New York AGRICULTURAL EXPERIMENT STATION. 97 
largely or altogether of grain food. With abundance of green 
forage and grit the result was the same. 
With chicks this advantage did not appear when care was taken 
to supply abundant mineral matter to the vegetable food ration, 
made more than usually palatable by using a large number of foods 
not always available. But with ducklings” a ration entirely of 
vegetable origin always proved inferior; and it seems necessary 
with all except costly or very unusual feeding materials to use con- 
siderable animal food for the most satisfactory results. In most 
of the feeding experiments from 35 to 40 per ct. of the protein in 
the efficient rations was derived from this source. To learn how 
much animal food in the prepared commercial forms could be used 
safely, and to get suggestions as to the proportion ordinarily de- 
sirable, supplementary feeding trials were made. 
No injury to the health of ducklings appeared at any time when 
different animal foods were moderately or quite freely used. 
Two lots, one two weeks old and the other seven weeks old, 
were fed for four weeks a ration in which 94 per ct. of the dry 
matter and 98 per ct. of the protein came from animal foods. 
Growth was about like the normal rate under efficient rations. 
Later the ration derived over go per ct. of its dry matter and nearly 
97 per ct. of its protein from the animal foods. These animal 
products consisted of “meat meal,” “animal meal,’ dried blood, 
bone meal and milk “albumen.” Nothing else, besides sand and 
water, was fed except some green alfalfa. The nutritive ratio of 
the ration was excessively narrow, not wider than 1:1. No injury 
to the health of the birds was apparent, though some of them were 
from inferior and somewhat weaker stock than usual. 
An experiment with four exactly similar lots of ducklings was 
made in which the rations differed according to the amount of 
animal food. The proportion of the total protein of the ration 
derived from this source was approximately 20 per ct. for the first 
lot, 40 per ct. for the second, 60 per ct. for the third and 80 per ct. 
for the fourth. So far as general experience went this grouping 
seemed to overlap the limits of most efficient feeding. To avoid 
any differences in amount of ash, and to prevent any possible 
deficiency of total mineral matter in any ration, bone ash was added 
to the three rations in varying proportion to compensate for the 
large percentage of bone carried by the animal meal fed. The re- 
* Bul. 259; also in Rpt. 23:31-44 (1904). 
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