Elanco’s latest Health Tracking System (HTSi) annual report shows a drop in broiler intestinal health during the summer months, linked to an increase in coccidiosis infection.
The 2023 HTSi report reviews intestinal health data collected during 2022 from 5,244 post-mortem bird examinations, from 743 broiler houses on 314 UK farms.
Explaining the findings, Louise Ashworth, Elanco HTSi technical consultant, said: “During the last couple of years, we’ve started to see a recurring trend where intestinal health destabilises during the summer months. In this latest data set, this dip is even more pronounced.
“In 2022, we saw a reduction in Intestinal Integrity (I2) scores during the spring, with a further decline, far beyond that seen in 2021, going into the summer. Scores began to improve again over the autumn into winter, with I2 returning to expected levels by the end of 2022.”
Ashworth said this emerging trend is likely due to producers perceiving the summer to be a lower risk period for coccidiosis.
“We’ve observed that producers often consider the summer to be a ‘safe space’ to change coccidiosis programmes or loosen biosecurity protocols. Whereas, over the winter, everyone tends to ‘buckle up’ when it comes to disease prevention.
“However, the data shows this really isn’t the case. The decline in I2 we’ve seen over the summer is inevitably linked to the increase in coccidiosis, most notably E. maxima, seen over the same period,” she said.
The report shows during 2022, 18% of birds presented with gross and microscopic E. maxima lesions over the summer, compared to just 5% in the same period in 2021.
The latter stages of summer also saw a five-fold increase in E. tenella – the coccidia species most likely to cause an increase in mortality, and generally not seen in high levels in the UK. Infection with this species results in a greater need for medical intervention.
“Despite the improvements in I2 going into winter, the instability of the summer still impacted birds, especially with pododermatitis, where wet litter was a major contributor to the highest levels of seasonal disease seen in recent years.”
With I2 score strongly correlated to bird health, welfare, and performance, Ashworth said producers should make sure coccidiosis prevention programmes remain stable throughout the season.
“Maintaining and improving I2 will support the profitability and environmental sustainability of broiler production.
“For example, for every one unit increase in I2, ADG increases by 0.04g and FCR improves by 0.13 points1,” she said.
“To put this into perspective, a poultry company producing 100 million broilers per year, could see an income boost of £614,900 by improving their I2 by five points, a very achievable target with the right interventions.”