Do you know the good, the bad and the ugly of inflammation in poultry?

Do you know the good, the bad and the ugly of inflammation in poultryInflammatory responses in birds are because of an immune response. These immune responses can be non-specific (innate) immunity and specific (adaptive) immunity.  Thus, the inflammatory responses can be cell specific as in case of cell mediated immune responses which include T or B lymphocyte responses. These are localised or site specific whereas non-specific responses are more generalized involving phagocytic cells and innate antibody.  A generalised mass inflammatory response has an overwhelming effect on today’s commercial poultry. The chain reaction of events caused by an antigen always involves the innate immunity reaction prior to the involvement of cell mediated immunity. As we learnt in in vaccination basics, vaccines improve specific antibody titers to prevent infection of target microbes. But does this stop inflammatory responses arising from the innate side of the bird? Do these inflammatory responses affect poultry?

Immunity in its most non-specific forms has more demerits than otherwise. The preventive blanket of mucin and ciliary responses as in case of respiratory and gut associated infections is affected the most in the generalised inflammatory tidal wave. Many researchers have associated tethered mucin thinning and reduced ciliary activity as a primary reason for an active infection in birds. Once opportunistic commensals evade, they spread fast. Most cell mediated responses which may are associated with these commensals would respond very late to such an onslaught. The most pronounced effects of these infections would be in high stress conditions especially in heat stress.Heat stress and high ammonia concentrations or similar stresses would require rapid panting behaviour which would mimic generalised inflammatory responses.

Immunisation reactions are common in poultry where the generalised immunity might be one of the reasons for morbidity. The birds are at this stage in their young but antibody deficient forms. As it is, Vaccination is a boon in the poultry industry but frequent respiratory outbreaks could point a direction towards controlling the span of their inflammatory reign. We have seen protection from certain diseases provided by warmth generated from poultry body, and have seen several mortalities from heat stress, similarly balancing this double edged sword should be left to nature. It is most reassuring to see the improving specifics in immunisation but at the same time it is scary to see the broadening antigen carrying potential of the microbes. All considered, surely inflammation would play a vital part in the future of poultry rearing.

Antibiotic Alternative & Growth Promoter

Antibiotic Alternative & Growth PromoterAnimal diseases have a large impact on the economy of the livestock industry having total estimated global losses up to $2773 million annually. The disease may have a direct effect on performance through decreased production of milk, wool, or eggs, reduced fertility, delays in reaching maturation of reproductive system, decreased draught power or decreased weight of cull animals. These epidemics have the direct effect on farmers, consequently affecting agricultural sector and the national economy.
There is no doubt in the fact that certain dietary antibiotics have been playing a pivotal role in promoting good growth and health in animal production and feed conversion efficiency. However, the emergence of drug resistance among pathogens and public concerns of antibiotic residues in meat has led the European Commission (EC) to draw a critical decision to ultimately ban (January 1st, 2006), the marketing and application of antibiotics growth promoters (AGP) as feed additive (EC Regulation No. 1831/20031). This verdict was taken on the basis of the precautionary principle: ‘Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation’ (Principle 15 of the Rio Declaration, 19922).

Will the ban on antibiotic growth promoters in animal feed have the desired effect of reducing the overall level of antimicrobial use in animals? At the moment, this looks to be highly unlikely, as statistics continue to show a sudden rise in the use of AGP used for remedial purposes, even though there is a significant reduction in the usage of antibiotic growth promoters. In countries such as the USA the use of AGP in the poultry industry has been formally declined. This has led to increase in FCR and rise in the incidence of necrotic enteritis. Necrotic enteritis (NE) is an acute infection caused by Clostridium species. This is characterized by excessive dehydration, severe intestinal tissue necrosis with an increase in death rate. Such sick birds that do not have access to appropriate treatment are likely to carry much heavier loads of bacteria at the time of processing. The escalating usage of treatment antibiotics is essential for the effective control of prevalent diseases such as coccidiosis and necrotic enteritis in poultry, diarrhoea and inflammation of ileum in pigs, which have serious consequences and may badly affect production performance. From a veterinary point of view, withdrawing AGPs and in-feed anticoccidials may open the door to more enteric pathogen invasion.
In light of recent publicity surrounding the use of antibiotics by livestock and poultry industries, there are reports claiming to be alternatives to antibiotics which have the direct or indirect effect on microflora. Ideally, the alternatives to AGP should function in a same way as growth promoters without hindering its beneficial effects i.e.

