114
Sire Index for Milk Production in Cattle
These observations are in confirmity with
those of Steyn [1931], though Frohner [1919]
reported the death of a horse within 52 hours of
feeding 2.25 kg. of mature seeds.
ACTIVE PRINCIPLE
Van Itallie and Bylsma [1928] found the
total alkaloidal content of 0.2 to 0.5 per cent
to consist chiefly of hyoscyamine in the leaves
and 0.2 to 0.4 . per cent of hyoscyamine and
hyoscine respectively in the seeds; Steyn [1934]
reported a total alkaloidal content of 0.43 per
cent, chiefly hyoscyamine. Chou [1935] dis-
covered datugen and datuguinine amounting to
0.3 per cent., in addition to hyoscyamine,
hyoscine and atropine. Fluck [1939] found that
re-wetting or checking the drying process and
harvesting the wet plant gave low alkaloidal
yields. Sirgo [1939] observed that Datura
seeds exposed to acetylene or carbon monoxide
gases matured earlier but contained a lower
alkaloid content than normally-ripened seeds.
DISCUSSION
The observations recorded in Table I and II
indicate the innocuous nature of Datura stramo-
nium growing in the two localities. A number
of factors affect the toxicity of the plant, import-
ant among them being (1) the amount eaten in
a given period of time; (2) the condition of the
soil—its porosity, moisture and oxygen content;
(3) climatic conditions, which may be responsi-
ble for the production of a variable quantity of
the alkaloid by their direct action on the micro-
biological processes, which in their turn may
affect the toxicity of the plant; (4) cultivation,
which not only decreases the toxicity but in
some cases, as in gourds, causes the entire toxi-
city to be lost [Suyi Chen and Wei Jenkao,
1936], while the difference in toxicity between
the so-called wild plants of one region and
another may be due to their being recent escapes
from cultivation [Watts, 1908]; (5) the time of
year, and even the time of day, which may in-
fluence the toxicity of a plant, [Miklos Jamesek,
1932]; (6) the distribution of the toxic principle,
which may not be the same in all parts of the
plant; (7) the transmission of toxicity to pro-
geny as seen in different degrees in Atropa
belladona and other plants; (8) the stage of
growth of the plant and (9) the nature and in-
tensity of light, which influences the alkaloid
content of Datura from 0.1 to 0.254 per cent
[Werner Braun, 1939].
It seems that the alkaloidal content in these
plants was not high enough to cause typical
toxic symptoms. However, from some of the
mild symptoms observed by feeding the plant
at Izatnagar it appears that the hill variety is
even poorer in these alkaloids.
SUMMARY
Two samples of Datura stramonium Lin, a
hill variety and a plains variety, were fed to
bulls, sheep and goats, to study their toxicity.
The hill variety appeared to be considerably
poorer in alkaloid content than the plains
variety. Both the plants were innocuous.
REFERENCES
Chou, J. Q. (1935). Chin J. Physiol. 9, 77
Fluck, H. (1939). (Abst.) Biol Abstr. 34, 3878
Frohner, E., (1919). Lahrbuch der Toxikologie. Verlag
Von Ferdinand Euke. Stuttgart.
Miklos Jamesek.
(1932).
Mezodazd Saji Kuhetasok.
5, 283
Sirgo. V. (1939). Pharmacia.
(Ertoma) 19, 78
Steyn D. G. (1931). 17th Rep. Dir. Vet. Ser. and An.
Industries, Union of S. Africa
Steyn D. G. (1934). Toxicology of Plants in S. Africa.
Central News Agency Ltd., S. Africa.
S. Suyi Chen & Wei Jenkao (1936). J. Chin. Pharm.
Assoc. 1, 38
Van Itallic and Bylsma U. G. (1928). Toxicologie en
Garechlelika.
Watts, G. (1908). The Commercial Products of India.
John Murrey, London.
Werner Braun (1939). (Abst.) Biol. Abstr. 1940. 34,
4228.
NOTE ON THE METHOD OF CALCULATING SIRE INDEX FOR MILK
PRODUCTION IN CATTLE
By P. V. SUKHATME, PH.D., D.Sc., Statistician, Imperial Council of Agricultural Research,
New Delhi
(Received for publication on 27th March 1944)
THERE are two ways of using the information
about the progeny of a sire in judging his worth:
Progeny Test and Sire Index.
The former
consists in making a test of significance of the
difference in yields between the daughters of
a sire and their mothers and shows whether a
sire can produce daughters which average better
in milk yield than their dams, when the dams,