190;.] 



Feeding Value of Mangolds. 



29 



The question of improving the feeding value of roots and of 

 ascertaining the factors on which the feeding value depends, is 

 the subject of experiment at several of 

 Feeding Value of the Agricultural Colleges.* At Cam- 

 Mangolds, bridge, attention has been chiefly directed 

 to mangolds, and the possibility of 

 breeding improved strains has been under trial for several years. 

 There is very great variation in the percentage of dry matter 

 in different roots, and there seems no reason why the careful 

 selection, of roots as seed-mothers should not ultimately result 

 in raising the percentage of dry matter without decreasing 

 the cropping power. But it is a question whether the feeding 

 quality of the mangolds is in direct proportion to the percentage 

 of dry matter which the roots contain ; for example, if yellow 

 globe mangolds contain 10 per cent., and long reds 12 per cent, 

 of dry matter, is a 30-ton crop of the latter worth as much to 

 the feeder as a 36-ton crop of the former ? To obtain some 

 information on this question the Agricultural Department of 

 Cambridge University has carried out seven experiments 

 during the past three years under conditions which may be 

 taken as representing the common practice of the stock-feeder 

 in the Eastern counties. 



The experiments are described in detail in the "Guide" for 

 1906 issued by the department. They indicated that the 

 feeding value of mangolds is not always directly dependent on 

 the percentage of dry matter present ; at the same time there 

 was no evidence that one variety of mangold is more whole- 

 some than another, and the stock fed on the different varieties 

 were equally healthy. If further work should prove, as it very 

 likely may, that the dry matter of certain kinds has a relatively 

 high value, the explanation will probably be found in the 

 quantity and character of the proteids contained in the dry 

 matter. This, it is stated, opens up a question which is not 

 yet ripe for discussion ; doubts have been raised as to the 

 value of the usual analytical methods employed in estimating 

 proteids, and practically nothing is known of the food value of 

 the different proteids in mangolds. 



* See Journal, vol. xii, p. 353, September, 1905 ; vol. xiii, p. 2S2, August, 1506 : 

 and vol. xiii, p. 416, October, 1906. 



