Dairy and Veterinary Sciences| Lupine Publishers

Opinion

Mycotoxins are biologically active, toxic metabolites produced by toxigenic fungi mainly belonging to Aspergillus, Fusarium and Penicillium species, which invade crops in the field and may grow on feedstuffs during storage under favourable conditions of temperature and humidity [1]. FAO estimated that about 25% of food and feedstuffs are contaminated with mycotoxins and strong efforts have been made to decontaminate them by the use of physical and chemical adsorbents but the success made so far is limited [2]. Like other environmental pollutants, mycotoxins also adversely affect the health and productivity in animals and esecially in poultry [3,4]. The economy of poultry industry is heavily affected due to wide mycotoxin exposure or contamination of various agricultural commodities. The economic losses are primarily due to the decreased growth rate, feed conversion efficacy, carcass yield, carcass quality and increased susceptibility to other diseases caused due to their immunosuppressive effects among the affected poultry. A mycotoxicosis is a disease caused by a natural toxin produced by a fungus. In poultry, this usually results when toxin producing fungi grow in grain and feed. Hundreds of mycotoxins have been identified, and many are pathogenic. Mycotoxins may have additive or synergistic effects with other natural toxins, infectious agents, and nutritional deficiencies. Many are chemically stable and maintain toxicity over time. Out of more than 350 mycotoxins identified in nature, aflatoxins, T-2 toxin, diacetoxyscirpenol, vomitoxin, zearalenone, ochratoxins, ergot alkaloids, oosporein, cyclopiazonic acid, and tricothecenes are the most common and important in poultry [5].

Mycotoxicosis and Their Effect in Poultry

Aflatoxicosis: The aflatoxins are toxic and carcinogenic metabolites such as Aspergillus flavus. Aflatoxicosis in poultry primarily affects the liver but can involve immunologic, digestive, and hematopoietic functions. Aflatoxin can adversely affect weight gain, feed intake, feed conversion ratio, pigmentation, carcass yield, egg production, male and female fertility, and large hatchability problems. Some effects are directly attributable to toxins, whereas others are indirect, such as reduced feed intake. Susceptibility to aflatoxins varies, but in general, ducklings, turkeys, and pheasants are susceptible, while chickens and Japanese quail are relatively resistant. Clinical signs vary from general unthriftiness to high morbidity and mortality. At necropsy the lesions are found mainly in the liver, which can be due to necrosis and congestion or yellow due to lipid accumulation. Hemorrhages may occur in liver and other tissues. In chronic aflatoxicosis, the liver becomes yellow to gray and atrophied.

Fusariotoxicosis: The genus Fusarium produces many mycotoxins injurious to poultry. The trichothecene mycotoxins produce caustic and radiomimetic patterns of disease exemplified by T-2 toxin and diacetoxyscirpenol (DAS). Deoxynivalenol (vomitoxin, DON) and zearalenone are common trichothecene mycotoxins that are relatively nontoxic for poultry but may cause disease in large concetratin in feed. Fusariotoxicosis in poultry caused by the trichothecenes results in feed refusal, caustic injury of the oral mucosa and areas of the skin in contact with the mold,acute digestive disease, and injury to the bone marrow and immune system [3]. Lesions include necrosis and ulceration of the oral mucosa, gastro intestinal mucosa, mottling of the liver, atrophy of the spleen and other lymphoid organs, and visceral hemorrhages. In laying hens, decreased egg production can be accompanied by depression, recumbency, feed refusal, and cyanosis evident in the comb and wattles [6]. Other Fusarium mycotoxins cause defective growth of long bones.

Ochratoxicosis: Ochratoxins are quite toxic to poultry. These nephrotoxins are produced chiefly by Penicillium viridicatum and Aspergillus ochraceus in grains and feed. Ochratoxicosis causes primarily renal disease but also affects the liver, immune system, and bone marrow. Severe intoxication causes reduced spontaneous activity, huddling, hypothermia, diarrhea, rapid weight loss, and death. Moderate intoxication impairs weight gain, feed conversion ratio, pigmentation, carcass yield, egg production, fertility, and hatchability [5, 6].

