FOODS ANIMAL PRODUCTION. 915 



A sample of wheat grown in a sandy soil in Michigan was also 

 examined lor alumina and none was found. 



"The tindiuj;: of zinc in the :ish of this wheat may l>e mentioned as a point of 

 special interest. The amount found would ecpial about 1 11». of i)ure zinc to each 

 500 l)u. of wheat. So far as it has l)een possible to learn, this small amount of zinc 

 has no special influence u])on the growth of the i)lant nor is it in any way injurious 

 to animals or human beings eating the grain. It is found most abundantly in the 

 ash of the outer portictns of the grain, and is jtresent in the tlour ash in much less 

 (luantities than in the ash of the bran. In the ripened wheat it seems to have been 

 trausferred almost comi)letely from the straw to the grain. Zinc was also found in 

 oats, clover hay, and corn cut before tasseling. All of these were produced upon 

 soil in the vicinity of that producing the wheat which was used in the milling trial. 

 An examination of the first 6 in. of this soil showed it to contain about 1 lb. of zinc 

 to each 1.000 lbs. .of earth.'" 



Experiments to determine the coefficients of digestibility of 

 grain by hens, I. Kalugine {ZapisM Novo-Alelsandriislayo instituta 

 St'lcskago KJiozjjai.stva 1 Ly€.sovo(lstva,9{1896), III^pp. 217-357). — Exper- 

 iments were made with 2 hens on the digestibility of peas, buckwheat, 

 wheat, and barley. Each experiment lasted 7 days and was preceded 

 by a preliminary period of '1 days. The hens were kept in large, wooden 

 cages. The floor and sides were lined with oilcloth, which could be 

 removed at will aiul the feces easily collected. The details of food con- 

 sumed and the composition of the food aud excretory products are 

 expressed in full in tabular form. The average coefficients of digesti- 

 bility are given in the following table: 



Average coefficients of digestibility of different grains fed to hens. 



Pea.s 



Buckwheat. 



Wheat 



Barlev 



Organic Crude 

 matter. proteiu. 



Fer cent. Per cent. 

 75. 00 90. 32 



Crude 

 fat. 



Per cent. 

 83. 71 

 89.22 



69. 38 59. 40 



81.92 5e. 91 I 55.21 



77. 17 79. 22 68. 29 



Nitrogeu- 



free j Cellulose, 

 extract. 



Per cent. Per cent. 

 91.65 . 13.74 



86.99 I 2.02 



93.30 29.95 



89.17 



The following conclusions were reached: In digestion experiments 

 with hens the i)reliminary period may be limited to 2 days. 



In some cases tlie percentage of nitrogen of metabolic products in 

 the feces was the same as was found in experiments with swine; in 

 other cases it was 2 or more times as great. 



In the ability to digest the crude protein of peas and barley, hens do 

 not differ fiom the ordinary farm animals. In their ability to digest 

 the crude protein of buckwheat and wheat they are much inferior. In 

 ability to digest fat they resemble in some respects herbivora aud in 

 other respects swine, liens digest nitrogen-free extract very com- 

 pletely. In this respect they differ very little from farm animals. 

 They digest crude fiber less completely than horses or swine. The 

 gTavel which liens consume is worn d()wn in the intestinal tract to .sand 

 of different degrees of fineness and is excreted in the e.vcretory 

 products. 



