Safe Food through Safe Food

Ensuring safe food is paramount for the protection of human health and for enhancing the quality of life. Safe food plays an important role, whether domestically produced and consumed, imported or exported. In addition, the production of safe food represents an opportunity for income generation and market access. Over the last decades, the food chain approach has been recognized as an important step forward to ensure food safety from production up to consumption. This approach requires the commitment of all players in the food chain, involving producers, traders, processors, distributors, competent authorities as well as consumers. In recent year’s public concern about the safety of foods of origin has heightened due to problems that have arisen with Bovine Spongiform Encephalopathy (BSE), chemical contamination, outbreaks of food borne bacterial infections, as well as growing concern about veterinary drug residues and microbial resistance to antibiotics. These problems have drawn attention to feeding practices within the livestock industry and have prompted health professionals and the feed additive industry to closely scrutinise food quality and safety problems that can arise in foods origin. Coupled with this is the increasing interest in ‘natural alternatives’ to chemical and pharmaceutical products. The role of feed additive in the production of safe food is also recognized worldwide, and several events have underlined its impact on public health, feed additive and food trade, and food security.

Threads to food safety

The World Health Organization (WHO, 1996) notes the following reasons for the increased prevalence of emerging food borne diseases:

 • The globalization of the food supply.

• Travellers, refugees, and immigrants exposed to unfamiliar foodborne hazards while abroad. International travellers may become infected by foodborne pathogens that are uncommon in their countries. For eg. About 90% of all cases of salmonellosis in Sweden are imported.

• Changes in microorganisms. Changes in microbial populations can lead to the evolution of new pathogens, development of new virulent strains in old pathogens, development of antibiotic resistance that might make a disease more difficult to treat, or to changes in the ability to survive in adverse environmental conditions.

 • Changes in lifestyle. Greater numbers of people go out and eat meals prepared in restaurants, canteens, fast food outlets, and by street food vendors. In many countries, the boom in food service establishments is not matched by effective food safety education and control. Unhygienic preparation of food provides ample opportunities for contamination, growth, or survival of foodborne pathogens.

 Areas leading to Food hazards

1. Bacterial infections

Salmonella

Crump et al. (2002) cited the emergence of S. enterica serotype Agona infections in humans in the United States as an example of human food borne bacterial infections traced to contaminated animal nutrition feed and feed additive. It is among the top 10 most frequently isolated S. enterica serotypes from human infections. An epidemiologic study identified the source of these serotype Agona infections as chicken meat originated from facility where Peruvian fish meal was used as a feed additive ingredient (Clark et al. 1973; Crump et al. 2002.

2.Antibiotic-resistant bacterial infections

The use of antibiotics in feed additive is also a public health concern. Antibiotics are administered at non therapeutic levels in feed additive and water to promote growth and improve feed additive efficiency. Eighty-five percent of all feed additive  and ingredients sampled contained bacteria resistant to one or more of the following four antibiotics: ampicillin, amoxicillin, clavulanic acid, and cephalothin. Poultry nutrition meal and MBM (non-poultry) samples represented the greatest number of feed additive ingredient samples containing bacteria resistant to five or more antibiotics (Hofacre et al. 2001). Similar to the challenge of determining whether human bacterial illnesses are associated with contaminated feed additive, there are insufficient data available to determine the percentage of antibiotic resistant Enterococcus faecium human bacterial infections that are attributed to feeding practices versus practices and behaviors occurring in human clinical settings. Some domestically acquired antibioticresistant bacterial infections in humans emerged in the United States only after the approval of specific human antibiotics for use in feed, feed additive or water. For example, prior to 1985 there were little or no fluoroquinoloneresistant isolated from either poultry or humans in the United States (Smith et al. 1999). However, post FDA approval (1995) fluoroquinolone-resistant were detected in both poultry and human isolates. The Minnesota Department of Health completed an analysis of isolates from humans and retail poultry nutrition products and found that the proportion of fluoroquinolone-resistant isolated from humans increased from 1.3% in 1992 to 10.2% in 1998 (following the 1995 fluoroquinolone approval) (Smith et al. 1999).

