فهرست مطالب زهرا نوره

In most parts of the world, poultry are exposed to mycotoxins-containing foods. Aflatoxins are the most common mycotoxins formed primarily by the fungus Aspergillus. Fungi that produce aflatoxin can grow and multiply on different materials and under different conditions of humidity, temperature and pH (Mohammadi et al., 2015). A variety of additives, including organic acids, plant essential oils and extracts, probiotics, enzymes, vitamins, and minerals, have been tested to alleviate the negative effects of aflatoxins. Medicinal plant extracts contain active natural substances with antifungal and antioxidant properties that are able to reduce the toxicity of aflatoxins in food (Abdulmajeed, 2011). Ferulago angulate is one of the Apiaceae (Umbelliferae) families native to western Iran (Hosseini et al., 2012) that has been shown to have antioxidant properties and to improve the humoral immune system (Govahi et al., 2013). The aim of this experiment was to investigate the comparative effects of hydroalcoholic extract of Ferulago angulate (FAE), antifungal sorbate, probiotic, and vitamin-selenium complex (containing vitamin C, vitamin E, and selenium) on growth performance, immune response and intestinal morphology in broilers chickens challenged with aflatoxins.

A total of 350 one-day-old broilers (Ross 308) were distributed to 7 treatments with 5 replications/treatment in a completely randomized design. The experimental groups were: 1) negative control (NC; basal diet without any feed additive or aflatoxin B1); 2) positive control (PC; basal diet + 0.5 mg aflatoxin B1/kg); 3) PC + 1 g toxin binder/kg (TB); 4) PC + 1 g/kg probiotic PrimaLac (Pro); 5) PC + a vitamin-selenium complex preparation (ECSe; 200 IU vitamin E/kg feed + 250 mg vitamin C/kg feed + 0.2 mg selenium/kg feed); 6) PC + 200 mg/kg FAE (FAE200), and 7) PC + 400 mg/kg FAE (FAE400). Body weight gain and feed intake were recorded during starter (d 1 to 10), grower (d 11 to 24), finisher (d 25 to 42) and whole of the experiment (d 1 to 42), then the FCR was calculated. At the end of the experiment (42 d), 2 birds of each replicate were randomly selected and then slaughtered by Islamic method. Spleen, bursa of Fabricius and thymus weights were measured and relative weight to total BW of broiler chickens were determined. At 42 d of age, blood samples were collected from two birds in each replicate into vials containing EDTA to avoid blood clot formation. The values of hemoglobin (Hb) and hematocrit (Hct), red blood cell (RBC), white blood cell (WBC), as well as blood leucocyte profiles were measured. In order to assay the primary and secondary antibody responses against sheep red blood cell (SRBC), at 28 and 35 d of age, two birds per replicate were immunized intramuscularly with 1 ml of 2.5 % SRBC in PBS. Blood samples (1.5 mL/bird) were obtained from brachial vein at 7 d after each injection (d 35 and 42). For histopathological examination, the jejunal tissues of slaughtered broiler chickens (1 per replicate) were fixed in 10% of neutral buffered formalin, routinely embedded in paraffin, cut into 6-μm thick sections, and processed for hematoxylin and eosin staining.

The results showed that aflatoxin challenge adversely affected growth parameters; while treatments antifungal and FAE200 during the growing period and all additive-containing treatments during the finisher and whole experimental periods reduced the negative effect of aflatoxin on growth performance (P<0.05). The heterophil count and the heterophil to lymphocyts ratio were decreased by all dietary treatments than those determined in the PC group (P<0.05). All treatments, except probiotic, increased the values of red blood cells, white blood cells, and hematocrit as compared with PC group (P<0.05). The antifungal, probiotic and FAE400 treatments also increased the secondary IgG titer against sheep red blood cells in the aflatoxin-challenged birds (P<0.05). Furthermore, vitamin-selenium and FAE-containing treatments alliviated the negative effect of aflatoxin on villus surface area (P<0.05). According to a previous study (Hussein, 2015), the weight loss during aflatoxin challenge have been attributed to the toxic effects of mycotoxins on different cell organs, resulting in chickens refusing to consume toxins in their diets. It has been documented that the use of additives like selenium is used to remove fungi such as Aspergillus in poultry feed (Hatfield et al., 2012), which can explain the reduction of negative effects of aflatoxin on performance by vitamin-selenium mixture treatment in the present study. It is also reported that lipid peroxidation and the production of free radicals can cause damage to cell membranes during aflatoxicosis (Manafi and Khosravinia, 2013). Therefore, due to their antioxidant properties, vitamin C, vitamin E, and medicinal plants can prevent the production of free radicals in biological systems and thereby improve performance and health status under aflatoxin-inducing conditions. The phenolic compounds, especially polyphenolic compounds in the FAE have been reported to have a high ability to scavenge free radicals and thus can be used as a natural antioxidant in food and pharmaceutical industry (Hosseini et al., 2012). As a result, consuming FAE might reduce the impact of aflatoxin on growth performance, immune response and gut morphology, which is likely due to the antioxidant properties of this medicinal plant and its ability to scavenge free radicals caused by aflatoxin consumption.

In general, according to the findings of this study, Ferulago angulate extract, particularly at a dose of 400 mg/kg of diet, can improve growth performance, immune response, and health status during aflatoxin exposure, which appeared to be comparable to those recorded in the prebiotic and vitamin-selenium treatments. However, the growth benefits by Ferulago angulate extract were poorer than those recorded in the chickens fed with the NC and antifungal diets.

