ABSTRACTS
245
predominates according to the conditions during incuba-
tion. The possible bearing of this on the utilization of non-
protein nitrogen and on the biological value of the proteins
for ruminants is briefly discussed. pH of the rumen ingesta
was found to vary from time to time between 6.3 and 7.4.
No correlation was found between the pH. during incubation
and the amount of protein synthesis, provided the pH lies
within the above limits. Relative amounts of protein syn-
thesis in presence of various carbohydrates have been studied.
Starch appeared to have the most stimulating effect. [A.
W.Z.]
Improved breeding for milk production.
JOHN HAMMOND (1943). Agriculture 50, 242-5
To make the best use of the limited animal feeding stuffs
available at the present time and in the immediate post-war
period, it is necessary to breed cows with high efficiency
in milk production, as the dairy cow is the most economical
converter of feeding stuffs into human food. The practical
means by which this can be brought about may be divided
into:
(a) The breeding of dairy bulls which will transmit high
milk-producing capacity with a great degree of certainty.
This can be achieved by breeding young bulls from progeny-
tested bulls only. By using a succession of proven bulls
in a herd it is possible to breed bulls which will transmit
a high degree of productive capacity. Provided the sire is
well bred for milk, bulls for commercial herds can be ob-
tained by grading-up cows of high productivity. To over-
come the difficulties of breeders in the United Kingdom in
rearing all their bull calves to breeding age, it is suggested
that either the bull calves should be reared on the War
Agricultural Executive Committee's farm (if suitable faci-
lities are available) or week-old calves should be supplied
to the commercial dairy farmer to rear for himself.
(b) The means by which the commercial milk producer
can grade up his herd by the use of such bulls. The keeping
of heifer calves for rearing from the best cows is a good
practice, but it is slow because of the limited number of
offspring produced by a cow. A bull will produce on an
average 35 calves in a year (and with artificial insemination
up to 1,000, given great density of cow population), as com-
pared with only one from a cow. Progress can thus be made
much more rapidly by concentrating attention on the bull
used. Dairy cattle should be bred pure or graded up to
a pure breed. The factors to be considered in deciding the
pure breed to which a herd should be graded up are : (1) the
suitability of the soil, climate and the environment of the
holding for a particular breed ; and (2) the purpose for which
the breed is kept. The rapidity with which grading up to
a high-producing pure breed can be effected is often not fully
appreciated. A low producing non-descript herd can in two
generations be made into a herd of quite reasonably good
production and type by grading up with high-producing,
pure-breed bulls. In small herds, artificial insemination
from a well-bred dairy bull may perhaps be very convenient
and economical.
The need is emphasized for the problem of breeding for
milk production to be attached on a broad community basis
for the common good of dairy farmers. [T. A.S.]
The treatment of mastitis by irrigating the
udder with a solution of proflavine sulphate
combined with the use of a mixed vaccine.
H. S. COCKBURN (1942). Vet. Rec. 21, 54
THE author reports that cows tolerate an udder infusion
at one in 5,000 or even one in 2,500 proflavine sulphate
(as compared with standard one in 10,000 solution of acri-
flavin) without any apparent injury to the udder or loss
of milk. His report is based on experiments in 39 cows
in which 71 quarters which were treated by irrigation in
this way (except in 2 cases in which one in 7,500 solution
was used). A maximum of three irrigations were given at
an interval of about one week and a mixed mastitis vaccine
was in most cases given subcutaneously at first and second
irrigations in doses of 0.5 and 1.0 c.c. 28 cases showed clini-
cal recovery in a period of one to three weeks and of the
71 quarters irrigated 49 resolved, i.e. a recovery rate of
71.8 per cent in cattle and 69 per cent in affected quarters.
He concludes that with its foregoing treatment quarter
figures are slightly better in comparison with its acrifla-
vine combined vaccine method. [W.M.K.]
The value of alfalfa and certain of its fractions
in the nutrition of breeding ewes
IN further study by the Indiana Experiment Station
of the deficiencies of the oat straw, corn silage, yellow corn
silage, yellow corn, and cane molasses ration for sheep, a
nutritive value for growth, maintenance, and milk pro-
duction in ewes was demonstrated for dehydrated and
field-cured alfalfa hay. All of 14 lots of 15 yearling ewes
each received rations of yellow corn, corn silage and corn
meal. Average daily supplements were provided in different
lots of about 2.5, 1.6, 0.86 and 0.42 lb. (1.2, 0.72, 0.38,
0.19 kg.) of dehydrated alfalfa hay with varying amounts
of oat straw meal sufficient to supply necessary roughage.
Other lots received field-cured alfalfa meal, concentrated
alfalfa juice, residue from fresh alfalfa and ether extract
from alfalfa cake, cottonseed meal, commercial casein, or
dehydrated oat grass. The energy content of the ration
was equalized by variations in the amount of corn fed.
The oat straw ration was improved with casein and cotton-
seed meal but was not as good as with supplements of alfalfa
hay or alfalfa products. A supplement made up of the com-
bined fractions of alfalfa press juice, fat solubles from alfalfa
hay. and pressed alfalfa cake produced growth in ewes of
30.9 lb. (14 kg.) which was comparable to 38.5 lb. (17.5 kg.)
by the lot receiving the largest amount of dehydrated alfalfa.
An average gain of 50.9 lb. (23.1 kg.) in the ewes during
pregnancy was produced with dehydrated oat grass supple-
ment. The weight of milk consumed by the lambs was
ascertained by weighing the lambs before and after nursing.
[Scientific Newsletter, Agriculture, Genetics No. 10, The
United States Office of War Information.]
Studies on the creeper fowl. XV. Maternal
inheritance in survival of embryos from
reciprocal crosses involving the creeper
factor
RECIPROCAL brother-sister matings between creeper and
normal chickens were arranged in order to determine whether
creeper-laid eggs hatched less well than normal laid eggs.
Owing to the fact that the effect was slight, elaborate pre-
cautions were taken against errors. The results showed
that there was a significantly larger mortality for creeper-
laid eggs in the 18-22 day incubation period, but not earlier.
The ratio of creeper-normal chicks hatching was not affected.
The explanation given is that, owing to defective endosteal
bone trabeculae of the hens caused by the creeper factor,
less calcium can be stored, thus causing eggs laid to have
too thick or too thin shells. [Scientific Newsletter, Agricul-
ture, Genetics No. 10, The United States Office of War Infor-
mation.]
MGIPC—M—III-1-117—28-6-46—520.