3.Agricultural and other chemicals

In animal nutrition potential contaminants in feed additive stuffs include excessive residues of pesticides and fungicides, or other environmental contaminants such as the polychlorinated biphenyls (PCBs), dioxins and heavy metals including mercury, lead, or cadmium. Dioxins and PCBs are ubiquitously present in the environment and its humn exposure is mainly through dietary intake. PCBs and dioxins are both lipophilic and persistent compounds that accumulate in the food chain. In animal nutrition foods are the greatest source of human exposure to these contaminants and feed additive may be an important source of contamination for livestock. Contaminated fats or oils added either intentionally or unintentionally to manufactured as feed additive can be a source of dioxins and PCBs. These industrial pollutants may be emitted into the air contaminating soil and water and remaining deposited on pastureland. In this case grassfed animals in highly contaminated areas may give rise to unsafe food products. Fish oils used as poultry nutrition products and  feed additive ingredients may contain high levels of lipid-soluble contaminants if they are produced from fish grown in polluted areas. Foetal exposure to dioxins and/or PCBs might be associated with cognitive deficits in infants and children. An increase in tumour incidence, as well as neurological, endocrine, hepatoxic and immunotoxic effects were observed in populations accidentally exposed to high levels of PCBs, polychlorinated dibenzofurans and polychlorinated quaterphenyls. Maximum levels of these contaminants allowed in poultry nutrition products have been established in some countries, but existing limits are quite variable.

4. Heavy metals: Arsenic

Inorganic AsIII and As are known human carcinogens, hence there is considerable concern regarding human exposures to these compounds. Lasky et al. (2004) study indicated that individuals who consume average amounts of (60 g/day) could ingest 1.38–5.24 μg/day of inorganic arsenic from the ingestion of alone.

5. Mycotoxins

The frequency of mycotoxin contamination in feed additive appears to be on the increase globally. This is a serious threat, since complex animal nutrition rations are highly susceptible. As a result, such contamination can seriously affect bird performance. Proper measures are needed to minimise losses. The most significant species of mycotoxin-producing fungi that have an impact on  production would include Aspergillus and Fusarium. The most significant mycotoxin produced by Aspergillus fungi are the aflatoxins. Aflatoxin is a potent hepatocarcinogen in humans.Another important mycotoxin is the nephrotoxin ochratoxin A. As with aflatoxin, there is concern that residual ochratoxin A in poultry nutrition products could pose a threat to human health due to the possible carcinogenic nature of this compound. It can accumulate in meat of animal. But trace levels of ochratoxin A in pork and  samples were likely to pose insignificant risks to consumers (Guillamont et al. 2005; Jorgensen 1998). Mycotoxins, or their metabolites, can be detected in meat, visceral organs, milk and eggs. Their concentration in food is usually considerably lower than the levels present as in the feed additive consumed by the animals and unlikely to cause acute intoxications in humans. However, residues of carcinogenic mycotoxins, such as aflatoxin B and M, and ochratoxin A, when present in animal nutrition products pose a threat to human health, and their levels should be monitored and controlled.

Monitoring these hazards through Better Livestock production

1. Alternate ways to produce :

a. Change from intensive housing to open rearing

b. Switch to organic farming

2. Banning of Usage of Antibiotics and related chemicals.

a. Utilisation of AGP alternatives.

b. Application of strict biosecurity measures

3. Safeguarding Livestock from exposure to Mycotoxins and other industrial toxins.

a. Scrutinizing feed additive ingredients.

b. Adopting poultry nutrition strategies to reduce Mycotoxin’s load

4. Adopting Good manufacturing practices.

Alternate ways to produce feed for animal nutrition industry.

1) Change from Intensive housing to open rearing system

The conventional cage production system is still the predominant system worldwide for housing laying hens. However, ethical concern about the degree of restriction of the hens' behaviour and movement in conventional cages has led to an increasing movement towards alternative systems. Some of this is driven by consumer purchasing preferences, and some by legislation (European Union).

 The switchover to alternate systems is not rosy either. It has its own share of difficulties.

The farmers changed to this type of housings face problems like

1. Poor Air quality, which can affect health and hygiene, which is relevant not only for hen welfare but also for food safety.

