In North America, the majority of producers have not yet experienced raising pigs without antibiotics, and therefore such a decision can be overwhelming. For some producers that already took this road, the transition has brought positive remarks, while for others, economic losses were demotivating. At BIOMIN, we have worked closely alongside the swine industry globally for decades to achieve effective, science-based non-antibiotic solutions.
In general, farms with a good health status have had a smoother transition compared to farms with a history of enteric and respiratory problems. Most often, these farms were located distant from other farms, creating a higher firewall for pathogens—signaling that the foundation of an ABF production system is prevention. Moreover, rigorous hygiene and biosecurity practices have to be accomplished. Revisiting the basis will provide the groundwork to implement strategies that can contribute to reduce stress and enhance growth. In particular, we examine 5 factors: water quality, mycotoxins, weaning age, prevention and performance.
1) Water quality
Water quality is commonly ignored, although water intake is two to three times greater than feed intake. Water analysis is required to understand the potential hazards present. Water pipelines can allow the growth of yeast, molds, and bacteria. A practice that is highly recommended is to clean the water pipelines after barn closeout. In poultry, the use of organic acid in the water has helped to improve water sanitation. However, cleanness of water pipelines are essential to successfully see the benefit of organic acid in the water.
Mycotoxins are toxic metabolites produced by fungi. Mycotoxins are typically found in the corn, corn distiller‘s dried grains with solubles (DDGS) and soybean meal, etc. They might be also present in vegetable oil such as corn and soy oil. Feed contaminated with mycotoxins negatively affect the health of pigs, especially young pigs.
Mycotoxins contribute to intensify enteric and respiratory infections. For instance, deoxynivalenol disrupts epithelial cell integrity allowing the invasion of pathogenic bacteria (Vandenbroucke et al. 2011). In addition, mycotoxins suppress the immune system. Mycotoxins can reduce the efficacy of vaccines, a foundation in an ABF program, and can reduce the ability of a pig to overcome a respiratory problem.
A basic knowledge in mycotoxins types and counteractive actions can help you to understand the risk. A proper mycotoxin risk management can significantly help to prevent disease episodes, which is why it is worthwhile to consider the following:
- Proper feed storage. Reduce moisture infiltration and mold. Allow the bins to empty more frequently to reduce the chance of mold build-up.
- Regular monitoring of feed. It is recommended to regularly test raw commodities and finished feeds for mycotoxin contamination using proper sampling methods.
- Biotransformation. This represents a cutting-edge approach which converts toxins into non-hazardous metabolites. The safety and effectiveness of said method are recognized in jurisdictions such as the European Union.
3) Weaning age
The gastrointestinal tract (GIT) absorbs nutrients and minimizes the entrance of pathogens. A healthy and capable GIT will ensure a successful growing period. However, interruption in the development of the GIT occurs during weaning and can bring long-term consequences. A functional GIT is able to produce a sufficient activation of the immune system without reaching over-stimulation. An excess in the activation of the immune system can be energetically very costly to the young pigs. It is understood that as a pig ages, the immune cells conforming the mucosal immune system can response more rapidly to the presence of pathogens. Therefore, the immune system is more effective to control the spread of an infection.
McLamb et al. (2013) demonstrated that pigs weaned at 16 and 18 days of age, and later inoculated with E. coli on day 35 of age, had more clinical signs of E. coli infection compared to pigs weaned at day 20 of age and also inoculated with E. coli. Feces of pigs weaned at day 16 were 60% softer compared to the feces of pigs weaned at day 20, and feces of pigs weaned at day 18 were 25% softer compared to pigs weaned at day 20. In addition, increasing the weaning age reduce mortality from post-weaning to market. Main et al. (2004) reported 6.8% and 3.7% closeout mortality when pigs were weaned at days 18 and 21 of age, respectively.
Increasing weaning age will bring benefits to a conventional and ABF systems; however, space and pig transportation to the nurseries can be the limiting factors. While selecting a sow farm that will provide ABF pigs, it is recommended to consider sow farms that can have split weaning during a week. This will reduce the number of weaned pigs under 21 days of age.
4) Prevention of enteric challenges
Antibiotics have served to prevent, control, and treat enteric disease caused by bacteria. In combination with improved biosecurity and a good vaccination program, organic acids and phytogenic substances can help producers to reduce or eliminate the use of antibiotics for preventive purposes.
In the post-weaning, E. coli is the main cause of diarrhea, while Salmonella spp. and Lawsonia predominate in the growing-finishing phase. Controlling the population of these bacteria will reduce the risk of an outbreak. An acidic environment favors the growth of beneficial bacteria and discourages the growth of pathogenic bacteria. Organic acids have the potential to enter the bacteria and alter the internal pH. Reduction of internal pH impairs cellular metabolic functions, causing bacteria to die. Therefore, the antimicrobial properties of an organic acid relies in the ability to enter the bacteria. Organic acids with greater antimicrobial properties have pKa near to four, and a small molecular weight.
Moreover, phytogenic compounds have gained special attention in the last years. According to the 2017 BIOMIN Phytogenic Feed Additives Survey, the antimicrobial effect of phytogenic feed additives ranked as the second most popular reason that respondents applied phytogenics to livestock feed.
Phytogenics are plant metabolites capable of reducing the growth of bacteria. The mode of action varies according to their chemical characteristics. For instance, carvacrol and thymol, mainly found in oregano oil, alter the fatty acid composition of the bacteria membrane and disturb membrane integrity. Cinnamaldehyde, found in the cinnamon bark oil, impairs bacteria replication by preventing the allocation of the site of division. Bacteria elongate and do not divide (Domadia et al. 2007). The antimicrobial properties of organic acids and phytogenic can be synergistic. A wise and deliberate combination provide greater efficacy in reducing E. coli and Salmonella growth (Riemensperger et al. 2012) (Figure 1).
5) Performance recovery
Antibiotic growth promoters (AGPs) have historically been used to increase growth and feed efficiency. In markets such as the EU and the US, antibiotics as growth promoters (AGP) are already banned. The mode of action of AGPs is not entirely understood. However, the most predominant hypotheses are modulation of the microbiota and anti-inflammatory effects. The effect of dietary supplementation of phytogenic compounds in combination with organic acids on the performance of pigs were evaluated and compared against an AGP program (Mendoza et al. 2017). Nursery pigs fed phytogenics and organic acids had similar feed efficiency compared to pigs fed the AGP (Figure 2). Phytogenic compounds have also demonstrated to improve growth of growing-finishing pigs. Soto et al. (2016) reported that growing pigs fed a blend of phytogenic ingredients had similar market weights compared to pigs fed ractopamine (Figure 3).
Consumer preferences are encouraging us to adopt more preventive practices at the farm and to look for sustainable alternatives to antibiotics. In an ABF program, rigorous hygiene and biosecurity practices have to be accomplished. Water quality, weaning age, mycotoxin risk management, prevention and performance are all important factors to maintain pig health and profitability. Novel growth enhancers are sustainable alternatives to increase feed efficiency and growth.
Revisiting conventional procedures with an open-mind and scientific knowledge can be very fruitful to achieve successful transition to antibiotic-free production.