Nutrition in Relation to Diseases and Heat stress in Poultry

Different diseases conditions and stress factors are responsible for high morbidity and mortality of present day poultry. Nutritional strategy and proper feed formulation with specific dietary regimen can combat this up to a certain extent. The incidence of various infectious diseases, nervous disorders and metabolic disorders can be minimized through proper feed regimen. There is a stiff competition and restrictions in the global market of poultry products which can be addressed with proper management of emerging and important diseases with economic productions and quality poultry products free of elements detrimental to human health. Researchers have made efforts to prevent such damage to poultry and poultry product through dietary manipulations. Heat stress can lead to a reduction in the defense mechanisms of birds or to a relative state of immunosuppression. The health status of the poultry is facing new challenges today which can be suitably addressed by the right scientific and advanced nutritional manoeuvres and make the poultry farming more profitable and presentable in the global market.


Introduction Nutrition and Disease Interaction Infectious Diseases
Birds frequently suffer with the chronic disease Coccidiosis causes a great economic loss in the condition or repeated stress, as a result, there is poultry industry due to high rate of morbidity, redistribution of body resources including energy and mortality, sub optimal growth, feed conversion protein at the cost of decreased growth, reproduction efficiency and loss of egg production (Williams, and health (Beck, 1991).
2005).Different vitamins and proteins contribute a lot Nutrition plays a fundamental role in in prevention of incidence of coccidiosis.It has been determining the health and performance of birds and a shown that chickens infected with oocysts of correctly balanced diet is essential to avoid disease coccidian receiving ten times more vitamin A than the associated with a deficiency or toxicity of a particular minimum requirement, gain their appetite faster and nutrient.Furthermore, disease and nutrition are also grow faster.Vitamin-A reserve in the body is less closely interlinked regarding a number of clinical conditions which arise independently of errors in the in infected birds as compared to healthy birds.It is diet, but in which dietary modification forms an reported that during a severe attack of Coccidiosis, important part of the poultry management practice.administration of 60 I.U.Vitamin A per chicken per day almost completely prevents mortality.Nutrition mana-gement of birds involves assessment An interrelationship between vitamin K content of the nutritional requirements for various life stages of the diet and coccidiosis has also been reported.As and operational tasks, and formulations of complete much as 8 mg of vitamin K per kg of diet was needed at and balanced economic diets and/or therapeutic diets times for maximum growth and feed efficiency in for different physiological and pathological infected birds, while Vitamin K needs were much conditions.Poor managemental conditions with lower (1.2 mg/kg diet) under normal conditions.Water respect to supply of nutrients may lead to starvation medication is generally preferred over feed medication and infectious diseases in birds (Dohms, 1990).
for treatment.Antibiotics and increased levels of vitamins Different nutritional strategies should be followed to A and K are sometimes used in the ration to improve eliminate all avoidable form of stressors and minimize rate of recovery and prevent secondary infections.unavoidable stressors under control.
