ABSTRACTS
119
Millk secretion studies with Newzealand Romney Ewes.BARNICOAT, C. R., LOGAN,
A. G., and GRANT A. I. (1949). J. Agric. cult. Sci. 39, 44
T HE authors have determined the milk yields of over 200 New Zealand Romney
ewes, and the factors affecting milk yield by allowing the lambs to suckle
usually six times during a 24 hours period and weighing the lambs on a balance
sensitive to 1/4 oz. before and after every feed. It was found that there was fair,
agreement between the yields estimated on two occasions with one day's rest between
each. Usually 8 or more experimental milkings were carried out during each ewe's
lactation cycle of approximately 12 weeks with one week's interval between
two consecutive recordings at the beginning of the lactation and at 10 to 14 days
interval later on. From the curve obtained by plotting these milk yields against
the period of lactation, the milk yield for any other period was obtained.
It was observed that the milk yield per animal per day varied from 23 to 73 oz.
with an average of about 4 lb. for 100 ewes. The yields of ewes with twin lambs
were about 3 higher than those of ewes with single lambs. The milk yield of 6 year
old ewes was found to be 15 per cent higher than that of 2 year old ewes. The corre-
lation coefficient between the live weight and milk yield was not significant. Ewes
lambed in the beginning of September were found to have the maximum milk yields.
The low yields of early lambers is attributed to the quantity and quality of the
pasture, and that of late lambers to the quality of the pasture available immediately
before and during lactation. Suckling by twin lambs produced more milk. Lambs
from ewes on a low plane of nutrition were of a lower birth weight. Nutrition
during lactation was found to be more important than nutrition during late preg-
nancy in determining milk yield. But maximum yield is obtained only by liberal
feeding during late pregnancy and throughout lactation.
The fat content of the milk of these ewes was found to be high (usually above
7.0 per cent) with considerable variation from milking and from day to day. (T. M. P.)
Observations on efficacy of Vitamin supplements for New Born Calves. ERR, R. E.
SCOTT, G. W., NORTON C. L. and Morrow K. S. (1949). J. Anim. Sci. 8, 3, 425, 431
T HE findings indicate, superficially at least, that massive supplementation of
Vitamin A and D on the day of birth should not be expected to compensate for
inadequate care and housing of calves, neither it tends to reduce incidence of cold,
pneumonia, scours and death losses, on tests under a wide variety of conditions.
Special pellets with different markings containing 250,000 I. U. of vitamin A,
50,000 I. U. of vitamin D and 500 mg. of niacin and white placebo pellets were alter-
nately fed on the day of birth to 347 calves located on 59 farms in Washington,
Rhode Islands and New Hampshire and their records on cold pneumonia and death
losses were maintained.
There was no difference in the incidence of scours ; 31.7 per cent of the calves
supplemented with A and D on the day of birth scoured as compared to 32.3 per
cent when no supplement was given.
The mean blood plasma vitamin A level of 32 experimental Holstien calves was
11.06 micrograms per 100 ml. of plasma as compared to 9.78 for 36 control Holstien
calves at 46 and 47 days of age respectively.