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Experiments with Dried Blood. [june, 



SOME FEEDING EXPERIMENTS WITH 

 DRIED BLOOD. 



L. F. Newman, Dip. Agric. (Camb.), 



• School of Agriculture, Cambridge University, 



\^RY considerable quantities of blood are available daily 

 in the abattoirs and slaughterhouses of Great Britain. The 

 blood is collected in pans or allowed to drain away into a 

 collecting gully. In some of the smaller slaughterhouses the 

 blood is either wasted or used for manure, as only a small 

 amount is obtained daily. In the North of England some of 

 the public abattoirs collect blood for the production of serum 

 and for the manufacture of " black puddings/' etc. 



The quantity of blood potentially available for these pur- 

 poses may be estimated from the fact that about 30 lb. are* 

 obtained when a bullock is slaughtered, and during the years 

 before the War about 3,080,000,000 lb. of meat per year was 

 home-killed. 



In recent years several firms have placed dried blood on the 

 market as an animal food, and considerable claims have been 

 made as to the value of this preparation when used as part of a 

 fattening animal's rations. A certain amount of dried blood 

 is thus available as a food for animals, and during the War the 

 difficulty of obtaining nitrogenous foods, especially for pigs, 

 but also for other animals, led to a number of inquiries as to 

 its value and safety as a nitrogen- supplying form of diet. It 

 was, therefore, considered desirable by the Food Investigation 

 Board to institute a series of trials in which blood was the 

 main source of nitrogen, with the object of obtaining data as 

 to its value. The two ordinary grades of blood obtainable are 



(1) blood dried immediately after collection, and hence free 

 from objectionable odours or decomposition-products ; and 



(2) blood collected in small lots and stored before drying. The 

 second grade is only suitable for manure, while the first is on 

 sale as an animal food. As fresh blood can always be obtained 

 at the larger abattoirs in quantity and dried down immediately, 

 a constant supply is obtainable, Hmited only by the output 

 from the drying plants. 



Dried blood, when properly prepared, is a- dry powder with 

 little smell, a pleasant meaty taste, and a salt flavour, and is 

 quite different from the fresh clots of blood which are sometimes 



