ABSTRACTS
203
discharge from the eyes and nose, in some cases ulceration
of the correa, rapid respiration during the warmer part
of the day and frequent convulsions. Four of the experi
mental animals were given different doses of cod liver
oil and they made a rapid recovery. Three other animals
were given the same doses of cod liver oil in which
the vitamin A was destroyed and the animals showed no
improvement. At this stage the feed was supplemented
with alfalfa hay and pure crystallire carotene in maize
oil. The animals made a rapid recovery. The animals
without vitamin A supplement died on the 179th day of
experiment. Observations showed that night blindness
was the first noticeable symptom in the development of
vitamin A deficiency syndrome, and the author used it
as a guide in determining the depletion of vitamin A
body reserve. It was ascertained that the optimum re
quirement of carotene for cattle was 2,500—3,000 γ
per 100 lb. body weight, and this would prevent
the animal from developing night-blindness.
Further experiments were arranged to determine the
vitamin A requirement of the sheep and angora goats.
The picture of vitamin A deficiency in sheep and goats
was different from those of cattle. Loss of appetite
lasting for several weeks, loss of weight with an unthrifty
appearance, night-blindness and nasal discharge could
be noted. Opacity of the cornea swelling of the limbs
and convulsions were not a costant feature. The de-
pletion time varied according to the exact seasonal time
that they were put on the experiment. It was noted that
the depletion time of the goats born around the first of
March and placed on the deficiency diet in latter part of
November was longer than those animals born about
the same time and placed on experiment in the middle
of February. This indicated that young animals grazing
during their first summer acquire a definite body store
of vitamin A. The survival period in sheep and goats
on vitamin A free diet varied from 226-455 days and 160-
312 days respectively. When night-blindness was used
as a yardstick, the determination of the depletion period
in sheep and goat was much more difficult than it was
in cattle. Also there were no other clinical indications
to determine accurately the depletion period. It was
pointed out that 750 γ carotene per 100 lb. of live weight
might be sufficient under ordinary circumstances but
in the case of stress might be too low. It was also pointed
out that in the vitamin A deficient animals urinary
occlusion developed from 112-343 days.
The author described the sources of vitamin A under
natural condition. Green plants contained abundance
of carotene but as soon as the plant died, be it when it
was cut for hay or from other causes, the destruction
of the carotene began and proceeded at a rapid rate espe
cially in presence of light.
Rapid drying at high temperature of freshly cut green
alfalfa hay preserved much of the carotene.
The author analysed the liver of the young born and
found vitamin reserve. He pointed out that they must
receive carotene or vitamin soon after birth. [D. N. M.]
Post-mortem changes in New York dressed
poultry at 35°F. G. F. STEWART, BELLE LOWE
and MARY MOOR (1941). U. S. Egg and
Poultry Mag., 47, 542
MOST of the poultry sold in the large consuming markets
of the United States of America are New York dressed
(bled and plucked but not drawn). During the course
of marketing they are held at 30-40°F. for varying inter
vals, sometimes for several days, before being eviscerated
Consequently there is likely to be variations in flavour
and aroma as well as tenderness of the carcass. This
investigation was undertaken to determine how long
young chickens (boilers and fryers) should be held at
35°F. to permit the passong of rigor mortis and bring
about the optimum degree of tenderness, as well as to
study the kind and degree of deteriorative changes which
occur in New York dressed poultry held at the above
temperature.
White Leghorn cockerels weighing 2.3 lb. after being
killed, bled and plucked were placed in a room at 35±1°F.
After various intervals of time carcasses were removed,
eviscerated, ccoked and studied. Cooking, palatability
and shearing tests were carried out with the meat of
these birds.
The results of the study showed that New York dressed
birds hung in air at 35°F. began to undergo deteriorative
changes within 8 hours after killing : the first of which was
the appearance of a bile stair on the liver. Off-odours
in the kidney area became clearly noticeable after 24
hours. These gradually spread and intensified finally rea
ching the wing joint in four days whereafter there seemed
to be no further increase. From the flavour scores of the
cooked meat it was evident that deteriorative changes
set in almost at once as seen in the meat of the thigh and.
breast muscles and became plainly noticeable in 48 hours
but progressed less rapidly in the latter. Rigor
mortis was found to set in during cooking when birds were
held less than 4 hours and often remained even after cook
ing but never occurred after eight hoursof holding. Tender
ness in poultry meat increased rapidly with the passing
of rigor. The loss of shearing force in the cooked breast
muscle seemed to coincide exactly with the increase in the
judges score of tenderness. There seemed to be little
increase in tenderness after 24 hours at 35°F.
(The
term 'shearing force' is used to denote the force necessary
to cut off a portion from the whole, in this case the
reference is to meat. [T. S. K.]
The effect of high-temperature short-time
forewarming of milk upon the heat stability
of its evaporated product. B. H. WEBB and
R. W. BELL (1942). J. Dairy Sci., 25, 301
THE effect of high heat treatment or 'high-temperatur e
forewarming, of milk upon the heat stability of evap
orated milk made from it has been studied.
Milk
standardized to a fat, solids-not-fat ratio of 1: 2.29, was
forewarmed (by forcing it through 0.18 inch I.D. stainless
steel tubular heaters) over a range of temperatures from
101°C. to 165°C. in 4 seconds, held for 25 seconds and
cooled to a temperature less than 38°C. in 4 seconds.
The forewarmed milk was then concentrated under 28 to
29 inches of vaccum to less than one half of its initial
weight, quickly heated to 80°C., homogenized at once
under 2500 pounds per square inch pressure, cooled and
standardized with water to 26 per cent total solids (18
per cent solids content in the case of skim milk). As
skim milk did not always produce the same type of heat
stability curve as whole milk, most of the experiments
were conducted with whole milk. Control samples
were forewarmed (by heating with thorough agitation
in a steam jacketed kettle) to 95°C. and held for 10
minutes. Heat stability determinations were made by
heating the samples of concentrated milk in small cans
in a pilot sterilizer (sterilization temperature 115° C. for
whole milk and 120°C. for skim milk) until coagula
tion was observed. When stabilizing salts were used,
1 ml. of standard salt (phosphate or calcium) solution
was added to 130 ml. of milk.
Heat stability of the test samples was generally about
two and occasionally as much as six times greater than
that of the control samples. The degree of stability
brought about was not the same in various samples of
milk and the average values for the stability of whole