Ergotism: Toxic ergot alkaloids are produced by Claviceps spp, which are fungi that attack cereal grains. The mycotoxins form in the sclerotium, a visible, hard, dark mass of mycelium that displaces the grain tissue. Within the sclerotium are the ergot alkaloids, which affect the nervous system, causing convulsive and sensory neurologic disorders, the vascular system, causing vasoconstriction and gangrene of the extremities and the endocrine system, including neuroendocrine control of the anterior pituitary gland. In chicks, the toes become discolored due to vasoconstriction and ischemia. In older poultry, vasoconstriction affects the comb, wattles, face, and eyelids, which become atrophied and disfigured. Vesicles and ulcers develop on the shanks of the legs and on the tops and sides of the toes. In laying hens, feed consumption and egg production are reduced [6].

Mycotoxicosis Diagnosis in Poultry

Mycotoxicosis should be suspected when the history, signs, and lesions are suggestive of feed intoxication, and especially when moldy ingredients or feed are evident. Toxin exposure associated with consumption of a new batch of feed may result in subclinical or transient disease. Chronic or intermittent exposure can occur in regions where grain and feed ingredients are of poor quality or when feed storage is substandard or prolonged. Impaired production can be a clue to a mycotoxin problem, as can improvement because of correction of feed management deficiencies. Definitive diagnosis involves detection and quantitation of the specific toxins. This can be difficult because of the rapid and high volume use of feed and ingredients in poultry operations. Diagnostic laboratories differ in their respective capabilities to test for mycotoxins and should be contacted before sending samples. Feed and also poultry that are showing sings of sicknes or recently dead should be submitted for pathological examinatios. A necropsy and related diagnostic tests should accompany feed analysis if mycotoxicosis is suspected. Concurrent diseases can adversely affect production and should be considered. Sometimes, a mycotoxicosis is suspected but not confirmed by feed analysis. In these situations, a complete laboratory evaluation can exclude other significant diseases. Feed and ingredient samples should be properly collected and promptly submitted for analysis. Mycotoxin formation can be localized in a batch of feed or grain. Multiple samples taken from different sites increase the likelihood of confirming a mycotoxin formation zone. Samples should be collected at sites of ingredient storage, feed manufacture and transport, feed bins, and feeders [5, 6].

Prevention of Mycotoxicosis in Poultry

Prevention of mycotoxicoses should focus on using feed and ingredients free of mycotoxins and on management practices that prevent mold growth and mycotoxin formation during feed transport and storage. Regular inspection of feed storage and feeding systems can identify flow problems, which allow residual feed and enhance fungal activity and mycotoxin formation. Mycotoxins can form in decayed, crusted feed in feeders, feed mills, and storage bins, cleaning and correcting the problem can have immediate benefits. Temperature extremes cause moisture condensation and migration in bins and promote mycotoxin formation. Ventilation of poultry houses to avoid high relative humidity also decreases the moisture available for fungal growth and toxin formation in the feed. Antifungal agents added to feeds to prevent fungal growth have no effect on toxin already formed but may be cost effective in conjunction with other feed management practices [6]. Propionic acid are effective inhibitor, but the effectiveness may be reduced by the particle size of feed ingredients and the buffering effect of certain ingredients. Sorbent compounds such as hydrated sodium calcium aluminosilicate effectively bind and prevent absorption of aflatoxin. Esterified glucomannan, derived from the cell wall of the yeast Saccharomyces cerevisiae, is protective against aflatoxin B1 and ochratoxins. It reduces toxicity through the binding and reduction in bioavailability of fumonisins, zearalenone, and T-2 toxin. Various other fermentation products, algae and plant extracts, and microbial feed additives have demonstrated ability to bind or degrade mycotoxins and may be applicable and appropriate for the situation.

Acknowledgement

The paper is a part of the research work on the project III 46012 financed by the Ministry of Education, Science and Technological Development of the Republic of Serbia.

