Holistic approach to help deal with antimicrobial resistance

Thursday, February 9, 2017

Holistic approach to help deal with antimicrobial resistance




Antimicrobial resistance (AMR) is an increasingly serious threat to global public health that requires action across all government sectors and society. Without effective antibiotics, the success of major surgery and cancer chemotherapy would be compromised. The cost of health care for patients with resistant infections is higher than care for patients with non-resistant infections due to longer duration of illness, additional tests and use of more expensive drugs. Globally, 480 000 people develop multi-drug resistant TB each year, and drug resistance is starting to complicate the fight against HIV and malaria, as well. (Source:http://www.who.int/mediacentre/factsheets/fs194/en/).

Antimicrobial resistance happens when microorganisms (such as bacteria, fungi, viruses, and parasites) change when they are exposed to antimicrobial drugs (such as antibiotics, antifungals, antivirals, antimalarials, and anthelmintics). Microorganisms that develop antimicrobial resistance are sometimes referred to as "superbugs". As a result, the medicines become ineffective and infections persist in the body, increasing the risk of spread to others. Resistance in E. coli to one of the most widely used medicines for the treatment of urinary tract infections (fluoroquinolone antibiotics) is very widespread. There are countries in many parts of the world where this treatment is now ineffective in more than half of patients. (Source:http://www.who.int/mediacentre/factsheets/fs194/en/).

Besides the US, in November 2016, Colistin was banned as a feed additive in Brazil and in China, with an ongoing transition period of extended use as a medical feed additive. Antibiotic resistance was the reason for the ban, showing that the Chinese feed sector has also taken a significant step forward towards a more prudent use of antibiotics (Source: Feedinfo News Service; dated 24/01/2017)

Colistin is the last resort treatment for life-threatening infections caused by Enterobacteriaceae which are resistant to carbapenems. Resistance to colistin has recently been detected in several countries and regions, making infections caused by such bacteria untreatable. (Source:http://www.who.int/mediacentre/factsheets/fs194/en/).

Antimicrobial resistance occurs naturally over time, usually through genetic changes. However, the misuse and overuse of antimicrobials is accelerating this process. In many places, antibiotics are overused and misused in people and animals, and often given without professional oversight. Examples of misuse include when they are taken by people with viral infections like colds and flu, and when they are given as growth promoters in poultry and livestock. (Source:http://www.who.int/mediacentre/factsheets/fs194/en/).

Hence, one way of reducing the incidence antimicrobial resistance is the judicious use of antibiotics which are used for prevention or treatment of diseases in farm animals.

With the increasing pressure on producers to reduce the use of antibiotic growth promotants (AGPs), application of eubiotics is on the rise. However, as Europe and more recently South Korea have learned, it is not as simple as replacing the AGPs with the aforementioned additives (e.g. organic acids, essential oil compounds, probiotics), expecting them to perform similar action of antibiotics.

Although in the past antibiotic growth promoters (AGPs) have been an effective tool, eubiotics not only are an increasingly popular solution to meet consumer demand with regards to a more responsible use of antibiotics but also represent a paradigm, a new way of looking at nutrition that resonates to more and more stakeholders, all along the value chain. (Source: Feedinfo News Service; dated 24/01/2017)

When it comes to sustainable optimum gut health, there is no silver bullet which can fully replace antibiotics and cure any intestinal disorder. However, eubiotics are often able to deliver a comparable zoo-technical response encompassing all these different product categories. Furthermore, it is essential to properly understand the challenges that swine or poultry producers might be facing to be able to propose the most relevant combination of high quality products and deliver the best possible results. It is also important to say that eubiotics are not the only ingredients proven to support gut health, vitamins, carotenoids and enzymes also play a role in gut health and immunity. (Source: Feedinfo News Service; dated 24/01/2017)

The desire amongst the poultry producers and its consumers for sustainable solutions avoiding the high risk of AMR is the reason why demand for antibiotic-free (ABF) poultry is growing fast, and what was once considered a passing trend has become a well-established, health-conscious requirement for consumers worldwide.

However, ABF production presents challenges for meat producers, who are taking distinct approaches to its development, with different results.

While some producers still have difficulties in controlling health challenges, others have had success, due to improvements in housing and changes in feeding, management and health programs. The various approaches to ABF production can be grouped as:

1.  Managing nutrient intake

A common misconception in ABF production is to focus only on controlling intestinal diseases. These are the main health issues when any ABF program is implemented but the reality is that they are the consequences, not the causes, of the real problem.

