Using organic acids to promote growth and reduce cellulitis rejects in broilers

Rejects across the broiler industry have been rising year-on-year and are often down to cellulitis. The reasons for the cellulitis can include disease challenge such as gumboro, water sanitation and high bacterial loading.

The benefits of promoting a healthy gut bacterial population is well documented. However, trials into the use of organic acids specifically to reduce cellulitis rejects, as well as to promote growth have been limited.

Trials carried out by the UK’s leading independent poultry veterinary practice however have looked specifically at the use of organic acids – ABC Start and ABC pH – to reduce the number of rejected birds in the abattoir, as well as to promote growth rates.

Cellulitis and gut health

For cellulitis to develop, birds need a scratch or some type of wound damage that is infiltrated by bacteria – usually E. coli.

Using acids reduces the E. coli levels in the gut which in turn reduces the E. coli levels that are shed through the droppings. The reduced E. coli burden in the environment consequently reduces the risk of contamination into the wounds.

Another benefit of good gut health is that birds tend to become less flighty and therefore less prone to scratches generally.

Background to the trial

The trial site, that consisted of eight houses with 40,000 birds in each that were all identical and managed in the same way, had consistently underperformed and struggled with poor gut health. Growth weights were average however there were a high number of cellulitis rejects regularly.

After a review of the brooding and the environment that included extensive sampling, including water hygiene, the only issue identified was consistently high cocci and enteritis across the site.

The trial

At the start of the crop, four houses were placed on the organic acid program and four houses were not.

The organic acid program consisted of ABC Start for the first 13 days, followed by ABC pH from day 18 to 38. ABC Start contains lactic acids, copper and organic acids to encourage the development of the microflora, and ABC pH is a buffered solution with propionic acid, lactic acid and acetic acids, that together with other components create an environment that benefits the good bacteria. Water sanitation was also important intermittently to prevent biofilm build up.

The entire crop progressed well with no particular issues in any of the houses. Faeces were firm and of the appropriate coloration and consistency throughout.

The results

The following are the first crop’s results into the factory.



TMLS (21d)

Acid Houses




Non-Acid Houses




In addition, post-mortems were carried out at 22 days, with no awareness of which birds came from an acid, or non-acid house.   

The cocci scores from the acid houses were half that of the non-acid houses and the gut health was significantly better, with minimal signs of enteritis. To add to that, no medication was using in the organic acid houses. 

For the first crop, the cost per bird of the acids was 1.3p. The benefit per bird equated to 8.8p. 

Future trials

A focus area for future trial crops will be the effect using organic acids has on cocci, as the decreased total mean lesion score was unexpected in the phase 1 trial. As a secondary effect, it’s possible that the improvement in gut health has reduced the cycling of cocci.