Antibiotics used as growth promoters in feed (AGPs) have been banned in the European Union for more than a decade. But how did the European livestock industry react and can plant extracts be considered as viable alternatives? A short review on these developments and what we have learned from it.
Antibiotics were discovered in the 1920s, and soon after showed to be a major medical milestone that multiplied the possibilities to treat diseases in both humans and animals. After World War II, the widespread introduction of antibiotics improved human life expectancy by more than ten years (more than any other medical treatment) and eradicated major diseases: tuberculosis, plague and leprosy, just to name a few. With respect to livestock, the use of antibiotics at low-dosages dates back to Europe in the 1950s. During these periods, they showed to be very efficient as growth promoters, especially to increase weight gain, regulate gut flora and increase productivity. However, the excessive use of antibiotics led to the development of antibiotic resistance, a serious risk for animal and human health. Resistance is developed as a reaction of the bacteria to defend itself and offer resistance to antibiotics through mutation. Then they become more tolerant and more resistant to drugs. The phenomenon and its implication were scientifically proven in the 1980s and represent today a global public health concern. The facts say it all: Drug-resistant bacteria are responsible for about 25.000 human deaths annually. On the animal side, common bacteria causing diarrhoea or respiratory infections in several animal species have become more resistant to commonly used veterinary antimicrobials. And regarding the economical side of it: direct and indirect costs and productivity losses related to this phenomenon reach € 1.5 billion.
Antibiotic resistance is therefore a major public issue drawing attention from the health authorities, the food production and distribution chain, and the consumers. Several consumers associations, for instance, are asking for a prudential use of antibiotics, claiming their right to healthy and safe food. Euro Coop (European Community of Consumers) has been calling for proper and limited use of antibiotics, for more transparency and responsibility in the food processing. Other influent consumers’ associations like the French “UFC – Que choisir” are monitoring the issue on a regular basis, through surveys. But not only in Europe. In a press conference held in September 2014 in Washington, US company Perdue announced that it ceased using any sort antibiotics for growth promotion or for disease preventions. “When we started hearing from consumers that they were becoming concerned about the amount of antibiotics used to raise chickens they were buying, we were listening” said Jim Perdue, Chairman. Carrefour – one of the major global supermarket chains – developed in 2011 an offer of chickens raised without antibiotics, in partnership with 150 producers. Antibiotics were replaced by natural plant-based alternatives. In September 2013 the chain announced that their antibiotic-free chickens’ sales were four times superior to their objectives, in spite of a higher price for the consumer.
By way of consequence, only a limited number of such feed additives were still allowed after 1999 in the European Union. Only four antibiotics remain allowed: flavomycin, monensin, salinomycin and avilamycin. This year, 11 growth promoters were banned in Europe (avilamycine, avoparcine, zinc bacitracine, flavophospholipol, monensin, tylosine, salinomycine, spiramycine, virginiamycine, carbadox, olaquindox).
In 2001, the use of AGP dropped by 50% in the European continent (from 1.600 T in 1997 to 800 T in 2001).
The use of veterinary prescribed antibiotics increased, though, in a sort of compensation phenomenon. The total ban of antibiotics used as growth promoters for pigs and poultry has been enforced in 2006. In 2011, the European Commission put in place a 5-year action plan to fight against antibiotic resistance through better monitoring, the promotion of the proper utilisation of antibiotics and a more targeted distribution. This strategy intends to develop the rational use of antibiotics instead of the current mass strategy. Recourse to antibiotics must be prudential and targeted, with the prescription and administration of no more than the quantities strictly necessary to meet the therapeutic need: the objective is quantitative and qualitative. A number of alternatives have been considered over the years, as part of a quite comprehensive review of some farming approaches, namely: organic acids, probiotics and prebiotics, enzyme, clays and minerals, trace elements, botanicals.
The ESVAC (European Surveillance of Veterinary Antimicrobial Consumption) project collects information on how antimicrobial medicines are used in animals across the European Union. Its fourth report published in 2014 notes a decline in sales in a large majority of countries (Table 1). The explaining causes are the development of responsible-use campaigns, changes in animal demographics, restrictions of use and increased awareness of the threat of antimicrobial resistance. For three countries, we will delve a bit deeper.
Sweden: From ban to opportunity
The use of AB was prohibited in Sweden in 1986, mainly for ethical reasons: enhance the breeding practices and hygiene and improve the animal conditions. The first years were difficult (higher mortality and lower productivity) especially on farms were hygiene and nutrition were not well mastered. By 1999, the antibiotics sales had dropped, representing only 30% of the amounts sold in 1986. Today, Swedish farmers are using the smallest amount of antibiotics in the EU, according to the European Medicines Agency. Antibiotics are only used for medical reasons and with a veterinary prescription; farmers consider that the total ban was eventually an opportunity for them to breed healthier and more productive animals.
