242 EXrEKLMEXT STATION. [Jan. 



paratively little variation in the composition. The cob is 

 characterized by its very low protein and fat content and its 

 high extract matter and fiber. It is donbtlnl if the cob from 

 any number of different varieties would show substantial varia- 

 tions from the figures reported above. Lindsey and Holland ^ 

 have shown tlie cob to contain over 30 per cent, of pentosans 

 which have a digestibility of G3 per cent., and, further,- that 

 the total dry matter of the cob has a digestibility of 59 per 

 cent. So far as known, further studies of the chemical character 

 of the extract matter have not been made. It is evident that the 

 chief feeding value of the cob is to be found in its 59 per cent, 

 of digestible carbohydrates. 



On the basis of the work done by Kellner,^ the net available 

 energy in 100 pounds of cob containing 11 per cent, water is 

 40.2 therms, as against 8-5.5 therms in a like amount of corn 

 meal ; or 100 pounds of corn cob has 47 per cent, of the energy 

 value of corn meal. 



The practical feeder, therefore, cannot afford to pay grain 

 prices for the cob when used as an adulterant of wheat-mixed 

 feed, hominy meal or the like. Its use, however, is warranted 

 when produced upon the farm and g-round together with the 

 kernel as a food for farm animals. 



Summary. 



Yield. — The small, early maturing types of corn are not 

 economical for Massachusetts conditions ; the medium dent and 

 flint varieties that will mature in the average season are quite 

 well suited for grain, and also serve fairly well for silage. The 

 larger medium dent varieties that in an average season bring 

 their ears to the milk stage are, all conditions considered, 

 rather preferable for silage purposes, while the coarse, late 

 maturing varieties, v.-hich never ripen seed in this locality, ai'e 

 not satisfactory because of the less net available energy pro- 

 duced (actual food value). 



The season has a marked influence upon the yield of the 

 corn crop, the same variety of corn under otherwise identical 



' Fifteenth Rept. of the Hatch Exp. Sta., pp. 78-79. 



' EiKhteenth Rept. of the Hatch Exp. Sta., p. 243. 



' Die Ernahrung die Landw. Nutzthiere, fiinfto Auflapo, pp. 150-100, also p. fiOl. 



