272 EXPERIMENT STATION EECORD. [Vol. 41 



The spring pigs sliowed tlie same general resnlfs. Tlie time from birth 

 required to reach the successive 100 lb. weights were 12.5, 182, 231. 286, and 362 

 days, respectively. The amounts of feed required per pound of gain averaged, 

 respectively, 2.9. 3.9, 4.-5, 5, and .5.3 lbs. in the successive growth periods. 



Some financial computations are given which suggest that " smaller returns 

 over the total feed cost may be expected from pigs carried beyond the point 

 at which the maxinuuu rate of gain is reached than from those marketed before 

 the rate of gain begins to decrease." 



Effect of ag'e of pigs on the rate and economy of gains, W. L. Robison 

 {Ohio Sta. Bui. 335 (1919), pp. 545-575, flys. 11).— A final detailed report is 

 made of the three ex]»eriments noted above. The pigs used were Duroc-.Terseys. 

 The tabulations include the individual weights and feed records of each of 

 the 37 animals from birth to slaughtering. I'roximate analyses are presented 

 of the feeds given the spring pigs and the first group of fall pigs, including 

 linseed meal and skim milk fed to some of the pigs in the interval between 

 weaning and individual feeding. 



Considerable attention is given to the economic conditions which determine 

 the most profitable time to stop a feeding operation in view of the data secured 

 in the experiments. " The weight at which it is most profitable to market pigs 

 full fed from birth is influenced by the method of proportioning the supple- 

 mental feed, by the amounts of supplement used and its relative price with 

 that of corn or other carbonaceous feed, and by the relative price of feed and 

 the market value of hogs." The most profitable market weight was heavier 

 in the case of the groups in which the proportions of supplement was gradually 

 reduced than in the case of the spring pigs where this proportion remained 

 constant. 



Three other experiments are briefly reported. (1) Two lots of 3.5-11). pigs on 

 rape pasture were compared, one receiving a full grain feed throughout the 

 three 7-week periods of the test, the other a limited (2 to 3 per cent) grain 

 ration for 2 periods and a full feed for the last period. At the end of 14 

 weeks the limited feed lot were not as heavy nor in as high condition as the 

 full-fed pigs, but during the last third of the experiment they made more rapid 

 gains. Their concentrate requirement per unit of gain was 13 per cent lower 

 than the full-fed lot. (2) A duplication of this experiment with 40-lb. pigs 

 during three .5-week periods yielded similar results. (3) A comparison was 

 made of narrow, medium, and wide rations of corn and tankage during 18 weeks 

 of dry-lot feeding divided into 6-week periods. " The medium ration contained 

 approximately one-half as much tankage as the narrow one, and the wide 

 ration one-half as much as the medium one. In all three rations the proportion 

 of tankage to corn was decreased each week. For the first and second periods 

 the pigs fed the most tankage made the most rapid gains and required the least 

 feed per unit of increase in live weight. For the third period, however, they 

 gained more slowly and required more feed per unit of gain than those of either 

 of the other two lots." 



[Swine feeding' studies], {Iowa t<ta. Rpi. 191^, pp. 19-22, 2.9).— Short pre- 

 liminary reports are presented of several swlne-feeding experiments. 



Variously prepared moat meals and tankages (all made up on the 60 per 

 cent protein basis) were tested as supplements to corn in the dry-lot fattening 

 of hogs under the free choice system. A bone and blood meal nuxture produced 

 a pound of gain at an outlay of 3.8 lbs. of corn and 0.28 lb. of supplement. 

 AVith blood meal as sole supplement, 4.2 lbs. of corn and 0.5 lb. of supplement 

 were required for a pound of gain. 



