254
ABSTRACTS
Foot-Rot in sheep: A transmissible disease due to
infection with Fusiformis
nodosus (n. sp.).
Studies on its cause, epidemiology and control.
W. I. B. BEVERIDGE (1942). Bull. Coun. Sci.
Industr. Aust. 140
THE author discusses Foot-Rot of sheep in rainy areas
in South Australia and the nature of the causal organism.
The incidence of the disease is highest on lush pastures. A
possible predisposing factor is percutaneous infection
with larvae of Strongyloides papillosus. The author
refutes the claim that Fusiformis necrophorus or Treponema
podovis is the cause of Foot-Rot, and states that a gram
negative, non-motile, non-sporing and anaerobic bacillus,
F. nodosus (n. sp.) is the causal factor. This organism
grows on plate cultures only in the presence of horse serum,
and surface colonies etch in this medium. Sheep serum
inhibits the growth and the best growth is obtained on
cystine V.F. agar medium in an atmosphere of 10 per cent
CO 2 . An atypical spirochaete (S. penortha) and a motile
fusiform organism are commonly found in association
with this organism. The disease is readily transmitted
experimentally. The lesion is typified by a slow separa-
tion of the horny parts of the foot as the result of an un-
derrunning infection of the soft tissue. Differential diag-
nosis is made clinically or by the detection of the causal
organism in smears from the diseased part. The author
concludes that F. nodosus is the primary causal agent and
that S. penortha is probably a ' specific' accessory cause.
The motile fusiform is regarded as a secondary invader.
These findings were confirmed by studies on Foot-Rot
in U. S. A., New Zealand and England.
A scheme for control measures is described, which con-
sists in removing all affected animals and carriers, es-
pecially in summer when the disease is quiescent. Green
pastures are decontaminated by leaving them unstocked
for 2-3 weeks. Large scale field trials for eradication of
the disease gave satisfactory results. [W.M.K.]
The need for pantothenic acid and an unidentified
factor in reproduction in the domestic owl.
M. B. GILLIS, G. F. HEUSER AND L. C. NORRIS
(1942). J. Nutri. 23, 153
THE role of pantothenic acid in the nutrition of the hen
is not so well established as that of the chick. The authors
in the present investigation have presented evidence which
shows that pantothenic acid is required for reproduction
in hens. Five groups, each having twelve White Leghorn
pullets, were selected for uniformity in egg production,
body weight and general physical condition. The males
were rotated frequently among the different groups, in
order to eliminate differences in breeding capacity. The
basal diet contained an adequate amount of all the known
vitamins, other than pantothenic acid. The pantothenic
acid contained in the cereal portion of the basal diet was
destroyed by heating in an oven for 36 hours at a tem-
perature of 120°C. The liver extract used in the experi-
ment was also heated in an oven for the same length of
time as the cereals.
The birds in all groups were fed on the basal diet for a
preliminary period of eight weeks. This was followed by
two experimental periods of 10 weeks each, during which
time the different groups received various combinations
and amounts of pantothenic acid, heated liver extract and
heated yeast filtrate. At the end of the preliminary
period, the hatchability of all groups of eggs was zero
which proved that the basal diet was deficient in a factor
or factors necessary for reproduction. The result obtained
during the experimental period showed that heated yeast
filtrate and heated liver extract, when added to the basal
diet, were ineffective in promoting hatchability. The
addition of pantothenic acid alone to the basal diet
increased hatchability from zero to 10-30 per cent.
The hatchability was increased to 50-60 per cent when
pantothenic acid was added to the basal diet along with
heated liver extract. This proved that for reproduction
the hens required besides pantothenic acid an. unknown
heat stable factor or factors present in heated liver ex-
tract. The heated liver extract alone had no influence on,
hatchability, except in the presence of pantothenic-
acid. [S.B.]
Refrigerated brine sprays for cooling dressed
poultry. M. H. SWEET AND G. F. STEWART
(1942). The U. S. Egg and Poultry Magazine
48, 261 (8 Refs.)
THIS paper describes experiments undertaken to discover
a rapid, practical method for cooling dressed, undrawn
poultry. From a review of the literature the authors
conclude that prompt cooling of undrawn poultry is a
primary essential in quality preservation and that much
loss in storage is incurred through improper cooling.
The factors which affect the cooling rates are the amount
and distribution of fat and the weight and surface area
per unit of volume. Since the thermal conductivity of
fat is only 30 per cent that of water, a layer of subcutane-
ous fat acts as an insulator and thereby retards the
cooling process.
With air cooling (temperature of 35°F.) it took 8 hours
to cool 2½ lb. Leghorn cockerels to 36°F. With roasters
weighing 53/4 lb. the corresponding time was only 11 hours.
The adverse effect of fat on cooling is clearly shown for
fat fowls weighing 63/4 lb. required 16 hours to cool to
36°F. Other lots of fowls were cooled by spraying with
water at 33-35°F until the internal temperature dropped
to 35-38°F. The birds were hung so that the spray
struck the thigh region and flowed down over the body,
wings and head. With water cooling the time required
to cool was reduced to 20-27 per cent of that in air at 35°F.
However, this method even though resulting in a consider-
able saving of time in cooling was too costly for commercial
plants. Cooling birds in a brine spray at 32°F. for periods
of 15-60 minutes followed by cooling in a room at 35°F
reduced the cooling time over that in air at 35°F. but prov-
ed slower than cooling in a continuous water-spray at 33-
35°F. In other experiments it was found that by spray-
ing the dressed carcasses with refrigerated brine (22-28°F.)
for periods of 10-60 minutes and then hanging in air at
35°F. (cold shock method) the total cooling time was-
less than when continually in air at 35°F. but longer than
when continually in spray at 35°F. In another series of
experiments with roasters it was found that brine spraying
at 20°F. for 25 minutes gave even quicker cooling results
than continuous water spraying at 35°F.
By using a continuous water spray (33-35°F) turkeys
of 15-25 lb. weight were cooled to 36°F. in seven to ten
hours, but from the commercial aspect this period was too-
long. From the results of the study it would appear that
the most rapid and practical method for cooling turkeys
would be a 20-21°F. brine spray for 20-30 minutes
followed by a rinse with cold water and storage in air at
35°F. [A.J.M.]