THE CHEMICAL COMPOSITION OF FOODS 21 



the same for any two samples, so that only an average 

 composition can be stated. The composition varies with 

 the many variations in the conditions of growth and pre- 

 paration of the material. The crop in a wet season has 

 a different composition to that in a dry one, and this is 

 true for every variety of weather and climate. Good 

 land, well manured, will produce a crop very different 

 from that obtained from poor, worked-out soil. Again, 

 as has been already pointed out, the time of harvesting 

 and the degree of ripeness of the crop will materially 

 affect the analysis. Grass in flower and before the seeds 

 are ripe is a very different substance from over-ripe 

 grass wdth many of the seeds blown away. The stems 

 have become more woody and fibrous and much less 

 digestible. Then, too, the method of harvesting affects 

 the composition. Hay got in fine weather with little 

 handling is vastly better than that left lying, or often 

 turned and spread, in wet, dull weather. Fermentation 

 or heating in the stack further alters the composition, 

 and similarly the harvesting and storage of grains affects 

 their feeding value. 



In the calculations throughout this book it is assumed 

 that the sample is a good, unadulterated one, properly 

 harvested and stored, and above rather than below the 

 average sample on the market. It cannot be too strongly 

 impressed on those responsible for feeding horses that 

 the only true economy consists in buying the best quality 

 of foodstuffs. The horse is a particular, and even dainty, 

 feeder, and, further, his digestive powers are such that 

 he is unable to make the best of rough, coarse fodder 

 on which the less particular ruminant would thrive. 

 A poor sample of a foodstuff contains less nutritive 

 material, and that in a less digestible form, than a 



