Substitution of soybean meal with extruded rapeseed meal improves growth performance, slaughter performance and...

1. This study evaluated the effects of replacing soybean meal (SBM) with extruded rapeseed meal (RSM) on growth performance, meat quality and digestive function in local Chinese Langshan chickens.2. A total of 192, 30-day-old male chickens with similar body weight were randomly divided into four dietary treatments: control group (CON) fed a maize-soybean meal basal diet, 10% replacement of SBM with RSM (10% RSM), 10% replacement with extruded RSM (10% ERSM) and 20% replacement with extruded RSM (20% ERSM). The experiment consisted of two phases (30-51 and 52-72 d of age) with sample collection at each phase.3. The results demonstrated that, compared with CON, the birds fed 10% RSM had significantly lower eviscerated carcass and breast muscle yields at 72 d of age (p < 0.05). The 10% ERSM diet gave significantly higher weight gain, eviscerated yield and better FCR at 51 d of age (p < 0.05). The 20% ERSM birds had significantly improved daily weight gain and eviscerated yield at 51 d of age and increased villi height at 72 d of age (p < 0.05). Compared with 10% RSM, the birds fed 10% ERSM had significantly enhanced weight gain, thigh muscle yield, crude protein digestibility, jejunal enzyme activities, villi heights and lower FCR (p < 0.05) at 51 d of age. The 20% ERSM birds had significantly increased feed intake and villi heights at 51 d of age. Relative to birds fed 10% ERSM, the 20% ERSM group had elevated serum aspartate transaminase at 72 d (p < 0.05).4. Feeding the 10% RSM diets negatively affected slaughter yields, whereas both 10% ERSM and 20% ERSM treatments improved growth performance, slaughter performance and digestive function in Langshan chickens aged 51 d.