|
Statistical modelling
No parameter estimate is shown for the pure
breed DD, which is used as a reference level against which the estimate for each
of the other genotypes is compared. The least squares 'predicted' means,
however, are calculated for all four genotypes. They indicate that the purebred
RR lambs had the lowest mean weaning weight of 10.512 ± 0.193 kg, whilst the
purebred DD lambs had the highest mean weaning weight of 11.552 ± 0.159
kg.
From the corresponding parameter estimates it can be seen
that the RR parameter estimate of -1.04 is highly significant (t=-3.84, P <
0.001). In other words, the mean weaning weight of RR lambs was significantly
lower, by 1.04 kg, than that of DD lambs (P < 0.001). The parameter estimates
also suggest that the crossbred RD and DR lambs have a similar mean weaning
weight lying between those for the pure breeds.
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Response variate: WEANWT
Fitted terms: Constant + YEAR + SEX + AGEWEAN + DL
+ DQ + GENOTYPE
*** Estimates of parameters ***
|
|
estimate |
s.e. |
t(687) |
Constant |
2.702 |
0.929 |
2.91 |
|
YEAR 92 |
-1.565 |
0.293 |
-5.34 |
YEAR 93 |
-1.099 |
0.276 |
-3.99 |
YEAR 94 |
-2.820 |
0.359 |
-7.85 |
|
YEAR 95 |
-3.215 |
0.346 |
-9.30 |
YEAR 96 |
-2.342 |
0.391 |
-5.99 |
SEX M |
0.476 |
0.170 |
2.81 |
AGEWEAN |
0.07026 |
0.00886 |
7.93 |
DL |
2.725 |
0.315 |
8.65 |
DQ |
-0.269 |
0.034 |
-7.90 |
GENOTYPE RD |
-0.389 |
0.220 |
-1.77 |
|
GENOTYPE RR |
-1.040 |
0.271 |
-3.84 |
GENOTYPE DR |
-0.511 |
0.304 |
-1.68 |
*** Accumulated analysis of variance ***
|
Change |
d.f. |
s.s. |
m.s. |
v.r. |
|
+YEAR |
5 |
1208.149 |
241.630 |
48.92 |
|
+SEX |
1 |
55.983 |
55.983 |
11.34 |
|
+AGEWEAN |
1 |
344.206 |
344.206 |
69.69 |
|
+DL |
1 |
151.513 |
151.513 |
30.68 |
|
+DQ |
1 |
275.795 |
275.795 |
55.84 |
|
+GENOTYPE |
3 |
75.857 |
25.286 |
5.12 |
|
Residual |
687 |
3392.947 |
4.939 |
|
|
Total |
699 |
5504.450 |
7.875 |
|
|
GENOTYPE |
Prediction |
s.e. |
|
DD |
11.552 |
0.159 |
|
DR |
11.041 |
0.240 |
RD |
11.163 |
0.176 |
|
RR |
10.512 |
0.193 |
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