The Bangladesh Model and Other Experiences in Family Poultry Development
Common diseases of smallholder poultry and their control in Bangladesh
Mondal, M. M. H., Das, P. M., Haque, M.A. and Islam, M. K.
Bangladesh, the world’s biggest delta landscape is situated between 20o 34’ and 26o 38’ north latitude and between 88o 01’ and 92o 41’ east longitude. The country is bounded on three sides- west, north and east - by India with a small strip of boundary with Myanmar at the extreme south -east. In the south lies the Bay of Bengal.
The climate of Bangladesh is dominated by tropical monsoon with high to fairly high rainfall and an equable temperature. The relative humidity varies from 40% to 99%. The country is one of the most densely populated and least developed in the world. The majority people live in rural areas and are solely dependent on agriculture, and from time immemorial the system of agriculture is very much integrated consisting of crop, fishes, livestock and poultry.
More than 80% traditional farmers still raise native scavenging chickens, with little or no inputs, mostly for domestic consumptions and petty income. However, in recent years due to rapid urbanization around major cities lands are becoming scarce for crop production, and also due to increased demand for meat and eggs in the urban areas people are switching over from scavenging native chickens to commercial chickens, which are mainly exotic purebred and/or hybrids, and various crosses. The commercial layer or broiler farms operated by low-income group people in rural situation, with around fifty or more chickens, raised in semi-intensive to intensive operations in our study have been put under ’Smallholder Poultry’ (SP).
Recently, Rahman et al. (1997) have highlighted the prospects of rearing exotic hens by the rural poor in Bangladesh. They found SP projects as important tool for poverty alleviation and social empowerment for the poor, especially for the rural women. Seeing the prospects, various government and non-government organizations (NGOs) have come forward helping distressed women and unemployed youths across the country in establishing SP farms so as to make them self reliant. However, in the existing socioeconomic and environmental conditions SP farming yet is not so profit making because of various problems including diseases. And coupled with many other problems diseases have been encountered as the number one problem so far.
The geo-climatic conditions and attached territorial location of the country with India and Myanmar is very much conducive for the development and spread of a wide variety of diseases. The economic losses caused by different diseases in terms of low production, mortality and cost of medicine is enormous. In this paper an attempt has been taken to focus on the most commonly occurring diseases of SP in a rural development project and their control at farmers level, and possible suggestions thereof.
This study was conducted in a rural setting at Bailor and Kanthal union of Trishal, Mymensingh, located at about 100 km north of Dhaka and about 18 km south of Mymensingh district headquarters on both sides of the Dhaka- Mymensingh highway. This is a moderately highland area and less frequently gets inundated during floods. The major part of the area is under rural electrification and well communicated with the district headquarters of Mymensingh.
Majority people of this area are poor and involved in agriculture with little lands and infrastructures. Considering the poor economic backgrounds of the common people the local Rotarians underscored the need of poverty alleviation in the area through improved agriculture, and livestock and poultry development. Consequently, the Rotary Club of Mymensingh, Bangladesh district 3280 with the financial support of the Rotary Foundation of Rotary International launched its 3-H (Health, Hunger and Humanity) project in two phases 1988 to 1992 and 1995 to 2000 named ’ Livestock and Poultry Development Project’ and ’Integrated Farming Development Project’, respectively.
Amongst the many objectives of the projects, SP development was a focal target to help income generation of the women and unemployed youths. To this end, side by side of rearing of indigenous chickens, improved pure breeds (White Leghorn, Rhode Island Red, Fayoumi, and Australorp) and various crosses (Sonali, and Rupali), and ultimately different high yielding layer and broiler hybrids were introduced in the area. Farmers were motivated, trained and where possible incentives, loans were provided. Later a poultry hatchery unit has been established near the project centre to facilitate distribution of day old broiler and layer chicks. A qualified Veterinary Surgeon and several trained auxiliary personnel/ vaccinators were deputed for disease surveillance, treatment and control. We as a counterpart of the project management monitored the disease situations in SP in the project area during the period from May 1995 to April 2000.