To know more about our Veterinary Sciences click on https://lupinepublishers.com/dairy-veterinary-science-journal

To know more about Lupine Publishers click on https://lupinepublishers.us/

To know more about Open access publishers click on Lupine Publishers

Bit of new research out and about:

RAW CHICKEN LINKED TO PARALYSIS IN DOGS

Chicken necks are a common treat for dogs, but pet owners are being warned they have been linked with a potentially fatal form of paralysis

A new study, led by the University of Melbourne’s U-Vet Werribee Animal Hospital, found the consumption of raw chicken meat increases the risk of dogs developing a paralysing condition called acute polyradiculoneuritis (APN) by more than 70 times.

“It is a rare but very debilitating condition where the dog’s hind legs first become weak. It can then progress to affect the front legs, neck, head and face. Some dogs may die from the disease if their chest becomes paralysed,” he says.

“Most dogs eventually recover without treatment but it may take up to six months or more in some cases.

Dr le Chevoir says the bacteria Campylobacter is now considered a triggering agent in up to 40 per cent of GBS patients. It is present in undercooked chicken, unpasteurised milk products and contaminated water.

“Our team at U-Vet Animal Hospital wanted to understand if consuming raw chicken could also be triggering APN in dogs. Many of us have previously worked overseas and know that a raw meat diet is less common there, so we were intrigued by this potential connection,” Dr le Chevoir says.

“These bacteriological results were consistent with the hypothesis that the uncooked chicken meat was the source of the Campylobacter and as a result, triggered APN.”

Introduction

In recent years, in farm and private livestock farms in Uzbekistan there has been a decrease in the resistance of animals and, especially, young animals to various bacterial and viral infections. Often there is a decrease and a complete lack of protective action of known vaccines and serums, which causes serious economic damage to livestock. One of the leading factors of this pathology is the unfavorable ecological situation which has developed in many regions of the Republic owing to various anthropogenic influences, including: application of pesticides and other toxic xenobiotics and also emissions of industrial productions. The use of synthetic pyrethroids and organophosphorus compounds in crop production and veterinary medicine helps to preserve crop yields, reduce production costs and reliably protects farm animals from various infections and invasions.

Abstract

Fine-grained products are harvested in two manual and mechanized forms. Nowadays, common combine harvesters are used, but fine-grained products such as rapeseed, sesame and sorghum cannot be harvested with conventional heads of combine harvesters due to the excessive loss in the head of the combine harvester. Therefore, the necessity of design an d fabricating machines and heads of combine harvesters became the center of attention to researchers because fine-grain products have lots of nutritional and medicinal benefits. In this research, we are going to have an overview of the special headers and machines for harvesting fine-grain products.

