Poultry Farming: New Perspectives and Applications Chapter – Parasitic Diseases of Chickens

Abstract

Fowls and their eggs provide animal protein for human populations. Parasites are very common in fowls and heavy infection can affect the growth, and egg production, and cause death. Fowls during feeding pick the parasitic infective stage by ingesting contaminated food, and water. There are two groups of parasites infecting fowls: external (ectoparasites) and internal parasites (endoparasites). The clinical findings of the examined affected chickens showed that symptoms vary from healthy to subclinical symptoms. The main clinical signs were dullness, emaciation and weakness, hemorrhagic enteritis, congestion of ceca, mucoid and watery diarrhea Besides. The research refers found 2 species of lice namely Mencanths stramineus and Goniocotes gallinae. One species of soft tick, from genus Aragas persicus, was recorded. While internal parasites included different types of Eimeria oocysts. The current study did not reveal any blood parasites or Cryptosporidium oocysts in all of the examined fowls. Different types of intestinal nematodes which were recovered with Subulura species followed by large roundworms, Ascaridia galli, Heterakis gallinarum, Capillaria. Regarding tapeworms, six species were recorded and identified, which were Raillietina tetragona, R. echinobothrida, R. cesticillus, Fimbriaria fasciolari, Davainea proglottina, and Amoebotaenia sphenoides.

1. Introduction

Domestic fowls are the most important protein sources of human populations in every part of the world. As is demonstrated that during the last 30 years, eggs and poultry meat were constantly increasing. Poultry industries make a significant contribution to improving the nutritional status and economic income of many countries of the world [1].

Animal welfare is a big problem in today’s factory farming. And the widespread abuse of birds serves as an example of it. Every year, 9 billion chickens are grown and killed for food in America alone. Broiler chickens are the name given to chickens grown on factory farms for meat. They are kept in cramped, gloomy sheds. Despite the meat industry’s best efforts to conjure up images of happy birds frolicking in green fields, 99.9% of hens raised for food are kept in factory farms where they are deprived of access to sunlight and fresh air. And it confines them to filthy areas that serve as ideal breeding grounds for disease [2].

Parasitic infections of poultry are the major factors responsible for economic losses through a reduction in productivity and increased mortality. A lot of losses in poultry are linked to disease-causing pathogens such as viruses, bacteria and parasites. Poultry is subjected to a wide variety of diseases including Newcastle disease, salmonellosis, respiratory disease and a large number of ecto-endoparasites. Their diseases are often fatal resulting in high mortality and low productivity. Domestic fowls feed on different types of food materials, these materials include grains, fruits and insects which may harbor infective stages of parasites, particularly gastrointestinal helminths [3].

Gastrointestinal helminths of poultry are commonly divided into three main groups: nematodes, cestodes and trematodes. Nematodes are considered the most important group of helminths of poultry such as the species which belong to the genera Capillaria, Heterakis and Ascaridia. The most important genera of cestodes are Railleitina and Hymenolepsis. Regarding the types of trematodes, they are not very common like the other groups [4].

Gastrointestinal tract worms, in particular, are known to cause poor feed conversion and utilization that lead to emaciation and poor weight gains. Various ectoparasites are reported in the local fowls such as lice, fleas, mites and soft ticks [5].

In general, there is a need to understand the epidemiology of the various fowl parasites in order to plan strategies to increase the productivity of chickens [6]. Limited work has been done on ectoparasites and endoparasites of fowls in Iraq including the Kurdistan Region [7].

2. Types of ectoparasites in fowls

Ectoparasites of poultry are arthropods that live on the skin and feathers including lice, fleas, soft ticks and mites [8]. Ectoparasite problems may be controlled by:

• Cleaning of houses between flocks,

• Whole flock replacement rather than partial replacement,

• Using mesh to keep out wild birds,

• Rodent eradication program,

• Maintenance of manure in a dry condition to avoid flies breeding [9].

Members of the animal phylum Arthropoda, which is distinguished by having outwardly segmented bodies, jointed legs, appendages, and chitinous exoskeletons, include poultry ectoparasites [10].

