208 ALKALI-TREATED STRAW [Vol. XXV, Part III,
Similar data were collected for other centres also, but since these have not been
subjected to statistical analysis, they have not been reported here. Like other
centres the milk data for Izatnagar centre also referred to unknown lactation
numbers of some animals. It is well-known that milk yield depends a good deal
on the lactation number. The randomisation of this factor, as has been done in
the present case, has, therefore, increased the inherent variation in the data but
has not made the application of a statistical test invalid. The results of statistical
analysis of the data are presented in Table VI.
TABLE VI
Analysis of variance of milk data from feed trials on cows, collected at Izatnagar
|
Source of variation |
Analysis of variance table for yields |
||
|
d.f. |
M. S. (lb.)2 |
||
|
Between weeks |
|||
|
10 |
7.3501 |
||
|
Between groups |
|||
|
2 |
177.3786 |
||
|
Interaction between weeks and groups |
|||
|
20 |
1.1798 |
||
|
Between feeds |
|||
|
2 |
60.9811** |
||
|
Interaction between feeds and groups |
|||
|
4 |
41.0784 |
||
|
Error |
|||
|
60 |
0.9439 |
||
|
TOTAL |
98 |
||
|
Standard error of difference between two feed means |
=0.239 |
|
Critical difference for such means=0.239 x 1.96 |
=0.468 |
Means of feed
|
Alkali-treated straw |
Control |
Water-washed straw |
|
17.15 |
15.67 |
14.43 |
All different significantly