22 
BULLETIN 12f77, U. S. DEPARTMENT OF AGRICULTURE 
Table 20. — Net relation of various feeding practices to feed requirements for 
beef production, and for pork by-product — Continued 
C. DIFFERENCES IN THE LENGTH OF FEEDING PERIOD 
Days on feed 
Relative gains per 
unit of feed 1 
Relative feed re- 
quired per unit 
of gain 
Beef 
Pork by- 
product 
Beef 
Pork by- 
product 
90 
Per cent 
108 
102 
97 
95 
94 
94 
94 
Per cent 
138.5 
117.0 
101.7 
92.0 
87.4 
87.0 
87.0 
Per cent 
0.925 
.98 
1.03 
1.053 
1.065 
1.065 
1.065 
Per cent 
0.720 
120 
.850 
150 
.785 
180 
1.085 
210 
1. 143 
240 
1.150 
270 
1.150 
Taking the gains predicted by A and B as 100%. 
D. WEIGHT OF ANIMALS AT BEGINNING OF FEEDING PERIOD 
Initial weight per head 
Relative gains per 
unit of feed 
Relative feed re- 
quired per unit 
of gain 
Beef 
Pork by- 
product 
Beef 
Pork by- 
product 
820 pounds 
Per cent 
102 
99 
96 
95 
94 
92.5 
92 
92 
Per cent 
137.3 
118.5 
104.3 
93.1 
86.5 
87.5 
89.2 
91.1 
Per cent 
0.98 
1.02 
1.04 
1.05 
1.06 
1.08 
1.09 
1.09 
Per cent 
0.73 
860 pounds 
.84 
900 pounds 
.96 
940 pounds 
1.07 
980 pounds 
1.16 
1,020 pounds 
1.14 
1,060 pounds 
1.12 
1,100 pounds 
1.10 
The procedure in applying these figures to a practical problem 
in feeding is first to compute the gain due to the different feeds 
used, and then to adjust this output according to the length of 
period and initial weight of the animals. 
Further tables showing the unit requirements under different as- 
sumed conditions could be presented. Table 21 is an example. 
Table 21. — Estimated grain input per pound of gain for a steer weighing 
1,000 pounds at beginning of feeding period, by rate of feeding grain and 
length of period 
(In addition to gain due to roughage fed) 
Daily rate of feeding grain 
Length of feeding period 
90 days 
120 days 
150 days 
180 days 
10 pounds 
Pounds 
8.6 
9.9 
10.9 
12.7 
14.2 
Pounds 
9.1 
10.5 
11.5 
13.4 
15.0 
Pounds 
9.6 
11.0 
12.2 
14.1 
15.8 
Pounds 
9.8 
15 pounds 
11.8 
20pounds... 
12.4 
25 pounds 
14.4 
30 pounds 
16.1 