One pair of antennae is linked to the head, three pairs of legs are attached to the thorax, and some mature insects have wings. These characteristics identify lice, flies, bugs, and fleas as members of the class Insecta [11].

Some ectoparasites of poultry such as lice eat the dead cells of the skin and skin acts as a medium through which they suck blood and from which they obtain shelter. Lice may be closely confined to their hosts during their entire life cycle, while other parasites wander freely from bird to bird. Some are highly hosted specific while; some species may maintain host nonspecific relationships [12].

3. Types of internal parasites in chickens

3.1 Blood parasites of chickens

Birds may be hosts for a number of blood-inhabiting protozoan species and nematode worms which are transmitted by haematophagous arthropods [13]. Protozoan parasites include haemosporidia which belong to several genera such as Plasmodium, Haemoproteus, Leucocytozoon, Hepatozoon, Babesia, and haemoflagellates that belong to the genus Trypanosoma. Most of the birds are susceptible to being infected with blood parasites and the prevalence rate, especially in the tropics, maybe more than 30%. Blood parasites vary in their host, both for the arthropod vectors and the vertebrate host, specificity. While some are restricted to a small number of host species, others can survive and reproduce in a wide variety of birds and arthropods [14]. Internal parasites are mainly classified into two groups (Protozoa and Helminthes). Protozoa include gastrointestinal and blood protozoans while helminths include three groups: Trematodes, Cestodes and Nematodes [15].

Many recent studies have focused on avian blood parasites as a model system for host–parasite interactions in evolutionary and ecological aspects. Extensive laboratory studies have been conducted describing their pathologies, especially for species of Leucocytozoon). Based on the current taxonomy, three species of Leucocytozoon and three species of Trypanosoma are found in the domestic chicken Gallus gallus domesticus, mainly in tropical and subtropical regions worldwide [16].

These are:

Leucocytozoon macleani.

Leucocytozoon caulleryi.

Leucocytozoon schoutedeni.

Trypanosoma numidae.

Trypanosoma calmettei.

Trypanosoma gallinarum.

All of these species are well distinguished based on the morphology of their blood stages and/or laboratory experiments documenting their transmission and life cycles. The pathogenicity of many species of Leucocytozoidae (Sporozoa, Haemosporida) in wild birds is unclear, many cases of mortality have been reported in domestic chickens and other poultry. The most common vectors of avian trypanosomes are arthropods that belong to the families Hippoboscidae, Culicidae, Ceratopogonidae, and Simuliidae [17]. In addition, dermanyssid mites have been identified as avian trypanosome vectors. Little is known concerning the pathogenic effects of trypanosomes in chickens although artificial infection with Trypanosoma brucei showed no obvious impairment of health. Previous accounts of blood parasites in chickens in Africa are relatively rare. In a study in Zimbabwe, 4 of 94 examined chickens harbored Leucocytozoon sabrazesi, and 5 of the 94 examined chickens harbored L. macleani in Ghana; however, no Leucocytozoon or Trypanosoma infections were detected [18]. Earlier studies showed Leucocytozoon species infected 55 of 163 (34%) examined chickens in Ibadan, Nigeria. In a study of 110 chickens observed in Anambra, and Nigeria, none was infected with blood parasites. In Tanzania, it is reported that out of 150 chickens tested, more than 50% were infected with L. schoutedeni [19].

3.2 Helminthes of chickens

The name “helminths” is derived from the Greek word helmins or helminthos, a worm, and is usually applied only to the parasitic and non-parasitic species belonging to the phyla Platyhelminthes (flukes, tapeworms and other flatworms) and roundworms (Nemathelminthes). The helminths are invertebrates characterized by elongated, flat or round bodies. The flatworms or platyhelminths (platy from the Greek root meaning flat) include flukes and tapeworms [20]. Round worms are nematodes (nemato from the Greek root meaning thread which includes helminths have similar anatomic features that reflect common physiologic requirements and functions. The outer covering of helminthes is the cuticle or tegument; nutrients must be absorbed through the tegument. A helminths also has a head and tail end, and its tissues are differentiated into three distinct tissue layers: - ectoderm, mesoderm and endoderm [21]. Parasitic helminths of chickens are commonly divided into three main groups:

3.2.1 Nematodes

They constitute the most important group of helminth parasites of poultry both in a number of species and external damage they cause. The main genera include Capillaria, Heterakis and Ascaridia (Figure 1) [23].

