Reducing antibiotics: A case study

Farmers and integrators are actively developing strategies to assure animal health and maintain productivity. These usually involve a combination of measurable areas, such as vaccination, biosecurity, hygiene and nutrition. Numerous studies have for instance demonstrated the effects of feed and water additives on gastrointestinal health, with acidifiers having a prominent position in the toolbox of additives to achieve responsible use of antibiotics. However, reports of large-scale field validation studies to assess the effects of these in real-life conditions are in general scarce. Such field studies are difficult to conduct as it is a big challenge to assess the application of controls versus treatments, and to establish adequate trial management and data collection in many farms.

Big Data on chicken performance & nutrition

For this reason, the decision was taken to cooperate with a provider of ICT solutions for broiler farm management to analyse data in a large-scale longitudinal study. The aim was to monitor the productivity of broiler birds by firstly assessing the effect of a mix of management measures, and subsequently the effect of implementing a feed additive strategy, comparing antibiotic usage. With this in mind, data from 11 independent farmers, selected in 2010, participated in the study. These farmers had in total 885,000 broiler places, and were situated in a high-density animal region. Over a 5-year period, consisting of 477 production cycles, these farmers produced 40,260,000 broilers, whose performance data are included in this field case. The data obtained was used to analyse the performance of the animals and to provide advice on nutrition and management, in close cooperation with veterinarians.

From baseline to completion

The farmers were not applying water acidifier strategies at the start of the study, and were not yet actively involved in management programmes to reduce the use of therapeutic antibiotics. Performance and health data were recorded for the first 2 cycles. These results served as baseline control levels for studying the effect of subsequent measures over the 5 years. After analysing the farm data to establish the individual situation, targets were set for each farm. During the study period, feed and water intake, mortality, and registration of veterinary treatments and antibiotic usage were recorded on a daily basis. The farmers started their improvement programmes in 2010 and 2011.

In the first phase, several management measures were implemented and the effects studied. These measures mainly included best practices in biosecurity, health care, climate control and nutrition. Feed digestibility was regulated according to market conditions in order to achieve the best selling price.

In the second phase, several feed and water additives were introduced to support the farms’ performance goals. These products were provided by a range of different suppliers. The effects of the integrated approach (i.e. of using management improvements together with feed additives) were measured as well. If necessary, adjustments were made to the programme. In the final study phase, only feed and water additives from one supplier (Trouw Nutrition) were studied.

Complementary modes of action

The feed additive programme was composed of products with specific modes of action, intended to work together to support animals’ performance when fed antibiotic-free diets. One additive (Selko Fysal), containing a synergistic blend of organic acids with their ammonium salts, was used to pre-treat wheat to improve its microbiological quality. A second additive (Selko-pH) was used to reduce the pH of the drinking water and to support the control of microbial activity in the stomach after feed ingestion. A third in-feed additive (Selko Presan), containing a blend of coated butyrate, medium chain fatty acids and plant extracts, was used to support mucosal barrier function in the small intestinal tract. Other suppliers’ feed additives were also included in the study. The effects of the feed and water additives from all suppliers were assessed and then compared with the effects of those from Trouw Nutrition alone.

Results over a 5-year period

The results demonstrate that over the period from 2010 to 2015 the usage of therapeutic antibiotics was significantly reduced, with the most marked decrease in the period in which the additive programme was applied (Figure 1). The greatest decrease in the use of antibiotics (mg/kg broiler) was 59%. This relates to the application of management improvements together with the Selko feed and water additives.

Figure 1 – An integrated approach of management improvements and Selko feed additives reduced antibiotic use by 59%.

These results highlight the importance of using water and feed additives based on organic acids to target the microbial quality of the water and feed, and to achieve greater microbiotic control in the gastrointestinal tract of broiler chickens. The improvement in health status during the period when the additive programme was applied was also reflected by a reduced mortality rate and improvements in productivity (Figure 2). Average mortality was reduced by 28%, and the feed conversion ratio (FCR) improved by 5.3%. Management practise changes usually account for improvements in FCR as well, but in this case, in the management period diets were formulated with lower energy levels (hence slower digestion), which causes no changes in the FCR, but does lower feed cost and diarrhoea incidence.

Figure 2 – Mortality rates decreased significantly in all programmes, while the best results for FRC were achieved by using improved management in combination with Selko feed additives.

Both productivity parameters have high economic value, thereby compensating for the additional costs of the additive programme. The profitability score calculated in this field example showed a 100% increase (from 52 to 103) calculated on using a range of feed additives in combination with improved management. This figure rose to 116% when only Selko feed additives were applied (with a score of 112). The profitability score is calculated based on weight losses by mortality during the growing period, weight losses by ‘dead on arrival’ and losses in the processing plant, antibiotic usage and protein conversion. A score of 100 or higher is considered to be good.

Integrated approach is essential

The results of this large-scale field study demonstrate that the best results are achieved by using feed and water additives in combination with best practices in husbandry, health care and nutrition. This integrated approach enables farmers to establish a responsible and prudent use of antibiotics while maintaining performance and profitability.