142 



THE SCIENTIFIC FEEDING OF ANIMALS 



Meals and Brans of Rye, Wheat, Barley, Corn and Oats 



According to their origin these show — 



1. The more or less characteristic starch grains. 



2. Characteristics brought out by Vogl's reagent (not applicable to rye). 



3. When sifted through Nobbe's sieves, bran particles, etc., should not appear 

 in any considerable amount. 



In the case of brans which may contain a few traces of the glumes (chaff) of the 

 species of grain in question (Figs. 74 and 75), those of other varieties, or dark- 

 colored, woody particles, should not be present. 



4. Schafifnit's method (p. 137) should not reveal the presence of sand, mineral 

 matter, hairs, etc. 



5. Shells, hulls, and other woody parts should not be present. For the detection 

 of these substances the contents of the coarser sieves or, better, the whole meal, 

 should be used. The examination is conducted according to instructions given 

 under "Examination of By-products Containing Shells, Hulls, Skins, etc." 



o.®fb " 



Fig. 74. Rye. (After Wittmack.) 

 Explanation: h and h', Hairs; 1, longitudinal. 



Fig. 75. Wiieat. 



(After Wittmack.) 



transverse cells; s, tubular cells of the seed coats; 

 /.pigment layer of the seed coat; fe, aleurone layer; jt, starch grains; st', the 

 same converted into paste at 62.5°C. (144. 5°F.). 



The glumes (chaff) of the cereals are either bright or dull in appearance, smooth 

 or carinated, and consist chiefly of long bast fibers and woody or silicified, closely 

 packed cells (Fig. 76). 



6. Test for ergot. Vogl's method does not suffice for this. For the chemical 

 determination of ergot, make an emulsion of a small quantity of the suspected 

 feeding stuff with a 60 percent solution of chloral hydrate, allow to settle for a 

 few minutes and filter. The filtrate, if ergot is present, has a bright cherry red 

 color. A drop allowed to dry on filter paper leaves a reddish spot which, when 

 treated with alcohol-ammonia, becomes a dirty violet. The balance of the solu- 

 tion is agitated with ether. After settling, the supernatant ether has a pink color 

 while the sediment is colorless. Microscopic examination is unreliable unless char- 

 acteristic pieces of ergot are accidentally met with. In a shake mixture the ergot 

 and bran particles float on the surface after the mixture has been allowed to stand 

 a while. Centrifuging has the same effect. The floating particles are cleared by 

 boiling in 1 to 2 percent hydrochloric acid solution and then treated with chloral 

 hydrate, or the particles, thus treated with hydrochloric acid, are stained with 

 dimcnthylamidoazobenzol, thionin and safranin. The ergot tissues stain yellow, other 

 tissues blue, violet or variegated, and may thus readily be recognized under low 

 magnifying power. 



