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Behzad Mobini
Department of Anatomical Sciences, Faculty of Veterinary Medicine, Islamic Azad
University, Shahrekord Branch, P.O.Box:166. Shahrekord, Iran.
Author Email: [email protected]
%#
To study morphometric changes of different parts of small and large intestines with age, 100
Ross broiler chickens were divided into five age groups: 10, 20, 30, 40 and 50 days. The
following parameters of intestines were analysed: the duodenal length (DL), and weight
(DW), jejunal length (JL), and weight (JW), ileal length (IL), and weight (IW), caecal length
(CeL), and weight (CeW), colon length (CoL), and weight (CoW), alimentary canal length
(AL), and weight (AW), with relation to the birds’ body weight (BW). The weights of all the
various parts of small intestine in the 10 days group had significantly higher values for bigger
females, compared to the smaller males, whereas in other age groups that males, larger than
females, were more than females. As the age increased, all the indices of relative values of
intestinal parameters decreased. In all age groups, the highest and lowest weights, lengths and
all the intestinal parameters indices were belonged to jejunum and colon respectively. All the
intestinal weight and length parameters were highly correlated with body weight and
alimentary canal length. These findings suggest that morphometry of alimentary canal might
be one of the major determining patterns of growth in a bird species, especially in different
ages.
+ ,Morphometric, chicken, broiler, intestine, age.
#
The modern commercial broiler continues to show increased yearly genetic gains. This
selection for increased growth rate has resulted in changes in gastrointestinal development
during growth of the animal (Tottori
, 1997). The bird intestines have a major influence
on growth performance of broilers as it affects feed digestion, nutrient absorption and
mortality (Santos, 2005). The small intestine which consisted of duodenum, jejunum and
ileum, is relatively simple and short but highly efficient nevertheless (Dibner and Richards,
2004). Despite the name, the large intestine which consisted of paired caeca and colon or
rectum, is actually shorter than the small intestine (Getty, 1975). Both intestines are
characterised by a great morphometrical and functional variability, both between and within
species. For example, many familiar avian species, such as chickens and ducks, have very
large caeca, which aid in the digestion of vegetation and in water balance (Clench and
Mathias 1995, Kehoe and Ankney 1985). Ross chicken is the most commercial broiler which
use widely in Iran. To the knowledge of the author, no published reports exist describing the
morphometric characteristics of the intestines of this species. Therefore, this study was
designed to understand the morphometrical changes of different parts of both intestines of the
ross broiler chickens with age increasing.
%
% %
!
One hundred (50 each sex) ross broiler chickens were divided into five age groups: 10, 20, 30,
40 and 50 days. The birds were killed by cervical sub-luxation method and then were weighed
with accuracy of 0.01g. The alimentary canal from the proximal esophagus to the cloaca was
carefully removed from the body cavity. The canal was stripped of fat deposits and the
mesentery and each component was separated, emptied of contents and washed. Thirteen
measurements of both intestines were taken: the duodenal length (DL), and weight (DW),
jejunal length (JL), and weight (JW), ileal length (IL), and weight (IW), caecal length (CeL),
and weight (CeW), colon length (CoL), and weight (CoW), alimentary canal length (AL), and
weight (AW), with relation to the birds’ body weight (BW). The linear parameters of both
intestines were measured with accuracy of 1mm.
The statistical study of results consisted of establishing differences between females and
males and between age categories of the chickens in absolute average values of the intestines
measurements and average values of selected indices of relative size of those organs using
Student's t test (2-tailed test assuming equal variance). Pearson’s (r) linear correlation
coefficient was calculated to examine the relations between the intestines’ parameters and the
birds’ body weight and those characterising the alimentary canal length.
)
%
#
As birds grew, increases in food intake rate were matched by increases in weights and lengths
of the both small (Table 1), and large intestines (Table 2). Jackson (1992) also found the
intestinal length to scale positively with body mass in 13 seabird species investigated.
