نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم دامی، دانشکده کشاورزی، دانشگاه بیرجند، بیرجند. ایران
2 گروه صنایع غذایی، پژوهشکده علوم و فناوری مواد غذایی جهاد دانشگاهی مشهد، مشهد. ایران
3 مدیر عامل شرکت دانش بنیان گلچین توس (شرکت زایشی جهاد دانشگاهی مشهد) مشهد. ایران.
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The aim of this experiment was to investigate and compare the effectiveness of the microencapsulated of medicinal plant extracts and raw extracts of six plants involved thyme, oregano, rosemary, fennel, turmeric and peppermint on growth performance, carcass components and immune response of broilers. In invitro condition, the extracts were microcoated with different ratios of carbohydrate wall (1:10, 1:15 and 1:20). The results showed that the ratio of 1:10 microencapsulated is more efficiency in terms of quality indicators. For this experiment, 650 one-day-old chicks of ROSS 308 were used in a completely randomized design with 13 treatments, 5 replicats and 10 birds for 42 days. The amount of 600 mg/kg of raw extract and 6.6 gr/kg of micro-encapsulated extract of plants was added to the rations in a mixed component. Data on feed intake, weight gain and feed conversion ratio were recorded in periods of 0-10, 11-24 and 25-42 days. On the seventh day of the experiment, Newcastle and influenza vaccines were injected, and at the 35th day, one bird from each replicate were bleeding and the antibody titer was measured. The results showed, as compare to control, treatments containing a microencapsulated extracts increased body weight in the starter and grower periods, and improved the FCR in the starter, grower an d whole period of experiment(P<0.05). However, the treatments containing raw and microencapsulated extract had no effect on feed intake. The treatments of raw and microencapsulated extracts increased the relative weight of carcass and abdominal fat, but had no effect on the antibody titer against Newcastle disease and influenza. Therefore, the addition of different proportions of microcapsule extract may improve the growth performance of broiler chickens.
کلیدواژه‌ها [English]
Extended Abstract
Introduction
In recent decades, after banning the use of growth promotors and therapeutic compounds with a negative impact on human health, such as antibiotics, in many countries, including the European Union, there is a tendency to use alternative substances such as herbal bioactive compounds, which are particularly more effective. Medicinal plants and their compounds have long been of interest to traditional and industrial livestock and poultry farmers. One of the most important advantages of effective herbal substances is the lack of resistance of bacteria and pathogens to these compounds due to their long-term use from the past to the present day. Due to the sensitivity of plant compounds and on the other hand to protect them until the bird consumes them and reaches the desired organs in the body, processes such as microcoating are used. During the microencapsulation process, the active substances of the plant (essence or extract) are trapped inside lipid, protein, or carbohydrate membranes. These valuable compounds are protected from oxidation and degradation until they are consumed and enter the digestive system. On the other hand, it is easier to store, transport and mix plant extracts in the form of microcapsule powder compared to raw extracts that are in liquid form. The purpose of this experiment is to investigate and compare the effect of microcapsulated extract and free extract (without capsules) of six plants: thyme, oregano, rosemary, fennel, turmeric and mint on performance, carcass components and immune response of broiler chickens.
Materials and methods
Medicinal plants including thyme, oregano, rosemary, fennel, turmeric and mint extracts were prepared and then encapsulated in three ratios of 1:10, 1:15, 1:20 plant extract/ carbohydrate wall on a laboratory scale. The microencapsulation efficiency (%) was evaluated with some quality indicators. Capsules with a ratio of 1:10 plant extract/carbohydrate wall showed higher encapsulated quality and lower cost than other ratios. Therefore, this ratio was used for production in industrial scales. The final product of the powdered microencapsule were combined with each other according to each treatment and added to the diet of broiler chickens. To conduct the in vivo experiment, 650 one-day-old chicks of ROSS 308 were used in a completely randomized design with 13 treatments and 5 repelicates and 10 birds for 42 days in the battery cage system of Zarin Roshd Kosar Research Farm. The amount of 600 mg/kg of free extract and 6.6 gr/kg of microencapsulated extract of plants was added to the diets based on dietary treatments. The diets were adjusted and used for the 4 periods involved starter 1-10 days), grower (11-24 days), finisher (25-35 and 36-42days). The feed intake, weight gain and feed conversion ratio were recorded in periods of starter, grower and finisher. On the seventh day of the experiment, Newcastle and influenza vaccine (Razi) was injected, and on the thirty-fifth day of the experiment, one bird was selected from each repelication and the antibody titer was measured. At the end of the experiment, one bird was selected and slaughered from each repelication, and the relative weight of the carcass components was determined.
Resuls and Discussion
The results of the experiment showed that the treatments containing the mixture of microencapsulated extracts increased the weight gain in the starter and grower compared to the control treatment, however all the treatments containing raw extract and most of the microencapsulated treatments had no effect on feed intake. Adding of microencapsulated mixed plant extracts to the diet improved the feed conversion ratio compared to the control treatment and some treatments of raw extract were grown in the starter. In the growth period (11-24), chickens fed with the diet containing microencapsulated extracts with the formulas of treatment 7, 9 and 11 and raw extract treatment with formula 8 showed an improvement in feed conversion ratio compared to the control treatment and raw extracts diets. In the whole experiment, the addition of microcapsule extracts with the formula of treatments 3 and 13 and raw extract of treatment 8 improved the feed conversion ratio compared to the control. Treatments contained raw and microencapsulated extract increased relative carcass weight and abdominal fat, but had no effect on antibody titers against Newcastle disease and influenza. Using of different proportions of microencapsulated plant extracts significantly improves the growth performance in the whole period and in the starter. The starter period is one of the most sensitive periods due to the possibility of bacterial infections such as yolk sac infection, lack of development of the digestive system and low secretion of digestive enzymes. According to the results, the use of microencapsulated compounds of plant extracts improved growth performance in starter period. The positive effects of plant extracts can be due to antibacterial effects, improvement of the morphology of the villi of the digestive tract, and an increase in the secretion of digestive enzymes. On the other hand, the use of microencapsulated extracts can be more effective, and the powdered microcapsule can be better mixed with the poultry diet compared to the liquid form of the raw extract. And it does not need to be stored in special temperature and environmental conditions until consumption, and it can easily be used in breeding farms. The treatments contained raw or microcapsule extracts increased the relative weight of carcass and abdominal fat, but had no effect on the antibody titer against Newcastle disease and influenza.
Conclusion:
Therefore, the addition of different proportions of microcapsule extract may improve the growth performance of broiler chickens.
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