MORPHOMETRIC CHARACTERISTICS OF THE ALIMENTARY CANAL IN AMERICAN MINK (MUSTELA VISON SCHREBER, 1777)

Jan Wach¹, Włodzimierz Nowicki¹, Witold Brudnicki¹, Benedykt Skoczylas¹, Karol Grzywacz², Krzysztof Kirkiłło-Stacewicz¹, Adam Brudnicki^1
1 Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
² Department of Animal Morphology and Hunting, University of Technology and Life Sciences in Bydgoszcz, Poland

ABSTRACT

The research involved 66 adult, one-year-old individuals of American mink bred in enclosure in the region of Kuyavia and Pomerania. There were taken measurements of the body length and trunk with the neck. Then the abdominal part of the alimentary canal was prepared. Having removed the mesentery, there were taken measurements of the total length of intestine and its components. The total length of intestine in American mink was on average 190.56cm. Small intestine accounted for 85.82% of the total intestine length, while large intestine – only for 9.22%. The ratio of the body length to the intestine length was 1:5.32.

Key words: American mink, morphometric characteristics, alimentary canal.

INTRODUCTION

The study of the anatomy of the alimentary canal of mammals most frequently concerns the abdominal section. The following are investigated: the shape and size of the alimentary canal as the whole as well as its respective parts. There is also determined the ratio of the intestine length to the animal body length and the ratio of respective intestine sections to one another. The morphologic structure of the digestive system remains closely connected to its function, it is also connected with the type of food uptaken. The type of food is also the cause of changes which occur in the animal appearance and behaviour [8].

Metrical characteristics of the alimentary canal in comparative aspect have already been described by Babak [1].

Among the publications describing the metrical characteristics of the alimentary canal in predator animals one can mention papers describing the size of the alimentary canal in badger [7], wolf, jackal, dingo [6], as well as red fox, wild form commonly referred to as red fox, Brudnicki et al. [2], as well as the length and the capacity of intestine in racoon dog, Brudnicki et al. [3].

With that in mind, one has decided to investigate the metrical characteristics of respective sections of the alimentary canal in American mink and to compare the results with those reported for other predator species.

MATERIALS AND METHODS

The research involved 66 adult, one-year-old individuals of American mink from close breeding in the region of Kuyavia and Pomerania, including 32 males and 34 females. For most animals the following measurements were taken: body length and trunk length. The body length was measured from the tip of the nose to the base of the tail. The trunk length was measured from the squamos part of occipital bone to the base of the tail. The body weight was assessed as well as the liver weight. Then the abdominal part of the alimentary canal was prepared. Having removed mesentery, the length of respective intestine sections was measured. The following measurements were taken: the total length of the alimentary canal, the total intestine length, small intestine length, duodenum length, the length of jejunum and ileum and the length of large intestine. The intestine length was measured with the metal tape having placed them onto wet non-adhesive surface. There were also determined the stomach capacity.

The capacity of stomach along with the wall was defined when submerged in water at the pressure of 5cm of the column of water applying a special dish set and scale cylinders. For the purpose of comparison there was calculated the ratio of the body length to the intestine length. There was also determined the percentage share of respective intestine sections – as the whole. The data was verified with the statistical analysis, calculating the arithmetic mean, standard deviation, coefficient of variation and the coefficient of correlation between respective intestine sections.

RESULTS

The data describing body length, trunk length and body weight of the American mink individuals are given in Table 1. It was proved that the males show advantage over females in their body length by an average of 7.22 cm and the trunk length by an average of 6.32 cm. The average males weight was 1878g, in females it was 976,94g. The differences across individuals of both sexes were significant both in the case of the body length and the trunk length.

Table 1. Body length, trunk length and body weight in American mink

Group researched		n	Body length (cm)	Trunk length (cm)	Body weight (g)
♂	Interval	32	44.2–48	37.5–40.1	1640–2120
			46.24	38.71	1878
	Sx		1.16	0.97	116.75
	Vx		2.52 %	2.51 %	6.22%
♀	Interval	34	36–43.5	29.8–37.5	720–1400
			39.02*	32.39*	976.94
	Sx		1.89	1.85	146.51
	Vx		4.84 %	5.73 %	15.00%

* Differences significant at p ≤ 0.05

As given in Table 2, the total length of the alimentary canal in American mink was 251.21 cm in males and 183.06 cm in females. The total intestine length in males was 221.79 cm, while in females – 159.33 cm.

The small intestine length was on average in both sexes 167.57 cm, which accounted for 85.82% of the entire intestine. In the case of males, the length of that intestine was on average 190.35 cm (85.82%), while in females – 144.78 cm (90.87%), respectively. Duodenum reached on average in males 17.57 cm, which accounted for 7.92% of the entire intestine, and in females – 13.5 cm, which accounted for 8.47%, respectively. The total length of jejunum and ileum in males was on average 184.51 cm (83.19%). In females the length of that part of small intestine reached 139.61 cm, which accounted for 87.62% of the total length of intestines. The length of large intestine was in both sexes on average 17.57 cm (9.22%). In males the length of that intestine was on average 19.71 cm (8.89%), while in females – 15.42 cm, which accounted for 9.68% of the total intestine length.