.%
Comparison of weights and lengths of various parts of small intestine in males and
females of the ross broiler chicken among age groups
/
0 "%
1
2.25
2.06
0 "%
0.13
a
a
140.80 6.10
d
132.90 5.11
d
%,
(
%
0.12
3.85
0.25
4.17
5.30
%
0.32
4.56
b
0.21
1
f
f
(
176.39 4.98
h
184.74 5.63
h
608.30
0.60
b
44.35
529.60
e
9.59
0 "%
0.76
%
0.13
0.42
c
0.06
c
14.71
54.96
1.93
53.8
3.53
0.56
1.10
0.12
1.17
0.13
e
0.37
10.71
g
g
%,
%,
1
3.68
(
197.64
1
7.02
0.20
6.43
0.55
3.70
200.59
7.24
0.16
10.39
1.29
707.00
13.01
719.66
15.71
117.60
13.96
2.32
15.47
2.64
1.63
1154.90
21.25
89.05
1.84
1213.90
21.80
65.52
3.22
6.22
0.25
134.00
16.08
2.44
0.13
120.24
2.18
1.81
0.35
141.20
3.22
2.57
0.52
%,
(
1
259.80
8.40
25.03
0.46
262.80
8.84
40.80
0.64
1179.47
30.80
115.34
1.95
1230.50
31.26
112.25
2.24
154.76
12.33
3.86
0.30
167.97
27.50
4.06
0.29
%,
(
339.90
28.08
347.10
19.65
1498.40
44.09
1512.50
42.14
200.03
15.90
226.49
i
15.24
i
D: duodenum J: jejunum, I: ileum, W: weight (g), L: length (mm), Similar small letters:
significant at < 0.05
The total length of duodenum, jejunum and ileum in ross broiler chickens was found 13.29 to
34.71, 52.96 to 151.25 and 5.38 to 22.65 cm respectively (Table 1), whereas in domestic fowl
was found 22 to 35, 85 to 120, 13 to 18 cm respectively (Getty, 1975). These values in other
species including duck and goose were found 22 to 38, 90 to 140 and 10 to 18 cm and 40 to
49, 150 to 185, 20 to 28 cm, respectively (Dyce et al., 1995).
In all age groups, the highest and lowest weights, lengths (Tables 1,2) and all the intestinal
parameters indices were belonged to jejunum and colon, respectively. Also the lowest indices
of relative values of various parts of small and large intestines in both sexes were belonged to
the ileum and colon, respectively (Tables 3,4,5). The greatest portion of the alimentary canal
was comprised by the jejunum. This higher weight was partly due to the presence of yolk sac
on jejunum portion of the canal. Early rapid growth of the chicks at the 10 days group appears
to be due to the yolk sac providing necessary nutrients.
.%
Comparison of weights and lengths of various parts of large intestine in males and
females of the ross broiler chicken among age groups
$
$
/
0 "%
1
0.73
(
146.40
%,
%
0.06
14.63
0.07
1.99
0.65
0 "%
0.11
151.30
9.59
2.07
0.10
1
a
a
(
233.39 7.23
c
241.51 6.30
c
%
0.19
0.02
0.18
0.01
22.20
2.53
22.69
1.06
0.06
0.67
0.52
b
0.05
b
%,
%,
1
2.35
(
267.96
1
0.37
43.03
4.54
0.16
2.38
0.37
285.86
5.77
4.22
41.84
2.15
44.45
d
0.89
0.88
d
0.14
0.96
0.11
60.39
6.50
63.45
4.42
0.80
1.09
0.08
1.17
0.17
25.31
71.73
3.74
83.18
%,
(
1
285.23
29.77
287.06
e
0.16
4.03
4.39
f
0.22
3.14
6.20
e
0.65
3.58
0.23
f
%,
(
372.70
26.12
g
398.44
21.72
108.35
10.41
107.30
4.61
g
Ce: cecum Co: colon, W: weight (g), L: length (mm), Similar small letters: significant
at < 0.05
Numerous studies indicate differences in digestive organs size in birds at different age. These
differences are visible both in absolute parameters and in the relative size of digestive organs.
