22 BULLETIN 873, U. S. DEPARTMENT OF AGRICULTURE. 



and protected stack if the same kind of hay (cured to the same degree) 

 were placed in each. There are no. experimental data showing that 

 hay in the barn loses more by shrinkage than hay in the stack. In 

 fact, the average loss of the hay stored in the barn, in the data cited 

 on pages 4 to 7, amounted to 14.7 per cent, while the average loss in 

 the stacked hay was 18.6 per cent. 



An earlier statement from the same investigator regarding the aver- 

 age amount of shrinkage does not agree with the one just reviewed. 

 In speaking of the shrinkage of alfalfa he says: "The average shrink- 

 age of well-cured alfalfa hay put into the stack or mow by loss of 

 moisture should not be greater than 10 per cent." 29 Again: "Men 

 experienced in the handling of hay usually figure on about 20 per 

 cent loss in weight after the hay is put into the stack or until it is 

 sold or baled.' ' 



In these instances the implication is that there will be the same 

 amount of shrinkage in the mow as in the stack, and in either case it 

 "should not be greater than 10 per cent." This estimate is about 

 half of the amount of shrinkage figured by men experienced in 

 handling hay in Kansas. 



From these and other data presented it will be seen that any gen- 

 eral rule for measuring shrinkage would have to allow for such wide 

 variations that it would cease to be a rule, while a rule based on the 

 average amount of shrinkage would be of no value to the individual 

 hay grower. 



The shrinkage of hay is influenced by such variable factors as the 

 weather, stage of maturity when harvested, and different methods 

 of curing, and the resulting product varies from half-cured forage to 

 dry-sunburnt hay. What the individual haymaker wants to know is 

 approximately how much hay shrinks when cured by a given method 

 under given weather conditions. For example, the man who lives in 

 a dry, irrigated section and cures his hay in the swath and windrow 

 wants to know the average shrinkage of hay cured under such condi- 

 tions. Again, those who put their hay into the cock and leave it 

 standing until it is really well cured, want to know how much hay cured 

 in this manner will shrink. The average shrinkage of hay from all 

 hay-growing sections means nothing to the individual. The results 

 of experiments already made show such a wide variation that they 

 are of but little value, if any, to the haymaker in any specified hay- 

 growing section. (See p. 7.) 



This being true, how then can the haymaker, who so desires, 

 estimate the shrinkage of his hay ? There are two ways of determin- 

 ing shrinkage. First, when the hay is cured in a more or less hap- 

 hazard manner — that is, when no definite system is used — or when 

 unfavorable weather interferes with the curing, average samples of 



m Kansas Agricultural Experiment Station Bull. 155, 1908, p. 258. 