Table 2. Morphometric characteristics of the intestine in American mink

Variable	♀			♂			♂ ♀
		Sx [cm]	Vx [%]		Sx [cm]	Vx [%]		Sx [cm]	Vx [%]
TACL	183.06	13.44	7.34	251.21	15.67	6.24	217.135	1.58	0.73
TIL	159.33	12.17	7.34	221.79	15.34	6.91	190.56	2.24	1.18
SIL	144.78	11.51	7.95	190.35	14.42	7.58	167.57	2.06	1.23
DL	13.5	1.48	10.99	17.57	1.04	5.93	15.54	0.31	2.00
LOJaL	139.61	11.23	8.04	184.51	13.86	7.51	162.06	1.86	1.15
LIL	15.42	2.12	13.77	19.71	2.21	11.23	17.57	0.06	0.36
ROTBL	1:4.92			1:5.73			1:5.32

Notes: – arithmetic mean, Sx – standard deviation, Vx – variation coefficient, TIL – total intestine length, SIL – small intestine length, DL – duodenum length, LOJaI – length of jejunum and ileum, LIL – large intestine length, TACL – total alimentary canal length, ROTBL – ratio of the body length to the total intestine length

Table 3. Correlation matrix

	TL	Tl	BW	DL	LOJaI	SIL	LI	OL	SC	LW	TIL	TACL
TL		0.98	0.93	0.78	0.89	0.90	0.73	0.71	0.86	0.92	0.90	0.90
Tl			0.95	0.79	0.91	0.92	0.73	0.74	0.87	0.91	0.92	0.92
BW				0.84	0.91	0.92	0.73	0.74	0.91	0.94	0.92	0.92
DL					0.82	0.85	0.70	0.75	0.81	0.81	0.86	0.86
LOJaI						0.99	0.72	0.78	0.91	0.90	0.98	0.99
SIL							0.73	0.79	0.91	0.90	0.98	0.98
LI								0.45	0.72	0.72	0.77	0.76
OL									0.71	0.67	0.77	0.80
SC										0.86	0.92	0.92
LW											0.91	0.90
TIL												0.99
TACL

Correlation: slight or low-correlated 0.0-0.1; poor 0.1>0.3; average  0.3>0.5; high 0.5>0.7; very high  0.7>0.9; certain  >0.9 Notes: TL – trunk length, DC – total length, BW – body weight, DL – duodenum length, LOJaI – length of jejunum and ileum, SIL – small intestine length, LI – large intestine, OL – oesophagus length, SC – stomach capacity, LW – liver weight, TIL – total intestine length  TACL – total alimentary canal length

Table 3 gives the correlation matrix between the length and the weight of the body and respective intestine sections as well as other organs of the digestive system. The correlation coefficient was calculated in total for individuals of both sexes. It was found that all the correlation coefficients calculated were highly significant. A very high value of the correlation coefficient was reported between the small intestine length and large intestine length and the trunk length and the total length of the intestines. The same value was recorded between the length of the trunk and the total length of the alimentary canal and the length of small intestine and the liver weight. A certain coefficient of correlation was recorded between the total length of intestine and the length of jejunum and ileum, the total length of intestines and the length of small intestine and the total length of the alimentary canal  and the length of small intestine. The average coefficient of correlation was reported between the length of oesophagus and the length of large intestine.

The results of the present research facilitated determining parameters concerning the body size and the weights of some internal organs as well as the lengths of respective intestine sections as well as stomach capacity in American mink.

DISCUSSION

The absolute intestine length in American mink ranged from 147.7 cm and 245.5 cm, on average 223.27 cm in males and 159.33 cm in females. In badger the length was on average 457.58cm. Of the other predator species researched by Gill et al. [6], in wolf the intestine length ranged from 307 cm to 436 cm, dingo from 217 cm to 267 cm, jackal – on average 185cm. The intestine length in raccoon dog, as reported by Brudnicki et al. [3], is on average 275cm, while in red fox it ranged from 115.9 cm to 238.6 cm [4]. As compared with the body length, the total average intestine length in both American mink sexes is 1 : 5.32. The same parameter in other predators reaches on average in badger 1 : 5.13 [7], wolf 1: 3.64, jackal 1 : 2,50, dingo 1 : 2.65 [6], racoon dog 1 : 4.92 [3]. In dog the intestine length exceeds the body length 5 times, in bear – 8 times, in pig – 15 times. In ruminants the ratio is even greater and is in cattle 1 : 20, while in sheep 1 : 25.

