Investigations with Swine. 



501 



The concentrates fed consisted of half ground corn and half wheat 

 middlings. Davies estimates that the equivalent of 1 per ct. of the 

 weight of the sow in concentrates would support her for 1 day, and 

 that but one-third of what she ate went for the support of her own 

 body, while two-thirds was used in the elaboration of milk for her 

 young. (592) It required but 146 Ibs. of grain and 336 Ibs. of skim 

 milk fed to sow or pigs for 100 Ibs. of gain by the pigs an exceed- 

 ingly small allowance. 



By weighing the pigs at 6:30 a. m. and 6:30 p. m. daily, Davies 

 found that they increased 84 Ibs., or 29 per ct., in daytime and 202 

 Ibs., or 71 per ct., in the night. These figures seem to indicate that 

 most of the body increase of young pigs occurs at night. 



818. Food and maintenance. At the Wisconsin Station 1 Dietrich 

 gradually reduced the feed of four 50-lb. pigs during 2 weeks until 

 they were neither gaining nor losing in weight. They were held on 

 this allowance for 7 days to confirm the figures and then gradually 

 brought back to full feed again. When the pigs averaged 100 Ibs. 

 the process was repeated, with the results shown in the table: 



Feed required to maintain a pig at different weights. 



The table shows that a 50-lb. pig held its weight on a daily allow- 

 ance of but 0.15 Ib. each of corn meal and wheat middlings and 1.2 

 Ibs. of skim milk, drinking 2.3 Ibs. of water. This quantity of food 

 supplied only 0.37 Ib. of dry matter. The maintenance require- 

 ments for other weights follow in the table. From these data Diet- 

 rich concludes that the pig can be maintained for 1 day on about 

 1 per ct. of its live weight of food in the form of wheat middlings. 



After each maintenance period the pigs were gradually returned 

 to full feed, which was continued until the next maintenance period 

 was reached. The dry matter required for 100 Ibs. of gain in the 

 intermediate stages is given in the table, together with the estimated 

 food of support and gain. 



The table shows that the 50-lb. pig, when gaining nearly 1 Ib. a 

 day, used only 18 per ct. of this food for the support of the body, 



1 Ept. 1899. 



