Background: Organic products for animals are becoming more widely accepted by consumers. Using herbal additives may lead to more healthy animal products. In this research, it is hypothesized that thyme essential oil (TEO) and/or selenium yeast (SY) would be helpful to enhance production performance in broilers.Objective: In the current study, the effects of adding TEO and/or SY to the diet on broiler performance and blood parameters were evaluated in broiler chickens.Methods: A total of 480 chicks were distributed in 24 cages with 20 chicks (10 males and 10 females) each and assigned to be fed four iso‐caloric and iso‐nitrogenous diets including two levels (0 and 250 mg/kg) of TEO and two levels (0 and 0.3 mg/kg) of SY in a 2 × 2 factorial arrangement with six replicates.Results: Adding SY significantly decreased feed intake in finishing period (22–42 d) (p < 0.05). Supplementation with SY and TEO significantly decreased plasma uric acid and triglyceride levels, respectively (p < 0.05). However, neither of the supplements had any influence on the plasma glucose and albumin levels (p > 0.05). The lowest level of plasma cholesterol was detected in the birds fed the TEO‐supplemented diet (p < 0.05). Addition of SY significantly increased blood glutathione peroxidase activity (p < 0.05).Conclusions: Dietary supplemental TEO has a favourable effect on feed intake, weight gain, and body weight values. Besides, SY may decrease blood concentration of uric acid, as well as blood glutathione peroxidase activity. An interaction is detected between TEO and SY on blood cholesterol.

Objectives: The effects of dietary supplements, including magnesium sulfate (Mg), zinc oxide (Zn) and vitamin B6 (Vit B6), on the performance of laying hens reared under normal (NC) and heat‐stress (HSC) conditions were investigated.Material and Methods: A total of 288 30‐week‐old Lohmann LSL‐Lite laying hens were randomly divided into 48 cages and assigned to receive one of the eight diets with six replicates and six hens per replicate, based on a 2 × 2 × 2 factorial arrangement of treatments. Dietary supplements, including two levels (0 & 600 mg/kg) of Mg, two levels (0 & 30 mg/kg) of Zn and two levels (0 & 8 mg/kg) of Vit B6, in normal and heat‐stress conditions, were tested at 30–40 and 41–45 weeks of age, respectively.Results: In the Vit B6 group, a decrease in feed intake (FI), egg production (EP), albumin, Zn, Fe and Mg, and an increase in triglyceride and insulin in HSC were observed, in addition to a decrease in cholesterol and an increase in egg weight (EW) in NC. Supplemental Mg decreased EP, blood triglycerides and copper in NC, and Zn, Fe and Mg in HSC as well. Feeding Zn, increased egg shape index, total protein and copper in addition to yolk index in NC and Fe in HSC. EWs were higher in hens supplemented with Vit B6+Mg in HSC. Increased insulin and decreased glutathione peroxidase activity were detected with the Vit B6+Zn compared to feeding either Vit B6 or Zn in HSC.Conclusions: The results indicated Vit B6 could improve EWs and suppress blood cholesterol in NC. Zn improved the egg shape index in NC.

In this study, 160 73-week-old laying hens (HyLine W-36) were used to investigate the changes in production performance and egg quality parameters of aged laying hens after injection of different doses of growth hormone (GH) and a fixed dose of testosterone (Ts). The hens were weighed individually, placed in laying cages and then randomly assigned to four treatments with four replicates of 10 birds each, in a completely randomised design. The experiment was started at the 75th week and lasted until the 82nd week of age. The treatments were: 1: injection of 100 µL distilled water (control group), 2: injection of 500 µg Ts/kg liveweight + 50 µg GH/kg liveweight, 3: injection of 500 µg Ts/kg liveweight + 100 µg GH/kg liveweight and 4: injection of 500 µg Ts/kg liveweight + 150 µg GH/kg liveweight. In this study, ovulation rate (egg production percent), egg mass and feed intake were significantly higher in Treatment 3 than the control group (P < 0.05), and in Treatment 4, feed conversion ratio was significantly higher than for the other experimental groups (P < 0.05). In addition, the birds in Treatment 3 showed greater egg weight, albumen height, eggshell weight, eggshell density and eggshell weight per surface area than the control group (P < 0.05). In Treatment 3, egg length significantly increased compared with Treatments 1 and 4 (P < 0.05), and in Treatments 2 and 4, shell breaking strength was significantly lower than for the control group (P < 0.05). In conclusion, our results showed positive effects of GH and Ts administration on egg quality parameters and production performance in aged laying hens. Taken together, in the present study Treatment 3 was found more effective in improving egg quality and production performance of the old laying hens.

Background: Animal food shortage and finding efficient ways to produce poultry products are getting more and more important issues in the world.Objectives: This study was aimed to determine the effect of replacing corn with pasta wastes (0%, 50% and 100%) in the diet on production performance, some blood variables and the egg quality traits of laying quails.Methods: A total of 240 laying quails were allocated into 3 experimental groups with 8 replicates for 8 weeks. Egg production percentage, egg mass, feed intake and also mortality rate and percentage of abnormal eggs, egg quality traits and blood variables were evaluated.Results: None of the pasta wastes inclusion had significant effect on egg mass, abnormal egg percentage, mortality rate, yolk diameter, yolk weight, albumen height, yolk index, shell weight percentage, egg shape index and blood parameters (except for triglycerides). Replacing 100% corn with pasta by‐product reduced feed conversion ratio and increased egg weight values. Replacing 100% corn by pasta wastes significantly increased the albumen weight, shell weight and also egg length and width and decreased the Haugh unit. Replacing 50% and 100% corn had a significant increase in yolk height, egg surface area and significantly decreased shell thickness and yolk colour. Overall, 100% replacement of corn by pasta by‐product increased blood triglycerides compared to the 50% group.Conclusions: Based on the result of current experiment, total replacement of corn with pasta wastes could increase the egg weight and also improve feed conversion ratio in the laying quail diets.