Figure 1.

Small intestines of a broiler chicken impacted with Ascaridia galli [22].

A. galli is a parasitic roundworm belonging to the phylum Nematoda. Nematodes of the genus Ascaridia are essentially intestinal parasites of birds. Nematodes and cestodes) are common GI parasites of commercial poultry. The parasites typically cause acute irritation and might occasionally result in bleeding. The gut lining may erode severely and cause death. Deep litter households may experience a serious problem with these parasites. Heavy infections may lead to decreased fertility, egg production, and growth. Nematodes of poultry infection are widely distributed in different parts of the world, and numerous types of research have existed to prevent the mortality of poultry from parasitic diseases [22].

• Ascaridia

The genus Ascaridia was first established by Dujardin in 1845. Nematodes of this genus are hosts specific to the class Aves. A large number of species have been reported from fowl; the common ones are as follows: A. galli is a parasitic roundworm belonging to the phylum Nematoda. A. galli is the most prevalent and pathogenic species, especially in domestic fowl. It inhabits the small intestine and causes ascaridiasis, a condition that affects poultry, especially hens and turkeys, and is caused by severe worm infestation. In birds, A. galli is the biggest nematode. The body is cylindrical, creamy white, and semitransparent. The mouth is prominent and is bordered by three broad trilobed lips on the anterior end. There are teeth-like structures on the borders of the lips [24]. detailed in fully the anatomy of A. galli, a creature whose body is totally wrapped in a thick protein structure known as a “cuticle.” The cuticular alae are underdeveloped, and the cuticle is striated transversely over the length of the body. The dorsal lip has two noticeable papillae, and the sub-ventral lips have one each. The nematode’s sensory organs are these papillae. A. galli exhibits clear sexual dimorphism and is diecious. With a vulva opening roughly in the middle of the body, halfway between the anterior and posterior ends, and an anus at the back end, females are noticeably longer and more robust [25]. It is typical for females to have a blunt, straight tail end. Males tend to be smaller and shorter than females, and they have distinctively pointed, curved tails. To the rear of the body, there are 10 pairs of caudal papillae that are grouped linearly into distinct groups such as precloacal (3 pairs), cloacal (1 pair), post-cloacal (1 pair), and sub-terminal (3 pairs). All types of poultry are affected by the nematode, however, young birds under the age of 12 weeks frequently exhibit the most severe damage. Reduced egg production and weight depression in poultry husbandry are primarily caused by heavy infection. Intestinal obstruction can happen in cases of severe infections. In heavy infections, adult worms may move up the oviduct and be found in hens’ eggs, and sometimes they are also found in the feces of the infected birds [26].

• Heterakis

The genus Heterakis was first described and named by Dujardin in 1845. The parasites belonging to this genus are characterized by the following features: they are small worms with the anterior end bent dorsally, and mouth surrounded by three small equal size lips. Small white worms are found in the tip or blind ends of the caeca. The female measures 10–15 mm long and the male 7–13 mm long. Esophagus end in a well-developed bulb, containing a valvular apparatus. Pre-anal sucker well developed in males, papillae present, spicules unequal, uterine branches in the female opposite, vulva near the middle of the body, and eggs with thick and smooth shells [27], while studying six species of Heterakis, emphasized that they do not have certain points of interest, especially those related to the sense organs which reveal the possibility of identifying their larval forms since these organs are well developed in larvae The most important gastrointestinal nematode responsible for considerable production losses in poultry is Heterakis gallinarum [28].

