During the last few decades, poultry production has become an important sector of the livestock economy worldwide. In Pakistan, every rural family and almost every 5th urban family is associated with poultry production. According to a survey report, about 66 per cent of Pakistan natives are deficient in their proteins diets, whereas; the available proportion is 61.69 g/person/day, which is far behind the actual protein requirement (102.7 g/person/day). Ever increasing prices of mutton and beef encourage the poultry production to meet the daily protein requirements in terms of eggs and chicken meat as it is the most important, profitable as well as economical source of protein supplementation.
The pultry production is getting strength in Pakistan and is augmenting at the rate of 20-25 per cent per year. This sub sector of livestock production started in Pakistan in 1963 in collaboration with PIA while commercial scale poultry production started in 1965. Currently, Pakistan is ranked 11th in the poultry production among all the Asian countries. This industry has shown a remarkable growth in Pakistan during the last decade or so without involvement of th government. Now-a-days commercial production is mostly being practised in Sindh (MirpurKhas, Sukkur and Nawabshah), Punjab (Rawalpindi, Faisalabad, Multan, Lahore, Bahawalpur, Rahim Yar Khan and Mianwali) and Khyber Pakhtunkhwa (Peshawer). At present, 390 million birds are being raised in the country including 43 per cent (137 million) rural, 50 per cent (160 million) broiler, 5 per cent (32 million) layer and 2 per cent (5 million) breeding stock. Out of 32 million layers, 61 per cent is in Punjab, 32 per cent in Sindh, 5 per cent in Khyber Pakhtunkhwa while 2 per cent is in Baluchistan. At present, poultry production is sharing 1.1 per cent in the total GDP, while 4.8 per cent in agricultural GDP. During the past year (2011-2012), meat production from poultry was estimated as 834 million tons of the total meat produced in the country in which share of commercial birds was 75.7 per cent while that of domestic birds was only 25-28 per cent. Total egg production was 13144 million in which shares of commercial and domesticated layer birds were 58.4 per cent and 41.6 per cent, respectively. More than 1.5 million manpower is engaged with this industry in Pakistan to run their families.
Gastrointestinal (GI) parasitism (caused by helminths and/or protozoa) is a potential threat in layers (Gallus domesticus) causing huge economic losses in terms of impeded growth, reduced weight gain, lowered egg production, loss of meat production, waste of feed, cost of labor, equipment as well as control, treatment and eradication measures. Clinical picture of GI parasitism includes: loose droppings, intestinal obstruction (heavy worm burden), anaemia, lowered blood haemoglobin concentration, cachexia and nervous manifestations. Necropsy examination of infected birds reveal nodular, hemorrhagic and ulcerative enteritis, atrophy of villi, formation of granulomas in the duodenum and desquamation of epithelial cells.
Among helminths, cestodesare the most prevalent (52 per cent), followed in order by nematods (16 per cent) and trematodes (less than 1 per cent). Infections with protozoa are common in poultry that may range from mild to severe resulting in the disease. Among GI tract protozoa, coccidian are of unquestionable significance. Other well-documented protozoa of GI tract in layers includs: Histomonasmelagridis; transmitted by cecal worm Heterakisgallinarum causing black head disease in turkeys.
An overall prevalence of all kinds of parasites in the indigenous and exotic layers was investigated which ranges from 1 per cent to 85 per cent. Factors associated with GI parasitism include the species, rearing system, climatic conditions and the geographical location. Diversity of intermediate hosts in the transmission of helminth infections in layer birds necessitates the taxonomic identification of the parasitic diversity over the period of years for planning specific control measures.
Epidemiology of parasites changes from time to time. Recently, a descriptive epidemiological study was conducted to investigate the spread of parasitism in layer birds for a period of one year (from March 2012 to February 2013) in the department of Parasitology, University of Agriculture Faisalabad.
Of 1996 birds of different farming systems screened, 746 (37.37 per cent) were found infected with GI parasitism (helminthes and/or protozoa). Four species of parasites were procured; Ascaridiagalli, Heterakisgallinarum, Reillitinatetragona and Eimeriatenella. The results of this study provide the diversity of endo-parasitic fauna in the layer population of district Faisalabad. Moreover, information collected on the associated risk factors may be helpful in providing a sustainable preventive regimen for the small holder layer farmers of the district according to its geo-climatic conditions.
On the basis of the results driven, it was concluded that:
GI parasitism is prevalent in the layer bird population of district Faisalabad.
Laying birds (25-72 weeks) are more proned to GI parasitism in study area.
Higher incidence of GI parasitism was observed during the summer with a peak in July.
Different husbandry practices including manual method of feeding the birds in soiled feeders, dusty feed and grains having developmental stages of parasites, watering the birds in soiled waters, open housing with soiled floor and lack of biosecurity measures have been found positively associated with the disease occurrence in the layer birds of district Faisalabad.
Following are some recommendations to the farming community in order to reduce the risk of GI parasitism:
Use of anthelmintics before the start of summer and mixed coccidiostats in the feed for endoparasitic control to prevent the horizontal transmission of infection (if any).
Drinkers and feeders should be clean, better to use automated systems. Try to adopt floor rearing in closed housing.
Birds should be kept separate according to their age groups. Litter material should be dry. Maintain recommended humidity and temperature in the shed according to age of birds.
Susceptible birds must be screened for as early as possible.
Culling of infected flock as early as possible and clearing of shed.
Attention on vaccination development and implementation of regimen against parasitic diseases. Personnel having expertise should be hired to work on this specific aspect.
Wide-scaled awareness campaign for sustainable parasitic management.
Loans should be given to small holders to run large scale farming.
Regular monitoring of government farms is necessary.
The writers are associated with the Department of Parasitology, University of Agriculture, Faisalabad, Pakistan.