As a consequence, sick and/or dead chickens brought by the SP contact farmers and/or project field personnel at the project clinic were investigated for various diseases/ ailments. The diagnosis was based on history, clinical signs and symptoms, clinical examinations and postmortem lesions. Factors influencing diseases, and treatment /control measures adopted by the farmers were recorded.
In this investigation as many as 20 different diseases were recorded including deficiency disorders (Table 1). The most common diseases were, infectious bursal disease (IBD), Newcastle disease (ND), salmonellosis, mycoplasmosis, vitamin and mineral deficiency disorders, colibacillosis, fowl cholera and coccidiosis. Incidences of IBD, ND, colibacillosis, mycoplasmosis, coccidiosis and deficiency disorders were very high in chickens aged between 3 weeks and 4 weeks, where as salmonellosis was common in laying hens.
Of the reported cases, more than 73% birds were affected with infectious diseases (mostly viral and bacterial) causing high morbidity and mortality. In some farms mortality was even up to 100% due to IBD and/or ND.
IBD or Gumboro disease: The disease occurred in the chicken flocks in intensive management mostly. Clinical signs included vent picking, depression, ruffled feather, rapid weight loss and whitish diarrhoea. Chickens died due to severe dehydration. Postmortem showed haemorrhages in the thigh and/or pectoral muscles, and the bursa of Fabricius was swollen.
ND or Ranikhet disease: It was a very common disease in the project area in semi-intensive system of rearing. The affected birds showed varied types of symptoms. These included difficult breathing, cough, loss of appetite and sudden drop of egg production. Paralysis of the leg and/or wings along with torticollis and in coordination of movement was also noticed. Greenish/greenish white diarrhoea was a common feature. Postmortem examination revealed petechial haemorrhages in the proventriculus.
Lymphoid leukosis: The disease affected the heavier breeds of chickens during pre- and post- production stage. Enlargement of liver and spleen with white nodules of various sizes were the characteristic postmortem lesions.
Salmonellosis: This was recorded in about 11% cases. The affected chickens showed inappetance, slow growth, and debility. Chalky white materials were found to attach with the vent. Diarrhoea and subsequent dehydration was very common. There was catarrhal enteritis, peritonitis and pericarditis and also in long lasting cases ruptured yolk materials in the abdominal cavity.
Fowl cholera: The disease was common in scavenging native chickens, which also affected hybrid chickens in the project area. The affected birds showed fever, anorexia, mucous discharge from the mouth and nasal passage, and diarrhoea. The most striking sign was cyanosis of combs and wattles. Postmortem lesions included swollen liver with focal coagulation necrosis. Lungs were also congested and pneumonic.
Mycoplasmosis and/or Chronic Respiratory Disease (CRD): It was observed in about 9% cases and usually occurred sub-clinically. Clinically the disease was manifested by tracheal rales, nasal discharge, cough, anorexia and emaciation. On postmortem fibrin deposition on the surfaces of visceral organs were common.
Colibacillosis: It was recorded in about 8% cases. Chickens died suddenly showing no visible symptoms. However, postmortem examinations revealed petechial haemorrhages in the spleen, heart and liver.
Necrotic enteritis: The disease was detected in less than 1% cases characterized by anorexia, listlessness, ruffled feather, emaciation and diarrhoea. The main lesion consisted of necrosis and haemorrhage in the wall of intestine and in some cases necrosis of the liver.
Infectious Coryza: The disease has been encountered occasionally with the symptoms of serous and/ or mucous discharge from nostrils, facial oedema and conjunctivitis.
Aspergillosis: The disease was recorded in about 2% cases characterized by gasping, ruffled feather and depression. The carcasses were very much cachectic. Yellowish and/ or whitish nodules of various sizes and shapes were seen mostly in the lungs, and sometimes on the intestinal surface, pleura and peritoneum. Respiratory passage was plugged with mucous exudates.
