زهرا تهامی

[1]Selenium is an essential mineral for many metabolic functions of the body, including the activation of enzymes and the optimal biochemical and physiological function of birds (Antongiovanni et al., 2007). Selenium protects cell membranes from oxidative damage and can therefore improve nutrient efficiency (Arner et al., 2012). The small intestine is the most important part in the digestion and absorption of nutrients, while the large intestine and intestinal tract are very important areas for the accumulation of microbes (Chitra et al., 2013). Gastrointestinal health is one of the most important and effective factors in bird function. Gastrointestinal microbial population affects the nutrition and health of various animal species, including poultry. These microorganisms need trace elements such as selenium to perform their normal metabolic functions. Selenium may affect bacterial cells by disrupting the respiratory chain (Pappas et al., 2005). In addition to improving the quality and composition of intestinal microflora, selenium can have a positive effect on the morphology of the intestine as an antioxidant (Haghighi-khoshkhoo et al., 2010). Despite these benefits, the effect of selenium on intestinal microbial population is largely unknown, so the aim of this study was to investigate the effect of different levels of organic and inorganic selenium in the diet on microbial population, intestinal morphology and intestinal acidity in laying hens.

The experiment was conducted in a completely randomized design with 300 laying hens of high-line strains from 23 to 35 weeks of age with 5 treatments, 6 replications and 10 hens per replication. Experimental treatments include 1- Base diet (without selenium), 2- Base diet + 0.5 mg/kg sodium-selenite, 3- Base diet + mg/kg 1 selenite-sodium, 4- Base diet + mg/kg 0.5 selenium-methionine, 5-base diet + 1 mg/kg selenium-methionine. At the end of the experiment, two birds were randomly selected from each replicate; To evaluate the microbial population, a sample of the contents of the cecum on the culture medium was used (1). Tissue samples were prepared and then measured using a microscope, villi length, villi width, crypt depth, and number of goblet cells (9). To measure acidity, samples were taken from the contents of the cecum, and acidity was measured by a pH meter.

The results indicate that consuming 1 mg/kg of selenium-methionine increased the villi area compared to the control treatment. The experimental treatments did not affect villi length, villi width, crypt depth, number of goblet cells, and the ratio of villus length to crypt depth. The consumption of 1 mg/kg of selenium-methionine significantly decreased the population of Salmonella and increased the population of Lactobacillus in the cecal compared to other experimental treatments. The consumption of 0.5 and 1 mg/kg of selenium-methionine caused a significant decrease in the population of aerobic bacteria compared to the control treatment. The acidity of cecal contents in the treatment containing 1 mg/kg of selenium-methionine was significantly reduced compared to the control treatment. Several studies (Langhout et al., 1999, Lukaszewicz et al., 2011, Pappas et al., 2005) have reported that using organic sources of selenium reduces the coliform population. In mice, dogs, and laying hens, selenium intake has been shown to increase the number of Lactobacillus and decrease Escherichia coli and Staphylococcus aureus in the cecum (Langhout et al., 1999, Lukaszewicz et al., 2011, Pappas et al., 2005). Increasing the population of beneficial bacteria due to the provision of sufficient selenium for their synthesis is also an antioxidant property of selenium in preserving the life of these bacteria. It appears that beneficial bacteria, such as Lactobacillus, can competitively eliminate harmful bacteria such as Escherichia coli in the gut (Lukaszewicz et al., 2011). An increase in the number of pathogenic bacteria in the intestine causes the villi to shorten and the lining to shrink (Attia et al., 2010).Numerous studies demonstrate that the consumption of diets containing selenium compounds has destructive effects on harmful intestinal bacteria (Chantiratikul et al., 2008, Hashemi et al., 2012, Heindl et al., 2010, Horn et al., 2009, Langhout et al., 1999). Adding organic selenium to the diet of broilers increases the weight of the intestines due to the growth of villi and intestinal lamina propria (Haghighi-khoshkhoo et al., 2010, Heindl et al., 2010). The lack of selenium consumption on morphology can be attributed to the levels of selenium used, as well as the bird's lack of stress. Selenium can exert its effect more effectively under stress conditions. Most harmful bacteria grow in an environment with acidity close to 7 or slightly higher, while beneficial bacteria multiply in an acidic environment and compete with pathogenic bacteria (Cooke et al. 1973). An increase in acidity leads to a decrease in Escherichia coli and Salmonella in the gastrointestinal tract. Therefore, the consumption of organic sources of selenium reduces the population of pathogenic microorganisms (aerobic bacteria, Escherichia coli, and Salmonella) and increases the population of Lactobacillus competitively, followed by an increase in gastrointestinal acidity. This improvement may lead to an increase in digestion, absorption, and performance (Kasaikina et al., 2011).