Keywords: Machine, head of combine harvester, harvesting, fine-grained products

Introduction

The effort to achieve agricultural development depends on concentration on mechanization. Fine-grained products such as sesame, sorghum, and canola have been hand-picked in the past, while nowadays the use of special machines and heads of combine harvesters makes it easy to harvest them. To begin with, let’s take a look at the physical and mechanical properties of these products. Rapeseed (Brassica napus L.), also known as rape, oilseed rape, rapa, rapeseed, and canola, is a bright yellow flowering member of the Brassicaceae family (mustard or cabbage family). Rapeseed is widely cultivated throughout the world for the production of animal feed, vegetable fat for human consumption, and biodiesel. Leading producers include the European Union, Canada, the United States, Australia, China and India [1]. World production is growing rapidly, As FAO reports say 48.97 million tons of rapeseed was produced [2]. Rapeseed grains are fine and round and the weight of one thousand seeds is 3.5 to 7gram. Canola pigments are brown to black. Some physical properties of rapeseed seed were measured and analyzed (based on wet) by Calisir et al. At three levels of the moisture content of 4.7, 14.13 and 23.96 percent [3]. Physical properties of rapeseed oilseeds are essential for the design of the required devices or for determining their motor behavior for displacement [4]. Sorghum (Sorghum bicolor L. Moench) is an important crop species in the United States and around the world. Because of its substantial heat and drought tolerance, sorghum production is traditional in semiarid, subtropical and tropical regions. In addition to abiotic stress tolerance, sorghum is very responsive (in terms of productivity) to more favorable conditions. While primarily known as a cereal grain, sorghum is grown throughout the world as a forage, syrup and more recently, energy crop. In 2008, U.S. farmers harvested about 2.9 million hectares of grain sorghum [5]. The sesame is thermophilic and basically, a particular product for tropical and subtropical regions and is sensitive to low temperatures, but by implementing a breeding program, it is possible to extend its cultivation to temperate regions. Sesame seed is from 40 degrees north latitude to 40 degrees south latitude, it is usually cultivated at the height of 1200 meters above sea level. This plant needs warm weather and an abundant amount of light and shows sensitivity to low temperatures [6]. Sesame is harvested when the seeds are ripe in the lower capsule. Capsules usually come up from the bottom of the stem, and the left loss begins, and while the capsules are still green, they must be removed before they dry [7]. Sesame is a strategic product with high nutritional and medical value, that the daily increase in the number of the lands under cultivation due to sesames high consumption in the world and to make some reductions in harmful effects of spraying to increase plant resistance to seed loss are the reasons which necessitate the mechanized harvesting of this product [8]. As the cultivation area of this product is increasing in the world, there are many industrial and pharmaceutical properties for sesame. Nowadays, the consumption of sesame oil in the world is increasing, but because of the high head of combine loss in common combines, it is often taken manually in some countries, which is, costly and time-consuming and in some other countries it is carried out by combine harvesters which is a special head of combine harvester for fine-grained products, In this case, the losses rate is too high [9]. According to the research on the physical and mechanical properties of some fine-grained products and the need for the use of special heads of combine harvesters and machines for their harvesting. In this research, the activities carried out in the field of construction and design of these hedges and harvest machines have been studied.

Sesame harvesters

a. In 1981, Taylor et al. from the United States invented a special head of combine for harvesting sesame. This head of the combine harvester is used to harvest sesame seeds existing in plant’s capsules. The frame of this head of combine harvesting consists of two parts with a cylindrical structure and a concave structure. The cylinder structure has a rotary motion and a concave structure in a fixed position mounted on the frame. This head has an inlet area, outlet area, and separation area. The sesame plant enters by the feeder between the cylindrical and concave structures of the entrance area. Then the separator zone separates seeds from the pods, and the stems, straw, and the remaining straw are driven to the outlet area by the walker. The head of combine harvester designed for harvesting sesame seeds (Figure 1) by Taylor [10], which is used to harvest sesame seeds contained in the plant’s capsules. In this head of the combine harvester due to the flatness of the fingers, the seeds are spilled on the ground and there is no the system for transferring the collected seeds Due to the short height sides of the separators, the losing probability is high. Its advantages are also extremely low cutting force while cutting the product and connecting it to a combine harvester for harvesting sesame on large lands and high maneuverability [10].

b. In 2015, Zhang Dawi [11] invented a large-scale sesame the harvesting machine. This harvesting machine includes a reaper at the front, and the reaper section passes through conveyors and connects to the Threshing Unit of the machine. The bottom of the threshing unit also passes through the product entry into the reaper and connects by the feeder. The cutting unit has a frame equipped with a back and forth blades in its front bottom. In the upper part of the cutting section, there is also a reel. The sloping conveyors are also connected to the threshing unit, on the other side, it is connected to the center of the back of the cutter section and is equipped with at least one helix for transferring the product, which completely separates the seeds of sesame in the threshing unit. This harvesting machine provides the advantage of creating the conditions for large-scale sesame harvesting with a simple structure and logical design. The sesame Harvesting Machine designed by Zhang Dawi for a large scale (Figure 2), has the advantages of having a complete system from harvesting to seed separation and utilization for harvesting sesame in large farms. Its disadvantage is the fact that the reel is not tall enough, while the sesame’s height is sometimes about two meters and also it lacks a system for collecting lost seeds in the part of the head of combine harvester [11].