Parasites and parasitic diseases:
In all, about 8% chickens were affected with various parasites. Among the metazoan parasites, Ascaridia galli, Heterakis gallinarum, Raillietina spp. and Capillaria spp. were detected. However, only A. galli and tapeworms caused intestinal obstructions in some cases. The most striking effects of A. galli infection in layers were drop in egg production and in broilers stunted growth. In A. galli affected broilers the breast and thigh muscles were very much emaciated. The only protozoan disease of considerable economic importance was coccidiosis. About 5% chickens died due to intestinal/caecal coccidiosis. The disease was characterized by droopiness, depression, ruffled feathers and blood mixed diarrhoea. On post mortem the affected intestinal tract, particularly caeca were swollen and congested. Ectoparasites like lice,flies, flea, red mite and scaly leg mite were detected in some laying flocks. Whereas, housefly caused great nuisance to the broiler flocks.
Nutritional deficiency diseases:
About 12% birds were found affected with nutritional deficiency disorders. The most common was hypovitaminosis B (thiamine and riboflavin). Thiamine deficiency caused paralysis of the neck muscle and the affected birds were in star gazing position. Deficiency of riboflavin caused curled toe paralysis. Vitamin E deficiency was characterized by encepalomalacia, ataxia, subcutaneous oedema, in coordination of movement, prostration and death. Deficiencies of calcium, magnesium and selenium have been observed in growing and layer chickens.
About 8% diseases were encountered in this category. Among the diseases/conditions, non- specific pneumonia was very frequently detected. The other conditions were visceral gout, heat stroke and ammonia intoxication. Visceral gout was detected in laying hens above 20 weeks age. The affected birds showed anorexia, listlessness, dizziness and drop in egg production. Postmortem examination revealed deposition of chalky white materials in the visceral organs and the kidneys were enlarged. In several occasions both layers and broilers died due to heat stroke during hot summer months. At necropsy muscles looked just cooked, in particular the breast muscles. Ammonia intoxication due to production of ammonia gas in the poultry litter was also detected in poorly ventilated houses. The affected birds showed the symptoms of leg and wing paralysis and blindness.
Treatment and/or control at farmers level:
A great majority of the farmers in the locality did not practice proper treatment and/ or control regimens to combat poultry diseases. Feeding, housing, medication, vaccination, and disposal of dead birds and waste materials were very casual and haphazard. The farmers reported to the project veterinary clinic or elsewhere for help only when a large numbers of productive birds were sick and/ or dead. Farmers vaccinated their flock mostly against ND, fowl pox and fowl cholera with the help of the project. They had very little opportunity to go for vaccination against IBD (gumboro), Marek’s disease, salmonellosis, mycoplasmosis and other emerging or re-emerging epidemic diseases. Therefore, farmers were mostly dependent on antibiotics and sulphur drugs to keep this disease incidences minimum. About 95% farmers used coccidiostats as a feed additive, and to get rid of helminth parasites (A. galli and others) majority farmers used anthelmintics. Farmers cared very little about ectoparasitic problems.
In spite of growing awareness in commercial poultry farming, cost effective poultry rearing is still in a nascent stage in Bangladesh. In particular, SP farming in Bangladesh is facing a major seat back towards sustainability due to various diseases/ ailments. On average 30% poultry birds die annually due to diseases (Ahmed and Hamid, 1992). BRAC experiences also suggest about 35% to 40% poultry die due to various diseases and predators (Saleque, 1999).
Various biological, cultural, social and economic factors greatly influence healthy flock management in the villages. High chick mortality has always been found associated with poor feeding, housing and health control practices. Although farmers, poultry development specialists, research workers and poultry health related academics believe diseases are the main obstacle to profitable poultry production in Bangladesh but no disease surveillance programme has been undertaken so far. Therefore, obviously there is a dearth of published literature in the field of village poultry and/ or SP in the country. Based on our present observation IBD and ND are the two main diseases causing high mortality in SP.
In Bangladesh IBD is an emerging disease. The disease first occurred in an outbreak form in 1992 and caused mortality as high as 70% in layers and 30% in broilers (Islam, 1996). However, in present systems of SP farming mortality ranged from 10% to 20% (Bhattacherjee et al., 1996; Islam, et al., 1998). Immunization history suggests, in spite of vaccination of the chicken flocks with imported IBD vaccines mortality could not be checked. IBD vaccines are not produced in Bangladesh; therefore, it is imperative to search for a suitable vaccine that is antigenically related with the IBD virus prevalent in Bangladesh. ND is an old disease endemic in this country, causing havoc in scavenging chickens.
