suit is equivalent numbers of eggs for the two groups and a small increase 

 of two or three hatching eggs per bird for the restricted fed pullets. 



Table 4 presents results for the combined effects of restricted feeding 

 and artificial light on fall-hatched pullets. In general the results do not 

 differ from those obtained in the experiments conducted with 14-hour light- 

 ing. Likewise the results do not differ from those obtained in experiments 

 in which lighting effects alone have been studied (10. 11). This would indi- 

 cate that lighting effects and restricted feeding effects are not additive in 

 altering sexual maturity and associated factors in pullets grown during 

 the shorter daylight periods of the year. Hence either artificial lighting, 

 restricted feeding, or the combination of both practices will produce the 

 same end results. Artificial lighting offers the advantage of simplicity, ease 

 in usage and low cost while restricted feeding offers the advantage of feed 

 saving and economy although it is more difficult to apply. 



Table 5. Summary of Average Results from Experiments 1-8. 



* Significant at the 5% level of probability 

 ** Significant at the 1% level of probability 



In general the results from these experiments, conducted during the period 

 from 1952 to 1958, agree with reports published during the course of this 

 research (Milby and Sherwood, 1953; Sunde et al., 1954; Singsen et al., 

 1954; Davis and Watts, 1955; Schneider et a/., 1955: Milby and Sher- 

 wood, 1956). Schneider et al. (5) were the only workers to report sig- 

 nificantly lower mortality in the laying house (13.2 percent) for the "slow" 

 grown pullets. They state that the exact reason for this difference in re- 

 sults is not known. Thev suggested that in part this difference mav be due 

 to extremely high protein feeding to the "fast" grown pullets and to severe 

 restriction practiced on the "slow" groups for a period of six weeks after 

 the "fast" groups were fed laving mash. The author would add also that 

 only one experiment was reported and variability at times can become 

 quite large. 



An incidental observation from these experiments has been that feather 

 pulling and cannibalism has never been a problem. Perbaps this may be ac- 

 counted for in part by the fact that care was always exercised that adequate 

 feeder space was available so that all chickens could eat at the same time. 



14 