• Subulura

Subulura also named Allodaba, which is still used as a synonym. Subulura genus usually has lateral cervical alae and mouth dorsoventrally elongated, vestibule with a thin chitinous lining or heavily chitinized, Esophagus dilated posteriorly and followed by a bulb. The male has a fusiform pre-anal sucker, located, a distance anterior to the cloaca and the caudal alae is slightly developed or absent. The caudal papillas are sessile and arranged in two longitudinal rows and the spicules equal in length. In females, the vulva is near the middle of the body and uterine branches diverge. The female may be oviparous or ovoviviparous and the eggs sub-globular and thin-shelled (Figure 2) [30]. Subulura infections in fowls are insignificant due to their low pathogenicity. Pathological changes suggestive of acute cecal hemorrhagic enteritis were recorded. Infection occurs in the cecae of fowl, turkey, guinea fowl, and wild-related birds in Africa, North and South America, and Asia.

• Capillaria

Figure 2.

Anterior end Sublura sp. [29].

There are several species of Capillaria that occur in poultry in Figure 3. Male capillaria are 15–25 mm length and female capillaria are 35–80 mm long filamentous worms (females). Males only have one spicule, and many also have an early form of a bursa. The size of the eggs varies depending on the species; they contain bipolar plugs and thick shells. Important species include; C. annulata, C. anatis and C. contorta. Capillaria annulata and Capillaria contorta occur in the crop and esophagus. In the lower intestinal tract, there may be several different species but usually, Capillaria obsignata is the most prevalent. These species may cause thickening and inflammation of the mucosa. The life cycle of this parasite is direct. The adult worms may be embedded in the lining of the intestine. The eggs are laid and passed in the droppings. The created embryo will take 6 to 8 days, the eggs are infective to any other poultry that may eat them. The most severe damage occurs within 2 weeks of infection [29]. Approximately 1 cm (0.39 in) long, adult Capillaria are “threadlike” worms that are extremely thin. Their barrel-shaped eggs contain clear pugs on each pole and can only be seen under a microscope. There are various different Capillaria species, and each one infests a certain area of the chicken. Some species, including C. annulata and C. contorta, can infiltrate the esophagus and crop, thickening and inflaming the mucous membranes. Other pathogens, including C. bursata, C. caudinflata, and C. obsignata, attack the lower intestinal tract and cause inflammation, bleeding, and erosion of the intestinal lining. Capillaria can be lethal to the chicken if they are present in large enough quantities.

Figure 3.

Adult male of Capillaria sp. [31].

3.2.2 Cestodes

There are two important genera infecting chickens, Railleitina and Hymenolepsis. Raillietina is the name of a genus of tapeworms that includes helminth parasites of vertebrates, and mostly of birds. The genus was named in 1920 by Louis-Joseph Alcide Railliet. of the 37 species recorded under this genus, Raillietina demerariensis, R. asiatica, and R. formsana are the only species reported from humans, while the rest is found in birds. R. echinobothrida, R. tetragona, and R. cesticillus are the most important species in terms of prevalence and pathogenicity among wild and domestic birds (Figure 4) [31]. There are many different species of tapeworms that can infect backyard poultry. The majority of these species are totally harmless, however, large numbers of tapeworms may cause weight loss and loss of egg production.

Figure 4.

Cestode in the small intestine of chicken [32].

Raillietina tetragona occurs in the posterior half of the small intestine (ileum) of the chicken, guinea fowl, pigeon and other birds. It is cosmopolitan in distribution. It is one of the largest of the fowl tapeworms and the adults reach up to 25 cm in length. The scolex is smaller than that of R. echinobothridia and the rostellum is armed with one or two rows of hooks and the suckers are oval and armed. The genital pores are usually unilateral and the eggs are found in egg capsules each containing 6 to 12 eggs. The eggs are 25–50 um in diameter (Figure 5) [33].

Figure 5.

Scolex of Raillietina tetragona 336×448 pixels [32].

