Univ. j. zool. Rajshahi Univ. Vol. 25, 2006. pp. 37-40

© Rajshahi University Zoological Society

ISSN 1023-6104

Effect of the traditional parched rice husk incubation techniques on the hatchability of duck eggs
M. Khalequzzaman*, Shah Hussain Ahmad Mahdi and M. Mahbur Rahman
Department of Zoology, University of Rajshahi, Rajshahi 6205, Bangladesh
*Corresponding author, email: kzaman@ru.ac.bd Abstract: The present study was carried out to know the seasonal effect on the hatchability of duck eggs in five private poultry farms at Gaibandha, Bangladesh. Eggs were set in artificial hatching bamboo made cylinders from different number of ducklings. Present observation revealed that the hatchability of duck eggs is highest in March (88.966 ± 2.11) and in June it is lowest (66.398 ± 0.63). In June the highest unfertilized eggs (25.532 ± 1.22) have been recorded followed by March (4.822 ± 0.68), January (10.164 ± 0.12), April (10.408 ± 0.31) and May (13.250 ± 1.37). The loss eggs were recorded highest in January (21.244 ± 1.36) and the lowest in March (4.874 ± 2.05). Least-square analysis of variance showed that individual months had significant effects on the hatchability of duck eggs. Key words: Duck egg, artificial incubation, hatching

Introduction The duck population in Bangladesh is 35 million that are commonly tended for meat and egg. In nature they are reared under traditional system in rural areas (FAO, 1990). Ducks have several advantages over other poultry species, in particular their disease tolerance. In Asia, most duck production is closely associated with wetland rice farming, particularly in the humid and subtropics. An added advantage is that ducks normally lay most of their eggs within the three hours after sunrise (compared with five hours for chickens). This makes it possible for ducks to freely range in the rice fields by day, while being confined by night (Farrell, 1986). Local ducks in Bangladesh are ubiquitous in the country and most smallholder farmers keep them under a subsistent level of management (Islam et al., 2003). Duck comprises about 10% of the total poultry population, occupying second place to chicken in the production of table eggs in the country. It is an important component of farming system and plays a significant role to 80 per cent rural people of Bangladesh. It provides cash income and creates employment opportunity for rural people, particularly for small and landless farmers (Khan et al., 1999). It appears that the ducks can be raised cheaper than broiler and if market is properly organized (Singh, 2001). The process of hatching, which, in the span of 28 days for duck eggs, changes a microscopic germ into a downy chick, capable of walking, eating and expressing its needs by its voice and actions seems nearly magical (Banerjee, 1991). Novice poultry producers usually become interested in artificial incubation of their own chicks. The success of this type of project depends on proper care and incubation of the hatching eggs so healthy, vigorous chicks are produced (Smith, 2000). The artificial parched rice husk incubation process is started in some parts of

Bangladesh. The incubation generally performed from January to June. No study so far been done their performance, particularly on the hatchability of duck eggs and as such the present study was carried out. Materials and Methods Study Area: The present study was carried out in six private duck farms at Gaibandha, Bangladesh, where traditionally huge duck eggs are incubated artificially. The farms were selected at random including small, medium and large ones. Those farms also supply ducklings to the farmers once a week. The farms used to hatch ducklings from January to June. From late July to December they remain closed because during that period the air temperature drops and not suitable for artificial hatching of the eggs. Rearing: The birds were reared in intensive system. The birds were kept in floor and large spacious shed surrounded by wire mesh/bamboo made sheets. Open space and water area were provided. Birds were fed outside the houses and the feed was allotted at the rate of 130-160 gm per head twice a day. Cleaning and sanitary programmes were followed regularly. Ducks were vaccinated with duck plague vaccine. In breeding flock one male duck was provided for every five females. Flock wise eggs were collected and graded for hatching purposes. Good quality clean eggs were collected for hatching purposes avoiding cracked ones. The eggs were stored with the narrower end pointed downward. Incubation: This rice-husk system was adopted on a large scale in Bangladesh after being introduced by poultry development projects in the 1980s. The system has evolved, and the cylindrical egg baskets are now set into larger bamboo frame setting boxes, with more insulating rice husk material placed between the cylinders and the walls of the enclosing setting boxes.

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The cylinder wall is about 10 cm from the setting box wall and 8 cm from the next cylinder. With this greater insulation, there is less heat loss, thus less need to provide supplementary heat from costly fuels. Eggs (45-50) were packed in black cloth and kept within the preheated (by 100w electric bulb) for one hour. Thus each cylinder contained 450-500 eggs. For the first three days, reheated paddy rice husk is added three times a day at regular intervals. During days four to six, this may be reduced to twice a day. The object is to ensure that the eggs are kept at the temperature most suitable for embryo development. The spare basket is used to transfer eggs from an adjoining basket while adding freshly warmed rice or rice-husks. Thus the top layer of eggs becomes the bottom layer and the bottom layer ends up on top of the spare cylinder. The newly emptied basket is then ready to receive eggs from the third basket, and so the cycle continues. The eggs were candled on days 5 and 13, both to identify infertile eggs and dead embryos and to assess the degree of embryo development; which is used as one of the guides in adjusting basket temperature. Placing the egg on the upper eyelid allows the egg temperature to be assessed. Eggs in the advanced stages of incubation produce a lot of heat, so on days 17 to 18, the "old eggs" are transferred to hatching beds, where they are placed in a single layer for final development and hatching. The surface of the bed is covered with a thin layer of rice husks and then covered with a straw mat. The edges of the bed are lined with padding to protect the eggs. The covering for the developing eggs in the bed may be heavy or light cloth, depending on the degree of insulation required. The temperature in the hatching bed is maintained at 36 to 37°C, slightly lower than that of the basket. The temperature can be adjusted by changing the thickness of the covering, varying the space between the eggs, and moving the eggs twice a day so that those on the perimeter change places with those at the centre. In very hot dry weather, the eggs are sprayed with a fine mist of water. They are kept in the bed until the chicks hatch out and dry. Results and Discussion Month wise hatchability of duck eggs has been presented in Table 1. Highest hatchability was found in March (88.966 ± 2.11) and the lowest in June (66.398 ± 0.63). The least-square analysis of variance showed that the effect of month was highly significant (P