Watch out for broiler health during summer months

A drop in broiler intestinal health among poultry flocks during the summer months is becoming more pronounced, suggests the latest data.

The decrease is linked to an increase in coccidiosis infection, according to Elanco’s latest Health Tracking System annual report. It which analysed data from 5,244 post-mortem bird examinations involving 743 broiler houses on 314 UK farms.

Elanco technical consultant Louise Ashworth 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.”

‘Safe space’

The emerging trend could be due to producers perceiving the summer to be a lower risk period for coccidiosis, said Ms Ashworth.

“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.

But Ms Ashworth warned: “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.”

The report shows that 18% of birds presented with gross and microscopic E. maxima lesions during summer 2022, 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, producers should make sure coccidiosis prevention programmes remain stable throughout the season, said Ms Ashworth.

“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 points.

To put this into perspective, Ms Ashworth said  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.”