March, 1949]
ABSTRACTS
91
15 to 18 females in each breeding pen. Any sires already proven superior by pre-
vious progeny tests are recommended to be used continuously through the breeding
season, in order to produce the maximum number of superior birds.
In regard to breeding for viability in the fowl the authors endorse the old saying
that the sire is more than half the flock, further males are more easily progeny-tested
than females. When the mortality in the flock ranged from 37 to 53 per cent in
the test period, the records of 86 sires each of which had 50 daughters or more, on
analysis, revealed that about 30 daughters were enough for testing the ability of a
sire's progeny to live. More daughters were, however, found necessary in the case
of the population with lower mortality. Familial differences in resistance to a
specific disease (avian leucosis complex) were obvious when it killed 12.6 per cent
of the population or more, but not when it killed only 8 per cent. As the numbers
of daughters raised from single dams in one season are too small for differentiation
of families the authors conclude that tests of dams are less reliable than those of
sires. On the other hand the number of daughters necessary for egg laying trials
is much less than that required for tests in regard to viability. Six daughters with
completed records appeared adequate for tests of dams for ability to transmit egg
laying qualities. (S.G.I.)
THE EFFECT OF COBALT ON GROWTH AND CERTAIN BLOOD
CONSTITUENTS OF SHEEP
Pope, A. L, Phillips, P. H. and Bohstedt, G. B. (1947). J. Ani. Sci. 6. (3)
I N 1944, the problem of low wool and lamb productions arose in Northern Wis-
cousin. In the begining it was considered to be a parasite problem complicated
by anaemia and a decrease of vitamins A and C in blood plasma. The symptoms
were weakness, emaciation, lowering of vitamins A and C and haemoglobin contents.
An internal parasitic infection was also noticed. The soil was sandy hence liable
to mineral deficiency; it was decided to find out effects of mineral trace elements
mixed with salt.
The authors divided the experimental animals (sheep) in two groups which
were similar in general condition and body weight. Group I was fed on a ration
consisting of iodine, manganese, copper and iron. Group II was given cobalt sul-
phate in addition to the ration fed to animals of group I. Sheep of group I developed
symptoms similar to those noticed in the dying sheep in the country around, while
the sheep of group II showed an increase in weight and haemoglobin content.
Later on, cobalt sulphate was added to the ration of group I and it was noticed
that the sheep regained their appetite and commenced feeding within three days.
After four weeks of feeding they showed an increase in weight, in haemoglobin con-
tent and in the concentration of vitamins A and C in the blood plasma. (K.C.)
CONTENT AND DIGESTIBILITY OF MORNING AND EVENING
CUTTINGS OF ALFALFA
Adolph, William H., Macdonald, H. A., Auilan Yeh and Lofgreen G. P.,August 1947.
J. Ani. Sci. 3, 6
I N 1944, Curtis reported that alfalfa plots cut in the evening yield 19 per cent more
of total dry matter than those cut in the morning. He suggested that there
would be a distinct advantage in cutting all the forage crops in the after-noon rather