They result from changing proportions of given parts of the digestive tract during the growth
and development of an animal (Dziala Szczepanczyk, 2005; AL-Dabagh and Abdulla, 1963;
Dunn, 1975; Lilja, 1981; Baranyiová et al., 1983; Przystalski, 1986).
The results of dimorphic comparisons concerning of intestinal parameters of the ross broiler
chickens clearly showed that the weights of all the various parts of small intestine of 10 days
females, larger than males, were significantly higher, whereas these parameters in other age
groups reached higher values in larger males than in smaller females (Table 1). The
morphometric results show a strong dependency of intestinal growth (all various parts) on
body weight. A certain regularity is found in many bird species: when males are considerably
bigger than females, absolute values of parameters of their digestive organs are usually also
higher. Such a regularity was also found in case of the examined chickens - the larger
chickens had relatively longer and heavier intestines than smaller chickens. The dimorphism
in relative size of some birds’ digestive organs was also observed in other species including
Shoveler
(Ankney and Afton, 1988), Mallard
(Miller,
1974) and Willow Grouse
(Pulliainen, 1976). The authors, attributed this
phenomenon to unfavourable surface volume ratio in smaller females, which is implies a
greater loss of heat and, in consequence, the need to take more food, hence the increase in
size of digestive organs and suggested that digestive organs of females may better adjust to
changing feeding conditions than those of males.
The total length of caeca and colon in ross broiler chickens was found 14.64 to 39.84 and 2.22
to 10.83 cm respectively (Table 2), whereas these values in bronze turkey, adult chicken,
penguin and tinamou were 64.4 to 91.4 and 33.4 to 42 cm (Dyce et al., 1995), 28 to 47 and 8
to 11 cm (Getty, 1975), 1.4 to 2.6 and 2.15 to 5.7 cm (Olsen, et al., 2002), 2.5 to 6.2 and 2.8
to 5.8 cm, respectively (Chikilian and Speroni, 1996). The total length of each caeca in ross
broiler was found 7.32 to 19.92 cm. These values in other species including duck, goose and
pigeon were found 10 to 20, 23 to 28 cm (Dyce et al., 1995) and 1 to 3.5 cm, respectively
(Nickel, et al., 1997). Also wild herbivorous birds like ptarmigans and grouse had large paired
caeca with a combined length of 70–150 cm (Pulliainen 1976).
The small intestine of the ross broiler was 4.2 as long as the large intestine, whereas the large
intestine of the ostrich was 2 and a half as long as the small intestine due to the presence of
the colon (Porcescu, 2007).
