Sept., 1941] PROTEIN REQUIREMENTS OF CHICKENS 5 



Records were maintained to measure the possible influence of pro- 

 tein source on the prevention of gizzard lesion. 



DISCUSSION 



STARTING PERIOD (0-12 WEEKS) 



This experimental procedure, as previously noted, has been limited 

 to a comparative study of three annual protein concentrates : name- 

 ly, meat scraps, fish meal and dried skimmilk. Table 2 presents by 

 stated weekly periods the weight records for the twelve groups of 

 birds studied. With little exception, as the protein content of each 

 ration increased, the growth rate of birds increased. These results are 

 in harmony with previous reports to the effect that 18 to 20 per cent 

 protein in the ration during the first twelve week period produces 

 the greatest gains in weight. 



To summarize by groups according to type of animal protein con- 

 centrate used, it will be noted that the mixed protein fed groups led 

 with an average weight at twelve weeks of age of 2.733 pounds. 

 Relatively slight differences between groups are apparent, however, 

 except for the meat scrap groups having the lowest average weight 

 of 2.470 pounds at 12 weeks of age. 



Table 3 presents a summary of the recorded feed consumption lev- 

 els by stated periods for all groups. It is noted that the widest 

 difference in consumption level of feed over the entire twelve week 

 period occurred between Groups 11 and 1, 10.250 pounds and 8.778 

 pounds respectively. All other groups were intermediate between 

 these figures. 



From the standpoint of efficiency in the utilization of feed accord- 

 ing to pounds of feed required to produce one pound of gain over 

 the initial twelve week period the reader is referred to Table 4. It 

 will be noted that Group 8 (17% dried skimmilk) was most efficient, 



TABLE 2A. SUMMARY OF WEIGHT RECORDS IN POUNDS PER BIRD BY STATED 

 WEEKLY PERIODS FOR MEAT SCRAP GROUPS 



Age Group 1 Group 2 Group 3 



1 day i)925 !0928 .0927 



4 weeks .4180 .4850 .4670 



8 weeks 1.330 1.312 1.392 



12 weeks 2.300 ^ 2.600 2.500 



16 weeks 3.225 3.375 3.500 



19 weeks 3.625 3.900. 3.950 



23 weeks 4.325 4.500 4.400 



27 weeks 4.900 5.050 5.200 



31 weeks 5.300 5.425 5.200 



35 weeks 5.400 5.400 5.150 



39 weeks 5.500 5.450 5.200 



43 weeks 5 450 5.350 5.350 



47 weeks 5.900 5.800 5.600 



51 weeks 5.750 5.750. 6.050 



55 weeks 5.750 5.800 5.500 



59 weeks 5.400 5.650 5.500 



63 weeks 5.250 5.250 5.700 



67 weeks 5.400 5.400 5.500 



70 weeks 5.364 5.364 5.455 



