284 K
. Kolstad Livestock Production Science 67 2001 281 –292
coefficient b was estimated by regressing the growth coefficients for each fat depot from 10 to 105
logarithm of component weight y on the logarithm kg live weight relative to CT-weight and total fat
of live weight or total fat X : log y 5log a 1b log X. respectively.
3.1. Genotype differences in amounts of depot fat
3. Results adjusted for CT-weight
Significant effects of main effects and interactions Absolute amounts of fat increased in all three
on fat depots at five live weights are indicated in genetic groups during growth Fig. 1. According to
Tables 1 and 2. Table 3 presents solutions for genetic the estimated allometric growth coefficients in Table
differences in depot fat adjusted for CT-weight, to 4 inter intramuscular fat increased in proportions
compare the breeds with respect to amounts of fat in relative to CT-weight b 51.0 in all three genetic
each depot at the five live weights. Table 3 also groups P ,0.05 except for the Landrace pigs with
presents solutions for breed differences in depot fat b-value ,1.0 for subcutaneous fat P ,0.05. The
adjusted for total fat to compare the breeds with genetic groups all differed in allometric fat growth
respect to fat distribution. Table 4 presents allometric relative to live weight in this experiment. LLP
Table 1 The influence of experimental factors on amounts of fat depots at five live weights when adjusted for CT-weight
a
LW Depen.
Independent variables kg
var. A
B S
T FT
BT BS
ST FB
FS CT-weight
Age
d e
c b
d c
10 Subf
ns ns
ns ns
ns ns
ns
d b
d
Imf ns
ns ns
ns ns
ns ns
ns ns
d c
d b
d
Intf ns
ns ns
ns ns
ns ns
d c
c d
Tfat ns
ns ns
ns ns
ns ns
ns
b c
b c
c d
25 Subf
ns ns
ns ns
ns ns
c b
d
Imf ns
ns ns
ns ns
ns ns
ns ns
c d
c c
b c
d
Intf ns
ns ns
ns ns
b c
c d
Tfat ns
ns ns
ns ns
ns ns
d b
b c
d
50 Subf
ns ns
ns ns
ns ns
ns
c c
b b
Imf ns
ns ns
ns ns
ns ns
ns
b d
d b
Inter ns
ns ns
ns ns
ns ns
ns
d b
d d
Tfat ns
ns ns
ns ns
ns ns
ns
d d
c c
b b
85 Subf
ns ns
ns ns
ns ns
b c
d b
c
Imf ns
ns ns
ns ns
ns ns
b d
d b
b b
d
Inter ns
ns ns
ns ns
b d
d b
c c
b b
Tfat ns
ns ns
ns
b d
c c
c
105 Subf
ns ns
ns ns
ns ns
ns
b c
d b
c
Imf ns
ns ns
ns ns
ns ns
b d
d b
b
Inter ns
ns ns
ns ns
ns ns
b d
d b
b b
Tfat ns
ns ns
ns ns
ns
a
B5effect of genetic group, S5effect of batch, FT5effect of feeding system from 10 to 25 kg live weight within batch, A5random additive genetic effect of animal.
b
Indicates effects at significance level P 50.05.
c
Indicates effects at significance level P 50.01.
d
Indicates effects at significance level P 50.001.
e
n.s.5not significant effect.
K . Kolstad Livestock Production Science 67 2001 281 –292
285 Table 2
The influence of experimental factors on proportions of fat depots relative to total fat at five live weights
a
LW Depen.
