472 



EXPEBIMENT STATION RECORD. 



[Vol. 37 



pp. 567-604; al>s- ed., pp. 3). — This bulletin reports results relating to the effect 

 upon the rate and economy of gains of variations in the amount of feed con- 

 sumed ranging from maintenance to full-feed rations, of variations in the pro- 

 portions of roughage and concentrates in the ration, and of the substitution of 

 a nitrogenous concentrate for a part of the grain In a ration of clover hay and 

 ground corn in the ratio of 1 : 5. 



The experiment reported lasted for 37 weeks and was divided into five test 

 periods, the first of five weeks, the second, third, and fourth of six weeks, and 

 the fifth four weeks in length. The animals used were 2-year-old choice feeder 

 steers, four lots of four each. One lot was fed a ration slightly above main- 

 tenance; another, an amount of feed equal to the maintenance ration plus 

 one-third of the difference between the maintenance and the full-feed rations; 

 another an amount equal to the maintenance ration plus two-thirds of the 

 difference between the maintenance and the full-feed rations; and another as 

 much feed as the animals would eat readily. The rations of the first test 

 period consisted of clover hay and ground com in the ratio of 1:1; that of 

 the second the same, in the ratio of 1:3; that of the third the same, in the 

 ratio of 1:5; of the fourth and fifth, of clover hay. ground com. and linseed 

 meal in the ratio of 1:4:1. 



The average daily gains per head for the entire experiment of 37 weeks were 

 for the maintenance ration 0.7 lb., for the one-third additional ration 1.32 lbs., 

 for the two-thirds additional ration 1.79 lbs., and for the full-feed ration 2.13 

 lbs. The variations for individual anim.ils were for the respective lots 0.37-1.05, 

 1.23-1.39, 1.75-1.81, and 1.98-2.29 lbs. These averages include, however, data 

 for two steers which were upon full feed from the thirty-first to the thirty- 

 seventh week, InclusiTe. 



Other data are shown in the following table: 



Consumption of digestible dry substance and net energy per pound o/ gain. 



Lot. 



One-third feed . 

 Two-thirds feed 

 Full feed 



Dry snbstance. 



Average. VartotJons. 



Digestible dry sub- 

 stance. 



Average. Variations. 



Poundt. 



>9.51 



19.40 



9.63 



Poundi. 

 » 9. 17-10.04 

 > 8. 95- 9. 64 



8. 41-10. 47 



Poundi. 



»6.96 



«6.67 



6.60 



Pounds. 

 « 6. 73-7. 29 

 I 6. 48-6. 86 

 5. 95-7. 23 



Net energy. 



Average. 



TtuTVU. 



>7.23 



16.90 



6.73 



Variations. 



Therm*. 

 •6.97-7.55 

 1 6. 67-7. 10 

 6. 10-7. 48 



> This average includes the data for two steers which were apon fall feed from the thlrty-flrst to the 

 thirty-seventh week, inclusive. 



It is concluded that " 2-year-old steers may be maintained on 8 to 9 lbs. of 

 dry substan<*e, 0..30 to 0.44 lb. of digestible crude protein, and 6.5 to 6.8 therms 

 of net energy per 1,000 Ib.s. live weight. Fattening 2-year-old steers may make 

 satisfactory gains over a period of 37 weeks on 14.3 to 22.1 lbs. of dry sub- 

 stance, 0.72 to 1.44 lbs. of digestible crude protein, and 11.9 to 13 therms of 

 net energy per 1,000 lbs. live weight. Fairly good gains may be made even on 

 less amounts than these." 



The rate of gains of 2-year-old steers is considered to depend upon the 

 amount of feed consumed. " However, the amount of feeil consumed between 

 one-third feed and full feed apparently has no effect upon the economy of 

 gains as measured by the consumption of feed, of totnl dry substance, of diges- 

 tible dry substance, and of net energj- per pound of gain." 



When a ration consi.sting of clover hay and groiiiul corn was changed to a 

 similar ration in which the amounts of digestible dry substance and net 