The level of protein content of the diet is a and exudative diathesis.Vit.E or synthetic antioxidants contributing factor in the incidence of coccidiosis.are equally effective in preventing nutritional Higher levels of dietary protein favour establishment encephalomalacia while Se is not able to prevent the symptom.Supplementation of selenium had been of occysts of coccidian.Similarly, low calcium diets reported to enhance the preventive effect of dietary are also reported to decrease the incidence of the vitamin E at a level which was too low to be effective disease.These observations have been explained on in preventing exudative diathesis and muscular the basis of the effect of protein and calcium levels of dystrophy.the diet on the activity of trypsin enzyme in the However, supplementation of selenium or intestine.Since trypsin has been found to be essential methionine with 2.5 to 10 mg vitamin E/kg had little for the establishment of coccidiosis infection, it is preventive effect against encephalomalacia in chicks proposed that the effect of low protein diets in fed dilauryl succinate.Since a toxic effect of selenium decreasing the severity of coccidiosis is due to the at the level of 10 mg/kg has been reported and a dietary effect of these diets on intestinal trypsin activity.
level not more than 5 mg/kg has been recommended Betaine and other pronutrients are used as (Poley et al., 1941), supplemental selenium higher coccidiostats for amelioration of the symptoms.(Bedford, 2000).
than 4 mg/kg would not be expected to have any Vitamin-K is required in early stages of preventive effect against encephalomalacia due to Ranikhet Disease.It has also been observed that dilauryl succinate.vitamin A in excess than the minimum levels needed Nutritional encephalomalacia is a problem in for growth is important in the prevention of severe poultry production which depends both on the actual lesions and losses from chronic respiratory disease vitamin E supply and the dietary amount of (CRD).polyunsaturated fatty acids.Uncontrolled lipid Vitamin A is involved in maintaining the oxidation caused by disturbances of that system may integrity of the cells of the mucus membranes and the play a crucial role in some important poultry diseases secretion of mucus.Thus, it seems one of the ways and toxicoses.The first route of lipid peroxide loading through which vitamin A increases the resistance to of the organism is via the feed, such as through pathogens.Vitamin A is helpful in increasing the oxidised lipids.In other two diseases both Vit E and Se antibody synthesis against pathogens which are able to appear to be involved.Although Se does not prevent gain entry in the body.It has been demonstrated in the muscular dystrophy, its addition to a Se low diet case of salmonella infection in chickens.Normal dicreases the amount of dietary Vit E needed to prevent vitamin A levels in the diet, increases the protein the disease.But exudative diathesis can be prevented content from 20% to 30% caused a marked increase in by either of the two.It is interesting to note, that the mortality of chicks infected with Salmonella Yoshida and Hoshii, famous nutritionists were able to gallinarum.It was suggested that excess protein above reproduce all the clinical signs of the disease by the normal requirements markedly increases the feeding dilauryl succinate.These signs could not be vitamin A requirements of chicks and decreases the prevented or reversed with vitamin E levels in the storage of this vitamin.Probiotics like S. cerevisia plasma.However, dietary inclusions of vitamin C supplemen-tation to diet prevent mycotoxicosis a minimized the dilauryl succinate-induced condition.certain extent.

