Constitutional Vigor in Poultry 



605 



that in some of these instances the weaker fowls laid the heavier eggs. 

 This variation in weight does not seem to be influenced particularly by 

 an increase or a decrease in the number produced. 



COST PER DOZEN EGGS PRODUCED 



The cost per dozen eggs produced was lower in the strong pens except 

 in the same weak flock (13) that laid a greater number than its corre- 

 sponding strong flock. This cost, however, as illustrated in Table 30, 



TABLE 30. Cost per Dozen Eggs Produced 

 (November 24, 1908, to November 22, 1909) 



is considerably higher than the cost of producing a dozen eggs the year 

 previous by the parents of these pullets. This is due to the increased 

 price of food rather than to increased consumption or decreased production. 

 It is interesting to note that the parents of these pullets produced eggs 

 during the same year at nearly as low a cost per dozen. 



incubation 



It is noticeable in Table 3 1 that the eggs from the strong and weak 

 pens varied indiscriminately in fertility and hatching power. In fact, 

 the average percentage of chicks hatched from all the weak pens was 

 greater than that from the strong ones. This was partially offset by the 

 higher average fertility of the eggs, heavier weight of the eggs and chicks, 

 and lower average mortality among the chicks from the strong flocks. 

 These inconsistent results may be due to the lack of any selection after 

 the original pens were mated up. No fowls were removed from the 

 pens until they died. All the eggs laid during certain periods were 

 incubated, and practically all the pullets matured were kept for further 

 observations. 



