اثر استفاده از مخلوط عصاره گیاهان دارویی بر عملکرد، خصوصیات لاشه، متابولیت‌های سرم خون و فعالیت آنزیمی در جوجه‌های گوشتی

این آزمایش به منظور بررسی اثر استفاده از مخلوط عصاره گیاهان دارویی در مقایسه با آنتی‌بیوتیک اکسی تتراسایکلین بر عملکرد، خصوصیات لاشه، متابولیت‌های خون و آنزیم‌های سرم خون جوجه‌های گوشتی سویه راس 308 انجام گرفت. آزمایش در قالب طرح کاملا تصادفی با 5 تیمار، 4 تکرار و 8 قطعه جوجه خروس گوشتی در هر تکرار به مدت 42 روز انجام شد. تیمارهای آزمایشی شامل تیمارهای حاوی آنتی بیوتیک، 50، 100 و 200 میلی‌گرم در کیلوگرم جیره از مخلوط عصاره گیاهان دارویی فلفل، دارچین و پونه بود. نتایج نشان داد مصرف خوراک در 101 روزگی و ضریب تبدیل خوراک در کل دوره آزمایش تحت تاثیر افزودن 100 میلی‌گرم در کیلوگرم مکمل عصاره‌های گیاهی به طور معنی‌داری کاهش پیدا کرد. افزایش وزن بدن جوجه‌های گوشتی بوسیله تمام سطوح عصاره‌های گیاهی به طور معنی‌داری افزایش یافت. وزن نسبی سینه و بال‌ها تحت تاثیر 100 میلی‌گرم در کیلوگرم مکمل عصاره‌های گیاهی به طور معنی‌داری افزایش یافت. کلسترول سرم خون جوجه‌های گوشتی تحت تاثیر میزان 50 و 100 میلی‌گرم در کیلوگرم مکمل عصاره‌های گیاهی کاهش پیدا کرد و همچنین غلظت hdl سرم خون در سن 42 روزگی با مصرف تمام سطوح عصاره‌های گیاهی به طور معنی‌داری افزایش یافت. سطوح 50 و 100 میلی‌گرم در کیلوگرم مکمل عصاره‌های گیاهی باعث افزایش معنی‌دار پروتئین و گلوبولین سرم گردید. غلظت آنزیم ast نیز تحت تاثیر 100 میلی‌گرم در کیلوگرم مکمل عصاره‌های گیاهی به طور معنی‌داری کاهش پیدا کرد. نتایج به دست آمده از این مطالعه نشان می‌دهد استفاده از 100 میلی‌گرم در کیلوگرم مکمل مخلوط عصاره گیاهان دارویی فلفل، دارچین و پونه می‌تواند اثرات مفیدی بر عملکرد، خصوصیات لاشه، چربی‌های خون و آنزیم‌های سرم خون جوجه‌های گوشتی داشته باشد.

Effect of Use of Mixture of Herbal Extracts on Performance, Carcass Characteristics, Blood Serum Metabolites and Enzyme Activity of Broiler Chickens

Introduction In view of rising concerns on the extensive use of antibiotics in animal production, there is an increasing interest for developing alternative disease control strategy to enhance animal health and to reduce the use of antimicrobials. One promising new possibility to achieve this goal is the use of natural foods and herbal products to enhance feed efficiency, gut health, and innate immunity. In clinical medicine, plantderived products are increasingly being used as feed supplements to enhance immunity to diseases and cancers. Among these products, the dietary effects of the mixture of three plant derived phytochemicals, carvacrol, cinnamaldehyde, and Capsicum oleoresin as antibacterial and antifungal agents have been reported. Carvacrol is a component of numerous aromatic plants, such as Origanum vulgare, thyme, and wild bergamot. The antimicrobial functions of these herbs are associated with carvacrol since carvacrol vapour has been shown to inhibit Salmonella growth in chickens. Cinnamaldehyde is a constituent of cinnamon and widely applied as flavoring. It has been proven to have strong antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, methicillinresistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Salmonella sp., and Vibrio parahemolyticus. Capsicum oleoresin, prepared by organic extraction of pepper fruits, contains antibacterial activity. It contains the pungent principles, capsicin which has effects on the resistance to Salmonella enteritidis infection by altering pH and histological changes. Materials and Methods In this study, 160 Ross 308 male broiler chicks were allocated in a completely randomized design with 5 treatments, 4 replicates of 8 chicks in each replicate for 42 days. Treatments contained 1 level of oxytetracycline antibiotic and 3 levels of extract supplementation (50, 100 and 200 mg/kg of feed). The rearing and management conditions were equal for all groups. Experimental diets were formulated to meet the nutrients requirements of the Ross broiler chicks. Chicks had full access to feed and water during the experimental period. Performance parameter such as body weight gain, feed intake and feed conversion ratio were recorded at 110, 1124 and 2542 d of age for each replicate. At the end of the experiment, two birds of each replicate were slaughtered and blood was collected to determine hematological parameters, and carcass characteristics were analyzed. Results and Discussion Based on the results, in 110 d period supplementing the broiler diet with 100 mg/kg herbal extracts decreased significantly feed intake (P <0.05). Herbal extracts significantly increased body weight gain of broiler chickens (P <0.05). Feed conversion ratio of the chicks fed 100 g/ton of herbal extracts were decreased significantly compared to control treatments (P <0.05). The relative weight of breasts and wings influenced by 100 grams per ton of herbal extracts supplement significantly increased (P <0.05). Blood cholesterol of broiler chickens decreased in treatment containing 50 and 100 g/ton of herbal extracts, also blood serum concentrations of HDL by use of all levels of plant extracts significantly increased (P <0.05). The concentration of the enzyme AST influenced by 100 g/ton of herbal extracts significantly decreased (P <0.05). The results obtained in the present study confirmed the stimulating growth and efficiency effect of the mixture of carvacrol, cinnamaldehyde, and capsicum oleoresin. Another study showed the effects of dietary oregano essential oil on live chickens performance where it improved the FCR significantly as compared with control chickens and birds fed the oregano oil diet consumed significantly less feed compared to controls from 21 to 42 d of age. It was reported that broiler chickens fed with herb extract had higher breast weight compared to control group. Contrary to our findings, another researches showed that supplementation of combination of two herb extracts had no effect on carcass characteristics. The positive change, that is increase in feed efficiency, is in agreement with the ability of spices and mixtures of spices to increase bile secretion, activity of the pancreatic, and brush border enzymes. The positive impact on poultry production of the used herbal compound in the present investigation could be attributed to its antioxidant activity, enhancing digestibility by stimulating endogenous enzyme activity and facilitating nitrogen absorption and/or its antimicrobial activities as essential oils. Conclusions The results obtained from this study showed that use of 100 g/ton of mix herbal extracts supplement could have beneficial effects on performance, carcass characteristics, blood lipids and serum enzymes of broiler chickens.