenience we ask pardon for the adjectival use, without
inverted commas, of the terms raw and pasteurized in relation to the animals fed.
G. S. WILSON, F. C. MINETT AND H. F. CARLING 59
though more or less adequate for the first few weeks of life, was found to be in-
sufficient for the calves as they grew older. The amount was therefore increased,
though not to a sufficient extent, as it subsequently proved, to allow of optimal
development. The following summarizes the diet received by the different ani-
mals :
(A) Raw calves 1—5, and pasteurized calves 2—6 were given daily 16 oz. of
milk per 10 lb. of body weight for eight weeks.
(B) Raw calf 6 and pasteurized calf 7 were given daily 20 oz. of milk per 10
lb. of body weight for eight weeks.
(C) Raw calves 7—25 and pasteurized calves 8—25 (with the exception of
P 20 ) were given daily 16 oz. of milk per 10 lb. of body weight for the first four
weeks, and 20 oz. of milk for the second four weeks.
The milk was fed at a temperature of about 90°F. morning and evening.
During the first year of the experiment each calf was given a special feeder, from
which it sucked its allotted quantity of milk through a teat. These feeders, how-
ever, proved rather troublesome, and later they were replaced by hand-feeding
from a bucket,
Besides milk, the calves were provided with hay ad lib. Observation showed
that during the first month of life they merely " played " with it, but after that
each animal consumed about 1 lb. a day, rising to 3 lb. by the eighth week.
After they had completed their experimental period of observation of eight
weeks, the calves that it was decided to keep in the herd were removed from the
experimental shed and were given flaked maize, bran, and roots or molassed sugar¬
boot pulp, together with a little milk for the next few weeks.
Recording progress.—Each animal was weighed when it entered the experi-
ment on the fourth day of life, and thereafter at weekly intervals. Careful obser-
vations were made on general condition, and a special watch kept for the develop-
ment of rickets. From time to time outside observers, such as the milk recorder
of the county and local farmers, were brought in to inspect the animals and make
an attempt to distinguish those in the raw from those in the pasteurized group.
RESULTS
The detailed results are set out in Tables I and II.
It will be noted that the average weight of animals in the raw group was
2.23 lb. greater than that of the pasteurized group at the commencement of the
experiment ; this was mainly the result of the smaller proportion of bull calves
60
Nutritive Value of Raw and Pasteurized Milk
in the pasteurized group. At the end of the experiment the average difference in
weight between the two groups was 2.09 lb. The average increase in the animals
of the raw group was 53.72 lb., and in those of the pasteurized group 53.86 lb. In
other words, so far as the average weight gained throughout the whole course of
the experiment was concerned, the two groups behaved for all practical purposes
identically (Fig. 1).
Fig. 1. Graph to show weights of all calves after 1-8 weeks.
This was all the more remarkable considering the difference in the sex dis-
tribution of the animals in the two groups. Male animals usually grow more
rapidly than female. This is well shown in the raw group, in which the bull calves
put on an average of 6½ lb. more weight than the heifer calves. In the pasteurized
group there were approximately twice as many female as male animals and the
average increase in weight of both sexes taken together might well have been
expected, independent of the nature of the diet, to have been less than that in the
raw group in which the sexes were more evenly distributed.