May, 1939] 



Protein Requirements of Chickens 



the higher protein content feeds were the heaviest in weight. At the end 

 of the period the group receiving 19 per cent fish meal was leading in 

 average weight per pullet by a very slight advantage over the 19 per cent 

 mixed protein group. 



If we again summarize by groups according to animal protein source, 

 we find the groups receiving the mixture of animal protein to be leading 

 with an average weight of 4.383 pounds per bird. The meat, fish and 

 milk groups follow closely with 4.371, 4.304, and 4.063 pounds per bird. 

 During the second gro\vi:h period feed consumption was materially in- 

 creased over that of the first period. There was a difference of less than 

 three pounds per bird between high and low groups. According to Table 

 IV the average weekly feed consumption per bird varied from 1.297 

 pounds in the 15 per cent milk group to 1.539 pounds in the 19 per cent 

 mixture group. 



The efficiency of feed utilization, based upon pounds of feed required 

 to produce one pound of gain, during the second growi^h period illustrates 

 to good effect the changing protein requirements as age increases. In all 

 cases the groups receiving the 15 per cent protein content rations were 

 most efficient in producing gains in weight. Of all the experimental 

 groups, Group 1 was the most efficient with 8.28 pounds of feed per 

 pound of gain. Group 11 was the least efficient with 12.06 pounds of 

 feed to produce one pound of body gain. 



The only bird which died during the second gro'^iih period was from 

 Group 11, receiving 17 per cent animal protein mixture. According to 

 autopsy examination the intestines were small in size, and the kidneys 

 covered with urates. Indications were that the bird was an individual 

 case showing indigestion and lack of assimilation of feed. Death oc- 

 curred in the 23rd week. 



The production of eggs previous to the 24th week varied to some 



Table III-c. Summary of weight records in ppunds per bird by stated 

 weekly periods for dried skimmilk groups 



