Fermented Feed Inclusion and Slaughter Age Improve Protein and Reduce Cholesterol in Breast Meat of Indonesian Local Chicken (ALPU)

<title>Abstract</title> <p>The Superior Local Meat Chicken (Ayam Lokal Pedaging Unggul, ALPU) is an improved Indonesian indigenous strain valued for high breast meat quality. This study evaluated slaughter age (A1 = 10 weeks; A2 = 12 weeks) and fermented feed inclusion (0, 10, 20, 30%; from tofu waste, rice bran, and corn meal waste fermented with Rhizopus oligosporus for 14 days) on moisture, crude protein, fat, and cholesterol of ALPU breast muscle, using a 2 × 4 factorial completely randomised design with four replications, analysed by two-way ANOVA and Duncan’s Multiple Range Test. Fermented feed inclusion significantly reduced moisture from 72.74% (B2) to 71.97% (B4; P &lt; 0.05); slaughter age had no effect. Both factors significantly elevated crude protein (P &lt; 0.01) with a significant Age × Diet interaction, peaking at 23.37 ± 0.15% at 12 weeks with 30% fermented feed, exceeding commercial broiler benchmarks. Fat content was consistently low (0.30–0.77%; P &gt; 0.05). Slaughter at 12 weeks significantly reduced cholesterol (76.73 vs. 84.18 mg/100g; P &lt; 0.01), with a non-monotonic response in 10-week chickens attributed to age-dependent hepatic regulation of de novo cholesterol synthesis. Pearson correlation identified slaughter age as the dominant predictor of crude protein (r = + 0.838, P = 0.009) and fermented feed level as the dominant predictor of fat (r = + 0.919, P = 0.001). Slaughter at 12 weeks combined with 20–30% fermented feed is recommended for high-protein, low-cholesterol ALPU breast meat production.</p>