In this experiment, the effect of hydroalcoholic grape seed extract (GSE) and vitamin C feed supplementation on some blood parameters and heat shock protein 70 (<em>HSP70</em> gene) expression of broiler chickens suffering from chronic heat stress was investigated. Experimental diets included control diet (with no additive), 3 levels of GSE (150, 300, 450 mg/kg), and one level of vitamin C (300 mg/kg). Each diet was fed to 5 replicates of 12 male chicks each, from d 1 to 42. The birds suffered from chronic daily heat stress under 34±1°C temperature with 65 to 70% relative humidity for 5 h from 29 to 42 d of age. Results showed that 300 mg/kg GSE supplementation increased body weight of broilers both before and after heat stress condition (at 28 and 42 d, respectively). Also, birds fed 300 mg GSE/kg diet had higher European production efficiency factor during the whole period of the experiment. Supplementation of GSE decreased the concentration of serum glucose at 28 and 42 d; at 42 d (during heat stress condition) and at 450 mg/kg diet it decreased cholesterol, triglyceride, lowand very low density lipoprotein concentration of serum blood. Vitamin C supplementation decreased serum cholesterol concentration of broilers suffering from heat stress. <em>HSP70</em> gene expression in heart and liver of broilers reduced by GSE and vitamin C supplementation pre- and during chronic heat stress condition.

The effect of dietary thyme-oil extract (TOE) supplementation on immune functions of broilers were assessed by feeding graded levels (50, 100, 200, or 400 ppm) of TOE to male broiler chicks during a 42-d feeding trial compared with negative-or positive-control diets. Dietary control treatments included a negative-control diet with no feed-additive supplementation and 2 positive-control groups supplemented with either virginiamycin or zinc bacitracin. In total, 300 1-day-old Ross × Ross male broilers were randomly assigned to 6 dietary treatments that consisted of 5 replicates of 10 birds each. On d 21 and 42, 2 birds from each replicate were killed by cervical cutting to measure the relative weights of spleen and bursa of Fabricius. At 25 d of age, chicks were injected with 0.5 mL of 10% SRBC suspension. Broilers fed with 200 ppm of TOE had heavier weights of bursa of Fabricius than those fed other dietary treatments at d 42 of age. Furthermore, dietary inclusion of 100 ppm of TOE resulted in higher (P < 0.05) total immunoglobulin response in primary antibody titer against sheep erythrocytes compared with other dietary treatments. On the other hand, diet modifications had no significant effect on blood leukocyte subpopulations and heterophil-to-lymphocyte ratio. These results suggest that dietary supplementation with TOE, especially at the level of 100 ppm, can improve immunological responses of broiler chicks.

An experiment was conducted to evaluate the effects of in ovo injection of chrysin, quercetin and ascorbic acid on hatchability, somatic attributes, hepatic antioxidant status and early post-hatch growth performance of broiler chicks. Four hundred and eighty embryonated broiler breeder eggs containing live 18-day-old embryos were divided into six groups of 80 eggs each. One group remained intact and served as a control group (i), whereas the other five groups were injected with the prepared injection solutions as follows: (ii) 0.05 ml distilled water; (iii) 0.05 ml distilled water containing 6 mg ascorbic acid; (iv) 0.05 ml dimethyl sulfoxide (DMSO); (v) 0.05 ml DMSO containing 4.5 mg quercetin; and (vi) 0.05 ml DMSO containing 4.5 mg chrysin. The hatchability rate, hatching weight, residual yolk sac weight, yolk sac-free body weight, liver weight, hepatic glutathione peroxidase and total superoxide dismutase activities, as well as malondialdehyde concentrations, were not affected by the injected solutions. There were no differences between chicks hatched from the control and in ovo injected eggs in weight gain, feed intake and feed conversion ratio from 0 to 11 days of age. However, the specific contrast performed between the in ovo injected groups and intact eggs revealed that in ovo injection significantly increased hatchability rate (p = .0493). This finding also implies that our injection procedure was harmless. In conclusion, the intra-egg injection of chrysin, quercetin or ascorbic acid at the injection rates used in this study did not have a significant effect on hatchability, somatic characteristics, early growth performance and hepatic antioxidant status of broiler chicks. However, the overall hatchability was higher in the in ovo injected eggs as compared to non-injected ones. These findings also confirmed the harmlessness of the procedure developed for in ovo injection in this study.