In 2019, Bazyar [12] invented small-scale head of combine harvester for harvesting fine-grain products especially for sesame. The design of the machine was based on the reduction of grain loss. It should be noted that this machine needs manpower to move and advance. The main parts of the machine include the collection tank, product cutting unit, separator unit with high elevation and nylon coverage, the stair frame system. The bowls with the overlap between them first make the stem of the cereal crop pass through these fingers. The stem is then bent and directed to the incision of the head. The presence of long dividers in the head with highheight nylon cover eliminates the possibility of any grain shedding from the head. Any spillage is also poured into the bowl. Due to the sloping design of these fingers, the grains inside the bowl are directed to the grain collection reservoir. The result of this research demonstrates that its head loss is about 16% (less than the head loss of ordinary headers). However, this was constructed with the least cost [12].

Canola Harvesters

In 2008, Sharobeem from Egypt invented the first head of a combine for harvesting Canola oil plant which was made at Abokeer Company and evaluated on Nobaria farms. The work of the head of combine begins after the canola plant is ripe, the combined harvester pulleys cut the rapeseed stems before they touch the plants. The designed head of combine harvester mainly consists of three parts: a frame, two cutting sections (horizontal and vertical) and a power transmission system. A cutting mechanism that includes two cutting sections (horizontal and vertical) is used. The horizontal cut includes forty fixed knives (76.2 mm) and forty movable knives, eight knife holder that is fixed in the cutter holder. The speed of 1.5 m / s moves with a 76.2 mm knife. Horizontal cutting is attached to a special frame. The vertical shearing strip has two strips, each of them has twenty-eight knives (50 mm) as a double knife. Vertical cutting is designed based on a 12 V electric motor. This head of a combine harvester is perfectly suitable for harvesting this plant and significantly reduces the amount of canola loss in the head of the combine harvester. The first head of combine harvester designed for harvesting the canola oil seed by Sharobeem (Figure 3) has a cutting mechanism that consists of two cutting sections (horizontal and vertical) and a variablespeed system which is used for power transfer. Due to the high compression of rapeseed plants, and also the plant’s tallness, which causes the decumbency and intertwinement of them, the chance of grain loss during cutting is high because the friction between the plants is high. Therefore, using this mechanism reduces the loss of canola seed but increases its power consumption. Also, by using a variable-speed system for the cutting unit which fits the product’s feed power the cutting speed can be changed [13].

In 2013, Tabatabaekoloor [14] has evaluated a special head of combine harvester for harvesting rapeseed mounted on a grain’s combine. In this research, a canola head model RH-3600 attached to front a John Dear 1055 combines and evaluated in the field. The results showed that the combine farm capacity with a mean working width of 335 cm and a forward speed of 3.7 km/hr was 0.88 ha/hr and its field efficiency was 80%. The mortality rate of grain loss from head parts including a carousel and horizontal shoulder blades to an average of 0.18%. The special head of combine harvester designed for harvesting canola has been evaluated by Tabatabaekoloor mounted on grain’s combine. In this study, an Rh-3600 that is special head of combine harvester for harvesting rape (Figure 4) installed on the John deer 1055 combine with a high capacity of large lands, high efficiency, and maneuverability. The cutting unit of this head of a combine harvester, likewise the head designed by the Sharobeem, has two cutting sections (vertical and horizontal), which reduces the grain loss [14].

Sorghum Harvesters

In 1990, Zhang Min [15] invented to combine harvester for sorghum. The utility model has a technological improvement of grain combine harvesters, and the components are added to the combine to improve grain combine harvesters including an ejector pin, a divider, an extruder, and an ear blocking device. Threshing spike-teeth are fixed on the bottom of a web notch of a threshing cylinder by a connector, and a grain harvester is refitted to a combine harvester for picking sorghum. The utility model is adapted to various self-propelled and pull-type grain combine harvesters, has a simple structure, and convenient manufacture and installation, and is ideal harvesting machinery for reaping sorghum. The combine harvester to reap sorghum was invented by Zhang Min (Figure 5), has some advantages and disadvantages. Some advantages are an adaptation to various self-propelled and pull-type grain combines, simple structure and convenient manufacture and installation, easy operation, low cost, less failure, however it has some disadvantages such as high power consumption, lack of lost seed collecting system, short height separator and high possibility of throwing grains [15].