 According to the results of this study, it can be said that consuming organic sources of selenium (levels of one and 0.5 mg of selenium-methionine per kg of feed) significantly reduces the population of harmful aerobic bacteria, bacteria. Salmonella and Escherichia coli and cause a competitive increase in the beneficial population of Lactobacillus; The consequence of this operation is to increase the acidity of the cecum and reduce the damage and microbial destruction to the intestinal tissue, and therefore with positive changes in the morphology of the small intestine will lead to improved bird function.

Today, the poultry industry tends to increase production per unit area, at the same time, the increase in flock density is faced with management and health restrictions and obstacles. Consuming medicinal plants can be an effective nutritional solution to overcome the challenge of high density. Therefore, an experiment was designed and conducted in order to investigate the effects of the essential oils of medicinal plants in two un-capsulated and microencapsulated forms in the diet on the performance, intestinal morphology and acidity of the digestive system of broiler chickens.

In this research, out of 250 broiler chickens of the Ross 308 strain in the form of a completely randomized design with a factorial arrangement of 2x2, with 4 treatments and 5 repetitions, and in each repetition, normal density of 10 chickens and high density of 15 chickens with a similar weighted average was used. Microcapsules containing essential medicinal plants containing effective compounds of thyme leaf, savory leaf, peppermint leaf and black pepper seeds developed in the Agricultural Biotechnology Research Institute of East and North-East region of Iran. The tested treatments were; The first treatment: normal density (10 chickens per square meter) + no plant essential oil (control), the second treatment: high density (15 chickens per square meter) + no plant essential oil, the third treatment: normal density (10 chickens per square meter) + 500 mg/kg of un-capsulated essential oil mixture, fourth treatment: high density (15 chicks per square meter) + 500 mg/kg of encapsulated essential oil mixture. The number of casualties, the weight of the casualties and the weight of the eliminated chickens were recorded separately. The amount of feed consumed and weight gain were measured weekly and the food conversion ratio was calculated. At the end of the experiment, 2 birds were randomly selected from each repetition and slaughtered after blood sampling. To study the structure of small intestine villi, samples were obtained from duodenum, jejunum and ileum. A microscope with 40 times magnification was used to measure the height and width of the villus, and a 100 times magnification was used to measure the depth of the crypt. The acidity of the caecum was measured by a pH meter.

The results showed that the addition of microcapsules led to a decrease in the percentage of losses, an increase in weight at high density compared to the absence of microcapsules. The use of microcapsules in conditions of high concentration led to a decrease in the oral conversion factor. Treatments using microcapsules in normal and high density conditions had significantly higher gastrointestinal acidity compared to treatments that did not receive microcapsules. Consumption of microcapsules in normal and high concentrations led to an increase in the length of intestinal villi.

It can be concluded that the addition of encapsulated essential oil improved the weight gain, feed conversion ratio, intestinal morphostructural characteristics.

