As antibiotics are increasingly on their way out of intensive animal production, it is good to take a look at different options. The ‘seed, feed and weed’ approach, developed at the University of Georgia, USA, paves the way for a healthy gut for pigs.
Antibiotics have been good for the world; since the introduction of penicillin and subsequent antibiotics early in the last century, antibiotics have allowed people to live safer, healthier lives. Antibiotics have also enabled intensive animal production, allowing farmers and producers to significantly increase their production economically and feed a rapidly growing population.
Initially, farmers used antibiotics to lower mortalities and address disease, but it quickly became apparent how much faster animals grew – even with less feed – when antibiotics were continuously used. Veterinarians pointed out that this improved animal performance was due to more efficient absorption of nutrients, as a result of better intestinal health.
The perceived benefits of antibiotics continued until the first resistance appeared. Bacteria are agile at adapting to their environment quickly, and their ability to resist the effect of antibiotic drugs has grown with each generation.
Meat specifically marketed as being raised free from antibiotics. Photo: Alamy
What are the options?
A global ban on antibiotics in animal feed may be imminent. In preparation for that possibility, producers are seeking alternatives to current methods. Some alternative options for farmers and producers include:
1. Reducing reliance on antibiotics;
2. Implementing gut health programmes;
3. Taking a holistic approach and reforming the entire system
To follow the first suggestion is to take the path of least resistance and effort. It focusses on supporting the animal’s immune and digestive system to reduce reliance on antibiotics. It has been observed that removing antibiotics from the weanling’s diet has clear consequences, including increasing disease problems and decreasing performance. In the diets of growing-finishing pigs, problems are not as readily observed and, as such, may not pose such a drastic risk for producers.
The second option is more involved and requires that the producer replace antibiotics with alternatives, which include mannan-rich fractions, live yeast cultures, acidifiers, prebiotics, probiotics and more. Many farmers and producers the world over have done this successfully, achieving the same results they saw with antibiotics across an array of species. With food retailers like Panera and Chipotle boasting of their antibiotic-free meats, it is clear that producers are able to rise to the occasion and produce the results needed through different means; they no longer require antibiotics as growth promoters in their herds.
What this has demonstrated is that being successful in the future will involve more than simply replacing one input for another – the programme must involve a holistic approach, embracing a ‘root-to-branch’ methodology, in order to succeed. All involved in the production process, from nutritionists and veterinarians to feed suppliers and managers, must work as one cohesive unit. No longer are the baseline metrics of feed efficiency and liveability the only measures of success: farmers must look beyond these measurements to productivity and must also consider such factors as animal welfare, human safety and consumer acceptability. When considering what type of feed alternative to use, producers would do well to consider the mode of action, how the new supplement can be supplied (will it survive temperature treating/pelleting?) and the animal’s response to this new programme.
Along the lines of this root-to-branch scenario is a programme called ‘Seed, Feed and Weed’, designed by Dr Steve Collett of the University of Georgia, USA. An alternative approach to gut heath, it is defined as follows: seed the gut with the right bacteria, then feed the good bacteria to maintain the proper environment for them to survive, and, finally, weed out the unfavourable organisms. Producers should also consider mycotoxins as a concern and can help their animals get the right start through proper nucleotide supplementation.
It is recommended that one of the primary components in a pig’s diet should be mannose-rich fractions (MRF). Naturally occurring as a component of yeast cell walls, MRF are indigestible by animals and, as such, are a key component of the ‘weed’ portion of the programme. Pathogenic bacteria seek something to bind to in order to colonise, and MRF act as an alternative to the intestinal tract itself. As the MRF pass through the animal’s system, so do the pathogenic bacteria that are bound to them.
Figure 1 – Cefotaxime resistance pattern of ESBL producing E. coli in the presence of increasing concentration of antibiotic and MRF.
Modulating immune response
MRF also modulate immune response, acting as one more component to a healthy animal without the need for antibiotics. Organic trace minerals also play a key role in feeding the gut and guarding the animal’s immune system against disease.
Evidence of the effect MRF can have in swine is demonstrated in the research illustrated below. In this trial, it was observed that exposure to MRF led to a reduction in microbial growth of extended-spectrum β-lactamase, also known as ESBL, producing E. coli that were resistant to ampicillin and cefotaxime antibiotics. Also, the rate of microbial growth in the presence of both MRF and antibiotics was reduced, further demonstrating that the inclusion of MRF in the production animal’s diet can reduce the potential for this regimen to further exacerbate the issue of antimicrobial resistance.
Taking this ‘Seed, Feed and Weed’ concept a step further, farmers should also consider what their breeding stock consume. Epigenetics research, both in animals and humans, describes the importance of the influence of a mother’s diet on her offspring, including colostrum production. Establishing strong piglet immunity starts with the sow.
Animal nutrition must evolve
In the fight against antimicrobial resistance, farmers and producers are being forced to consider the need to adapt their methods to achieve optimal results without reliance on antibiotics. In order to do this, animal nutrition must evolve beyond simply delivering the right nutrients to also becoming a tool for fostering the right microflora and, in turn, creating a probiotic environment that allows for optimal intestinal health, improved nutritional uptake and reduced disease outbreaks.
It is possible to feed the world without antibiotics. From an agricultural perspective, the main challenge is changing the mindset. This is not a ‘one size fits all’ concept; each farm needs to customise the ‘Seed, Feed and Weed’ approach to best meet the needs of its animals. This will allow for better decision-making, and – when combined with nutritional or veterinary guidance – the opportunities for improved performance are real, allowing antibiotics to once again be solely used to treat animals suffering from disease.