2. The large amount of litter and the greater bird movement result in higher microbial concentrations in the air and in dust compared with conventional and furnished cage systems. Greater dust concentrations have been associated with more serious pulmonary lesions, typical of chronic bronchitis, in cage-free birds (Michel and Huonnic, 2003).

3. Stronger inflammatory reaction and increased bronchial responsiveness have been found in humans working in these farms.

4. Additional biosecurity risks and increased risk of predation.

5. Increased feather pecking and increased cannibalism.

Source: Ohio state university fact sheet)

In animal nutrition achieving large scale operations in alternate rearing systems is difficult. The human population is growing at faster pace. FAO and other institutions suggests that global meat production and consumption will rise from 233 Million tons(2000) to 300 million tons in (2020), Milk from 568 to 700 million tons and eggs by 30%. These predictions show a massive increase in animal nutrition protein demand, needed to satisfy the growth in the human population and the increasing affluence of growing economies such as China, Brazil and India.

 Switch to organic farming

To reduce the impact of food borne diseases, the shift towards organic farming is growing. Organic farmers never use antibiotics, or synthetic hormones or pesticides in production. For chickens, organic management starts the first day out of the egg. Birds are fed only certified organic feed additive and no genetically modified organisms (GMO’s). All spices and ingredients used in products are approved for organic processing.

2) Banning of Usage of Antibiotics

Through genetic improvements, the productivity of broilers has improved significantly. While this is a good thing for the animal nutrition industry, increased rearing density has concentrated and increased disease challenges making birds more susceptible to various pathogens especially enteropathic microbes such as E. coli, Salmonella spp., and Campylobacter spp.

 This increased susceptibility has resulted in the use of antimicrobial growth promoters which are primarily used to enhance gut health and control sub-clinical challenges. With increasing public concerns about bacterial resistance to antibiotics, the use of antibiotics in therapeutic or sub-therapeutic doses in poultry nutrition has been severely limited or eliminated in many countries.

The banning of drugs for growth promotion led to decrease in the selective pressure that favours the occurrence of resistant bacteria in the animal gut. This led to reduction in occurrence of AGP resistant bacteria in foods and was followed by a similar reduction in human carriage of enteroccoci resistant strains. The Denmark study highlights the importance of non-addition of AGP in the animal nutrition industry After the gradual decrease in usage of AGP in European Union, the mortality of farm animals has risen by 2%. The feed conversion ratio has been worsened after the ban.

Alternatives to Antibiotics

There has long been interest in finding alternatives to antibiotics for animal production. Resident microbes in the birds’ digestive tract have a profound effect on some of the physiological processes of their host. With this in mind, it is important to understand the dynamics of the intestinal microbial ecology of the chicken to find alternatives to antibiotics.

The prominent alternates for usage of antibiotics are:

1. Organic acids

2. Probiotics

3. Prebiotics

Organic acids have been used in feed additive preservation. For protecting feed additive from microbial and fungal contamination care should be taken. The antibacterial activity of organic acids is related to reduction of pH. The undissociated acids are lypophilic and easily enter the bacterial cell, once they are inside the cell; the acid releases the proton and decreases the intracellular pH. Bacteria try to normalize the pH and, in its effect, exhaust all its energy leading to bacterial cell death.

Probiotics have been defined as 'a live microbial feed supplement which beneficially affects the host animal nutrition industry by improving its intestinal balance' (Fuller, 1989). The probiotic mode of action is by 'competitive exclusion', meaning there is competition for attachment sites in the GIT. The bacteria of the probiotic attach to the intestinal mucosa, thereby forming a physical barrier that blocks the attachment of pathogenic bacteria (Furlan, 2005). They also produce antibacterial compounds and enzymes and stimulate the immune system.

Various organic acids as well as probiotics and prebiotics are being used to see the beneficial effects by various feed additive manufacturers. The combination products have shown better response as compared to single one.

