A recent study at Texas A&M University was designed to investigate the growth-promoting effects of supplementing different sources and concentrations of prebiotic yeast cell wall (YCW) products containing mannan-oligosaccharides in starter broilers under an immune stress and challenge with Clostridium perfringens, the pathogen associated with necrotic enteritis in chickens.

In the paper, published in Journal of Applied Poultry Research, is by J. Fowler of the Department of Poultry Science and co-authors there and the Food and Feed Safety Research Unit of USDA–Agricultural Research Service.

They explain that, through a series of six individual studies, either 240 or 288 newly hatched chicks were randomly distributed to specific dietary treatments.

All birds received a commercial infectious bursa disease vaccine at 10 or 15 days age followed by an orally administered Clostridium perfringens challenge on days 15, 16 and 17; or 18, 19 and 20.

Weekly bodyweight, feed consumption and daily mortality were recorded per pen.

Each study was terminated after 21 days.

Pooled data analysis of all studies revealed no effect between different product sources of YCW.

Products from both sources produced a significant improvement in growth rate compared to control birds fed no YCW.

However, a blend of two YCW products showed an approximate 15 per cent improvement in growth rate and a 10 per cent reduction in feed conversion ratio.

The optimum dose of any YCW product among those tested was determined to be approximately 250ppm.

The Texas-based researchers concluded that prebiotic YCW additives increased bodyweight and improved feed conversion and may be considered as alternative growth promoters for starting broilers.

Reference

Fowler J., R. Kakani, A. Haq, J.A. Byrd and C.A. Bailey. 2015. Growth promoting effects of prebiotic yeast cell wall products in starter broilers under an immune stress and Clostridium perfringens challenge. J. Appl. Poult. Res. 24:66-72.

May 2015