Very recently, due to available vaccines (BCRDV and RDV) in the country the situation has been changed significantly. However, in our observations faulty farm management and improper vaccinations have led the farmers to heavy losses due to ND. As reported by Kamal (1989) and Islam et al. (1998) incidences of ND varied from time to time and place to place, which is also our present observation. Salmonellosis is always a problem of economic concern.
Although the disease has been reported in several forms depending on the causal agents but in this study most of the cases were suggestive of pullorum disease. Usually young chickens are severely affected with pullorum disease but in the present investigation laying birds were the victims. Salmonella vaccines are imported but not readily available to the common farmers. Colibacillosis was often found associated with mycoplasmosis. Strict hygienic measures and proper sanitation at all levels of farm management has been found the best method of control but a few farmers were able to adopt the practices.
About 2% birds depicted symptoms of brooder pneumonia (aspergillosis) and a very few with aflatoxicosis. The mycotoxicosis /aflatoxicosis should not be neglected, since it could be an important inducing factor to many infectious diseases (notably IBD, salmonellosis and colibacillosis) in hot, humid and rainy months in Bangladesh. It is a widely held view that mycotoxicoses can led to increased susceptibility to infectious agents because it impairs disease resistance through an alteration of various defence mechanisms (Thaxton et al., 1974). Although endo-parasites (Ascaridia and Heterakis) have been regarded as the main impediment of profitable production of poultry in tropical countries including Bangladesh (Islam and Shaikh, 1967; Oyeka, 1989;Jansen and Pandey, 1989; Mondal and Qadir, 1991); but it was not the case in this study. May be the heavy mortality caused by infectious diseases overshadowed the impact of less fatal parasitic ones.
On the contrary, farmers dewormed poultry routinely in the project area and also tried to clean poultry manures at regular intervals. Incidences of coccidiosis are also decreasing in Bangladesh because of routine use of coccidiostats and use of vaccines in some selected organized farms. But it will take time to reach coccidial vaccines to the smallholder farms. Necrotic enteritis was though not very common but it should be regarded as an important disease since it has been found associated with coccidiosis causing severe production losses in broiler industry (Vissiennon, 1996).
A high rate of deficiency disorders in SP reminds us scarcity of quality feedstuffs and careless feeding practices. An increasing trend of nutritional deficiency disorders may be correlated to faulty ration formulation, and indiscriminate use of feed additives and antibiotics. All the diseases under miscellaneous category like non-specific pneumonia, heat stroke and ammonia intoxication, were related to poor/ faulty housing and/ or feed and water management.
A closer look at SP farming showed that in spite of training and motivation farmer’s attitude towards healthy poultry management was still hazy. Most of the farmers vaccinated their flocks without maintaining cool chain and indiscriminately. The principles of bio-safety are yet difficult to implement by the SP growers because of various socio-economic barriers. Moreover, various deadly diseases are getting entrance through the importation of parent stocks, because we do not have adequate quarantine facilities. Quality feedstuffs, vaccines, medicines, chicks, and disease diagnosis facilities are still far from the reach of the majority SP farmers. Without taking any effort to tackle all this problems of SP farming on a regular basis, mere ad hoc programme will not help SP farming to grow anymore in the country, because disease situation might get worsen in the near future.
Sincere appreciations are due to Prof. Dr. M. A. Huq, the Director of the Project, Rtn. Reg. V. Collard, Coordinator Australian Co-sponsor Club, District 9600, Brisbane, Australia and members of the Rotary Club of Mymensingh, District 3280, Bangladesh for necessary help. We are also grateful to the 10th AITVM Conference Organizers and the Network for Smallholder Poultry Development, KVL, Copenhagen, Denmark for kindly accepting the paper for an oral presentation. The generous sponsorship offered by the organizers to the first author for presenting the paper in the conference is also thankfully acknowledged.
Table 1. Common diseases of Smallholder Poultry encountered at the Rotary International Project, Kanthal and Bailor of Trishal, Mymensingh from 1995 - 2000 (n= 24258).
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