France: A positive tendency seen
With 103 mg / PCU, France is within the European average (111 mg / PCU). In other terms, the exposition of animal to any kind of antibiotics (number and duration of the treatments) has decreased by 22% between 2010 and 2012, a tendency that has to be confirmed in the coming years. To do so, the French Ecoantibio plan was launched in November 2011 by the Ministry of Agriculture, with two objectives: Firstly, to reduce the contribution to bacterial resistance provoked by antibiotics used in veterinary medicine. And secondly, to preserve the veterinary medicine therapeutic arsenal on a sustainable basis, especially given that the prospects for development of new antibiotics are limited It aims to achieve a reduction of 25% in use over five years by developing alternatives capable of protecting animal health while avoiding recourse to antibiotics.
Netherlands: Impressive results
The Netherlands reduced the use of antibiotics by 50% in 3 years. Prior to 2008, the Netherlands was amongst the most important consumer of antibiotics. The Ministries of Health & Agriculture defined an objective of 20% reduction in 2011 vs 2009, then 50% in 2013 and 70% in 2015. The results were particularly good in pigs and poultry and were facilitated by the efforts of the major production sectors and veterinarians, who collaborated with the government to set these reduction targets for the use of antimicrobial
agents in animal production. The main key to success proved to be the strict monitoring of the veterinary antibiotics consumption that was set up in the farms: farmers and veterinarians have to declare their use of antibiotics and if an overflow is found, an improvement plan is set up together with the veterinarian. Critical antibiotics use is thus well framed in the Netherlands. A report from the Ministry of Economic Affairs, Agriculture and Innovation7 pointed out the responsible antibiotics use of the industry: the pig production quality system, for instance, has voluntarily ceased the use of cephalosporins of 3rd and 4th generation and fluoroquinolones in 2012. The milk industry also stopped the use of cephalosporins and this treatment has now almost disappeared from the Dutch farms.
Confronted with these regulatory adjustments and the food chain pressure, the animal production sectors has no choice but to improve their health and nutrition approaches. Part of the answer may be found in the vegetal kingdom, with the several benefits of plants in animal feed. Feed additives based on plant extracts aim at improving the animal health and the qualities of its feed: added in small quantities to the raw materials, they preserve the animal health, improve the rations efficiency, reduce the production costs, enhance the product features and reduce the environmental footprint. Today, several scientific researches define precisely the plants and plant extracts’ feed additives benefits. Their compounds are now well characterised and their ROI measurable.
Certain citrus extracts develop a prebiotic effect by promoting the growth of lactic flora (such as Lactobacillus acidophilus).
Prebiotic effect and gut flora control
Certain citrus extracts develop a prebiotic effect by promoting the growth of lactic flora (such as Lactobacillus acidophilus). They also enable a better flora control by inhibiting bacteria and pathogens, especially in monogastric species. At the same time, certain citrus extracts have shown interesting results, when compared to positive controls as Olaquindox, Avilamycin and an association of Penicillin and Aureomycin, with an improvement of the average daily gain in several species (between 3 and 15%) and the feed conversion ratio (-7% to -11%). The results of a trial, conducted with a citrus extract feed additive registered in the EU can be seen in Figure 1.
Balancing the antioxidant status
Natural antioxidants based on certain grape extract protect animals against free radicals, responsible of oxidative stress. They can be standardised in highly-concentrate actives polyphenols, anthocyanins and proanthocyanidins and can then diversify the antioxidants
intake in the animal feed, whatever the species. The main benefits of grape extracts feed additives are to: improve feed efficiency, especially starter feed, improve the animal immunity by fighting against free radicals and regenerate the effect of vitamin E and overcome its lack of bioavailability. Grape extract supports and regenerates vitamin E and antioxidants enzymes, especially in young animals which have an important need of antioxidants but hardly assimilate vitamin E. They also play a beneficial role in reproduction, as grape extracts allow a significant improvement of semen quality thanks to a direct effect on the seminal plasma antioxidant capacity.
Improving meat quality
Grape extracts also seem to improve meat quality. They maintain PUFA, prevent meat rancidity, stabilise the red colour and improve meat retention, leading to a finished product more flavouring and juicy. A comparative trial (done by Nor-Feed Sud) conducted with pigs showed that meat coming from the group of animals fed with a supplement of grape extracts did not show drip loss in the packaging after several days, keeping thus a fresher and tastier aspect for the consumers.
Saponins are secondary metabolites, with numerous properties described in the literature: antibacterial, anti-fungal, anti-inflammatory, antiviral, ammonia management, optimisation of zootechnical performances, odour control, stimulation of the immune system, etc. More than 10.000 saponins have been identified in 2000 species of plants, with specific activities. Figure 2 describes the positive activity of saponins on micro-organisms containing sterols into the membrane, such as rumen protozoa and Eimeria sp, leading to the disruption of eukaryotic cell membranes. Saponins based feed additives play a key role. They can act as a palatability enhancer for all animal species, improve water quality and mitigate environmental impacts (aquaculture), reduce stillborns and increase weight gain at weaning and stabilize physiological digestion (coccidiosis risk). A trial was conducted with a feed additive based on saponins plants. A comparative study made in France on broilers highlighted the efficiency of saponins vs. coccidiostats (narasine, nicarbazine and salinomycine) to improve the animal performance parameters. The results were slightly better in the saponins’ group (Figure 3).
[The article was featured in AllAboutFeed magazine no. 1 – 2015 – for more AllAboutFeed articles see the digital magazines]