Animal Molecular Breeding, 2013, Vol.3, No.2, 4
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chokla where as, Arora et al. (1975), Acharya and
Manimohan (1979), Acharya (1982) and Sahni (1985)
reported lower means for birth weight than present
study. Higher means were reported by Kushwaha et al.,
(1997)
for body weights at weaning and 6 months of
age, where as, Sahni (1985) reported lower values in
chokla. For 4 FYI, Sahni (1985), Kushwaha (1994) and
Anonymous (1993) reported lower estimates, where as,
Kushwaha et al., (1997) and Anonymous (1998) reported
slightly higher mean for the same breed. Acharya (1982)
also reported higher means for GFYI. The standard error
under model 2 was higher than model 8 for all the traits.
Table 2 Least squares means of birth, weaning, 6 month and first greasy fleece weight under model 2 and model 8 analysis
Effect
No. of observations
BWT
WWT
6
WT
GFYI
Model 2
1214
2.81
±0.02
12.12
±0.10
16.91
±0.13
0.95
±0.01
Model 8
1214
2.82
±0.02
11.87
±0.10
16.86
±0.12
0.96
±0.01
Sex of Lamb
Male
576
2.86
12.47
17.75
0.97
Female
638
2.75
11.76
16.07
0.94
Year of Birth
1974
65
3.01
13.65
18.92
0.95
1977
47
2.53
11.37
14.52
0.84
1979
38
2.32
9.21
11.10
0.39
1980
31
2.71
12.13
15.89
0.93
1981
28
2.60
14.53
18.45
1.41
1982
28
2.96
14.06
16.76
0.91
1984
31
2.61
14.20
18.67
1.08
1985
34
2.78
11.35
13.84
0.94
1986
37
2.84
13.43
17.01
0.94
1987
33
2.61
10.16
16.61
0.68
1989
40
3.04
14.13
22.54
1.30
1990
66
3.06
14.08
21.74
1.35
1991
67
2.95
14.61
19.96
0.92
1992
69
3.12
12.97
16.97
0.87
1993
80
2.97
11.99
17.63
0.95
1994
72
2.77
11.19
16.73
0.88
1995
103
2.59
9.42
14.73
0.87
1996
117
2.89
11.65
17.25
0.96
1997
92
2.85
8.67
13.96
0.85
1998
136
2.82
9.50
14.98
1.05
The coefficient of variation (C.V. %) presented in
Table 3 was almost similar for different traits under model 8,
univariate and multivariate. The C.V. increase with
increase with increase in age up to WWT but it
decreases at 6 WT and again increased at GFYI. GFYI
was showing maximum variation under all methods
followed by WWT and 6 WT birth weight showed least
variation. Lower C.V. observed for 6 month weight
was due to culling of some lambs between 3 and 6
month of age that may have reduced the variation.
More over, the weights become more uniform after the
maternal influence and weaning stress over, as
reported by Bathaci and Leroy (1998). High C.V. at
GFYI was because of the fact that all the animals were,
practically, not shorn exactly at similar age i.e. 6 month of
age. Forgrty (1995) reported declining trend in the
mean coefficient of variation for live weights with
increasing age form birth (17%) to weaning (15%)
yearling (11%) and hogget (10%). He reported consistency
among coefficients of variation. Multivariate analysis
had explained more variation than model 8 and univariate.
It indicates that data had shown multivariate distribution. In
general REML analyses using animal model explained
more variation than the model 8 of least squares. Malik
et al. (1971) had also reported the similar results whereas
Arora et al. (1981) and Chaudhary and Malik (1972) had
reported higher values than the present study in Chokla sheep.
1.1
Factor Affecting Body Weights and First
Greasy Fleece Yield
The fixed effect of year had highly significant effect
on all the traits studies under model 2 (Table 4) and