SPECIAL FEATURES 181 
for in healthy birds and an increased egg yield. To promote 
exercise it is well to keep the floor of the laying pen or scratching 
shed covered to a depth of four or more inches with good litter, 
and during the winter throw therein at least half of all the feed 
consumed. 
Digestibility of Ground Grains——Experiments show that a 
greater efficiency is obtained from feed consumed if a part of the 
grains are fed.in ground form or as a dry mash. Experiments 
covering a period of two years show that birds receiving whole 
grains give a product valued at only 48 per cent above the cost 
of feed, while those receiving part of the ration in the form of 
ground grains showed an excess of 68 per cent. The actual differ- 
ence in the total value of product was found to be about one-third 
greater with the hens having ground grains in the ration. More 
energy is required in the digestion of whole grains than ground 
grains. The exact determination of whether or not it will pay to 
feed ground grains will depend on the nature of the ration. If 
too much time and energy are required for fowls to grind the feed, 
egg production will be retarded; but, on the other hand, if all 
grains are fed ground, exercise will be restricted and the health of 
the birds impaired by reason of the tendency toward too great a 
concentration. This undue stimulation to an unnatural egg yield 
is likely to result in lowering the bird’s vitality. 
Mineral Matter for Laying Hens.—The ash content of different 
feeds varies considerably, and the bird’s requirements also vary 
during the different periods of its life. The problem is to adjust 
properly these varying factors to each other. During the growing 
stage and during egg production, more ash is required than is 
supplied by the ash content in vegetable feeding stuffs. Wheat 
bran is very rich in digestible ash, and is easily adapted to the 
feeding of baby chicks, but it does not supply enough to meet 
the requirements of laying hens. The lack of ash in the ration 
of laying birds tends to induce egg eating, because soft-shelled 
eggs are then likely to be produced. This condition can be pre- 
vented by keeping crushed oyster shell, ground bone, and similar 
material constantly before the hens. The shell constitutes 8 per 
cent of the whole egg, and to lay 160 eggs in a year the hen will 
require 1.6 pounds of mineral matter for the shells alone. 
Use of Sharp Grit—Birds have no teeth with which to grind 
feed, this mastication being performed in the gizzard by muscular 
action. In order that this work may be properly done, sharp grit 
