Valorisation of dietary olive pomace with Pleurotus ostreatus spawn on amino acid digestibility, growth performance, physiological responses, and meat quality parameters in Jumbo quail

Abstract The effect of dietary olive pomace (OP) processed with oyster mushroom ( Pleurotus ostreatus ) spawn (OMS) on amino acid digestibility, growth performance, physiological responses, and meat quality attributes of Jumbo quail was investigated. Three hundred, one-week-old quail chicks were randomly allotted to 30 replicate cages, producing 6 replicates per treatment. The treatments were a standard grower diet (CON); and CON containing 150 g/kg of OP bioprocessed with OMS at 0, 10, 30, and 40%. Tyrosine digestibility showed a negative quadratic effect [R 2 = 0.641; p = 0.025], while overall feed intake linearly increased [R 2 = 0.302, p = 0.005] with dietary spent oyster mushroom substrate (SMS) levels. A negative quadratic effect for body weight gain [R 2 = 0.672, p = 0.002] and a positive quadratic response for feed conversion ratio [R 2 = 0.362, p = 0.049] were observed in the fourth week. Serum calcium [R 2 = 0.328, p = 0.043] and phosphate [R 2 = 0.314, p = 0.046] linearly declined with dietary SMS levels. A negative quadratic effect was noted for relative breast weight [R 2 = 0.244, p = 0.035]. Birds fed diet with 30% SMS had a lower (p < 0.05) water-holding capacity than birds fed the diet with 10% SMS but were both statistically comparable with the other treatment groups. In conclusion, dietary inclusion levels between 10 and 30% of the SMS enhanced feed intake, body weight gain, and breast weights. However, all SMS inclusion levels altered some blood indices, visceral organs, and meat quality parameters of Jumbo quail.