The widespread use of antibiotics in both humans and animals is now under ever closer scrutiny. Unfortunately, overuse of antibiotics has led to antimicrobial resistance, where some of our deadliest diseases are no longer effectively controlled by our existing antibiotics.
On a global basis it was estimated that from 2010 about 700,000 people die every year from drug resistant strains of common bacterial infections, HIV, tuberculosis and malaria (O’Neill, 2016). Based on scenarios of rising drug resistance for six pathogens to 2050, it was estimated that the burden of deaths from antibiotic resistance could balloon to 10 million lives each year by 2050. This would also add a cumulative cost to global economic output of $100 trillion. Therefore, it is crucial that we protect this precious resource by using them less and more prudently.
The European Union has also recognised the problem and the use of antibiotics for growth promotion has been banned since 2006. Then at the end of January 2022, new laws came into force, banning farmed animals from being routinely fed a diet of antibiotics. These new regulations mean that only sick, individual animals (and not whole herds) may be administered antibiotics. It is now illegal to use antibiotics to compensate for low welfare practices. The intention here is to reduce inappropriate use of antibiotics in animals.
Nevertheless, large quantities of antibiotics are still used in animal production in the EU and the UK. The latest report on European Surveillance of Veterinary Antimicrobial Consumption published by the European Medicines Agency (EMA, 2021) showed that 31 European countries used a total of 5,577.8 tonnes of active antimicrobial substances and the UK used 226 tonnes of active substances. One positive note was that in 25 countries, including the UK, in the years between 2011 and 2020 there was an overall decline in sales. Efforts are being made to reduce antibiotic use but much more needs to be done to offset the dangers of bacterial resistance to antibiotics.
Reducing antibiotic use requires some new strategies in animal feeding and management of animals. It is clear that animals do not need routine antibiotics to stay healthy. The focus now needs to shift to health maintenance and disease avoidance. We know that animals are more susceptible to disease when stressed as this reduces immunity by compromising the immune system. If animals are kept healthy through good husbandry and welfare, they should not require high levels of antibiotics and will have good immune resistance to diseases. Healthy animals also are more productive.
Fortunately, both nutritionists and veterinarians are coming round to the idea that the blanket use of antibiotics is not sustainable and the focus needs to be on health maintenance and disease avoidance. We have to recognise that in some cases antibiotics will be essential to protect animal health and welfare but this now needs to be a last resort rather than an overall strategy.
The dairy cow, particularly during the transition period is under a lot of metabolic stress. There is frequently a negative energy balance and the onset of various metabolic diseases such as ketosis, subacute ruminal acidosis (SARA), lameness, displaced abomasum, metritis, retained foetal membranes and hypocalcaemia or milk fever. Incidence of mastitis can also increase. These issues can lead to depression of the immune system and fertility problems and require antibiotic treatments. Indeed, more than 60% of all antibiotic drug use in dairy herds occurring in the first 60 days of lactation.
In order to reduce antibiotic use, a strategy of health maintenance and disease avoidance is critical here. A major challenge for the dairy cow is maintenance of good rumen function with dynamic rumen microbial biomass which will ensure maximum utilization of the feed and avoid low rumen pH and support the immune system.
Figure 1 shows the effect of Glycal Forte on rumen pH days post partum as measured by wireless telemetric device (E bolus) n=10.
Glycal Forte, a calcium-stabilized glycerol feed ingredient, plays an important role in maintaining good rumen function in the transition cow. As shown in Figure 1, work with pH-measuring boluses have shown that Glycal Forte can maintain a good optimal pH in the rumen. Moreover, Glycal Forte also encourages growth of the rumen microbial biomass. A more active and dynamic microbial biomass will ensure good feed utilization so the cow gets the maximum benefit from the feed consumed. University trial work has concluded that somatic cell counts are reduced in cows fed 250g/day of Glycal Forte® (see Figure 2). This reduction in SCC can be the result of a stronger immune system and therefore offers the potential to reduce the use of antibiotics in dry cow therapy.
Figure 2 shows the effect of Glycal Forte on somatic cell count (SCC) where n=94 (50 Control, 44 Treatment) P=0.019.
The use of Glycal Forte in dairy cows is a very beneficial way to maintain good cow health and productivity. Glycal Forte is a registered feed ingredient which can help reduce the need for antibiotics in the transition dairy cow. Nutrition-based health maintenance and disease avoidance is the way forward to preserve the efficacy of our antibiotics to treat serious animal and human diseases.
EMA (2021). European Medicines Agency, European Surveillance of Veterinary Antimicrobial Consumption, 2021. ‘Sales of veterinary antimicrobial agents in 31 European countries in 2019 and 2020. (EMA/58183/2021).
O’Neill (2016). Tackling drug-resistant infections globally: final report and recommendations the review on antimicrobial resistance. Welcome Trust and HM Government, UK.