BUTTERFAT PRODUCTION OF CATTLE 
Table 8. 
-Comparison of average initial and retest records of Guernseys having 
initial records made at age of 4 years {single-letter records) 
Num- 
ber 
of 
cows 
Average initial 
butterfat 
record made 
at 4 to 4^2 
years old 
Average reentry records made at ages shown in 
these columns by same cows as initial records 
shown in column at left (pounds of butterfat) 
In- 
crease 
due to 
age 
Portion of 
reentry rec- 
ord due to 
development 
Average 
due to 
develop- 
ment for 
this 
group 
Ho 
S 
to 
6 
o 
o 
o 
to 
o 
00 
o 
oo 
o 
00 
OS 
o 
$ 
oV 
o 
o 
o 
1 
o 
O 
o 
o 
o 
o 
13 
14 
10 
16 
8 
Pounds 
501 
fiflT 
Pounds 
23 
24 
21 
22 
20 
19 
22 
22 
22 
18 
24 
-2 
-2 
18 
21 
21 
23 
20 
18 
17 
15 
18 
-5 
Pounds 
83 
50 
148 
80 
54 
5 
79 
82 
36 
72 
59 
-28 
137 
80 
59 
187 
101 
110 
123 
124 
193 
-1 
123 
Per 
cent 
13.7 
8.6 
23.6 
14.1 
10.5 
1.2 
13.8 
14.3 
6.7 
119 
10.0 
-5.9 
28.5 
14.8 
9.7 
25.8 
14.8 
17.3 
20.7 
22.1 
32.5 
-0.2 
20.5 
Per cent 
506... 
457 1 
580 
626 
464 
Fififi 
442 
401 
473 
471 
481 
394 
507 
507 
346 
... 
516 
1 
1 
425 
4 
574 
\ 13. 3 
2 
575 
3 
539 
2 
484 
1 
590 
1 
477 
481 
1 
... 
540 
Made at 4H to 
5 years old 
9 
442 
526 
517 
559 
506 
452 
420 
386 
445 
483 
9 
606 
4 
725 
8 
683 
3 
636 
16.0 
4 
593 
2 
561 
1 
594 
1 
60i 
1 
Table 9.: — Comparison of average initial and retest records of Guernseys having 
initial records made at age of 5 years {single-letter records) 
Num- 
ber 
Average initial 
butterfat record 
made at 5 to 5^ 
years old 
Average reentry records made at ages 
shown in these columns by same cows 
as initial records shown in column at 
left (pounds of butterfat) 
In- 
crease 
due to 
age 
Portion of re- 
entry record 
Average 
due to 
develop- 
of 
cows 
to 
o 
tO 
o 
CO 
o 
00 
o 
00 
o 
00 
: 
o 
oo N 
as 
o 
o 
o 
os 
due to devel- 
opment 
ment for 
this 
group 
7 
Pounds 
534 
517 
496 
552 
458 
404 
454 
594 
Pounds 














Pounds 
60 
24 
2 
19 
121 
83 
101 
46 
95 
149 
98 
206 
219 
116 
Per cent 
10.1 
4.4 
0.4 
3.3 
20.9 
17.0 
18.1 
8.4 
14.8 
21.0 
16.6 
30.2 
33.3 
19.1 
Per cent 
7 
541 
2 
498 
1 
571 
I &2 
3 
579 
1 
487 
1 
555 
546 
Made at h\i to 6 
years old 
5 
500 
549 
561 
494 
477 
438 
492 
4 
644 
1 
710 
8 
592 
> 16.8 
2 
683 
1 
657 
"608" 
2 
47588°— 25f— Bull. 1352- 
