10 March, 1916.] Dried Yeast as Food for Stock. 187 



DRIED YEAST AS FOOD FOR STOCK. 



The outstandiug feature of yeast, regarded from the food stand- 

 point, is its high content of albuminoids, which commonly constitute 

 about 55 per cent, of the dry matter. 



Fresh yeast and pressed yeast have been used to some .=>xtent in 

 feeding cattle and pigs with apparently quite satisfactory results; but, 

 as in these forms the yeast deteriorates rapidly, its use for feeding pur- 

 poses is restricted to the neighbourhood of breweries 



With the construction of more efficient drying apparatus, it has now 

 become possible to place on the market a dried yeast which is free from 

 the foregoing objection, while retaining the nutrient matters of the 

 yeast in a highly digestible foi'm. 



To the author's knowledge there are at present four or five yeast- 

 drying jDJants at work in England, with an annual output of some 

 2,000 to 3,000 tons. 



The product has so far been mainly exported from Germany, where 

 dried yeast has grown in favour so rapidly that the demand is said 

 to have exceeded the supply. 



Dried yeast is of a ]jowdery to flaky consistency, varying in colour 

 from light to medium brown. It has an agreeable odour, and its flavour 

 would not be amiss but for a bitterness, arising presumably from top 

 residues. This bitterness, according to experience at Manor Farm, 

 Garforth, v/hich is the experimental farm of the University of Leeds 

 and the Yoi-ksbire Council of Agricultural Education, renders it dis 

 tasteful to cows, but not to pigs and calves. 



Percentage composition varies, but the following may be regarded 

 as an average value: — 



Moisture ... ... 4.3 per cent 



Nitrogen ... ... 7.76 per cent, (equal to 48.5 jjer it-m. 



albuminoids). 



Oil ... . . ..10 per cent. 



Crude Fibre ... .50 per cent. 



Ash ... ... 10.70 per cent. 



Nitrogen-free Extract 35.50 per cent. 



A summary of the results of the experiments at Garfortli states 

 dried yeast to be a safe food for cows, pigs, and calves. It proved good 

 food for pigs, but owing to the cows' aversion to the bitter flavour, it 

 is not strongly recommended as a cow fodder. It proved a safe food 

 for calves, but no evidence was obtained as to its merits in iroiiiitaiison 

 with other foodstuffs commonly used in calf-rearing. 



Tn tlie case of pigs, comparative trials with rations con-i.^^t nii; inawiiy 

 of "sharps" (pollard) showed that the substitution of one (piarter to 

 one-lhird of the lattt^r by an equal weight of dried yeast gave markedly 

 better results, and in spite of the higher coat of the yeast, the margin 

 of profit on the feeding was undoubtedly increased. 



— C. Crowtiikr, in the Joiirnul <■< ''- ''■■■■■■' ■■< \ 'rirn/turr, 1915. 