Raillietina echinobothrida is the most prevalent and pathogenic helminthic parasite in birds, particularly in domestic fowl (Gallus gallus domesticus Linnaeus), It requires two hosts, birds and ants, for completion of its life cycle [34]. The parasite is to blame for the chicken version of “nodular tapeworm sickness.” A typical tapeworm structure, the body of an adult R. echinobothrida is made up of a number of ribbon-like body segments that enlarge gradually from the anterior end towards the posterior. It is dorso-ventrally flattened, pale in color, extremely elongated, and fully covered in a tegument. The body can be up to 25 cm long and typically measures 1–1.5 cm in width. Raillietina cesticillus is very common throughout the world in domestic poultry, macroscopically is about 15 cm long and the anterior border of the segment is shorter than the posterior one. The scolex is cylindrical or nearly globular in shape and smaller in size [32] in Figure 6. Hosts. R. echinobothrida infections are observed in chickens and turkeys, tetragonal infections are most common in chickens, guineafowl, and pigeons, and domestic chickens are infected with S. cesticillus. The range of all three species is international. The worms are found in the small intestine, where the scolex is embedded in the mucosa, as their preferred habitat. 36 Morphology: S. cesticillus measures 9–13 cm, whereas R. echinobothrida and R. tetragona can grow to a length of 10–25 cm. All three species’ eggs are the same size, measuring 74×93, however, the quantity of eggs in each gravid segment differs. The R. tetragona gravid proglottid has the most egg capsules overall. R. echinobothrida and R. tetragona have different gravid segment morphologies than S. cesticillus because the segments of the first two are replaced by numerous fibrous walled egg capsules, each containing several eggs, as opposed to the numerous thin-walled egg capsules, each containing a single egg, in S. cesticillus.

Figure 6.

Scolex of Raillitinia cesticulls 150×141pixels [32].

The family of tapeworms known as Davaineidae contains helminth parasites of vertebrates. This family has 14 genera, of which Davainea is the best known and has been the subject of the most in-depth research. Members of the family can be identified by the rostellum, which is a crown of mattock- or hammer-shaped hooks, present at the tip of the scolex. Suckers with spines encircle the rostellum on both sides. The most frequent hosts of these tapeworms are birds, though they can also be discovered in some cases in mammals. Small insects like ants serve as intermediate hosts. The intermediate hosts for Davainea proglottina are slugs and chickens (Figure 7) [35]. Clinical symptoms and pathogenicity: Despite its small size, D. proglottina is one of the more dangerous species, especially in young birds and especially if it happens frequently. Clinical symptoms include a lifeless appearance, sluggish movements, decreased weight gain, emaciation, dyspnea (breathing problems), leg paralysis, and death. It is possible to notice microscopic necrosis, hemorrhages, and thicker mucosal membranes.

Figure 7.

Adult stage of Davainea proglottina, 186×480pixels [32].

Amoebotaenia sphenoids occur in domestic poultry and have a global distribution. It is a little tapeworm with dimensions of 2 to 3.5 mm in length and 1 mm in breadth. It is generally triangular in shape and has 20 segments. Earthworms serve as the cestode’s intermediary hosts during its development. About 4 weeks after consuming infected earthworms, mature tapeworms are discovered in chickens. Even though this parasite does not cause any clinical symptoms, enteritis and wasting have been linked to it when there are significant infections present (Figure 8) [37, 38, 39, 40]. It is small, up to 4 mm long, and roughly triangular in shape • The rostellum is armed • The genital pores usually alternate irregularly at the extreme anterior end of the proglottid margin • The uterus is sac-like and slightly lobed.

Figure 8.

Adult stage of Amoebotaenia cuneata = sphenoides 400×542pixels [36].