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The aim of this study was to examine the effects of various levels of supplemental calcium iodate (CI) on productive performance, egg quality, blood indices and iodine (I) accumulation in the eggs in commercial laying hens. A total of 240 White Leghorn layers (Hy-line W36) were divided through a completely randomized design into six treatments with five replicates and eight hens per each at 32 weeks of age. This experiment lasted for 12 weeks. Concentrations of I in the mash diets were 0.74, 3.13, 5.57, 8.11, 10.65 and 12.94 mg I/kg of feed in treatments 1-6 respectively. The added doses of CI were included 0.0 (control), 2.5, 5.0, 7.5, 10.0 and 12.5 mg/kg of diet for treatments 1-6 respectively. There were no significant differences in productive performance among the treatments. The highest eggshell strength was observed in group fed diet containing 3.13 mg I/kg (p = .014). The highest percentage of calcium and lowest percentage of phosphorus in eggshell were observed in group fed diet containing 12.94 mg I/kg (p = .0001). Feeding hens with diet containing 12.94 mg I/kg increased serum triiodothyronine-to-thyroxine ratio (p = .0001). Serum alanine aminotransferase activity in hens fed diet containing 12.94 mg I/kg was significantly more than control (p = .041). Blood Serum triglycerides in hens fed diet containing 8.11 mg I/kg were significantly higher than control (p = .0001). Edible fraction of the eggs of birds fed diet containing 12.94 mg I/kg was enriched by I almost 3 times more than those fed diet containing 0.74 mg I/kg. The results suggested that egg production, egg mass, feed intake and feed conversion ratio were not significantly affected by dietary I levels. Iodine accumulation in the eggs were increased by increasing dietary I levels and the level of 10 mg/kg CI could supply I enrichment of the eggs.

This study was carried out to investigate the effects of dietary supplementation of hydroalcoholic extract of Heracleum Persicum fruit (HPE) on performance, immune responses, small intestine morphology, haematological parameters and carcass characteristics of broiler chickens. A total of 300 day-old Ross 308 broiler chicks were used in a completely randomized design with five treatments and five replicates of 12 chicks each. The treatments were comprised of a corn-soybean meal base diet supplemented with five levels of HPE at 0(control), 100, 200, 300 and 400 mg/kg diet. Average daily feed intake (ADFI) was increased by 100 mg/kg of HPE comparing to control group during 11-24 d (p < 0.05). HPE at the levels of 200, 300 and 400 mg/kg, decreased (p < 0.05) serum cholesterol comparing to control group and showed a linear response to different levels of HPE (p = 0.0007). Also, LDL was decreased by 300 mg/kg of HPE (p < 0.05). The villus height to crypt depth ratio (VH/CD) was increased by 400 mg/kg of HPE, comparing to control group at 42 d (p < 0.05). Also, this ratio showed a linear response to different levels of HPE (p = 0.007). The results of this study indicated that HPE improves performance and intestine morphometrical and haematological parameters of broiler chickens. ARTICLE HISTORY

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An experiment was conducted to investigate the effects of hydroalcoholic extract of Withania coagulans (WC) fruit and 1.25-dihydroxycholecalciferol (1.25-(OH) 2 D 3 ) on bone mineralization, mechanical and histological properties of male broiler chickens at 21 and 42 d of age. A total of six hundred male day-old Ross 308 broiler chickens were randomly distributed according to a completely randomized experimental design in a 2×3×2 factorial arrangement with 12 treatments of five replicates of 10 birds each. Treatments consisted of two basal diets (positive control with adequate Ca level and negative control with 30% less Ca), three levels of WC (0, 100, or 200 mg/kg diet), and two levels of 1.25-(OH) 2 D 3 (0 or 0.5 μg/kg diet). Birds were housed in floor pens. The diets were fed ad libitum from one to 42 days of age. On day 21 and 42, one bird per replicate was sacrificed and its tibiae were removed. Both Ca and P retention increased when dietary Ca level was reduced (p<0.001). The addition of 200 mg WC/kg to positive control diet increased Ca retention (p<0.01). Except for tibia diameter, no significant main effects of experimental treatments were observed on tibia physical characteristics or on bone mineralization. The diet with 30% Ca reduction decreased tibia diameter at 42 days of age (p<0.05). The dietary addition of 1.25-(OH) 2 D 3 increased tibia fracture energy, width of tibia mineralized zone, and serum Ca at 42 days of age (p<0.05). At 21 days of age, supplementation of 100 mg WC/kg increased cortical thickness (p<0.05). At 42 days of age, supplementation of 100 mg WC/kg increased tibia shear force (p<0.05) and fracture energy (p<0.01). The results of this experiment showed that supplementation of 100 mg/kg hydroalcoholic extract of WC fruit increased tibia cortical thickness, shear force, and fracture energy.