Independent variable kg
var. A
B S
T FT
BT BS
ST FB
FS CT-weight
Age
b d
d c
e d
10 Subf
ns ns
ns ns
ns ns
ns
b d
d
Imf ns
ns ns
ns ns
ns ns
ns ns
b c
c b
b d
b
Intf ns
ns ns
ns ns
d d
d c
b d
d
25 Subf
ns ns
ns ns
ns
b c
c d
Imf ns
ns ns
ns ns
ns ns
ns
d d
d c
b b
d
Inter ns
ns ns
ns ns
c c
b b
d b
50 Subf
ns ns
ns ns
ns ns
c d
b b
d b
Imf ns
ns ns
ns ns
ns
b d
c d
Inter ns
ns ns
ns ns
ns ns
ns
c c
c c
d
85 Subf
ns ns
ns ns
ns ns
ns
c c
c d
Imf ns
ns ns
ns ns
ns ns
ns
b d
c d
Inter ns
ns ns
ns ns
ns ns
ns
b c
d b
d
105 Subf
ns ns
ns ns
ns ns
ns
b d
d b
Imf ns
ns ns
ns ns
ns ns
ns
b d
c d
Inter ns
ns ns
ns ns
ns ns
ns
a
B5effect of genetic group, S5effect of sex, T5effect of batch, FT5effect of feeding system from 10 to 25 kg live weight within batch, A5random additive genetic effect of animal.
b
Indicates effects at significance level P 50.05.
c
Indicates effects at significance level P 50.01.
d
Indicates effects at significance level P 50.001.
e
n.s.5not significant effect.
showed the highest allometric growth coefficients Some differences are seen between the LLP and
while Landrace showed the lowest for the three fat the modern breeds at weaning 10 kg and at 25 kg
depots P ,0.05. There were also differences be- live weight with respect to amounts of fat in each
tween the three fat depots in allometric growth depot Table 2, with LLP having significantly
coefficients, with inter intramuscular fat having a higher amounts of subcutaneous fat P ,0.05.
significantly higher growth than the subcutaneous fat Duroc pigs have more internal fat P ,0.010 at 10
depot relative to CT-weight P ,0.05. kg live weight, while Landrace pigs have somewhat
Table 3 presents differences between genetic higher amounts P ,0.10 and Duroc somewhat
groups in CT-weight adjusted fat amounts in the lower amounts P ,0.10 of internal fat than the LLP
three depots at each live weight. The amounts of at 25 kg. At 50 kg live weight, LLP has significantly
subcutaneous fat are somewhat higher P 50.10 in higher amounts of subcutaneous fat than the Duroc
Duroc than in Landrace at 50 kg, and significantly and Landrace P ,0.05, more internal fat P ,0.05
higher at 85 and 105 kg live weight. Amounts of and indications of more inter intramuscular fat P ,
inter intramuscular fat are significantly higher in the 0.10 than the Duroc, as well as indications of more
Duroc compared to the Landrace at 85 and 105 kg inter intramuscular and internal fat than the Land-
live weight P ,0.05 but not at 50 kg or lower. At race P 50. 10. At 85 and 105 kg live weight almost
10 kg live weight Landrace pigs have significantly all fat depots are significantly larger in the LLP
higher amounts of internal fat than pigs of Duroc compared to the two other genetic groups when
breed P ,0.010. This difference is maintained adjusting for total CT-weight P ,0.05, except for
throughout the experiment. the difference between LLP and Duroc in inter
286 K
. Kolstad Livestock Production Science 67 2001 281 –292 Table 3
f
Breed differences in amounts or proportion of each fat depot from 10 to 105 kg live weight when adjusting to CT weight or total fat weight Live
Fat depots Adjusted for CT-weight
Adjusted for total fat weight weight
e e
D–L LLP–L
LLP–D D–L
LLP–L LLP–D
b b
c c
10 kg Subcutaneous
0.043 0.163
0.120 0.097
0.073 20.023
a
Inter intramuscular 20.015
20.002 0.013
20.005 20.030
20.024
c c
c b
Internal 20.106
20.009 0.115
20.095 20.085
0.010
b b
b c
25 kg Subcutaneous
0.136 0.622
0.486 0.253
0.385 0.132
b a
Inter intramuscular 0.060
0.029 20.031
0.064 20.011
20.074
c a
d c
Internal 20.280
20.119 0.160
20.320 20.385
20.034
a d
c c
a
50 kg Subcutaneous
0.489 2.594
2.105 0.446
0.279 20.167
a a
Inter intramuscular 0.044
0.264 0.220
0.018 0.001
0.016
c a
c d
c
Internal 20.358
0.212 0.569
20.516 20.381
0.135
b d
d a
c c
85 kg Subcutaneous
1.292 7.105
5.812 0.324
1.151 0.827
c d
a d
c
Inter intramuscular 1.010
1.618 0.61
0.594 20.405
20.998
a c
d d
b b
Internal 20.302
1.832 2.134
20.846 20.431
0.415
b d
d c
c
105 kg Subcutaneous
1.458 7.415
5.957 0.248
1.694 1.446
b d
a d
a d
Inter intramuscular 1.211
2.251 1.040
0.848 20.505
21.353
c c
d d
c a
Internal 20.671
1.017 1.689
21.034 20.710
0.323
a
Indicate differences at significance level P 50.10.