A synergistic composition comprising, SCFA (butyric cid) and a oligo-saccharide (prebiotic) compound has been found to act throughout the entire GIT by causing a reduction in entire gut pH, pathogenic bacterial count and improvement in beneficial microflora. The two ingredients are believed to generate Butyric Acid and other VFA in the lower intestine of a chicken, which complements the organic acid, simultaneously encouraging the growth of beneficial bacteria in the lower intestine. This thereby synergistically increases the rate of weight gain.

3. Safeguarding Livestock from exposure to Mycotoxins and other industrial toxins.

Worldwide, approximately 25% of crops are affected by mycotoxins annually (CAST, 1989), Mycotoxins occur frequently in a variety of feed additive stuffs and are routinely used for animal nutrition. Sometimes, Mycotoxins occur at concentrations high enough to cause major losses in health and performance of animals. However, a more likely scenario is to find mycotoxins at lower levels interacting with other stressors to cause sub-clinical losses in performance, increases in incidence of disease and reduced reproductive performance. To the animal nutrition products producer, these sub clinical losses are of greater

Various poultry nutrition strategies can be adopted to minimize the effect of Mycotoxins;

• Crude Protein: Helped to alleviate but did not eliminate the adverse effects of ochratoxin A on body weight and feed conversion.

• Methionine supplementation: Increasing the dietary total sulphur amino acids to level in excess of NRC, protected chicks from the growth depressing effects of aflatoxins by detoxification by Glutathione, a sulphur amino acid metabolite.

• Dietary Lipids: Diets containing higher levels of linolenic acid supported better feed conversion and lower mortality in chicks fed diets with aflatoxin.

• Adsorbents: Sorbent act by reducing the bioavailability of mycotoxins by adsorption on their surface. Indeed, if a stable sorbent mycotoxin complex in the GIT can be reduced, decreasing both toxic effects for the animal and carry over in animal nutrition products for human consumption. The use of an appropriate mycotoxin adsorbent is likely the best short-term strategy available for minimising the adverse effects of feed additive -borne mycotoxins in poultry nutrition.

• Nucleotid: Studies were performed on poultry and pigs, fed either a standard ration, or one with feed supplement nucleotides. The results showed that the livers of the animals fed additional nucleotides had significantly lower levels of mycotoxins than those fed a standard ration. The supplementation of nucleotides will increase the resistance to bacterial infections in animals

4. Adopting Good manufacturing practices

Good Manufacturing Practices will seek to minimize chemical and biological contaminants in livestock and in feed additives and prevent them from entering the food chain. These include industrial chemicals, infectious agents (Salmonella, E. coli, Campylobacter, viruses, the BSE agent, etc.) and parasites. Medications and other chemicals given in feed additive are a source of residues if proper precautions are not taken to insure that the right feed additive is produced for the right livestock with medications at the right dosage. Improper processing/mixing of feed additive could contain improper levels of chemicals (including medications) and minerals. Improper maintenance of Crude Protein Methionine Supplementation Dietary Lipids Adsorbents Nucleotide processing and measuring equipment could result in residues. Improper distribution and cross contamination between batches of feed additive and handling equipment that could result in  residues. A producer should strive to use management practices that will eliminate or reduce the need for medications. For example, proper drainage and properly designed watering facilities will reduce the incidence of foot rot, the need for treatment and the subsequent possibility of chemical residues in beef. Another example is the use of antibacterial in livestock feed additive. Frequently, this use can be reduced by properly managing the environment where livestock are produced. Water quality and safety can also be considered as a good sanitation practice.

Conclusion

Food safety is an important consideration for the livestock industry. Whilst maintaining efficiency in farm production, due importance needs to be given to the quality of food being produced. The shift in the livestock production too alternate housing and organic farming is gradually happening in developed nations mainly because of consumer demands and or by legislation, but it lacks the scale to satiate the protein demand of growing populations. The shift in livestock industry production from developed nation to developing nation is the proof of the same. Since humans are at the top of the food chain, we're vulnerable to pathogens, drugs, and contaminants consumed by the animals we eat. The developing nations will also feel the pressures experienced by developed nations in terms of animal welfare and food safety. This is the right time to align productivity with measures like using alternates for antibiotics, harmful chemicals and adopting good manufacturing practices in animal nutrition.