VETERINARSKI ARHIV 69 (6), 301-308, 1999

ISSN 1331-8055 Published in Croatia

Morphometric studies of the ovary and oviduct of high and low egg producing chicken in Bangladesh

Abu Nasar Md. Aminoor Rahman¹, Mohammad Asaduzzaman², Nurul Kh. Islam³, and Mohammad Zahirul Islam Khan²*

¹School of Agriculture and Rural Development, Bangladesh Open University, Gazipur, Bangladesh

²Department of Anatomy and Histology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

³Department of Anatomy and Histology, Sylhet Government Veterinary College, Tilagor, Sylhet, Bangladesh

* Contact address:
Dr. M. Z. H. I. Khan,
Department of Anatomy and Histology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh.
Fax: 880 91 55810

RAHMAN, A. N. Md. A., M. ASADUZZAMAN, N. Kh. ISLAM, M. Z. I. KHAN: Morphometric studies of the ovary and oviduct of high and low egg producing chicken in Bangladesh. Vet. arhiv 69, 301-308, 1999.

ABSTRACT

The morphometry of the ovary and oviduct of high (ISA Brown) and low (indigenous) egg producing chicken in Bangladesh was analysed grossly and histologically in the present study. The mass of the ovary is significantly higher in the ISA Brown than in the indigenous chicken. At 12 weeks the ovary of the ISA Brown chicken presents numerous blood vessels, while the ovary of the indigenous chicken at this stage was granular. At 18 weeks the ovary of both strains presents numerous ovarian follicles, while the diameter and number of ovarian follicles were greater in all stages of ISA Brown chicken than in the indigenous chicken. Unlike the ovary, the mass of the oviduct of ISA Brown was also significantly greater. At 12 weeks the oviduct in both genetic breeds were fibre-like, and growth was noticed with the age increment being higher in the ISA Brown than in the indigenous chicken. From these data we would like to suggest that the high volume of egg production in respect of the ISA Brown chicken is probably due to the large size of ovary and oviduct.

Key words: ovary, oviduct, morphometry, egg production, chicken

Introduction

Bangladesh has a chicken population of 124.37 million (AHMED, 1994), which are mostly of an indigenous type known as "deshi chicken" (OKADA et al., 1988). It is often claimed that the reproductive performances of these chickens are very poor (OKADA et al., 1988) in comparison to different foreign pure breeds and hybrids. Various efforts have been made in the recent past at a number of research centres in Bangladesh to improve the egg production of indigenous chicken through cross breeding or by an upgrading program with different pure breeds (REZA and DHALI, 1984; HOSSAIN and AHMED, 1991; AMIN et al., 1992). It is important to know, therefore, the morphometric anatomy of the ovary and oviduct of these two breeds prior to any upgrading program. In this regard, literature was limited. Moreover, studies on the ovary and oviduct of hybrid and indigenous chicken have not been carried out in the climatic conditions prevailing in Bangladesh. In the present work, different gross anatomical parameters of the ovary and oviduct, including the number of ovarian follicles of low egg producing indigenous and high egg producing ISA Brown chickens, was studied with a view to narrowing the gaps in this field. This study will provide valuable information that will be helpful both to poultry anatomists and breeders.

Materials and methods

In order to compare the normal morphometric anatomy of the ovary of high (ISA Brown) and low (indigenous) egg producing chickens at different ages, a total of 36 chicken from these two genetic breeds (18 from each breed) were sub-divided into three age groups, viz., 12- 18- and 36- week-old chicken (each group comprising 6 chicken) were investigated at the Department of Anatomy and Histology, Bangladesh Agricultural University, Mymensingh, Bangladesh. The body mass of each bird was recorded prior to the killing of animals by cervical subluxation, and the masses of the ovaries and oviducts were recorded immediately after obtaining these organs from healthy chickens. Relative mass of ovaries and oviduct were calculated according to the formula used by FEDEROVA (1987) as follows:

Ovarian follicles of 36-week-old birds were considered for study purposes, due to the fact that yolky follicles were absent in 12- and 18-week-old birds. The follicles were carefully separated from the ovaries and divided into three categories according to diameter, viz. small (1.0-4.9 mm), medium (5.0-14.9 mm) and large (15 mm-above), and were then counted for study purpose. The tissues from different segments of the oviduct of two genetic breeds were also fixed in Bouins solution for conventional haematoxylin and eosin staining. Data obtained from various parameters were analysed using Randomised Block Design (ALI, 1973) and the differences were established at the accepted standard of probability of P<0.05 or better.