Disorders of the Nervous System
Riboflavin deficiency is associated with demyelination of peripheral nerves and consequent Neural disorders account a tremendous loss in locomotion difficulty.The classical disease associated rapid growing poultry industry.Vitamin A deficiency results in poor bone remodeling owing to inhibition of with this deficiency is known as curled toe paralysis.It osteoclast production.Affected birds become ataxic is reported that a condition similar to curled-toe because of compression of the central nervous system.paralysis, which occurred in turkeys fed with 3-Vitamin A deficiency is an extremely rare cause of leg Nitrogen, 4-hydroxyphenylarsonic acid.It was found weakness in the modern poultry industry and it is that dietary levels of this substance greater that 50 ppm much more likely that poultry suffer from caused demyelization of peripheral nerves.hypervitaminosis A. Vitamin E deficiency causes Very rarely, birds hatch with nervous disorders three distinct diseases such as nutritional encephalowhen supplemented with extra thiamine in breeder malacia or Crazy chick disease, Muscular dystrophy rations.

Metabolic Disorders
and ratio of Ca and P in the diet have also been implicated in affecting chondrocyte differentiation Metabolic disorders such as ascites, skeletal (Edwards et al., 1983) and thus in the incidence and disorders, aflatoxicosis, poor digestibility due to severity of TD.The mycotoxin fusachromanone, and inhibitors and presence of β-glucans and pentosans, all the dithiocarbamates thiram and disulfuram induce the cause considerable losses to the poultry industry.In occurrence of severe TD lesions.most cases target organs are liver, pancreas kidneys, The embryo has limited access to minerals, lungs and heart.Effective quality control of materials except Ca.Most are contained in the yolk, and their being used in manufacture of feeds prevent these concentration in general cannot be greatly influenced metabolic disorders and addition of central enzymes to by maternal diet.Access, however, can be improved feeds containing barley or wheat, can improve the by dietary mineral source selection.Use of growth and feed efficiency in broilers.Simple heat management methods to reduce metabolic diseases treatment destroys trypsin inhibitors in soybean meal that rely primarily on decreasing feed consumption, and thus provides one of the best source of protein for without increasing mineral concentration in the prethe chickens.Similarly, use of β-glucanase and starter phase (hatch to 8 or 14 d), may have negative xylanase can take care of metabolic problems caused unintended consequences on the sound development by use of barley, jowar and wheat in poultry rations. of the skeletal system.(Julian, 1998).Major parts of Combination of genetic and some managerial methods ingredients in the diet of poultry come from cereals will have to be used to control ascites which cause and leguminous seeds.The nutritional value of these concern especially in the fast growing broiler ingredients depends, besides their chemical chickens.As modern meat-type chickens show a high composition, on the extent to which the nutrients are incidence of leg problems, metabolic diseases and digested, absorbed and utilized.Various factors may increased fat deposition, a slower growth rate is interfere with these processes.pursued to avoid these negative selection responses.
A major class of factor are the so-called anti-Early quantitative feed restriction seems to be a nutritional factors (ANFs) which can cause metabolic possibility to control these unwanted losses without disorders resulting in poor growth, lower egg significant reduction in final body weights (Lippens et production and lower efficiency of feed utilization.

al., 2000).
There are factors which affect digestion and utilization In many parts of the world, poultry is confronted of protein (trypsin inhibitors) and then there are factors to aflatoxicosis with feed containing mycotoxins that which have negative effect on utilization of minerals are metabolites of moulds or fungi growing in field (glucosinolates, phytic acid, oxalic acid and crops or within stored grain.Mycotoxins can be very gossypol).harmful to birds, even to low concentration, exerting their effect by derangement of normal metabolic Heat stress and Nutrition functions in various major organs within the body.
Any departure from the normal routine causing Rickets is most often associated with a inconvenience to birds becomes a cause of stress.nutritional deficiency or imbalance.These imbalances Birds are more susceptible to high environmental or deficiencies may occur due to mixing errors; temperature than low due to absence of sweat glands in inaccurate ingredient nutrient estimates; variable the feathered body, fatty nature and high body content of Ca, P, or both, when formulating diets; and temperature.The degree of susceptibility to tropical vitamin deficiencies due to loss, primarily of vitamin heat stress is higher in broilers than layers.Among D activity in vitamin premixes.Deficiencies may also broilers, males are more susceptible to heat stress than occur as a result of transient or chronic intestinal females.Good layers housed in cages are more disease that impairs absorption (mal-absorption susceptible than poor layers reared on deep litter.syndrome, coccidiosis, etc.).Tibial dyschondroplasia Prominent effect of heat stress in poultry production is (TD) appears to be most prevalent in rapidly growing decline in eggshell quality due to excessive loss of birds and this may be related to transient deficiencies carbon dioxide through panting.Temperature has an during the rapid growth phase of long bones, inverse relationship with poultry feed intake, high specifically the tibia, because the proximal tibia is the relative humidity in the study area usually encourage site of the fastest-growing growth plate.The addition outbreak of poultry diseases which invariably reduce of vitamin D3 alleviates the clinical signs of this egg production.Heat naturally causes a decrease in disease primarily by inducing maturation of feed consumption as chickens eat primarily to meet chondrocytes (Driver et al., 2006).The concentration their energy requirements.The increase in balance as well as productive energy realized from the temperature decreases the energy requirement and feed, but this improvement was as fat not muscle.
Protein formation generates extensive heat production feed intake but the requirements for protein, minerals and vitamins do not decreases.
(Macleod et al., 1997) which appears to be limited by a bird's ability to cope with an adverse environment.The biological mechanism by which heat stress Some improvement in performance can be obtained by impacts production and reproduction is partly increasing water intake.This can be achieved by explained by reduced feed intake; but also includes cooling the drinking water and by adding salts.altered endocrine status, reduction in nutrient intake and absorption, and increased maintenance requirements