This study was conducted to investigate the effects of hydro alcoholic extract of Ferulago angulata, antibiotic, probiotic, and vitamin-selenium mixture on growth performance and immune responses of broiler chickens under heat-stress conditions. A total of 350 day-old male broiler chickens (Ross 308) were used in a completely randomized design with 7 dietary treatments and 5 replicates (10 chicks/replicate). Experimental treatments were as follow: no heat stress, without any additive in the diet (negative control; NC); challenged with heat stress, without any additive in the diet (positive control; PC); PC + antibiotic; PC + probiotic; PC + vitamin and selenium mixture; and PC + 200 or 400 mg/kg of Ferulago angulata extract. The results showed that all dietary supplements decreased the negative effects of heat stress on growth performance (P<0.05). All experimental diets(except diet containing antibiotic ) increased the lymphocyte counts, but decreased hetrophil counts and heterophil: lymphocyte ratio compared with the PC group (P<0.05). Secondary total titer and IgG titer against SRBC were higher in broilers receiving dietary supplements under heat stress conditions (P<0.05). The 400 mg/kg of Ferulago angulata extract increased the cell-mediated immune response after an intradermal injection with phytohaemagglutinin-P in the toe web (P<0.05). According to the results of this experiment, the use of 400 mg/kg of Ferulago angulata extract in broiler diets improves growth performance and immune response under heat stress conditions, and can be used as a suitable alternative to antibiotics and common supplements under the heat stress conditions.

The objective of this experiment was to investigate the effect of hydroalcoholic extract of Ferulago angulata (FA) as a substitute for common feed additive on performance and blood biochemical and hematological parameters of Ross 308 broilers. A total of 450 one-day-old male broiler chickens were used in a completely randomized design with six treatments and five replicates per treatment. The experimental treatments consisted of the basal diet with no additives (control); the basal diet containing Salinomycine antibiotic (500 mg/kg); Primalak® probiotic (recommended level), vitamin and mineral mixture (200 mg/kg of E and C vitamins and 0.3 mg/kg of selenium) and hydroalcoholic extract of FA at the levels of 200 and 400 mg/kg. During the entire experimental period, the birds fed diets with additives had better body weight gain and feed conversion ratio compared with the control birds (P<0.05). Feeding broiler chickens with experimental diets, except for the diet containing antibiotic, resulted in decreased concentrations of serum triglyceride and cholesterol compared with the control diet (P<0.05). The heterophil percentage and the heterophil to lymphocyte ratio decreased in the birds fed diets with evaluated additives, except for treatment containing 200 mg/kg of FA extract (P<0.05). Based on the results of this study, the FA extract, especially at the level of 400 mg/kg of diet, could be used as a suitable substitute for commercial dietary feed additives to improve growth performance and blood hematological and biochemical parameters of broilers.

This experiment was conducted in order to conside the effect of L-carnitine (0, 125 and 250 mg/kg) and butyric acid (2 g/kg) on Carcass characteristics and meat quality of broiler chicken. In a 2×3 factorial arrangement in randomized complete block design 192 Ross 308 one-day-old broiler chicks were assigned to 6 dietary treatments with 4 replicates and 8 birds. Results showed that broilers fed basal diet plus 125 mg/kg L-Carnitine and basal diet plus 125 mg/kg L-Carnitine plus 2 gr/kg butyric acid had lower FI and the better FCR as compared to control group (P>0.05). Broilers fed basal diet plus 250 mg/kg L-Carnitine had higher breast percentage as compared to 125 mg/kg L-Carnitine (P0.05). Broilers fed basal diet plus 2 gr/kg butyric acid without L-Carnitine had lower tight percentage compare to control group (P0.05). Broilers fed basal diet plus 2 gr/kg butyric acid without L-Carnitine decreased tight meat 45min postmortem and 125 mg/kg L-Carnitine without butyric acid treatment increased tight meat 45min postmortem pH as compared to control group (P 0.05). In conclusion basal diet plus 125mg/kg L-Carnitine and basal diet with 125mg/kg L-Carnitine plus 2 gr/kg butyric acid had the best effect on broiler chickens performance and using basal diet plus 250 mg/kg L-Carnitine increased broiler breast percentage while 2 gr/kg butyric acid decreased breast meat lipid percentage of broiler chicken.

Effect of L-carnitine and butyric acid on the performance and immune responses of 192 broiler chickens (Ross 308) was investigated with 3 levels of L-carnitine (0, 125 and 250 mg/kg) and 2 levels of butyric acid (2 g/kg) in a 2×3 factorial arrangement based on randomized complete block design with 6 dietary treatments, four replicates and eight birds per each. Broilers fed basal diet plus feed additives (L-carnitine and butyric acid) did not have significant differences on feed intake, body weight gain and feed conversion ratio when compred to control group. Broilers fed diets containing additives had higher blood lymphocyte count than control diet fed birds (P < 0.05). Primary IgG tiitter (31d) against SRBC in broilers fed diet containing 125 mg/kg L-carnitine was higher than that of the control birds (P < 0.05). Skin thickness in response to PHA in broielrs fed diet containing 250 mg/kg L-carnitine alone and 125 and 250 mg/kg L-carnitine in combination with butyric acid was lower than that of control group (P < 0.05). It was concluded that addition of 125 mg/kg L-carnitine and 2 g/kg butyric acid did not influenced broiler chicken performance while improved their immune response.