In 2008, Ghahraei [16] in Iran, invented a special head of combine for harvesting sorghum. The developed cutting mechanism in this research has a rotary disk with 50 cm diameter and four cutting blades that spin clockwise. The stalks are cut with impact and inertia forces at the linear velocity of 27 m/s, by cutting blades. This system has a simple bar mechanism guiding the wholestalk to one side. The cutting quality tests were achieved by two series of blades with 30° and 45° blade angles on the stalk. As the results showed the stalk cutting surface with a 30° blade angle was smooth, with no fracture. A head of combine harvester designed for harvesting sorghum (Figure 6) by Ghahraei whose cutting unit has a rotary disk and four cutter blades in the clockwise direction that cut the plant with impact and inertia by cutting blades. This head of a combine harvester has a system with a simple mechanism that directs all the stems to one side. Its advantages are simply the mechanism for cutting the product and cutting the product with a smooth cross-section and its disadvantage is the lack of a system for collecting lost grains in the state of vibration when cutting the plant stem [16] (Figure 7).

This research was designed to facilitate researchers’ access to study on special heads of combine harvesters and harvesting machines for fine-grained products and to get their advantages and disadvantages. In this part of the research each research to have detailed-knowledge about special harvesters for harvesting fine-grain products. Moreover, all of the designs are evaluated by considering their merits and demerits.

Result and Discussions

Due to the mentioned researches on special harvesters for harvesting fine-grain products, the mentioned devices have been analyzed from several points such as the rate of grain loss, collected grain transfer mechanism, power consumption, maneuverability, and farm capacity. Although each of fine-grain products has different physical and mechanical properties, Most of these products have a high head loss so there should be a mechanism for reducing it. In the head, which was designed by Taylor [10], was used as a mechanism to prevent the sesame seeds from falling on the ground. In the other research, Bazyar [12] designed bowl fingers with overlap and stair chassis to plunge the amount of head loss. This research was constructed for harvesting but it revealed successful results in harvesting canola. Therefore, in a special head made by Sharobeem, as well as the head of combine harvester designed by Tabatabaekoloor for rapeseed operates two cutting (vertical and horizontal), and reduces the friction between the plants so the grain loss reduces, but this head is specific to rapeseed and is not suitable for other fine-grained grains. Considering the power consumption of the head of combine harvester designed by Sharobeem and the head of combine harvester made by Tabatabaekoloor due to the usage of an additional vertical section and a head of combine harvester designed by Bazyar due to the usage of a suction system for transferring grain, they have the highest power consumption. In terms of farm capacity and maneuvering ability, all of the proposed projects have high maneuverability and farm capacity because of the connection to the combine harvester. Considering the results mentioned above, for harvesting rapeseed the head designed by Sharobeem is suitable because of the use of a specific mechanism for cutting rapeseed stems and it has high farm capacity for this plant. The combine for reaping sorghum invented by Zhang Min is specially used for sorghum and its disadvantages are greater than its benefits, also it is not appropriate for harvesting finegrained grains due to the lack of lost grained collecting system. For other fine-grain, the use of a harvesting machine designed by Zhang Dawi is the most suitable option because it has a complete system from harvesting to separating the seed from pod, and it does not need to be connected to the combine harvester. In this research, all of the designs are weighed to choose the best harvester for harvesting fine-grain products [17]. These designs are evaluated by some parameters for example Energy consumption, Easy to maintain, Weight of the machine, Authenticity low number of pieces, Cost of production, Convenience of shipping, Failure to lose to either side, Transfer grain to a reservoir. In Table 1, inventions (Taylor, Dawi, Bazyar, Sharobeem, Tabatabaekoloor, Min, Gahraei) are named (A, B, C, D, E, F, G) respectively [18,19].