Excess nutrients, especially protein and fat, may not be well digested and absorbed by the bird. Undigested feed increases microbial proliferation in the ceca, leading to potential infections. Appropriate digestibility is key to broilers' overall health and can help control microbes and resultant diseases.

Factors such as a balanced diet and sufficient water consumption are essential to improve digestibility. A pH between 5 and 7 and water temperature between 16C and 25C are ideal conditions to support the activity of most enzymes.

To further strengthen the effect of endogenous enzymes, additives such as proteases, phytases and xylanases can be added to feed. Moreover, to guarantee acidic crop, organic acids are a good option.

Feed management plays an essential role too. Grain damage and conditions that could increase mold and insect spoilage must be minimized and, at the same time, fat storage conditions should be frequently revised in order to control rancidity within the feed mill.

2.  Modulate microbiome

The gut microbiome plays an important role in supporting the immune system. In addition to a balanced diet and good housing conditions, feed additives and minerals can help maintain a healthy microbiome in all gut regions.

For example, additives, such as probiotics, can introduce desirable live microorganisms in the gut and, with the support of prebiotics, can help maintain a healthy gut balance.

Enzymes are good options for eliminating the anti-nutritional effects of water-soluble polysaccharides, while organic acids cause the inhibition of bacterial growth, and essential oils can support gut microbiome balance, stimulate digestive enzyme production and the immune system.

Regardless of the above single benefits, it is extremely important to understand that only appropriate testing and use can guarantee success. One solution working in one flock may not work in the next as the environment may have changed, e.g. the feed raw material properties.

3.  Improve house environment and biosecurity

Proper environmental conditions are the foundations of effective ABF poultry production. Optimum temperature, air velocity, and relative humidity according to the age, phase of production and size of the birds should be considered.

Environmental stress, due to heat, cold, very dry or very humid air could affect feed intake and intestinal motility, causing reduced digestibility.

Lighting programs may also affect feed intake, motility and digestion. Light intensities lower than 10 lux and 4 to 6 hours of total darkness per day improve feed conversion ratios, indicating slower feed intake and better digestibility.

Good house ventilation is key for ABF programs to maintain litter moisture below 30 percent, and to minimize condensation and caking.

Flock management is also important to allow the flock more space during the brooding period. This helps avoid excessive stress.

4.  Maintain flock health

Preventing coccidiosis and necrotic enteritis are normally the main concerns during ABF production.

In cases where no anti-coccidial medications are allowed, coccidiosis vaccines and litter management are the principal controls. Cocci vaccination for broilers has been applied in traditional poultry production systems and new ABF programs for years, in many countries.

Furthermore, the appropriate feeding regime and use of feed additives, such as the eubiotics category, may help maintain healthy microbiome adding to flock health.

Control of other intestinal parasites, worms and poultry diseases that affect intestines and immunity is also necessary.

Practices including bio-exclusion, limiting visitors, vehicles and equipment that visit other poultry farms, and bio-containment, isolating the houses, controlling insects, rodents and entry of wild birds and other animals to the houses, can help prevent new infections.

5.  Improve breeder health

Broiler breeder nutrition is fundamental for adequate development of their progeny.

Embryo development is totally-dependent upon egg nutrients deposited by the hen, and specific nutrients, such as vitamin D, trace minerals, carotenoids, and fatty acids, are key in immunity and gut development.

Hens also affect embryo nutrition and development via eggshell properties, including porosity and thickness, which determine conductance. Eggshell conductance dictates the capacity of eggs to exchange gases and water vapor, consequently affecting embryo yolk and general nutrient utilization.

These physical factors, especially the capacity to obtain sufficient oxygen, limit the type of metabolism, rates of tissue development, and embryo growth.

This is more important during the last three or four days prior to hatch, when development of many tissues, including the gastrointestinal tract, bones and muscles, is fastest.

As breeders can transfer intestinal microbes and immunity to their progeny, companies practicing ABF production should make sure that intestinal health is adequate in breeders and that vaccination programs are effective.

To emphasize, additives are only part of the solution and need to be integrated in a wider approach. The holistic approach must take into account proper vaccination, farm management, biosecurity and last but not least nutrition. Animal nutrition has been a bit overlooked in recent official discussions, reports or congresses dealing with AMR and the critical need of reducing antibiotic usage, especially when it comes to optimum early life nutrition, nutrient digestibility or dietary protein level in today's intensive livestock productions. (Source: Feedinfo News Service; dated 24/01/2017).



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Article made possible through the contribution of DSM