Results and discussion

The gross anatomical parameters of the ovary and oviduct of both genetic breeds of chicken at different ages are presented in Table 1 and Table 3. The data revealed that at 12 weeks, 18 weeks and 36 weeks, the mass of the ovary is statistically significant in ISA Brown (P<0.01). Reports regarding mass of the ovaries of chicken vary considerably in available literature. AMIN and GILBERT (1970) reported that the mass of the ovary was 0.40 g at 12 weeks of age, whereas, at 18 weeks in White Leghorn chicken the mass varies greatly (0.46 g) (FEDEROVA, 1987). In the present study, at 36 weeks in ISA Brown the mass of the ovary was 41.89 g (Table 1). In this connection, CHOWDHURY and DAVIS (1989) the obtained mass of the ovary of Hisex Brown chicken was 33 g, which indicated that among high yielding chickens the mass of the ovary varies considerably.

Table 1. Mass and relative mass of the ovary of ISA Brown
and indigenous chicken (mean±SD) (N=6 in each groups)

*Significant at 1% level of probability (P<0.01)

The ovarian follicles at 12 weeks in ISA Brown presented a solid mass with a vascular network, with ovarian follicles not being visible to the naked eye. In contrast, the ovary of indigenous chicken at the same age was granular and vascular network was not prominent (Figs. 1a, 1c). At 18 weeks of age, the ovary of ISA Brown chicken and indigenous chicken presents numerous ovarian follicles and minute follicles. Yolky follicles were present only in the ovary of 36-week-old birds (Figs. 1b, 1d). The diameter and the mean number of ovarian follicles of different categories of both genetic groups are presented in Table 2, from which it is clear that the diameter and the number of various sized follicles were higher in ISA Brown than in indigenous chicken. In this regard, variable data was reported by FEDEROVA (1987), who found 2-8 mm (small), 9-19 mm (medium) and 20-30 mm (large) diameter follicles in an experimental group of White Leghorn Chicken at 240 days of age. These variations may also be due to the different strain of chicken used in that study.

Figs. 1a-1d. Ovary of ISA Brown (1a-1b) and indigenous (1c-1d) chicken of different ages. At 12 weeks the ovary is vascular (arrowheads) in ISA Brown chicken (1a). In contrast, at 12 weeks the ovary of indigenous chicken is granular in appearance (1c). The ovary of 36 week-old ISA Brown (1b) and indigenous (1d) chicken represents many small (small arrowheads), medium (large arrowheads) and large (asterisks) ovarian follicles.

Table 2. Diameter and number of ovarian follicles of ISA Brown and indigenous chicken at 36 weeks of age (mean±SD) (N=6 in each groups)

The mass of the oviduct was statistically higher (P<0.01) in ISA Brown than in indigenous chicken in the present study (Table 3). The data of the present study correspond to reports by different authors (KAR, 1947; CHOWDHURY and DAVIS, 1989) while also differing from significant reports (EL-HAMMADY et al., 1975; KELANY et al., 1992). The oviduct of both strains of chicken at 12 weeks was fibre-like (Figs. 2a-2f), which corresponds with our previous report in the case of Dekalb strain of White Leghorn chicken (KHAN et al., 1996). With advancement of age, the size and length of the oviduct of ISA Brown chicken increased more significantly than in indigenous chicken (Table 3, Figs. 2a-2f). The histological findings revealed no significant differences between these two genetic breeds. However, at 12 weeks of age the villi of the magnum and vagina were greater in ISA Brown than in indigenous chicken (data not presented).

Figs. 2a-2f. Development of oviduct of ISA Brown (2a-2c) and indigenous (2d-2f) chicken of different ages. The growth of the oviduct is greater in ISA Brown chicken than in indigenous chicken at 12 weeks (a), 18 weeks (b) and 36 weeks (c) of age.

Table 3. Mass, relative mass and the length of the oviduct
of ISA Brown and indigenous chicken (mean±SD) (N=6 in each group)

*Significant at 1% level of probability (P<0.01)

From our present data we could conclude that the high volume of egg production in ISA Brown chicken was possibly due to the large size of ovary and oviduct. However, further work is needed regarding pituitary hormone release, and the production of sex hormones from ovary to correlate these hormones with the growth and development of the oviduct, and production of eggs by these high yielding and native birds.