3.2.3 Trematoda

Generally, infection with trematodes is not very common in domestic chickens. The only reference that dealt with trematodes was 309 heads of birds (83 chicken, 152 ducks, and 74 muscovy ducks) from two districts of Sukabumi and Serang, province of West Java, has been investigated for the presence of trematode infection. Chicken from Sukabumi had a slightly higher trematode infection rate than chicken from Serang, During the study was identified at least 13 genera of trematode were: Apatemon sp., Catatropis sp, Cotylurus sp, Echinostoma sp, Hypoderaeum sp, Notocotylus sp, Opistorchis sp, Paramonostomum sp, Philophthalmus sp, Prosthogonimus sp, Psilochasmus sp, Dendritobilharzia sp, and Trichobilharzia sp. The last two identified flukes were found in both ducks and Muscovy ducks but not in chickens [41].

4. Smart techniques for better poultry farming and management

• While constructing the farm’s shelter should be in an east–west facing to avoid excess sunlight.

• Adequate space required to avoid overcrowding should make sure 2 sq.ft. of space must be maintained for each bird.

What is the main problem facing poultry farming?

Eradication, elimination, and/or control of foodborne and zoonotic pathogens present a major challenge to the poultry industry [42].

5. New proposals for poultry farming

• Chicken Farm (Meat Production) The broiler industry’s sole goal is to raise chickens for their meat. Day-old chicks must be raised into adult birds until they have gained the proper weight and are prepared to be culled and sold.

• Farm - layer (Egg Production) In the layer sector, specialized hatcheries nurture birds to the point of lay before supplying them to egg producers, who are typically located close to feed sources and markets [43].

6. Practical part

Antemortem examination

The whole body of each chicken, including the skin and the feathers, was examined by the naked eye and with the aid of magnifying lens starting from the head to the legs including wings, thigh, and neck for the presence of ectoparasites.

Collection and examination of ectoparasites

Ectoparasites, which were visible in live chickens, were collected gently using thumb forceps. All the collected ectoparasites of each chicken were preserved in a test tube containing 70% ethyl alcohol until the time of identification. The legs of each chicken were carefully examined for the presence of any inflammatory lesion, and if it is present, skin scraping was obtained using a clean blade and the scraped sample was mixed with 10% KOH and examined under the microscope for the presence of mites. Ectoparasites were collected by spraying a commercial insecticide over all of the body and in areas where suspected lesions of ectoparasites were present the entire body and feathers were then gently rubbed over a white cloth with a strong light source.

Postmortem examination

Following the slaughtering of each chicken, the blood sample was collected directly in a sterile test tube containing EDTA anticoagulant for thin blood film. All the thin blood films were stained with Leishman’s stain for the presence of blood parasites.

7. Facilities and supplies

• Feeders

  • include both hanging feeders for older birds and trays for chicks.

• Waterers

  • Similar to feeders, they must be strong to prevent tipping over and should be simple to refill. To prevent drowning, fill the chick waterer with stones.

• Nutrition

  • Offer grit in little and larger sizes depending on the age of the bird. Sands from streams include minerals and stimulate the gizzard physically. Calcium can be found in abundance in oyster shells.

  • It’s crucial to include fresh green vegetable matter and hay chaff seeds to satisfy the higher nutritional needs of chicks and laying hens.

  • Think about sprouted grains that you have grown yourself or chick starts that you have purchased.

• Temperature

  • A heat source is necessary for chicks. For this purpose, heat lights and heat pads are frequently employed. When housing a lot of chicks in a brooder, heat lights can be fitted [44].

8. Conclusions

• The microscopic examination of droppings, intestinal scraping and cecal contents revealed the presence of different types of Eimeria oocysts.

• Blood parasites and Cryptosporidium oocysts were not recorded in all the examined chickens.

• The nematode Sublura followed by Ascaridia galli, Heterakis gallinarum and Capillaria.

• Six species of tapeworms were recorded and identified, namely: Raillietina tetragona, R. echinobothrida, R. cesticillus, Fimbriaria fasciolaris, Davainea proglottina, and Amoebotaenia sphenoides

• This article strongly suggests that ectoparasites and endoparasites were very serious problems of domestic local breed chickens, so appropriate control strategies need to be devised in order to limit the effect of infections on their productivity.

A.

No.	Host (male or Female)	Area or provinces	Date	Type of Parasites	% Infection
1
2
3
4
5
6
7