Sept.. 1941] 



PROTEIN REQUIREMENTS OF CHICKENS 



11 



flavin content of the various diets used indicated all milk groups to 

 be well above the minimum requirements. 



The differences in hatchability between the mixed protein, fish 

 meal and meat scrap groups are too small to be considered signifi- 

 cant. 



All chicks procured in the last five hatches were killed and their 

 gizzards were examined for the presence and severity of gizzard le- 

 sions. It is noted in Table 8 that the greater the content of meat 

 scraps or mixed proteins in the diet, the greater were the num- 

 ber of normal gizzards observed. The reverse condition was true 

 with regard to the dried skimmilk diets*. Since meat scraps contain 

 cartilage, and Bird, et al (1936) have reported this to possess the 

 anti-gizzard erosion factor, the results procured seem to substanti- 

 ate this report. 



Since it is quite conceivable that fish meal wotild also contain a 

 considerable portion of cartilage a qtiestion may be raised concern- 

 ing its "protective" vahie. However, Almquist (1937) has reported 

 the gizzard factor to be unstable to heat. The heat treatment of the 

 fish meal as used was 120° at a 26" to 27" vaciuim over a period of 

 several hours. This may have been sufficient to destroy partially the 

 effectiveness of the gizzard factor, if present. On the other hand, 



TABLE 6. A COST COMPARISON OF FEED CONSUMPTION AND EGG PRODUCTION 



PER BIRD FOR ALL GROUPS 



Group 



'More recent unpublished data from this station indicates dried skimmilk in combination with 

 the protein basal diet as fed to breeding birds gives somewhat better gizzard scores in 

 their resulting progeny than those fed the fish meal diet. The birds used on this test 

 were the same (one year older) as used on the project herein reported. 



