UK broilers’ intestinal integrity (I2) remained strong in the first half of 2025, with the positive trend from late 2024 continuing into this year.
The upbeat message comes on the back of data from Elanco’s Health Tracking System (HTSi). I2 is described as a unique, weighted index that gives birds a score of between 0 and 100, based on 23 health conditions which are known to negatively impact intestinal health, with higher scores indicating better intestinal health.
The average I2 score for the first six months of 2025 is higher than that of the same period in the previous three years, Elanco said, with June showing the highest average at 96.96.
Louise Ashworth, Elanco’s strategic services lead, said that December 2024’s record high I2 score set this year off on the right foot. “We’ve seen a slight dip in I2 in spring 2025, but this isn’t unusual,” she explained.
“High winter disease pressure and the challenges of effective clean-out during the colder months often take a crop or two to fully impact scores, which helps explain the delayed drop following December’s peak.”
Range of lesions monitored
As part of the overall I2 score, HTSi monitors a range of lesions, including cellular sloughing, hyperaemia, and intestinal haemorrhage.
“We’ve observed significantly lower incidences of these lesions across the board, including a reduction in coccidiosis prevalence,” Ashworth said. “The challenges posed by Eimeria have notably decreased, with no cases of Eimeria tenella recorded in June 2025.”
While it’s difficult to pinpoint the exact reasons behind these reductions, Ashworth said they are likely to be the result of a combination of factors. “The changes to stocking density seem to have lowered disease pressures, but it’s important not to become complacent with disease control,” she added.
Ashworth stressed that inadequate cleaning and disinfection to reduce turnaround time can lead to disease build-up.
Coccidiosis peak
The report also highlights a slight change in the age at which coccidiosis peaks, with E. acervulina and E. maxima being seen earlier and incidences of E. tenella peaking later.
Despite the figures showing that I2 is thriving, Ashworth said stable and continuous coccidiosis control throughout the flock’s lifecycle should not be compromised and producers are encouraged to keep up good practice.
She also noted an increase in tibial dyschondroplasia, which, while not contributing to the I2 score, has been observed more frequently during necropsies.
As a result Ashworth recommended monitoring culls due to leg health and lame birds, and consulting with your vet and nutritionist if high levels are seen.