The current study determined the ideal dose of choline in the diet of laying quails based on egg development, egg quality, and antioxidant capacity. A total of 120 female quails (244.7 ± 10.38 g) were randomly assigned to 6 experimental groups with 5 replicates of 4 quails each. In the 10-week trial, treatment diets were formed by adding 6 choline chloride−60% concentrations providing 1500 (control), 2000, 2500, 3000, 3500, and 4000 mg/kg of choline. The feed intake of quails was quadratically affected (p < 0.05) by the choline level of the diet, in other developmental parameters, and by egg quality among these treatments. The feed intake was reduced to 2500 and 3000 mg/kg levels of choline in the diet compared to the control group. Free radical scavenging capacity (DPPH) of the yolk increased linearly (p < 0.001) with dietary choline levels. In contrast, the thiobarbituric acid reactive substances (TBARS) value decreased as dietary choline levels increased, except for 4000 mg/kg levels. Based on the findings of the current study, 1500 mg/kg of dietary choline is adequate to maintain performance parameters and egg quality in laying quails. However, to increase egg antioxidant capacity, in terms of the DPPH value, the dietary choline dose needs to be increased to 3500 mg/kg.

This study set out to determine the effects of dietary supplementation of grape seed oil and Hypericum perforatum L. extract to the laying hens (Lohmann White, 40 weeks of age) on performance, egg quality and some blood parameters. For this purpose, a total of 336 hens were randomly distributed to the control and other treatment groups, 12 replicates/group with 4 hens/replication. Birds were fed with basal diet only (control group) and the basal diet supplemented with different levels (100, 200, 300 mg/kg) of grape seed oil (GSO-1, GSO-2, and Hypericum perforatum L. extract (HPE-1, HPE-2, HPE-3). Dietary treatments had no significant effect on performance parameters. GSO-3 and HPE-1 supplemental groups presented with increased shell weight (p<0.01) while only GSO-1 group showed increased egg albumen index (p<0.01) and Haugh unit (p<0.05). Among blood parameters, except for serum HDL and total protein, the other blood parameters (serum triglyceride, total cholesterol, LDL, AST, Ca and P) were not affected by the treatments. In conclusion, results showed a partial improvement in some egg quality traits, however, further studies are needed to fully investigate the beneficial effects of these additives in laying hens reared under different stresses.

The survey was carried out to establish the impact of red beet powder (RBP) on performance parameters and egg quality in laying quails. One twenty hundred (120) female laying quails aged 22 weeks were randomly assigned into five groups of 4 females each, and six replicates. Treatments diets were formed by adding 0, 0.2, 0.4, 0.6, and 0.8% RBP to the basal diet. The dietary inclusion of RBP did not affect performance parameters and egg production (P > 0.05) except feed conversion ratio, which was quadratically affected (P < 0.05). The feed conversion ratio was improved in the 0.4% group with concerning control. The inclusion of RBP did not modify the yolk color (L*, a*, b*) or egg quality (P > 0.05). However, the yolk index showed the highest value (P < 0.05) in quails fed 0.2% RBP. Free radical scavenging capacity (DPPH) of the yolk decreased (P < 0.05) when RBP levels increased above 0.6%. In contrast, the 0.6% RBP group had the highest level of thiobarbituric acid reactive substances (TBARS). Data from the present study provide valuable information to include RBP as an ingredient without affecting performance and egg production. It is an interesting option within the framework of the circular economy and of reusing vegetable products to use this ingredient in animal feed.

The goal of the current experiment was to investigate the effect of dietary concentrations of purple carrot powder (PCP) on performance, egg production, egg quality, and the antioxidant capacity of the yolk in laying quails. A total of one hundred and fifty 22-week-old Japanese laying quails were allotted to 5 dietary treatments each with 6 replicates of 5 quails. Quails were allocated to five dietary treatments (0, 0.1, 0.2, 0.3, and 0.4%) with PCP addition at an increasing level from 0 to 4000 mg/kg diet respectively, which were fed ad-libitum throughout the duration of the experiment. No differences were detected between dietary treatments for any of the performance parameters or egg production. Eggshell weight and eggshell thickness (P < 0.05) were linearly affected by PCP dietary, reaching maximum levels at 0.4% of PCP supplementation, while the percentage of damaged egg and egg-breaking strength remained similar for all experimental groups (P < 0.05). Quails receiving PCP diets showed a yellowness (b*) (P < 0.05) egg yolk color than those fed the control diet, without affecting the rest of the color parameters and egg internal quality. Increasing PCP levels in diets reduced linearly yolk TBARS (P < 0.01) and increased linearly DPPH (P < 0.01). The addition of PCP, a safe and readily available agricultural by-product, as a component of the diet of laying quail was effective without adversely affecting quail production. Moreover, the inclusion of PCP in the diet might benefit laying quails’ eggs by improving some quality traits and enhancing the yolk’s antioxidant capacity, which could improve their shelf-life and acceptability.

In this study, it was aimed to determine the effect of orange peel powder addition to laying quail diets on performance, egg external and internal quality, and egg antioxidant activity. A total of 120 female Japanese quails were randomly allocated to 6 treatment groups with 5 replicates each. Treatment groups were formed by supplementing 0, 1, 2, 3, 4 and 5 g/kg orange peel powder to the basal diet. Performance parameters such as body weight, body weight change, egg production, egg weight, egg mass, feed intake, and feed conversion ratio and egg quality parameters of laying quails were not affected by the addition of orange peel to the diet. Egg yolk DPPH (2,2 diphenyl-1-picrylhydrazyl) activity increased linearly with the addition of orange peel powder to the diet compared to the control group, but this effect was not observed at egg yolk TBARs (thiobarbituric acid reactive substances) level. At the end of the study, it was determined that orange peel powder could be used in the diet in order to improve the antioxidant activity of egg yolk without affecting performance and egg quality in quails.