b
Indicate differences at significance levels P 50.05.
c
Indicate differences at significance level P 50.01.
d
Indicate differences at significance level P 50.001.
e
L5Landrace, D5Duroc, LLP5crossbreed between Norwegian Landrace and a selection line selected for high backfat and slow growth.
f
CT-weight5sum of body components and total fat5sum of fat components, both measured by CT. Table 4
a
Allometric growth coefficients for fat growth from 10 to 105 kg live weight Fat depot
W5CT-weight Y 5total fat
Landrace Duroc
LLP Landrace
Duroc LLP
b,e c
d,e e
e e
Subcutaneous 0.89
0.96 1.13
0.933 0.91
0.94
b,e c,e
d,e b,e
c,e bc,e
Inter intramuscular 1.10
1.28 1.42
1.17 1.23
1.20
b c,e
d,e
Internal 0.98
1.08 1.22
1.02 1.02
1.01
a
Y 5fat depots, X 5CT-weight or total fat weight.
b,c,d
Means within a row and heading with different superscript letter differ P ,0.05.
e
Indicates allometric growth coefficients significantly different from 1 P ,0.05.
intramuscular fat at 85 and 105 kg, which is slightly tramuscular fat and not significantly different from
below significance level P ,0.10. 1.0 for internal fat. These indicate that subcutaneous
fat decreases as a proportion of total fat in favour of 3.2. Genotype differences in depot fat as a
inter intramuscular fat. Significant genotype differ- proportion of total fat
ences were found in allometric growth of inter intramuscular fat relative to total fat in the present
Table 4 also presents allometric growth coefficient experiment, with Duroc showing a significant higher
of each fat depot relative to total fat, i.e. proportional relative growth than the Landrace pigs P ,0.05.
changes in the fat depots. In general, the allometric After adjusting weights of each fat depot to equal
growth coefficient for subcutaneous fat is less than weights of total fat, the fat distribution can be
1.0 P ,0.05, above 1.0 P ,0.05 for inter in- considered. Table 3 and Fig. 2 show fat distribution
K . Kolstad Livestock Production Science 67 2001 281 –292
287
Fig. 1. a, b, c and d. Deposition of the subcutaneous, inter intramuscular and the internal fat depots and of total fat from 10 to 105 kg live weight in Landrace —, n 563, Duroc — —, n 562 and LLP ? ? ? ? ? ?, n 516.
288 K
. Kolstad Livestock Production Science 67 2001 281 –292
Fig. 1. continued
K . Kolstad Livestock Production Science 67 2001 281 –292
289
Fig. 2. Fat depots j subcutaneous, 9 inter intramuscular and h internal expressed as a proportion of total fat at 10, 25, 50, 85, and 105
kg live weight in Landrace n 563, Duroc n 562 and LLP n 516.
at each of the five live weights in the three genetic tramuscular fat while LLP shows a higher relative
groups. Significant differences in fat distribution proportion of subcutaneous fat and internal fat.
between Landrace and Duroc are found at all live weights. The relative proportion of subcutaneous fat
is significantly higher in the Duroc than in the
4. Discussion
