| چکیده انگلیسی مقاله |
Extended Abstract
Introduction and Objective: In recent decades, the poultry farming industry has used antibiotics in order to prevent, maintain health, and also to stimulate growth and improve production. Due to the increase in bacterial resistance, and their retention in the tissue and secondary effects, the growth promotor use of antibiotics in the livestock and poultry industry has caused concerns, Therefore, the concern of researchers is to use suitable and harmless alternatives instead of antibiotics in poultry diet. Recently, derivatives of medicinal plants (phytobiotics) such as medicinal plants, essential oils and herbal seasonings were introduced as alternatives. Among the characteristics of medicinal plants, we can mention desirable therapeutic properties, stimulation of food consumption, and antimicrobial and antioxidant activity. Previous studies have shown that the use of dexamethasone mimics the adverse effects of increased corticosterone in broiler chickens and causes an increase in free radicals and induction of oxidative stress. Research findings have confirmed that plant essential oils significantly help the development of the poultry's immune system and improve its performance in real or induced stressful conditions.
Material and Methods: This experiment was conducted to investigate the effect of Savofen© commercial product on performance, carcass traits yields, some blood metabolites, antioxidant enzymes in broiler chickens under the conditions of stress induction by dexamethasone. Experimental treatments include: 1) control treatment (positive control), 2) negative control treatment (treatment under stress by dexamethasone), 3) negative control with 200 mg of Savofen©, 4) negative control with 400 mg Savofen©. Body weight, feed intake and feed conversion were measured at the end of each experimental period. A total number of 400 one-day-old male broiler chicks (Ross 308) were used for 42-d period to investigate the effect of different level of Savofen supplementation in the corn-soybean meal based diet on performance, carcass traits, blood biochemistry and antioxidant status of broilers reared under heat stress conditions. The basic diet of experimental treatments was adjusted based on the needs presented in the Ross 308 breeding management guide by UFFDA software. All experimental diets were the same in energy, protein and other nutrients content. Feed consumption and body weight were measured at the end of each initial, growth and final periods. Daily weight gain and conversion ratio were also calculated. Glucose, protein, triglyceride, cholesterol, HDL cholesterol and LDL cholesterol serum etc. were measured using Pars Azmoun Enzyme Kits and spectrophotometer model Ce1010 of England.
Results: At the end of the period, the body weight of the positive control treatment and the treatment containing 0.4 savofen with dexamethasone stress had similar performance and were significant compared to the negative control treatment (P<0.05). The average body weight gain at the end of the period between positive control treatments and treatment with 0.4 Savofen with dexamethasone stress had the same performance and there was no significant difference (P>0.05). Also, negative control treatment and 0.2 savofen treatment with dexamethasone stress also had the same performance (P>0.05), but a significant difference was observed compared to other treatments (P<0.05). None of the blood traits, including blood glucose, triglyceride, cholesterol, HDL, LDL, VLDL, and glutamine had significant differences (P>0.05). Both aspartate aminotransferase and alanine aminotransferase enzymes had significant differences in the negative control treatment compared to other treatments (P<0.05). The two enzymes superoxide dismutase and glutathione peroxidase of the positive control treatment had significant differences compared to other treatments (P<0.05). In the malondialdehyde component, the positive control treatment of 0.2 savofen with stress induction and dexamethasone had similar performance, but compared to the 0.4 savofen treatment with stress induction and dexamethasone, they were significantly different (P<0.05). The total antioxidant capacity was also significantly different in the negative control treatment compared to other treatments (P<0.05). The components of corticosterone and triiodothyronine in the negative control treatment were significantly different from other treatments (P<0.05). On the other hand, there was no significant difference between the treatments in the tetraidothyronine component. The ratio of triiodothyronine/tetraiodothyronine was the same in all treatments and had a significant difference compared to the positive control treatment (P<0.05).
Conclusion: In general, the performance of treatment with 0.4 Savofen under the stress conditions showed its positive performance during the stress conditions and in most of the traits, its performance was similar to the positive control treatment, so it can be concluded that this supplement can be used to improve conditions in stressful situations rearing in broiler chickens.
Keywords: Broiler chicken, Blood metabolites, Dexamethasone stress Performance, Savofen©
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