6 Poultry Bulletin 



ment was contemplated. Fleischmann's Pure Dry Feed Yeast was chosen 

 as a source of yeast supply. First — because of its wide distribution and 

 availability. Second — it was chosen because of the fact that it was a pure 

 yeast product carrying no adulterants and containing no carrying agent. 

 Third — it was chosen because of the fact that it was a live yeast in that 

 when subjected to proper conditions of moisture and temperature the 

 yeast started to grow and multiply just as normal live yeast will do. 

 Lastly — the Fleischmann product was chosen because being in a dry state 

 it was easy to store and handle. 



Six hundred forty hens were used in the early 1924 test. They were all 

 yearling hens which had laid heavily the previous year and which had 

 been through an extended moult and had come back into normal produc- 

 tion about the middle of January. They were all Single Comb White 

 Leghorns. These hens were housed in eight similar breeding pens and 

 during January eggs from these various pens had been incubated result- 

 ing in a normal fertility around 90% with a very satisfactory hatchabil- 

 ity for that season of 66%. During early February the fertility from 

 these pens took a decided slump which condition is generally character- 

 istic at that particular season. It was at this time that the yeast feeding 

 was thought of and the experiment started. The eight pens containing 

 the 640 birds were then divided into two groups. Both groups had been 

 receiving a moist mash which they would consume in about an hour, 

 same being fed each day at about It o'clock. Group A consisting of pens 

 1, 3, 5 and 7 were, beginning February 15, — fed the same moist mash but 

 Yi°/o °f Fleischmann's Pure Dry Feed Yeast was added and the mash 

 allowed to stand and ferment in a warm room for about twenty hours 

 before feeding.* The remaining pens, 13, 15, 17 and 19 were given no 

 yeast but were handled just as they had normally been. The following 

 table shows the number of eggs set each month through May, the per- 

 cent of fertility and the percent of hatch of total eggs set. 



*Feeding Directions — Based on the weight of the dry mash used, \ of 1 % of dry yeast 

 was mixed with the dry mash and sufficient water (preferably warm) added to moisten 

 the mash. After thorough mixing the mash was set aside in a warm place and allowed 

 to ferment at a temperature of about 70° F. for twenty to twenty-four hours and was 

 then fed. The quantity should be such that it will be consumed in an hour's time. The 

 mash should be wet so that it will still crumble and a little moisture appear between the 

 fingers when a handful is tightly squeezed. Buttermilk may be used in place of water. If 

 a somewhat higher temperature (about 80°) can be maintained, \i of 1% yeast may be 

 used. The fermentation may be further accelerated by making the mash more moist. 

 In this case it should be dried out by the addition of a little dry mash just before feeding! 

 Fleischmann's Pure Dry Yeast may be fed in the dry mash which is before the birds 

 all the time, but best results are obtained by feeding the fermented mash as used by 

 Professor Lewis. Besides the beneficial action of the active yeast on the proteins and 

 carbohydrates of the mash, the yeast content in such a medium is multiplied about 

 ten-fold. When this moist mash is fed to the birds they are consuming the yeast in 

 a live active state in which it can best serve its purpose. 