References

AHMED, S. (1994): Epidemiological report on important disease of livestock and poultry in Bangladesh for the year 1993. Computer cell, Department of Livestock Services, Dhaka, p. 20.

ALI, M. A. (1973): Theory of Statistics (Vol. 2). Dhaka Book Mart. Dhaka.

AMIN, S. O., A. B. GILBERT (1970): Cellular changes in the anterior pituitary of the domestic fowl during growth, sexual maturity and laying. Bri. Poult. Sc. 11, 451-458.

AMIN, M. R., M. M. HOQUE, Q. M. S. ISLAM, M. M. R. KHAN (1992): The performance of crossbred and indigenous chicken under scavenging system. Bangladesh Journal of Animal Science 21, 77-81.

CHOWDHURY, S. D., R. H. DAVIS (1989): Comparison of the effects of two lathyrogens on the reproductive systems of the laying hen. Vet. Rec. 124, 240-242.

EL-HAMMADY, H. Y., A. M. OSMAN, M. N. MAKLED, F. ATTIA (1975): Reproductive performance and sexual maturity of growing Dokki-pullets. Al-Azhar Agric. Res. Bull. 30, 1-9.

FEDEROVA, N. N. (1987): Growth and development of the reproductive system in White Leghorn hens in different lighting systems. Sbornik Nauchnych Trudov. Moskovaskya Veterinarnya Akademiya 128, 37-40.

HOSSAIN, N. J., S. AHMED (1991): An observation on the body wieght of indigenous (Deshi). Rhode Island Red and Barred Plymouth Rock chicken. Bangladesh Journal of Animal Science 20, 123-124.

KHAN, M. Z. I., Y. HASHIMOTO, A. KONNO, Y. KON, T. IWANAGA (1996): Development of T-lymphocyte subpopulations in the postnatal chicken oviduct. Cell Tissue Res. 284, 317-325.

KAR, A. B. (1947): Studies on the ligaments of the oviduct in the domestic fowl. Anat. Rec. 97, 175-192.

KELANY, A. M., S. A. EL-SHAMY, A. ABOU-ELMAGD, A. A. SELIM, G. KAMEL, M. R. F. EL-BAB (1992): Studies on the development of the oviduct of high and low egg producing fowl. I-morphometric studies. Assiut Vet. Med. J. 28 (55), 93-106.

OKADA, I., Y. MAEDA, T. HASHIGUCHI, M. A. HASNATH, M. O. FARUQUE, M. A. MAJID (1988): Gene constitution of indigenous chicken in Bangladesh. Jap. Poultry Sci. 25, 15-26.

REZA, A., M. A. H. DHALI (1984): A study on the performance of exotic breeds and indigenous breeds under village condition. Bangladesh Journal of Animal Science 13, 36-40.

Received: 8 March 1999
Accepted: 15 December 1999

RAHMAN, A. N. Md. A., M. ASADUZZAMAN, N. Kh. ISLAM, M. Z. I. KHAN: Morfometrijska istrazivanja jajnika i jajovoda dobrih i losih kokosi nesilica u Bangladesu. Vet. arhiv 69, 301-308, 1999.

SAZETAK

U ovim morfometrijskim istrazivanjima makroskopski i mikroskopski su analizirani jajnik i jajovod u dobrih kokosi nesilica (ISA Brown) i slabih nesilica (domace kokosi) u Bangladesu. Masa jajnika dobrih nesilica je znacajno visa u dobrih nesilica nego u slabih kokosi nesilica. U jajniku 12 tjedana starih dobrih nesilica nalaze se mnoge krvne zile, dok je jajnik jednako starih slabih nesilica zrnat. U 18 tjedana starih nesilica obiju skupina na jajnicima uocavaju se mnogi folikuli, ali su folikuli dobrih nesilica uvijek bili brojniji i veceg promjera nego u slabih nesilica. Masa jajovoda dobrih nesilica je takoder znatno veca od mase jajovoda slabih nesilica. U 12 tjedana starih nesilica obiju genetskih skupina, jajovod izgleda kao nit, ali je kasniji rast znatniji u dobrih nesilica nego u slabih. Na osnovi ovih podataka vjerujemo da je veca proizvodnja jaja u dobrih nesilica (ISA Brown) vjerojatno posljedica vecih jajnika i jajovoda, nego sto su u slabih nesilica (domace kosi).

Kljucne rijeci: jajnik, jajovod, morfometrija, kokosi nesilice, nesivost