384 SECTIONAL TRANSACTIONS.—M. 
in the herbage may be due either to a complete impoverishment of the soil due to 
continuous grazing without any application of fertilisers or to a relatively great 
impoverishment in calcium, which then becomes the limiting factor in the growth and 
composition of the herbage. Soil data are not available for the British samples, 
but in the case of the Falkland Islands, where the herbage is extremely poor in mineral 
constituents, and especially in calcium, the soils are very deficient in calcium though 
containing reasonable percentages of available phosphoric acid and potash. 
It is shown that there is a definite seasonal variation in the mineral content of four 
cultivated pastures examined between May and October. This is most clearly shown 
by calcium, the percentage of which rises to a maximum and then steadily falls, and 
to a less extent by the silica-free ash, phosphoric acid and sodium. The period at 
which the maximum content was reached varied in the different fields, and was 
apparently controlled in great measure by the nature of the grazing. 
7. Capt. W. HE. Exxior, M.P., and Mr. A. Cricnton.—The Mineral 
Requirements of Sheep. 
An investigation on the mineral content of natural uncultivated pastures has 
shown that in many of the hill pastures in Scotland and England there is a deficiency 
of one or more mineral elements which are essential food constituents for herbivora. 
There appears to be a correlation between this mineral deficiency and the state of 
nutrition of sheep grazing on these pastures, as shown by size and constitution of the 
sheep, and the incidence of disease. There is, however, very little experimental data 
on the influence on nutrition of deficiency of minerals in the diet of sheep. 
A number of feeding experiments were therefore carried out to determine whether 
deficiency of calcium and chlorine in the diet of hand-fed sheep would lead to the 
development of signs of malnutrition. In these experiments the influence of cod- 
liver oil, which is known to increase the absorption of calcium from the intestine, was 
studied. It was found that on a diet of turnips, straw and cereal grains (which is 
relatively deficient in calcium, and to a less extent in chlorine), signs of malnutrition 
appeared in growing sheep provided the experiment was continued for five to six 
months. In control groups the addition to the diet of either a calcium-rich salt 
mixture or cod-liver oil prevented the development of these signs of malnutrition 
and was accompanied by a more rapid rate of growth. In two cases brought to our 
notice, in which ‘ bent leg’ (which appears to be similar to rickets) had occurred in 
hand-fed sheep on farms, a marked improvement in the condition followed the addition 
of calcium salts to the ration. There is evidence to show that deficiency of mineral 
elements in pasture is a common cause of malnutrition in herbivora in many pastoral 
areas throughout the world where the modern type of rapidly growing animal has 
been introduced into new countries where animal husbandry is being developed on 
uncultivated pastures. 
8. Mr. A. Cricuton.—Mineral Nutrients in the Ration of Dairy Cows. 
Previous investigations have shown that the mineral part of the ration is an 
important factor in maintaining health in dairy cows, and in maintaining the maximum _ 
milk production of which cows are capable. : 
In this paper there is described an experiment with twelve dairy cows, six of which 
were fed on an ordinary ration, and six on the same ration with the addition of certain ; 
minerals in which the ration was considered to be poor. The milk yield over two — 
lactation periods, the size and vigour of the calves, the health and condition of the 
cows, and the mineral composition of the milk are discussed. ‘ 
The results show that there was a tendency in the second lactation for the milk 
yield of cows receiving the additional minerals to increase, and for that of the cows — 
without such addition to decrease. Moreover, the cows fed with the minerals showed 
better condition and greater ability to resist disease. 
From the results it would appear that the nutritive value of certain rations can — 
be improved by the addition of minerals. An excess, however, may have a detrimental } 
effect. 
9. Prof. G.S. Ropertson and Mr. R. G. Basxerr.—The Influence of 
Minerals on the Growth of Chickens and the Egg Yield of Pullets. 
This paper gives an account of experiments covering a period of two years designed 
to ascertain the effect on the growth of young chickens of adding minerals and materials 
rich in vitamins such as cod-liver oil, marmite, &c., separately and together, to a cereal 
