Sustainable alternative feed ingredients: effects of palm kernel cake and decanter cake on broiler growth and production performance

This study evaluated the potential of palm kernel cake (PKC) and decanter cake (DC) as sustainable feed ingredients for broiler chickens. A total of 1,200 one-day-old male chicks were reared for a 35-day experimental period. The birds were randomly allocated into 15 dietary treatment groups, with each group consisting of 8 replicates and 10 birds per replicate. Treatment 1 is considered the control diet, without inclusion of PKC or DC. Treatments 2 to 8 contained 2% to 14% PKC in 2% increments, while treatments 9 to 15 included DC at the same inclusion levels. Statistical analyses were conducted using the General Linear Model (GLM) in Statistical Analysis System (SAS) software. One-way analysis of variance (ANOVA) was used to determine the treatment effects, and Duncan’s multiple range test was used to determine significant differences between treatment means at p < 0.05. The results showed that higher inclusion levels of both by-products, particularly above 6%, adversely affected broiler growth performance by reducing (p < 0.05) birds’ body weight (BW), carcass weight, average daily gain (ADG) and European Broiler Index (EBI), while increasing (p < 0.05) feed intake (FI) and feed conversion ratio (FCR). Likewise, growth hormone receptor (GHR) and insulin-like growth factor-1 (IGF-1) transcription were unchanged, indicating that performance effects stemmed from nutritional rather than endocrine factors. However, meat quality traits such as pH and water-holding capacity remained unaffected (p > 0.05). This study suggests that DC and PKC can be included in broiler diets at levels up to 4–6%, as higher levels may negatively impact growth performance and carcass characteristics.