18 BULLETIN 873, TJ. S. DEPARTMENT OF AGRICULTURE. 



a destruction of dry matter, because such hay does not contain 

 enough water to engender a temperature sufficiently high to injure 

 the dry matter. 



It should not be inferred, however, that such loss from well-cured 

 hay in the stack will be no greater than in the same kind of hay in the 

 barn. It is a matter of common knowledge that there is often quite 

 a serious loss when hay is stacked for several months. An unavoid- 

 able loss, caused by the action of the sun and rain, is sustained when 

 hay is stacked and left uncovered. The sun bleaches the outside of 

 the stack and rain often causes the hay to discolor or even to rot. 

 The amount of loss in such cases depends largely upon the skill exer- 

 cised in building the stack, and while the greater part of the loss is 

 caused by discoloration, which lowers the grade and, consequently, 

 the market value, there is also an actual loss of dry matter because 

 of mold and rotting. 



Lipscomb 22 in 1907 showed that there was a decided loss through 

 discoloration by rain, when hay had been stacked for several months. 

 Two stacks of timothy hay were put up in July. At the end of four 

 months 20 per cent of the hay in one stack was found to be unsalable 

 and fit only for bedding or feed as roughage. There was a loss of 

 about 40 per cent in the other stack at the end of eight months. As 

 a matter of fact, there was, strictly speaking, no great loss of dry 

 matter, but such hay is considered as worthless or lost since it is not 

 marketable. 



METHODS OF MAKING HAY TO PREVENT UNNECESSARY SHRINKAGE. 



There is no method known whereby hay can be so cured that it will 

 retain, indefinitely, a larger percentage of water than is normally 

 contained in such hay after it has gone through the sweat and is 

 thoroughly cured. The water m hay is not chemically locked up as 

 is the dr} T matter, and, for this reason, the haymaker is unable to con- 

 trol, except within very narrow limits, the water content of hay after 

 it has once become entirely cured. A knowledge of these facts should 

 not cause the haymaker anxiety, for, as will be shown later, the loss 

 of water or shrinkage does not ordinarily entail a real money loss to 

 him. 



It is very important that a close watch be kept on the water con- 

 tent, or rather on the rapidity with which water is being taken from 

 hay while in the various stages of curing in the field, not with a view 

 of checking the shrinkage to take place later in the barn or stack, but 

 because loss by shattering depends upon the dryness of the hay when 

 handled. The more dry h&y becomes in the windrow or swath the 

 more it will lose by shattering, and this is a real loss of the most nutri- 

 tious part of the plant, especially of legumes. Hence, it is highly 



22 U. S. Department of Agriculture, Farmers' Bulletin No. 362. 1909, p. 26. 



