3 Lessons to reduce antimicrobials in pigs

As concern about antimicrobial resistance and the threat it presents to human health grows, farmers are under increasing pressure to reduce or eliminate antimicrobials from their production practices. Challenges focus on reducing antimicrobials in swine production without compromising health and performance. Operating under different production conditions, within varying regulatory structures and in diverse climates, producers face many challenges. The following field studies show that a multi-stakeholder approach can help producers achieve their goals while reducing their reliance on antimicrobials.

1. Benchmarking optimises success

Legislation as well as market factors can inform production goals. One producer may target ‘responsible use of antimicrobials’ to comply with legislation while another producer may pursue ‘antibiotic-free’ as a point of competitive differentiation. Once goals are set, it’s time to assess the baseline and identify critical control points. Progress is only real when it is measurable.

Take-home message in action

A farm in Spain reduced standard antibiotic treatments in sow feed and experienced an increase in neonatal diarrhoea followed by a spike in pre-weaning mortality rate of 21%. While analyses showed that Clostridium played an important role in the diarrhoea challenge, different Clostridium vaccines failed to achieve the desired improvement. Subsequently, the farm stopped vaccinating sows against Clostridium.

To assess the starting threshold and establish performance goal metrics, samples of liquid sow feed were collected at different steps in the feeding process. Table 1 shows high levels of yeast, Enterobacteriaceae and Clostridium detected in the microbial analysis conducted at both the kitchen of the liquid feed, as well as in the feed lines. Data from the initial analysis determined goals to reduce the presence of Clostridium and other contaminants. This tailored approach to monitor and improve feed hygiene included using organic acid blends to clean the feeding lines.

The approach also included introducing several feed ­additives in the diet to stabilise the gut microflora and improve gut integrity. Just one month later, follow-up analysis revealed strongly reduced levels of Clostridium and Enterobacteriaceae in sow feed. The cleaning protocol was repeated, after which another analysis was performed (Table 2). The improvements led the farm to adapt its standard management routine to include periodic monitoring of kitchen and feeding lines, helping ensure safe, hygienic feed.

2. It is all about prevention

If production systems should be stable and predictable, efforts to prevent disruptions of the normal flow are essential. Once the disruption has occurred and the balance is lost, all there is left to do is to try to minimise the impact and return to a state of balance and predictability as soon as possible. Investing time and effort in fixing the root cause of a problem, and therefore preventing repetition of that issue, is crucial. Most challenges cannot depend on a single solution to work in all situations. Instead, benchmarking and collaboration among all stakeholders should ensure a good analysis of the situation, leading to identification of the correct risk factors that need to be managed, and where possible, prevented.

Take-home message in action

The weaning process potentially has a big impact on piglets’ performance. Feed intake patterns before and shortly after weaning are the biggest risk factors for a post-weaning dip. Preventing this dip is essential to ensure good animal health and performance. Thus, low feed intake is the risk factor to be controlled, meaning that piglets need to consume feed ­during their visits to the feeding station.

Figure 1 shows the success rates of two groups of newly weaned piglets visiting a feeding station. The success rate was defined as a piglet consuming feed during its visit to the feeding station. One group of piglets received creep feed before weaning, while the other group did not. Although both groups of piglets visited the feeding station in equal rates following weaning, the group that received creep feed prior to weaning showed a higher success rate, and thus feed intake, during visits.

Figure 1 – Success rates of piglets consuming feed at the feeding station.

Factors occurring even longer before weaning may also affect piglets’ performance later in life. Difficulty of birth is a risk ­factor that may affect growth performance. Figure 2 shows growth rates of piglets with equal birth weights but divided based on whether they had a normal or difficult birth. The piglets who experienced a ‘normal’ birth showed significantly higher growth rates before and after weaning compared to the piglets whose birth was characterised as ‘poor’.

Figure 2 – Growth rates of piglets with equal birth weights but divided based on whether they had a normal or difficult birth.

Both situations are examples of risk factors that have a big impact on performance later in life. With preventive measures, these risk factors can be avoided, making the production ­process more stable and predictable.

3. An integrated approach is key

Producers rely on close collaboration among several partners and consultants, each contributing their experience and ­expertise.

But when experts focus only on their own little piece of the production chain, there is minimal cohesion and awareness of the influence the elements have on each other. Therefore, it is no surprise that 2 of the key success factors in reducing reliance on antimicrobials are: collaboration among all stakeholders, and an integrated approach to achieving goals. Everybody contributing his or her part, working jointly toward the same goal, each from a different angle, and at the same time, helping to make sure all angles are covered.

Take-home message in action

Swine production components are interrelated and a change in feed, farm or health management will impact other areas. A good example is the influence a pig’s gut health can have on vaccination efficacy. The gastrointestinal tract of pigs functions as a barrier between the animal’s system and the environment. The health and balance of this barrier system are affected by the quality, safety and composition of water and feed, which in turn influence growth, immune response and systemic health.

Small changes in feed management, such as reducing the microbial load of feed by improving feed hygiene, can influence the animal’s systemic immune response, and thus vaccination efficacy.

At the Spanish farm mentioned earlier in this article, collaboration between the farm manager, veterinarian and feed consultant improved the liquid sow feed hygiene which led to improved effectiveness of the farm’s vaccination protocols. Integrating blends of organic acids (SCFA-MCFA) along with a Clostridium vaccine showed improvements in the Lactobacillus/Clostridium ratio of sow faeces. This ratio is considered a measurement to determine gut health.

Subsequent analysis of piglet diarrhoea showed fewer piglets were positive for E. coli and Clostridium perfringens. The sow vaccination programme against Clostridium was resumed with success, resulting in pre-weaning mortality being ­reduced from 21% to just 7%.

Plan, do, check and act

Looking ahead to the future, the EU is moving towards even more stringent requirements regarding the use of veterinary antimicrobials. These requirements are driven largely by concerns surrounding antimicrobial resistance and contamination of the environment with antibiotics and heavy metals. In 2022, a new ban on pharmaceutical zinc oxide levels will be implemented. There will also be restrictions on metaphylactic use of antibiotics, and the possibility to reserve certain ­antibiotics for human-use only.

Scientific insights applied to practical approaches on customer farms show that a multi-stakeholder approach, integrating feed, farm and health management can help swine farmers achieve production goals while reducing or eliminating their reliance on antimicrobials.