for more information about Concepts of Dairy & Veterinary Sciences archive page click on below link

https://lupinepublishers.com/dairy-veterinary-science-journal/archive.php

for more information about lupine publishers page click on below link

Dairy and Veterinary Sciences| Lupine Publishers

Opinion

Mycotoxins are biologically active, toxic metabolites produced by toxigenic fungi mainly belonging to Aspergillus, Fusarium and Penicillium species, which invade crops in the field and may grow on feedstuffs during storage under favourable conditions of temperature and humidity [1]. FAO estimated that about 25% of food and feedstuffs are contaminated with mycotoxins and strong efforts have been made to decontaminate them by the use of physical and chemical adsorbents but the success made so far is limited [2]. Like other environmental pollutants, mycotoxins also adversely affect the health and productivity in animals and esecially in poultry [3,4]. The economy of poultry industry is heavily affected due to wide mycotoxin exposure or contamination of various agricultural commodities. The economic losses are primarily due to the decreased growth rate, feed conversion efficacy, carcass yield, carcass quality and increased susceptibility to other diseases caused due to their immunosuppressive effects among the affected poultry. A mycotoxicosis is a disease caused by a natural toxin produced by a fungus. In poultry, this usually results when toxin producing fungi grow in grain and feed. Hundreds of mycotoxins have been identified, and many are pathogenic. Mycotoxins may have additive or synergistic effects with other natural toxins, infectious agents, and nutritional deficiencies. Many are chemically stable and maintain toxicity over time. Out of more than 350 mycotoxins identified in nature, aflatoxins, T-2 toxin, diacetoxyscirpenol, vomitoxin, zearalenone, ochratoxins, ergot alkaloids, oosporein, cyclopiazonic acid, and tricothecenes are the most common and important in poultry [5].

Mycotoxicosis and Their Effect in Poultry

Aflatoxicosis: The aflatoxins are toxic and carcinogenic metabolites such as Aspergillus flavus. Aflatoxicosis in poultry primarily affects the liver but can involve immunologic, digestive, and hematopoietic functions. Aflatoxin can adversely affect weight gain, feed intake, feed conversion ratio, pigmentation, carcass yield, egg production, male and female fertility, and large hatchability problems. Some effects are directly attributable to toxins, whereas others are indirect, such as reduced feed intake. Susceptibility to aflatoxins varies, but in general, ducklings, turkeys, and pheasants are susceptible, while chickens and Japanese quail are relatively resistant. Clinical signs vary from general unthriftiness to high morbidity and mortality. At necropsy the lesions are found mainly in the liver, which can be due to necrosis and congestion or yellow due to lipid accumulation. Hemorrhages may occur in liver and other tissues. In chronic aflatoxicosis, the liver becomes yellow to gray and atrophied.

Fusariotoxicosis: The genus Fusarium produces many mycotoxins injurious to poultry. The trichothecene mycotoxins produce caustic and radiomimetic patterns of disease exemplified by T-2 toxin and diacetoxyscirpenol (DAS). Deoxynivalenol (vomitoxin, DON) and zearalenone are common trichothecene mycotoxins that are relatively nontoxic for poultry but may cause disease in large concetratin in feed. Fusariotoxicosis in poultry caused by the trichothecenes results in feed refusal, caustic injury of the oral mucosa and areas of the skin in contact with the mold,acute digestive disease, and injury to the bone marrow and immune system [3]. Lesions include necrosis and ulceration of the oral mucosa, gastro intestinal mucosa, mottling of the liver, atrophy of the spleen and other lymphoid organs, and visceral hemorrhages. In laying hens, decreased egg production can be accompanied by depression, recumbency, feed refusal, and cyanosis evident in the comb and wattles [6]. Other Fusarium mycotoxins cause defective growth of long bones.

Ochratoxicosis: Ochratoxins are quite toxic to poultry. These nephrotoxins are produced chiefly by Penicillium viridicatum and Aspergillus ochraceus in grains and feed. Ochratoxicosis causes primarily renal disease but also affects the liver, immune system, and bone marrow. Severe intoxication causes reduced spontaneous activity, huddling, hypothermia, diarrhea, rapid weight loss, and death. Moderate intoxication impairs weight gain, feed conversion ratio, pigmentation, carcass yield, egg production, fertility, and hatchability [5, 6].

