Dietary supplementation of avocado (Persea americana) seed meal on growth performance, serum biochemistry, and meat quality attributes in Jumbo Coturnix quail

Rechanneling of agro-waste by-products such as avocado (Persea americana) seeds from landfills could be a sustainable approach to supply nutrients and functional bio-compounds to conventional quail diets. This study, therefore, examined the effect of dietary supplementation with graded levels of avocado seed meal (ASM) on growth performance, physiological responses and meat quality parameters in Jumbo quail. In a completely randomized design, 200 one-week-old mix-gender quail chicks (28.97 ± 1.391 g live-weight) were randomly allocated to 20 cages (experimental units) and assigned four experimental diets (five replicates each) containing 0 (ASM0), 90 (ASM9), 110 (ASM11), and 130 g/kg ASM (ASM13). The experiment was conducted for five weeks upon which all the birds were slaughtered for measurements. Results showed that cumulative feed intake [R2 = 0.535; p = 0.0002], body weight gain [R2 = 0.535; p = 0.0002] and final body weight [R2 = 0.309; p = 0.042] decreased linearly with increasing levels of dietary ASM. However, there were no linear or quadratic effects (p > 0.05) for cumulative gain-to-feed ratio and mortality. Serum lipase increased linearly [R2 = 0.237, p = 0.035] as dietary ASM levels increased. However, increasing dietary ASM levels linearly reduced relative visceral organ weights (p < 0.05) as well as carcass yield [R2 = 0.574; p = 0.0002]. Breast meat yellowness [R² = 0.735, p = 0.0001] and hue angle [R² = 0.672, p = 0.0001] increased linearly, while meat redness (a*) [R² = 0.420, p = 0.014] and chroma [R² = 0.368, p = 0.004] showed negative quadratic effects as dietary ASM levels increased. Although the inclusion of dietary ASM did not significantly affect feed efficiency and serum biochemical parameters indicative of the birds' health status, higher dietary ASM levels were associated with reduced cumulative feed intake, body weight gain, and carcass yield. These findings suggest that ASM can be included in Jumbo quail diet at levels up to 90 g/kg without adverse effects on growth performance or health, while also improving meat yellowness and hue.