(1) By reducing the amount of toxins and other metabolites produced by gram-positive bacteria;

(2) By increasing the intestinal wall permeability thereby improving absorption of nutrients;

(3) By blocking enzymes secreted by the pathogens thereby reducing the incidence and severity of sub-clinical infections.

Few of the most widely used alternatives for AGP along with their mode of action is briefly discussed:

Organic acids
Organic acids are widely distributed in animal tissues formed through catabolism of carbohydrates by microbial fermentation mainly in the caecum of the poultry intestine. The antibacterial nature of organic acid is mainly due to the low pH. The environmental pH change affects the dissociation of the acid which enhances the antimicrobial effect. The dissociated form of acid molecules freely diffuses through the semi-permeable membrane of microorganisms into the cell cytoplasm. Once in the cell, the acid molecules will disrupt the cell enzymes and nutrient transport mechanism.
To read more: Adams, C., 1999. Nutricines: Food Components in Health and Nutrition. Nottingham University Press, UK.

Probiotics and Prebiotics
Probiotics are mixed cultures of live bacteria which improve the growth and characteristics of the indigenous microflora thereby benefiting the host’. The most well-known group of probiotics is lactic acid bacteria. Most of the probiotic strains produce specific metabolites such as hydrogen peroxide, secondary metabolites, and organic fatty acids. It also stimulates the immune system while interacting with the various receptor sites. On the other hand, Prebiotic are non-digestible feed ingredients with selective effects on the intestinal microflora. The mechanism of action of prebiotics as an alternative is dependent on the nature of the compound. They are feed ingredients that improve the activity of the gut microflora because of selective stimulation of the growth or metabolic activity of a limited number of intestinal micro-biota species, such as Bifidobacteria and Lactobacillus sp. Thus, they may have a similar mechanism of action as probiotics.

Herbs and essential oils
It is not an unknown fact that the herbs are used for beneficial therapeutic properties derived from their specific bio-active components. Most of the bioactive compounds of the plant are mostly secondary metabolites such as terpenoids (mono- and sesquiterpenes, steroids, etc.), phenolics (tannins), glycosides and alkaloids (present as alcohols, aldehydes, ketones, esters, ethers, lactones, etc).Essential oils are concentrated products with very strong aromatic fragrance produced by  these secondary metabolites. The mechanism of action of bio-active compounds on chemical constituents, biological factors and so on. Bio-active constituents derive from plants play important role in inhibiting the bacteria by inactivation of the protein, loss of function, neutralizing free radicals. The study of microbial activity of essential oils and other bio-active compounds on micro-organisms still remains area of future research.

CONCLUSION
Alternatives for AGPs are only of practical significance which improves animal performance as compared to AGPs.  Microflora stimulating and immunomodulatory compounds have potential and are used as feedstuff of feed additives. Acids, probiotics, prebiotic and herbs or essential oils are some examples of different naturally available products which are used as alternatives for AGPs. Within each product class, numerous other products are available in the market, of which some products are potentially good, for others the efficacy is not clear. Hence, this brings us to a point to describe the mechanism of actions of these useful vital compounds in a whole scientific manner that meets high grades for AGP alternatives for poultry.

Poultry Gut Dysbacteriosis

Poultry Gut DysbacteriosisBroiler intestine is colonised by diverse microbial count. It is niche of complex ecosystem formed by microbes. This microbial count affects hosts response to nutrient digestion & absorption, general physiology along with local or systemic immunological reaction. The gut micro flora is relatively stable in healthy poultry. However when major qualitative and quantitative changes occur in the gut microbial count, the broiler host can face dysbacteriosis by showing clinical signs such as diarrhea, flushing, diuresis.