Ergotism: Toxic ergot alkaloids are produced by Claviceps spp, which are fungi that attack cereal grains. The mycotoxins form in the sclerotium, a visible, hard, dark mass of mycelium that displaces the grain tissue. Within the sclerotium are the ergot alkaloids, which affect the nervous system, causing convulsive and sensory neurologic disorders, the vascular system, causing vasoconstriction and gangrene of the extremities and the endocrine system, including neuroendocrine control of the anterior pituitary gland. In chicks, the toes become discolored due to vasoconstriction and ischemia. In older poultry, vasoconstriction affects the comb, wattles, face, and eyelids, which become atrophied and disfigured. Vesicles and ulcers develop on the shanks of the legs and on the tops and sides of the toes. In laying hens, feed consumption and egg production are reduced [6].

Mycotoxicosis Diagnosis in Poultry

Mycotoxicosis should be suspected when the history, signs, and lesions are suggestive of feed intoxication, and especially when moldy ingredients or feed are evident. Toxin exposure associated with consumption of a new batch of feed may result in subclinical or transient disease. Chronic or intermittent exposure can occur in regions where grain and feed ingredients are of poor quality or when feed storage is substandard or prolonged. Impaired production can be a clue to a mycotoxin problem, as can improvement because of correction of feed management deficiencies. Definitive diagnosis involves detection and quantitation of the specific toxins. This can be difficult because of the rapid and high volume use of feed and ingredients in poultry operations. Diagnostic laboratories differ in their respective capabilities to test for mycotoxins and should be contacted before sending samples. Feed and also poultry that are showing sings of sicknes or recently dead should be submitted for pathological examinatios. A necropsy and related diagnostic tests should accompany feed analysis if mycotoxicosis is suspected. Concurrent diseases can adversely affect production and should be considered. Sometimes, a mycotoxicosis is suspected but not confirmed by feed analysis. In these situations, a complete laboratory evaluation can exclude other significant diseases. Feed and ingredient samples should be properly collected and promptly submitted for analysis. Mycotoxin formation can be localized in a batch of feed or grain. Multiple samples taken from different sites increase the likelihood of confirming a mycotoxin formation zone. Samples should be collected at sites of ingredient storage, feed manufacture and transport, feed bins, and feeders [5, 6].

Prevention of Mycotoxicosis in Poultry

Prevention of mycotoxicoses should focus on using feed and ingredients free of mycotoxins and on management practices that prevent mold growth and mycotoxin formation during feed transport and storage. Regular inspection of feed storage and feeding systems can identify flow problems, which allow residual feed and enhance fungal activity and mycotoxin formation. Mycotoxins can form in decayed, crusted feed in feeders, feed mills, and storage bins, cleaning and correcting the problem can have immediate benefits. Temperature extremes cause moisture condensation and migration in bins and promote mycotoxin formation. Ventilation of poultry houses to avoid high relative humidity also decreases the moisture available for fungal growth and toxin formation in the feed. Antifungal agents added to feeds to prevent fungal growth have no effect on toxin already formed but may be cost effective in conjunction with other feed management practices [6]. Propionic acid are effective inhibitor, but the effectiveness may be reduced by the particle size of feed ingredients and the buffering effect of certain ingredients. Sorbent compounds such as hydrated sodium calcium aluminosilicate effectively bind and prevent absorption of aflatoxin. Esterified glucomannan, derived from the cell wall of the yeast Saccharomyces cerevisiae, is protective against aflatoxin B1 and ochratoxins. It reduces toxicity through the binding and reduction in bioavailability of fumonisins, zearalenone, and T-2 toxin. Various other fermentation products, algae and plant extracts, and microbial feed additives have demonstrated ability to bind or degrade mycotoxins and may be applicable and appropriate for the situation.

Acknowledgement

The paper is a part of the research work on the project III 46012 financed by the Ministry of Education, Science and Technological Development of the Republic of Serbia.

To know more about our Veterinary Sciences click on https://lupinepublishers.com/dairy-veterinary-science-journal

To know more about Lupine Publishers click on https://lupinepublishers.us/

To know more about Open access publishers click on Lupine Publishers