Deepak Subedi, The University of Sydney
Soybean meal (SBM) is the primary protein source in poultry diets, but its cost and availability in some regions have driven interest in alternatives. Canola meal (CM) and canola seed (CS), abundant in Australia, offer potential as substitutes for SBM. However, concerns about antinutritional factors and reduced energy density have limited their inclusion.
Researchers at the University of Sydney evaluated the effects of replacing SBM with CM and CS in broiler diets at varying inclusion levels. The trial involved 450 Ross 308 broilers fed nine dietary treatments from day 1 to 42 post-hatch. Diets were iso-energetic and balanced for digestible amino acids, with canola inclusions ranging from 50 to 300 g/kg across feeding phases. All diets contained xylanase and phytase.
Key Findings
Starter phase: 50 g/kg canola inclusion did not affect weight gain; 100 g/kg reduced body weight by ~2%.
Overall: Increasing canola inclusion consistently reduced feed intake and body weight gain. Highest inclusion reduced feed intake by 6.9% and weight gain by 7.1% compared to control. FCR remained unaffected.
Carcass traits: No significant differences in breast, leg, or abdominal fat weights.
Nutrient digestibility: AME and nitrogen retention were not significantly affected. AME:GE ratio was lower in canola diets due to higher oil and reduced starch. Starch and protein digestibility coefficients were similar across treatments, though disappearance rates were lower in high-canola diets.
Pellet quality: High canola seed diets had poorer pellet durability, correlating with reduced intake. Increased fiber, glucosinolates, and sulfur also negatively influenced intake.
Economics: Canola-based diets reduced feed cost per bird and per kg of live weight but increased days to reach 2.5 kg body weight.
Implications for ProducersHigh canola inclusion lowers feed costs but compromises growth due to reduced intake. Limit canola inclusion to ≤50 g/kg in starter diets to avoid early growth depression. Consider enzyme supplementation, improved pelleting, and nutrient density adjustments to mitigate intake issues. Canola products can partially replace SBM, offering economic benefits without major impacts on FCR or digestibility.
Bottom LineCanola meal and seed can be integrated into broiler diets as cost-effective protein sources, but high inclusion rates reduce feed intake and growth. Optimizing diet formulation and canola processing is essential.
Journal: Poultry Science
Full paper: “The impact of canola meal and canola seed inclusions in broiler diets” DOI: https://doi.org/10.1016/j.psj.2025.105017
#InterpretiveSummary #PoultryScienceJournal