.%
Comparison of indices of relative values of various parts of intestines in males and
females of the ross broiler chicken among age groups (As percent of alimentary canal weight)
/
%,
'%
0
1
0
%,
%,
%,
%,
14.50
0.73 a
10.55
0.81 b
7.54
0.78 c
9.54
0.55 d
7.80
0.49 c
14.90
1.09 a
10.60
0.28 b
7.11
0.79 c
9.03
0.81 d
7.96
0.60 e
34.09
1.52 a
26.26
1.05 b
28.21
2.27 c
28.86
1.62 c
28.97
B
1
32.72
3.21 a
27.24
2.87 b
29.25
2.17 b
27.30
2.10 b
27.70
B
0
0.68 a
A
3.01
0.30 b
3.31
0.44 bc
3.31
0.31 bc
3.58
0.22 ac
3.04
0.49 a
A
2.97
0.26 a
3.42
0.31 bc
3.20
0.36 ab
3.65
0.24 c
4.75
0.59 a
5.44
0.14 b
4.76
0.44 a
6.19
0.44 d
3.74
0.17 e
0.59 b
3.95
0.13 c
G
C
$ 1
4.67
0.41 a
5.27
E
0.18 b
4.52
0.48 a
5.27
C
0
1.30 b
F
3.84
1
0
1.08 c
F
E
1.22
0.17 a
1.41
0.12 a
D
1.82
0.30 b
1.48
0.11 a
2.90
0.53 c
1.31
0.16 a
1.71
0.09 b
D
1.83
0.15 b
1.47
0.11 c
3.22
0.19 d
G
$ 1
D: duodenum J: jejunum, I: ileum, Ce: cecum Co: colon, W: weight, F: females, M:
males, Similar capital letters in a column and Non-similar small letters in a row:
significant at < 0.01
The highest and lowest weight correlation coefficients were obtained with JW (R2 = 0.96) and
CeW (R2 = 0.79), respectively and the highest and lowest length correlation coefficients were
obtained with JL (R2 = 0.97) and DL (R2 = 0.88), respectively (Table 6). Since all the weight
and length parameters of both intestines of ross broiler chickens were highly and positively
correlated to body weight and alimentary canal length, derived equations that obtained on the
basis of these morphometric characteristics, can use to estimate of weight and length of
different portion of both intestines without the need of carcass analysis.
The total length of intestinal canal in ross broiler was found 249.1 to 257.99 cm, whereas in
duck and goose were found 155 to 233 cm and 85 to 120 and 250 to 365 cm, respectively
(Dyce et al., 1995). Comparison of relative lengths of the intestinal canal among species
shows that the relative length of the intestinal canal is very constant in a species. In all age
groups, the lowest indices of relative values of various parts of small and large intestines in
males and females were belonged to the ileum and colon, respectively (Tables 3,4,5). As the
age increased, all the indices of relative values of intestinal parameters with relation to the
birds’ body weight decreased in both sexes (Table 4). A comparison between Table 3 with
Table 4 shows that although the intestinal weights were increased with age, but this weight
increasing is less than those of in other body organs.
All the intestinal weight parameters were highly correlated (P < 0.001) with body weight.
Also all the lengths of various intestinal parts were highly correlated with alimentary canal
length (P < 0.001) in the examined groups of ross broiler chickens (Table 6).
.%
Comparison of indices of relative values of various parts of intestines in males and
females of the ross broiler chicken among age groups (As percent of body weight)
/
%,
'%
0
%,
1.25
0.09 b
B
0.60
0.04 c
0.73
0.05 d
0.56