Generally dysbacteriosis causes modifications in intestinal pH. Enteropathogenic bacteria like E.coli, salmonella grow in ileum & ceaca which produces toxins & metabolites increasing the gut motility, changing gut pH and irritation of the mucus membrane, which leads to inflammation and secretion of mucous. Enteropathogenic bacteria survive in slightly alkaline pH. But Herbofloxin maintains slightly acidic pH of average 6.8 in the gut. This gives 4 times reduction in Salmonella, E.coli, campylobacter count, thus maintaining the gut pH will help in reducing the Enteropathogenic bacterial count.

Antibiotics in feed for poultry-do we need them?

Antibiotics in feed for poultryThere is constant race for better meat yielding animals. As the grain costs increase on an annual basis, the drag co-efficient for the poultry industry has hit a new high. The need for cheap and not necessarily good quality raw materials is more than it ever was. As the nutritional basis for animal feed switches from cost effective to effective cost, there is need for the farmer to be more stringent in choosing the right feed formulation to meet rising demand for meat and eggs. While some choose to be eccentric and follow the all organic approach, more than 70 % of the farms choose to be otherwise. As the health of the bird becomes secondary especially in a short 28 day period, the drive for production is main reason for the advent of antibiotic use in animal feed in the 20th century with the intention to reduce mortality and improve weight gain. As antibiotics gained popularity, the heritage of newly discovered antibiotics passed quickly from human to animal use.

The approach towards poultry and other livestock used for food production has to be of a preventive medicine. The use of antibiotics for this purpose blurred the line between treatment and prevention. Let’s take some time to understand this briefly,  for human medicine, population medicine is individualistic, especially in case of microbial disease, whereas in case of poultry there is a close association between the birds in the house where it is always a sub population we intend to treat or prevent disease in. Using preventive medicine tools directs here to understand the trends and predict outcomes. We always try to go one better by improving bio security and management practices, so that we affix our outcomes of clean bird production.  Once we start using substances that kill micro-flora we are already invading the population by measures labelled as preventive, but actually treating a problem, so be it at a micro-scale. This so called preventive use of antibiotics in feed treats every birds differently, where in human medicine we consider parenteral as the route of choice for maximum efficacy, feeding birds orally forms one barrier, apart from not discussing how much one bird will consume and how often. Now we come to a question very recently asked by the pro –antibiotics lobby, how antibiotics used for the animal use and human use being different, have a chance to produce antibiotic resistance that is significant for human medicine. To put my point clearly below is a table published in one report that demarks different categories of antibiotics with respect to their in animal or in human use.

This report says as reported by FDA, but actually is an adaptation from the report and the table is not present in the original FDA version.

Even if we consider that the categories are different for human and animal use, how one ensures that antibiotics working on certain targets as cell wall or cell division are going to discriminate the categories. We are not even sure that how low dose of certain one category of antibiotics affects the cross development of antibiotic resistance.

So, where do we go from here, do we use antibiotics or not? Let’s now focus on what can be done.

We can list how we can collectively reduce antibiotics,

  1. Treat Invitro

This implies to enhancing the biosecurity measures in all inputs for the birds. Using safe, natural alternatives in these zones which include the water source, litter, House and feed. Using disinfectants of natural origin in these zones kill the microbes where they are most vulnerable that is outside the bird body.

  1. Focus on nutrition

Use bio-availability scales to improve the nutrition supply to the birds. Healthy birds survive on the accord on their own immunity and natural barriers. Remember the host also in the infection trilogy of pathogen, host and environment interaction.

  1. Clean processed birds for sale

The importance of slaughter house disinfection should not be lost. This is the last step that the producer can really control its quality of carcass. Using non-residual agents for cleansing of carcass.

  1. Gut is where all the action is

Improving gut flora results in better good micro flora dominance in the intestine. Additives that improve all supporting structures which enhance the micro climate for gut will improve gut associated lymphoid tissue and results in improved immunity and absorption. Gut health enhancement also reduces chances of pathogens passing into the blood and other vital organs. Reducing the endogenous losses from gut will also enhance amino acid turn-over in poultry.

Efforts should be made to cull such trends when they originate and the poultry industry should keep an open mind towards use of alternatives to antibiotics, as it would take some withdrawal time to wean off these dependencies.