Mitigating heat stress impact on laying quails: antioxidant effects of grape seed and black mulberry leaf powder on growth, egg quality, and biochemical parameters.

Heat stress (HS) has a significant effect on poultry husbandry, especially laying breed, which lowers productivity and egg quality. In this study, grape seed powder (GSP) and black mulberry leaf powder (BMLP) were evaluated as natural antioxidants against HS effects on laying quails. The trial involved 288 8-week-old laying quails in a 2 × 3 factorial design with (six replicates and eight quails in each) two temperatures (thermoneutral and HS) and three diets (Control, 3%GSP, 4%BMLP). Feed intake was shown to be negatively impacted by HS, however its effects were mitigated by GSP and BMLP (P < 0.05). Despite HS-induced reductions in egg and shell weight, BMLP significantly prevented egg weight loss (P < 0.05). A positive impact of GSP and BMLP could be seen on egg weight, albumen quality, and yolk color (P < 0.05). Serum biochemistry analysis indicated that GSP and BMLP reduced cholesterol and triglyceride levels, while BMLP showed superiority in decreasing malondialdehyde (MDA), an oxidative stress marker (P < 0.05). Furthermore, both additives improved albumen quality and reduced oxidative stress. These findings emphasize the potential of natural antioxidants, particularly BMLP, for enhancing quail resilience to HS and maintaining overall health. Therefore, incorporating GSP and BMLP into quail diets is recommended to mitigate the detrimental effects of HS on productivity and egg quality.