Dietary Soluble Non-Starch Polysaccharide Level Influences Broiler Performance and Excreta Dry Matter

Despite extensive research presenting both the benefits and detriments of soluble non-starch polysaccharides (sNSP) in poultry diets, its concentration and composition in feed ingredients is not commonly considered during commercial feed formulation. Consequently, a study was conducted in which birds were fed commercial-type diets formulated to Cobb recommendations (barley, corn, sorghum or wheat-based) formulated to contain similar protein levels but differing soluble NSP levels (Low, Medium or High), resulting in 12 dietary treatments. sNSP level was determined in the feed ingredients and final diets by measuring the constituent sugars using gas chromatography. These diets were fed to 1110 mixed-sex Cobb 500 birds, distributed into 108 pens, with 9 replicates per dietary treatment and approximately 10 birds per replicate. Body weight (BW), body weight gain (BWG), feed intake (FI) and feed conversion ratio corrected for mortality (cFCR) at d0-31 was determined per pen. Additionally, fresh excreta samples were collected per pen and dry matter content measured (Table 1). Data was analysed as a 4 x 3 factorial arrangement using IBM SPSS Statistics 25, with differences considered significant at P < 0.05.

Table 1- Effect of sNSP level and grain type on individual feed intake (FI), body weight gain (BWG) and feed conversion ratio corrected for mortality (cFCR) at age d0-31 and excreta dry matter (DM) content at d31

Generally, corn is thought to be a superior grain for broilers, and only the anti-nutritional effects of sNSP are considered, but in this study birds fed the corn-based diet with low sNSP presented the highest cFCR and lowest excreta DM content. This highlights that sNSP is required in poultry diets, due to its role in maintaining digesta passage rate, water absorption and as a fuel for beneficial microbiota. Also, barley was shown to be efficacious when the dietary sNSP level was low. This suggests it is advantageous to consider sNSP during feed formulation, to ensure there is sufficient, but not excessive, quantities in the diet to achieve optimal performance and litter quality.

ACKNOWLEDGEMENTS: The authors are grateful for financial support from AgriFutures Australia Chicken Meat Program.