0.05 c
2.56
0.35 a
1.11
0.02 b
B
0.57
0.07 c
0.71
0.14 c
0.55
0.06 c
6.18
0.40 a
3.13
0.19 b
C
2.25
0.26 c
2.20
0.17 c
2.06
0.10 c
G
5.67
1.23 a
2.84
0.07 b
C
2.33
0.20 b#
2.13
0.36 c
1.90
0.14 c
G
0.70
0.14 a
A
0.36
0.03 b
D
0.26
0.04 c
0.25
0.03 c
0.25
0.02 c
0.52
0.11 a
A
0.31
0.03 b
D
0.27
0.02 bc
0.25
0.05 c
0.25
0.02 c
0.86
0.10 a
0.65
0.03 b
0.38
0.04 c
0.47
0.02 d
0.27
0.01 e
0.81
0.15 a
0.55
0.02 b
0.36
0.05 c
0.41
0.08 c
0.27
0.01 d
0.22
0.03 a
0.17
0.01 b
0.14
0.02 c
0.11
0.01 d
0.21
0.03 a
0.22
0.02 a
0.18
0.01 b
0.15
0.01 c
0.11
0.02 d
0.22
0.02 a
1
0
%,
0.16 a
1
0
%,
2.63
1
0
%,
$ 1
0
$ 1
0
936.53
84.17 a
326.38
16.05 b
240.27
17.68 c
164.97
12.37 d
133.13
8.36 d
8.09 b
237.11
22.01 cd
162.19
23.55 cd
128.47
8.23 d
5.25 b
52.59
5.79 c
36.80
2.65 d
31.55
1.56 d
3.97 b
53.16
6.19 bc
35.74
4.31 c
31.11
2.67 c
E
(
885.41
94.37 a
272.23
E
0
195.57
20.69 a
89.66
F
((
213.70
27.54 a
75.83
F
D: duodenum J: jejunum, I: ileum, Ce: cecum Co: colon, Si: small intestine, Li:
large intestine, W: weight, L: length, F: females, M: males, Similar capital letters in a
column and Non-similar small letters in a row: significant at < 0.01
.%
Comparison of indices of relative values of various parts of intestines in males and
females of the ross broiler chicken among age groups (As percent of alimentary canal length)
/
%,
'%
0
(
0
%,
%,
%,
%,
13.12
0.65 a
12.35
0.32 b
9.67
0.87 c
11.53
0.49 d
11.92
0.85 bd
13.37
0.64 a
12.51
0.50 b
9.28
0.25 c
11.19
0.89 d
11.72
0.52 d
3.45 a
49.52
0.97 b
56.18
0.98 a
52.34
2.31 c
52.59
56.61
A
(
53.28
1.38 a
48.73
0.78 b
56.19
3.06 c
52.65
1.50 a
51.07
A
0
5.01
0.17 a
8.23
0.34 b
6.50
0.41 c
6.91
0.81 cd
7.03
0.65 d
H
0.30 a
8.14
0.18 b
6.54
0.34 c
7.21
1.14 d
7.64
0.39 bd
H
1.34 a
16.34
0.27 b
12.96
1.09 a
12.69
1.07 a
13.08
0.79 a
0.61 a
16.36
0.44 b
13.24
0.59 c
12.32
0.93 d
13.45
0.64 c
0.25 a
D
2.93
0.11 b
2.94
0.27 b
3.20
0.20 c
3.80
0.33 d
0.16 a
D
3.01
0.24 c
3.62
0.19 c
5.53
B
0
1.00 d
G
B
(
1.02 c
G
13.63
C
$ (
15.20
C
0
2.07
$ (
2.28
E
F
0.04 b
E
2.93
0.12 b
3.57
F
D: duodenum J: jejunum, I: ileum, Ce: cecum Co: colon, L: length, F: females, M:
males, Similar capital letters in a column and Non-similar small letters in a row:
significant at < 0.01
.%
Regression equations for estimate of various parts of intestine parameters in the ross
broiler chicken
'% %"
1
1
1
1
$ 1
$ 1
(1
1
(
(
(
(
$ (
$ (
((
23 %
1.96 + 0.004 x BW
3.81 + 0.017 x BW
0.30 + 0.002 x BW
6.00 + 0.024 x BW
0.97+ 0.002 x BW
0.22+ 0.002 x BW
0.73+ 0.004 x BW
12.65+ 0.062 x BW
18.89+ 0.105 x AL
13.82+ 0.52 x AL
13.07+ 0.077 x AL
21.58+ 0.70 x AL
42.79+ 0.11 x AL
22.73+ 0.04 x AL
20.21+ 0.16 x AL
)
0.87
0.96
0.95
0.95
0.79
0.85
0.94
0.98
0.88
0.97
0.89
0.996
0.91
0.95
0.94
D: duodenum J: jejunum, I: ileum, Ce: cecum Co: colon, Si: small intestine, Li: large
intestine, A: alimentary canal, B: body, W: weight, L: length.
All correlations were highly (P<0.001) significant.
#4 "
The author is grateful to the School of Veterinary Medicine of Islamic Azad University,
Shahrekord Branch, for providing financial assistance.
