Statistical modelling

Note that the effects of season and period are non-significant whether added before or after lagged (i.e. the effect of tsetse control) in the model (See accumulated analysis of variance).

If we click the 'Predict' button and then click 'Lagged' we get estimates of least squares means. We find that, the average weight of bulls increased from 231 to 248 kg after tsetse control was introduced. As there was no interaction of period and effect of tsetse control we can conclude that similar effects occurred both when targets and pour-on were used.


 

Regression analysis
Response variate: AM_WEIGHT
Fitted terms: Constant + Season + Period + Lagged
Accumulated analysis of variance

Change

d.f.

   s.s.

    m.s.

   v.r.

F pr.

+ Season

1

231.08

231.08

2.56

0.127

+ Period

1

762.28

762.28

8.46

0.009

+ Lagged

1

1579.05

1579.05

17.52

<.001

Residual

18

  1622.40

90.13

 

Total

21

4194.81

199.75

 

Fitted terms: Constant + Period + Lagged + Season
Accumulated analysis of variance

Change

   d.f.

  s.s.

 m.s.

  v.r.

F pr.

Period

1

762.28

762.28

8.46

0.009

Lagged

1

1680.01

1680.01

18.64

<.001

Season

1

130.12

130.12

1.44

0.245

Residual

18

1622.40

90.13

Total

21

4194.81

   199.75

   

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