The percentage share of small intestine in the species researched accounted for on average 87.93% of the total intestine length. A greater share of small intestine was noted in badger – 96.4% [7], wolf – 89.12% and dingo 88.23%, while the lowest value was reported in jackal 87.03% [6], raccoon dog 83% [3], red fox 84.6% [2]. Large intestine in American mink ranged from 8.89% in males to 9.68% in females. In some predator species, such as wolf, dingo, jackal, it is, respectively, 9.55–12.21%, 10.60–12.93%, 12.97% [6], badger 3.6% [7], raccoon dog 17% [3], in red fox 15.4–16.25% [2]. In silver fox large intestine accounted for as much as 18.75% of the total length. Such a low share of large intestine can point to the adaptation to the uptake of considerable amounts of meat food as it was found that the plant diet causes the elongation of the terminal intestine sections (coecum, colon, rectum), while meat diet results in their shortening [5,8].

CONCLUSIONS

1. The total intestine length of American mink measured against the body length reaches the value of 5.32 and it is higher than the value of that parameter in red fox and the other predator species researched.

2. The percentage share of the large intestine length is lower than in the other predator species, which is due to the kind of the food uptaken.

REFERENCES

1. Babak E., 1903. Ueber den Einfluss der Nahrung auf die Lange des Armkanals [The influence of food on alimentary canal length]. J. Biol. Centr. 23 (12), 477–483 [in German].

2. Brudnicki W., Skoczylas B., Nowicki W., Wach J., 2008. Cechy metryczne jelita lisa pospolitego (Vulpes vulpes L) [Biometrics of intestine in fox (Vulpes vulpes L)], Pr. Komis. Nauk Rol. i Biol. BTN, Seria B, 64, 21–26 [in Polish].

3. Brudnicki W., Skoczylas B., Jabłoński R., 2001. Metrical features of same parts of the alimentary canal and liver in raccoon dog (Nyctereutes procyonoides Gray) http://www.eipau.media.pl/series/volume4/issuel1/veterinarv/art-01.html

4. Brudnicki W., Nowicki W., Skoczylas B., Brudnicki A., Jabłoński R., Kirkiłło-Stacewicz K., 2008. Cechy biometryczne jelita lisa srebrzystego (Vulpes Vulpes L) [Biometrics of intestine in silver fox (Vulpes vulpes L)]. Pr. Komis. Nauk Rol. i Biol. BTN, Seria B, 65, 23–27 [in Polish].

5. Drożyńska N., Cymborowski B., Radzikowska M. 1971. Wpływ pokarmu na strukturę i funkcje przewodu pokarmowego u przedstawicieli różnych grup zwierzęcych [Influence of Diet on the Histological Structure and Function of Alimentary Tract in Representatives of Different Groups of Animals]. Przegl. Zool. XV, 1, 40–45 [in Polish].

6. Gill J., Hoffmannowa H., Piekarz R., 1964. Z badań nad fizjologią trawienia u wilka (Canis lupus L), psa dingo (Canis dingo L) i szakala (Canis ureus L), II Zdolności trawienne trzustki, duodenum i ślinianek, wielkość przewodu pokarmowego oraz ciężar narządów wewnętrznych [Studies on digestive psychology in the Wolf (Canis lupus L.), Dingo (Canis dingo L.), and jackal (Canis aureus L.).Digestive ability of the pancreas, duodenum and salivary glands and size of the alimentary tract and weight of internal organs]. Acta Physiol. Polonica, XV, 1, 137–148 [in Polish].

7. Nowicki W., Brudnicki W., Jabłoński R., Wiśniewska J., Kirkiłło-Stacewicz K., Skoczylas B., 2009. Cechy metryczne przewodu pokarmowego borsuka z Pomorza i Kujaw [Metrical features of alimentary canal in badger in the region of Pomerania and Kujawy]. Zesz. Nauk. Zoot. 37, no 252, 73–78 [in Polish].

8. Radzikowska M., 1981. Wpływ różnej diety na budowę i czynności przewodu pokarmowego szczura (Rattus rattus L) [The effect of diet on the structure and function of digestive tract in the rats (Rattus rattus L)]. Przegl. Zool. XXV, 1, 83–91 [in Polish].

 

Accepted for print: 7.02.2011

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Jan Wach
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: janwach82@poczta.onet.pl

Włodzimierz Nowicki
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: wlodek_novika@interia.eu

Witold Brudnicki
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: anat@utp.edu.pl

Benedykt Skoczylas
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: anat@utp.edu.pl

Karol Grzywacz
Department of Animal Morphology and Hunting,
University of Technology and Life Sciences in Bydgoszcz, Poland
Bernardyńska 6, 85-029 Bydgoszcz, Poland
email: kgz@tuchola.pl

Krzysztof Kirkiłło-Stacewicz
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: krzysztof.stacewicz@o2.pl

Adam Brudnicki
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: brudnicki.adam@gmail.com

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