) &
#
1. AL-Dabagh, M. A., Abdulla, M., 1963: Correlation of size and weights of liver and
spleens to the age and bodyweights of normal chicks with a note on the histology
of these organs in chicks. Vet. Rec., 75 (15): 397-400.
2. Ankney, C. D., Afton A. D., 1988: Bioenergetics of breeding Northern Shovelers:
diet, nutrient reserves, clutch size, and incubation. Condor, 90: 459-472.
3. Baranyiová, E., Holub, A., Ponizilová, E., 1983: Changes in the mass and chemical
composition of the gastrointestinal tract and liver of ducks in the first two months
after hatching. Acta Vet. Brno, 52: 39-47.
4. Chikilian, M Speroni, N.B.D., 1996: Comparative Study of the Digestive System of
Three Species of Tinamou .I . Crypturellus tataupa, Nothoprocta cinerascens, and
Nothura maculosa (
). Journal of Morphology, 228:77-88.
5. Clench, M. H., Mathias, J. R., 1995: The avian cecum-A review. Wilson Bull.,
107:93-121.
6. Dibner, J. J., Richards, J. D., 2004: The Digestive System: Challenges and
Opportunities. J. Appl. Poult. Res., 13:86–93.
7. Dunn E. H., 1975: Growth, body components and energy content of nestling
Double crested cormorants. Condor, 77: 431-438.
8. Dyce, K.M., Sack, W.O., Wensing, C.J.G., 1995: Textbook of veterinary anatomy.
W.B. Saunders, Philadelphia, 781-783.
9. Dziala, Szczepanczyk, E., 2005: Morphological and morphometric characteristics
of the glandnlar stomach and gizzard in the longtail duck (
).
Zoologica Poloniae. 50/1-4: 49-61.
10. Getty, R., 1975: Sisson and Grossmans. The anatomy of the domestic animals,
Vol.2. 5th Ed. W.B. Saunders, London, PP: 1872-1875.
11. Jackson S., 1992: Do seabird gut sizes and mean retention times reflect adaptation
to diet and foraging method?, Physiol. Zool., 65:674–697
12. Kehoe, F. P., Ankney, C. D., 1985: Variation in digestive organ size among five
species of diving ducks (
) Can. J. Zool., 63: 2339-2342.
13. Lilja, C., 1981: Postnatal growth and organ development in the Goose (
). Growth, 45: 329-341.
14. Miller, M. R., 1974. Digestive capabilities, gut morphology, and cecal fermentation
in wild waterfowl (
) fed various diets. M. S. thesis. Univ. California
Davis. PP: 87.
15. Nickel, R., Schummer, A., Seiferle, E., 1997: Anatomy of the domestic birds.
Volume 5, Parey, PP: 46-56.
16. Olsen, M.A., Myklebust, R., Kaino, Turid, Elbrond, V. S., Mathiesen, S. D., 2002:
The gastrointestinal tract of Adelie penguins – morphology and function. Polar
Biol., 25: 641–649.
17. Porcescu, G., 2007: Comparative morphology of the digestive tract of the Black
African ostrich, hen and turkey, Ph. D. thesis. Agrarian State University of
Moldova, was presented on the 19/ 10.
18. Przystalski, A., 1986: The structure and dimension of alimentary canal in
postembryonic development of the great tit (
). Zool. Poloniae, 33: 521.
19. Pulliainen, E., 1976: Small intestine and caeca lengths in the willow grouse
(
) in Finnish Lapland. Ann. Zool. Fennici, 13:195–199.
20. Santos, J. R., 2005: Poultry Intestinal Health through Diet Formulation and
Exogenous Enzyme Supplementation. Ph D. thesis. North Carolina State
University.
21. Tottori, J., Yamaguchi, R., Murakawa, Y., Sato, M., Uchida, K., Tateyama, S.,
1997: The use of feed restriction for mortality control of chickens in broiler farms.
Avian Dis., 41:4333-4377.