ABSTRACTS
297
(3) P-aminobenzoic acid has been found to
counteract the germicidal properties of sulfanilamide
on the Lancefield group B streptococci. Under the
conditions of these experiments, it was found that
one part by weight of p-aminobenzoic acid nullified
the germicidal effect of 25 parts by weight of sul-
fanilamide for strain F-12a-4.
(4) It appears from the results of these experi-
ments that the therapeutic basis of sulfanilamide for
Lancefield group B mastitis streptococci is based on
at least three factors : the temperature of the animal
at the time of treatment; the concentration of the
drug at the focus of infection ; and the sulfanilamide-
inhibiting substances which may be present
in the infected area.
REFERENCES
1 Khakavas, J. C., Palmer, C. C., Hay, J. R., and Biddle,
E. S.: Homogenized Sulfanilamide-in-Oil Intramammary
Injections in Bovine Mastitis. Am. J. Vet. Res., 3,
(1942): 274-284
2 White, H. J., and Parker, J. M.: The Bactericidal
Effect of Sulfanilamide upon Beta Hemolytic Streptococci
in Vitro. J. Bad., 36, (1938): 281-298
3 Heishman, J. O., and Miller, W. T.: The Action of Sul-
fanilamide on Mastitis Streptococci in Vitro J. Amsr. Vet.
Med. Ass. 96, (1940): 176-179
4 Marshall, E. K., Jr., and Litchfield, J. T., Jr.: The Deter-
mination of Sulfanilamide. Science, 88, (1938): 85-86
5 Woods, D. D., and Fildes. P.: The Anti-Sulfanilamide
Activity (in ritro) of P-Aminobenzoic Acid and Related
Compounds. Chen. Indust., 59, (1940): 133
6 Woods, D. D.: The Relation of P-Aminobenzoic Acid
to the Mechanism of the Action of Sulfanilamide. Brit.
J. Exper. Path., 21, (1940): 74-90
7 Fildes, P.: A Rational Approach to Research in Chemo-
therapy. Lancet, 1, (1940) : 955-957
8 Rubbo, S. D., and Gillespie, J. M. : P-Aminobenzoic Acid
as a Bacterial Growth Factor. Nature, 146, (1940) :
838-839
9 Ansbacher, S. : P-Aminobenzoic Acid, A Vitamin,
Science, 93, (1941): 164-165
ABSTRACTS
The water economy of farm animals. I. LEITCH
and J. S. THOMSON (1944). Nutrition Abstracts
and Reviews 14 (2), 197-223
ALTHOUGH water metabolism is an important
physiological factor having considerable bearing on
animal production, the subject has not received the
attention it deserves from research workers. In the
published literature, most of the reference is concerned
with cattle, references being very few on other farm
stock.
Since the dry matter of a ration is generally ad-
justed to the metabolic needs of the consumer, the
existence of a relationship of total water intake to
the dry matter of feed might be considered probable.
The available data, however, show the lack of such
straightforward relationship. The absence naturally
suggests several ascertainable causes which may
influence water intake.
A close examination of several methods of disposal
of ingested water should furnish data on which the
requirement can be based. The disposal of water
from the body takes place through faeces and urine.
A portion is vaporized to dissipate heat increment
incident to food consumption. In growing or fatten-
ing animal, water is retained for the newly-built
tissues. In milch cows, water is disposed of in the
milk.
The water content of the faeces is independent of
the protein content in the ration and of plane of
nutrition. When, however, the ration includes a
roughage of lower digestibility, the faeces voided is
more moist Although data are few to study the
possible correlation between the moisture and other
constituents of faces, it is noted that moisture content
increases with increasing crude fibre and nitrogen-
free extract, but by no semblance of mathematical
proportion. The fæcal moisture in cattle can be
approximately reckoned as 80 per cent in steers and
dry cows, and 85 per cent for milch animals. In
percentage the water content in the faeces of cows in
milk seems only slightly higher than that of dry
animals, but as the total weight of faeces voided by
the former is much greater, the difference becomes
highly significant from the standpoint of water
requirement. The quantity of urine in cattle is
determined primarily by the amount of some non-
nitrogenous substance or substances derived from
roughages. If the protein ingestion is high, the
urinary volume goes above that determined by the
roughage intake. In steers and dry cows on
maintenance ration or roughage, the weight of urine
excreted will be of the order 5—7 kg. daily. From
the existing data it is difficult to explain how the
environmental temperature should affect the urinary
volume.
Water lost as vapour from skin and lungs can
be determined directly in the calorimeter or indirectly
by determining the ' insensible loss of weight' minus
the weight of methane and the balance of carbon
dioxide expired over oxygen taken in. By using
both methods, data have been collected which on
critical examination show that the loss of water by
vaporization depends on : (1) Condition of coat; a
heavy coat of hair reduces heat emission by radiation
and conduction and thus an extra burden is put on
water evaporation, (2) Plane of nutrition ; with the
rise in plane of nutrition the amount of heat to be
dissipated increases which in turn necessitates greater
loss of water by vaporization, (3) External tempera-
ture ; the observations indicate that water losst by