Abstract
The existing duck production system and profile of duck farmers were investigated by six feeding experiments with diets of varying nutrient concentration by utilizing locally available feed resources. The objective of the study was to develop feeding technology for indigenous (desi) ducks in coastal areas of Bangladesh. For survey, two upzilas from two districts (Subarnachar and Begumgonj in Noakhali; Ramgati and Raipur in Lakshmipur) and five locations from each upazila were selected randomly. Fifty farmers each having at least six ducks reared throughout the year were selected from each upazila. Primary data were collected by using an interview schedule. Results showed that the majority of the farmers (43.25%) belonged to middle aged group (36-50 years). About 32.5% of farmers received primary education and 32% could sign only. About 90% duck farmers were housewives and 95% farmers were involved in rearing desi ducks under free range scavenging system. Majority of the respondents used rice polish, broken rice and boiled rice as a supplemental feed for adult ducks (51-80 g/day/duck). High price of feed and scarcity of feed during dry season were the major problems affecting production. Annual egg production of scavenging desi ducks was found to range from 51 to 70 eggs/year/duck and maximum egg production was found in rainy season. Duck Plague and Duck Cholera were the common diseases threatening duck production and 82.5% farmers did not use vaccine against these diseases. Samples of locally available feed ingredient were collected from Noakhali and Lakshmipur districts to determine chemical composition of scavengeable and non-scavegeable feed resources. Collected feeds were analyzed for proximate constituents, Ca, P and amino acids contents. There were considerable differences in nutrient content among the scavengable and non-scavengable feed resources of different origin and season. The first feeding trial (3rd experiment) was conducted with desi ducklings during 0-18 weeks of age in 30 households of two coastal districts of Bangladesh. The objective was to find out appropriate cost-effective diet(s) to explore higher growth performance under scavenging system. Five dietary treatments each of three replications of nine ducklings were considered for comparison. The control group was reared by a traditional feeding method while the remaining four groups received a starter ration containing either a mixture of broken rice and rice polish (BR+RP) (65:35), low nutrient density (LND) diet (18% CP and 2700 kcal ME/kg), moderate nutrient density (MND) diet (20% CP and 2900 kcal ME/kg) or high nutrient density (HND) diet (22% CP and 3100 kcal ME/kg) and grower ration containing either BR+RP (65:35), LND (15% CP and 2600 kcal ME/kg), MND (17% CP and 2800 kcal ME/kg) or HND diet (19% CP and 3000 kcal ME/kg). The birds, except the control, were fed ad libitum up to 4 weeks of age and there after fifty percent of the daily feed requirement was supplied through supplementary feeding. The results showed that body weight gain and survivability were increased and FCR improved (P<0.01) with an increase in the density of protein and energy in the diets. But, considering the feed cost and profit margin, it was concluded that MND diet was more cost-effective. The 4th experiment was conducted with 360 desi laying ducks of 5 months old to investigate the productive performance, egg quality and chemical composition of egg with supplementation of different nutrient density diets under scavenging system of rearing. The experiment was conducted following 4x5 factorial design with five dietary treatments having three replications in each group with six ducks in each replication. Ducks of control group received traditional feeding method and the remaining four groups received a layer ration containing either a mixture of BR+RP (50:50), LND diet (14% CP and 2500 kcal ME/kg), MND diet (16% CP and 2700 kcal ME/kg) or HND diet (18% CP and 2900 kcal ME/kg). Egg production and FCR significantly improved in HND and MND diets among the treatments. Egg production was significantly highest in Ramgati upazila followed by Subarnachar, Begumgonj and Raipur upazila. BCR was found to be highest in MND diet group. The fifth experiment was aimed at determining seasonal influence on production parameters and to find out appropriate cost-effective diet(s) to explore higher productive performance under scavenging system. Among three seasons, rainy season showed highest production than winter and summer seasons. The sixth experiment was conducted with indigenous ducks to find out appropriate and cost-effective levels of supplementation of MND diet under scavenging system during scarcity of scavengable feed resources in two coastal districts of Bangladesh. A total no. of 150 ducks (aged eight months) was divided into five dietary treatments each of three replications. Four groups of duck were supplied viz, 70g MND, 90g MND, 110g MND and 130g MND diet as supplemental feed while one group considered as control. The results showed that body weight gain and egg production increased linearly (P<0.01) with increasing levels of supplementation. But the best FCR was found (P<0.01) in 90g (3.05) followed by 110g (3.24), 70g (3.55) and 130g (3.64) supplemented groups, respectively. Considering the feed cost and profit margin, 90g MND diet appeared to be most cost-effective. It was concluded, therefore, that use of cost-effective balanced diets can have a decisive effect on duck rearing in the coastal areas of Bangladesh.