26 



X. II. Age. Experiment Station [Bulletin 265 



If we assume a farm with capacity for 1000 hens and with available 

 family labor and if it is further estimated that 250 of these hens will 

 produce only 100 eggs per year, culling them might reduce tin- gross 

 returns -$600. The gross expenses might be reduced $500. Tims if 

 these birds were Left in the flock the operator would have $100 more 

 cash at the end of the year. 



It is desirable to grow more pullets than are required and then to 

 eliminate carefully the poorest prospects until the number is equal to 

 the capacity of the housing. The farm can then operate to capacity 

 through most of the year, and the culled pullets can probably be sold 

 for enough to pay for their cost. 



The above discussion of culling applies only to market-egg flocks. 

 The breeder or producer of hatching eggs and baby chicks cannot be 

 too strict in his selection of birds in the fall nor in his culling through- 

 out the breeding season. 



Rate of Decrease in Population of Laying Flock 



The size of the laying flock during the various periods of the year is 

 dependent on three factors: (1) removal of birds through death — mor- 

 tality; (2) removal of birds for sale or use on the table— culling; (3) 

 addition of birds to the laying flock by housing or by purchase. 



The number of birds each week in the average laying flock is shown 

 in Figure 6. The maximum size of flock was reached the week of No- 



fc u s a 



<fi e z q 



3 £ 1 



Week Beginning 



■< 



Fioubb () — Average weekly size or population of 23 laying flocks. 



vember 17. Due to culling and mortality the number declined gradually 

 and at nearly a constant rate until about June 1. In spite of the fact 

 that culling was particularly heavy from dune on, the rate of decline 

 slackened because of the addition of early hatched birds from the new 

 crop of pullets. However, in spite of this increase, the total number of 

 birds dropped rapidly alter duly 1. reaching a low point about the first 

 of September. 



