How biofilms can improve litter quality and bird health

Broilers are in constant contact with litter, which absorbs excreta and bird detritus along with waste feed and water.

When litter quality is poor there is an increased risk of ammonia build-up that can damage the birds’ respiratory systems. 

Poor-quality litter can also lead to carcass condemnations and downgrades, with increased incidence of breast blisters, skin burns, scabby areas and hock burn.

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All of these issues are a threat to bird welfare and can significantly influence a flock’s bottom line. 

The problem lies in harmful bacteria that thrive in poor-quality, damp litter and then produce large quantities of ammonia. 

Putting in place rigorous disinfection and cleaning protocols between flocks is already common practice and helps reduce the risk of infection pressure within the shed.

However, as the flock grows over the following weeks, the benefit of the cleaning protocol diminishes.

In a bid to combat the issue, researchers have trialled positive biofilms – solutions that adhere to the litter and reduce the population of harmful bacteria.

They do this by introducing a mix of live bacillus and lactic acid bacteria (LAB). When sprayed into sheds, the bacteria outcompete the harmful, ammonia-producing bugs.

The positive bacteria colonise the walls, ceiling, floor and all equipment within the broiler house, preventing the build-up of undesirable bacteria.

On-farm trial

Researchers working in France for Lallemand Animal Nutrition carried out trials with a biological solution on a commercial broiler farm that had significant litter quality and bird welfare issues.

The aim was to measure the effect of the solution in establishing a positive microbial balance within the birds’ wider environment.

The trial ran for 35 days on two consecutive batches of 26,400 broilers on a sawdust litter.

It compared birds in a building that had been sprayed with a solution against a control group in a shed with no treatment applied.

The presence of positive biofilms was measured during the study by counting the number of positive bacteria present in both the treated and control buildings at days four and seven of the trial.

Litter quality, carcass quality, evenness of the birds and mortality were also measured.

For the first batch, the bacterial solution was applied to the first half of the farm building at day one and day 15. In the second batch it was applied to the second half of the farm building at day one and day 15.

What the results revealed

Lallemand Animal Nutrition environmental product manager Lientjie Colahan says when quantities of bacillus and LAB were measured within the building, the results were positive.

After four days the quantity of bacillus was 100 times higher in the treated building than the control building.

“By day seven the concentration was still significantly higher, showing how a positive biofilm can be maintained,” Mrs Colahan explains.

At day 35 of the trial, the litter quality was still significantly better where a positive biofilm had been created (see “Litter quality scores”).

The litter was scored against a scale developed by the French Applied Research Institute for Poultry (Itavi) – the higher the score, the wetter the litter.

The results clearly show a decline in scores four and five where the biological solution was applied. 

Further research indicated that the building treated with a biological solution had twice as many intact hocks – 4.4% compared with 2.2% in the control group.

Bird performance

Individual broiler weight and the evenness of the flock were also monitored throughout the trial.

Birds in the treated building were 54g heavier on average at finish than the control group. There was also 0.5% less variation in bird weights.

“What is important to note is that the birds were a similar weight on arrival, but creating a positive environment enabled the birds to better manage any potential challenges,” Mrs Colahan says.

This is particularly important when the hosts’ immune and digestive systems are not fully mature at the start of the production period.

She says this demonstrates why it is important to inoculate the environment with positive microbes before the birds arrive, as the first few days are when they are most vulnerable.

Mrs Colahan says the enhanced weight gain and evenness of the birds in the trial, alongside the reduced mortality and culling rates, were a result of improved bird health and welfare.

This was a result of enhancing the microflora within the birds’ wider environment.

Applying a bacterial solution may seem like an additional investment on top of the current cleaning and disinfection protocols in place.

But the enhanced performance can help turn out a product more in line with end-market requirements, she adds.

She advises selecting a bacterial solution which is formulated with optimal adhesion properties to ensure the effect is sustained.

“By doing this before the birds arrive, the positive bacteria have a head start, enabling them to become established in the environment and reduce the space for negative bacteria that may build up within the building throughout the crop.”