Effect of replacing soy in broiler diets on performance, carcass yield and cost of production

The study aimed to evaluate the effects of replacing soy bean meal (SBM) in broiler diets on production parameters. A randomized trial (36 d) was conducted using 20 pens (20 m2, 280 Ross PM3 birds). A starter and grower diet (12.6/13.0 MJ ME, 210/200 g CP, 12.8/12.2 g lysine) were fed as crumbs. The diets contained either a high level of SBM (HS; starter/grower: 28.7/26.8% SBM and 2.5/2.5% rape seed meal (RSM)), a medium level of SBM (MS; starter/finisher: 15.0/15.0% SBM, 15.0/15.0% peas, 5.0/5.0% RSM, 5.0/5.0% sun flower meal (SFM), 2.8/2.0% potato protein (PP) or no SBM (NS; starter/grower: 25.0/25.0% peas, 5.0/5.0% RSM, 10.0/10.0% SFM, 5.3/4.5% PP, 4.0/4.0% corn gluten). Treatments were HS/HS, MS/MS, MS/NS, NS/NS for starter/finisher diets. Performance parameters, litter quality, hock burns (HB) and foot pad lesions (FPL) were recorded and analysed by using ANOVA and Tukey-Kramer. Feed intake for HS/HS, MS/MS, MS/NS, NS/NS was 3438a g, 3481ab g, 3574b g, 3580b g (P, 0.003). Body weight (Ø 2234 g), FCR (Ø 1.57) and mortality (Ø 2.14%) did not differ between treatments. The ratio of water/feed intake was highest in HS/HS. This led to lower litter quality and significantly higher scores for FPL compared to the other treatments. Carcass yield (Ø 69.50%) and composition did not differ between treatments. Feed ingredient costs were 5% higher for NS/NS compared to HS/HS. Overall performance was comparable between treatments, however, SBM led to significantly higher occurrence of FPL