May, 1939] Protein Requirements of Chickens 11 



highest protein-fed groups. In the case of the other protein source 

 groups a considerable spread is noted between high and low protein-fed 

 groups. 



From these comparisons, it appears that fish meal was the most com- 

 plete and efficient animal protein source used in the tests. Meat scrap 

 and milk protein sources are either deficient in some very necessary food 

 essential and increasing their supply will not offset this deficiency, or 

 else some "abnormal" effect on the digestive process is occasioned by 

 their increased use. On the basis of the actual products used in this 

 test, the maximum level in a ration at which one may use either meat 

 scraps or dried skimmilk is quite definitely lower than the level at which 

 fish meal may be used in the compounding of rations. In Test I the 

 following percentage levels of the three animal protein sources were used 

 in Groups 1 to 9, respectivelv: 4.48, 9.19, 13.87, 4.32, 8.85, 13.39, 9.32, 

 19.08 and 28.84. 



Starting with the 35th w^eek of age periodic records of egg weight 

 according to groups were made. All eggs laid over a four- or five-day 

 period every two months were weighed and recorded. In this manner 656 

 eggs were recorded for the 12 groups. The average egg weight by protein 

 groups was 1.95 ounces for the fish meal groups; 1.89 ounces in the 

 mixture groups; 1.84 ounces for meat scrap groups; and 1.82 ounces per 

 egg for the groups receiving dried skimmilk. 



As noted in Table VIII there appears to be no significant relationship 

 between the percentage of protein fed and the size of egg laid. 



Test II — Discussion 



Starting Period (0-12 Weeks) 



As reported in the previous year's work the groups receiving higher 

 protein-carrying rations showed, generally, more rapid weight gains than 



Table V. Pounds of feed required to produce one pound of gain — all groups 



