How DNA metabarcoding insights can support the poultry sector

A recent study marked the first application odd DNA metabarcoding to elucidate the dietary composition of pasture-raised broilers. Photo: Canva

Consumer demand for pastured poultry in many parts of the world continues to increase, but its production is challenged by high costs.

While increasing the use of pastured resources, such as insects and plants, could help offset feed costs, few studies have looked at management strategies to increase poultry pasture use.

Researchers from the University of Kentucky introduced broilers to cover crop pastures over 3 growing seasons and assessed the impact of stocking density, sex, short-term feed restriction and breed on diet diversity.

Throughout each experiment, the researchers quantified pasture use by measuring the diet richness of pasture plants and arthropods through DNA metabarcoding of broiler faeces.

The results found that:

Pastured broilers consumed many cover crop and weed families.
The diet richness of insects was unexpectedly low.
Lower stocking density increased diet richness across all 3 years of the study.
A short-term feed restriction increased diet richness compared to an unrestricted feed treatment.
For fast-growing broilers, individuals with greater weight gain consumed the greatest diversity of diet items but the opposite was observed for slow-growing birds.

As expected from anecdotal evidence, slow-growing broilers tended to have higher diet richness compared to fast-growing birds. Despite increased diet richness, stocking density and short-term feed restriction did not increase the feed-use efficiency compared to fast growing-broilers.

The study marked the first application odd DNA metabarcoding to elucidate the dietary composition of pasture-raised broilers.

Future research, say the scientists, should expand on optimal rates of access to pasture, supplemental feed and breed selection to maximise the cost-effectiveness of pastured poultry production.

The study, ‘Increasing pasture diet diversity in broiler chickens: insights from DNA metabarcoding’, has been published in the journal Renewable Agriculture and Food Systems.