Oct. IS, I93I 



Nutrient Requirements of Growing Chicks 



145 



'POO 



200 



/oo 



A 



I o 

 %zoo 



consumption of each lot were also obtained. Clean wood shavings 

 were used for litter, and each lot was confined to a pen 2 by 8 feet 

 in size until the chicks were 8 weeks old, when the near normal lots 

 were given a yard 4 by 8 feet 

 in size. 



Methods of feeding are known 

 to have considerable influence on 

 the efficiency of a ration; so a 

 standard policy was established of 

 dividing the ration into two parts — 

 the scratch or coarse feed and the 

 mash or fine feed. The rations 

 were mixed so that equal quantities 

 of mash and scratch feeds were 

 provided. The mash feed con- 

 tained all the supplemental ingre- 

 dients, such as ash, butter fat, and 

 purified casein. 



The casein used in the rations was 

 purified by extracting repeatedly 

 with distilled water slightly acid- 

 ified with acetic acid . After extrac- 

 tion the casein was drained and 

 dried in an air oven at 70° to 100° C. and then ground. The butter fat 

 was purified by melting at 40° in a water bath and was then centrifuged 

 to remove ash, casein, and other material. The ash mixture^ used in 

 our rations was composed of the following ingredients, parts by weight: 



Bone ash .jV^/:'^: 't';^;! . V'^'v'. .'. 50 



Calcium carbonate 



Sodium chlorid 



Dipotassium phosphate 



Calcium lactate 



Magnesium sulphate 



Sulphur 



Iron sulphate 



^i9 



Fig. 7. — Graph showing that the addition of is parts 

 soybean meal did not improve ration of 80 parts 

 yellow corn and 5 parts ash mixture for chicks of 

 lot 210. The time at which chicks died is indicated 

 by A'. 



JXi.i . U. 



"■^^rA. 



14 

 IS 

 10 



5 

 3 

 2 



I 



The results of our inquiries may briefly be summarized as follows: 

 (i) Yellow com (maize) is deficient in several of the essential qualities 

 necessary for the complete nutrition of growing chicks. A deficiency in 

 the ash content of the yellow com kernel is no doubt responsible for the 

 early failure of baby chicks when restricted to a ration of corn alone. 

 Supplementing the corn kernel with 5 per cent of a complete ash mix- 

 ture improved the ration so as to enable very slow but persistent growth. 



1 Philips, A. G., Carr, R. H., and Kennard, D. C. meat scraps versus soy-bean proteins as a 

 StJPPLEMENT TO CORN FOR GROWING CHICKS. In Jour Agf. Research, v. i8, no. 7, p. 391-398, i fig. , pi. 50. 

 1920 



