40 University of New Hampshire [Sta. Bui. 330 



The post-mortem records maintained by the poultry department 

 show that ruptured egg yolk is one of the major disease conditions 

 responsible for adult mortality among chickens. Bacteriological an- 

 alyses indicate that bacteria are not the primary cause of this condi- 

 tion. For this reason, the department has carried on selective breed- 

 ing in order to determine to what extent the tendency toward a rup- 

 turd egg yolk condition is transmitted to progeny. Results to date 

 indicate that there is high, positive correlation between low inci- 

 dence of mortality from ruptured egg yolk in the family, and the in- 

 cidence of this condition in the progeny of the surviving members of 

 the same family. 



During the spring of 1940, 554 chicks were hatched from 16 dams 

 of the low mortality groups, and 671 from 22 dams of the high mor- 

 tality groups. These chickens are now being observed in further 

 investigation of the problem. 



{Purnell Fund) 



Poultry Litter Moisture (T. B. Charles, R. C. Durgin, and W. T. 

 Ackerman) 



Peat litter was put into each of three pens. In two pens, the 

 litter was spaded and raked to allow it to dry more rapidly, while in 

 the third pen the litter was untreated. The difference in the condi- 

 tion of the litter in the three pens appeared to have no effect on feed 

 consumed, on eggs produced, or on the percentage production of 

 eggs. Mortality was slightly lower in the pen where the litter re- 

 ceived the best treatment, but the difference may not be statistically 

 significant. 



It was found that the litter could be maintained in a drier con- 

 dition in those pens where drip guards were installed about the water 

 fountains. Improving the drainage about the buildings was also of 

 value. 



{Purnell Fund) 



Incidence of Gizzard Erosion (T. B. Charles, J. H. Gillespie, and C. 

 L. Martin) 



Fifty to seventy-five eggs were obtained from each of twenty-two 

 poultry departments at the various state experiment stations in the 

 United States. These eggs, together with 68 eggs from each of two 

 college flocks of New Hampshires, were placed in one incubator and 

 incubated under identical conditions. From these eggs, 715 chicks 

 were hatched and examined for gizzard erosion. Out of the total 

 number, only 13 males and 15 females showed a normal gizzard con- 

 dition as examined by the naked eye. There appeared to be no sig- 

 nificant difference between the gizzard conditions of different breeds, 

 and apparently there is no relationship between sex and incidence 

 of gizzard erosion. 



Of particular importance is the fact that gizzard erosion is wide- 

 spread. The chickens hatched from eggs of one locality of the Unit- 



