6 i 4 
Journal of Agricultural Research 
Vol. XI, No. ii 
Table; II .—Average measurements and ratios of measurements of lambs by periods (not 
including pure Rambouillet sheep ) 
Item. 
Age 
a weeks. 
Age 
4 weeks. 
Age 
8 weeks. 
Age 
12 
weeks. 
Age 
24 
weeks. 
Age 
40 
weeks. 
Age 
w£ks. 
Interval since last 
measurement, 
days. 
14 
21. 5 
28 
21 
91 
53- 5 
112 
84 
67 
Weight. 
iS-5 
37-5 
45° 
660 
Height. 
3^5 
415 
475 
505 
545 
575 
58s 
Heaci length. 
.mm.. 
no 
120 
*35 
145 
160 
*75 
185 
Head width. 
80 
85 
95 
100 
I0 5 
115 
*15 
Neck length. 
175 
I9O 
205 
220 
265 
280 
280 
Trunk length. 
320 
365 
440 
475 
500 
520 
540 
Chest depth. 
..mm.. 
145 
l6o 
195 
210 
235 
260 
265 
Chest width. 
100 
i*5 
130 
140 
*55 
170 
175 
Loin width. 
75 
80 
95 
100 
no 
120 
120 
Croup length. 
Foreleg length. 
*5 
95 
no 
120 
125 
*35 
135 
265 
280 
3 10 
320 
360 
380 
395 
Hindleg length. 
300 
320 
360 
375 
400 
435 
445 
Ratios: 
Head width 
o- 73 
0. 71 
0. 70 
0. 69 
0. 66 
0. 66 
a 67 
Head length 
Chest width 
•30 
•33 
•3i 
•3i 
•30 
•3i 
•33 
Trunk length 
Loin width 
Trunk length 
Croup length 
. 22 
•23 
.26 
. 22 
. 26 
. 22 
•25 
. 21 
•25 
. 22 
•25 
•23 
. 26 
•25 
Trunk length 
Foreleg 
.83 
•77 
.70 
.67 
•72 
•73 
•73 
Trunk length 
Chest depth 
•45 
• 44 
•44 
A A 
•47 
• 50 
• 49 
Trunk length 
Trunk length 
• 44 
•94 
.83 
.88 
•93 
.92 
.90 
.92 
Height 
Chest width 
.69 
.72 
.67 
.67 
.66 
•65 
.66 
Chest depth 
The curves in figure 2, of which Table II forms the basis, illustrate this 
point more forcefully. The most rapid development occurs during the 
earlier stages of life, decreasing with advancing age, as would be expected. 
The marked feature of these curves, however, is the fact that, allowing for 
some variations between different dimensions, they show such an exceed¬ 
ingly rapid growth for approximately the first three months. This 
period produces at least 50 per cent of the whole year’s growth in dimen¬ 
sions and over 60 per cent of the total weight increase for the year under 
normal care. In the following three months’ period there is a consid¬ 
erable decline, probably due in part to two severe temporary checks that 
occur at this time in this locality, the first occurring when the lambs go out 
on pasture and the second occurring when they are weaned. Approxi¬ 
mately 20 per cent of the whole year’s growth is the limit that can be 
expected for this second quarter. There is about an equal increase in the 
third quarter which comes during the fall of the year and not over 5 per 
cent in the last quarter, or winter period. 