Industrial poultry farming on a large scale and intensively has increased the possibility of disease outbreaks. Studies have shown that the use of antibiotics, in addition to environmental threats, causes microbial resistance in the body (Yakhkeshi et al. 2011). The presence of chemical residues in poultry products and its impact on human health was one of the reasons for the ban on the use of antibiotics in 2006 (Garcia et al. 2007). Much research has been done to find suitable alternatives to antibiotics. Essential oils and plant extracts with a variety of biological and physiological compounds have a very high potential for their use as new medicinal compounds (Hussain et al. 2008). Useful properties of medicinal plants are related to the presence of secondary metabolites in them (Efterpi et al. 2012). In addition to improving bird growth and production, medicinal plants have positive effects on health status parameters (Grashorn, 2010), intestinal microbial population (Bolukbasi et al. 2008), serum concentration of antibodies to viral diseases (Toghyani et al. 2010) and biochemical and hematological parameters (Toghyani et al. 2010). Among the medicinal plants, cinnamon, marjoram and pepper are aromatic herbaceous plants that are of great importance and have effective healing properties. In some studies, consumption of cinnamon in the diet has caused weight gain, decreased feed conversion ratio and improved liver function in broilers and mice (Mehdipour et al. 2013; AL-Kassie, 2009). Giannenas and Et al. (2005) reported that consumption of marjoram extract improves the performance of broilers. Capsaicin in pepper increases intestinal and bile secretions, increases the activity of pancreatic enzymes, slows the passage of substances in the intestine, and increases the absorption of nutrients (Farrell, 1978). Platel and Srinivasan (2003) reported that consumption of capsaicin by 0.15% in the diet increased salivary amylase secretion in mice; it also increased gallic acid salts by 17%. It has been reported that the consumption of several medicinal plants simultaneously has a greater effect on the production, functional and health parameters than the consumption of one medicinal plant alone (Mehdikhani, 2015). Farrokhnia et al. Reported in 2020 that the consumption of a mixture of Thymus vulgaris and Echinacea angustifolia extracts was reduced due to a reduced conversion ratio of broilers compared to separate consumption. According to the above, the aim of this study was to investigate the effect of consumption of a mixture of cinnamon, marjoram and pepper extracts on performance, weight and relative length of gastrointestinal tract, enzymes and blood minerals in broilers. This experiment was performed using 192 Ross 308 broilers in a completely randomized design with 4 treatments, 6 replications and 8 broilers per replication in a 42-day breeding period. Experimental treatments are: (1) base diet, (2) base diet + 50 mg/kg mixture of plant extracts, (3) base diet + 100 mg/kg mixture of plant extracts and (4) Base ration + 200 mg/kg mixture of plant extracts. Functional parameters of feed intake, weight gain and feed conversion ratio were measured at the end of 42 days of rearing. On the last day of the experiment, 3 chickens were selected from each replicate for blood sampling. Samples were transferred to the laboratory to measure the activity of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase; These parameters were measured by an autoanalyzer and commercial kits of Pars Azmoun Company. Also, the amount of calcium, phosphorus, magnesium and iron elements in the blood were measured by autoanalyzer by spectrophotometry (Biowave model S2100 made in England) by commercial kits of Biochemistry Company. Then the birds were slaughtered and after filling, separating the ventricular contents and separating the components, the relative weights of different parts of the gastrointestinal tract were calculated in terms of body weight, and the relative lengths of the duodenum, jejunum, ileum and cecum were measured (Daneshyar et al. 2012). Experimental data were statistically analyzed in a completely randomized design by SAS statistical software (2003) using GLM linear procedure. Mean comparisons were performed using Tukey-Kramer test at 5% level. The results showed that feed intake and feed conversion ratio were not affected by experimental treatments (P>0.05). However the treatments receiving 100 and 200 g/ton of mixed plant extracts had more body weight gain than the control treatment (P<0.05). Consumption of all three levels of plant extracts resulted in a significant increase in the length of jejunum and ileum of chickens (P<0.05). On the other hand, duodenum and cecum length were not affected by experimental treatments (P>0.05). There was no significant difference between the relative weights of the duodenum, jejunum, ileum and cecum between the experimental treatments (P>0.05). The results showed that the levels of liver enzymes aspartate, transaminase and alkaline phosphatase were not affected by experimental treatments (P>0.05). However, consumption of 100 and 200 g/ton of plant extracts reduced the amount of alanine aminotransferase and lactate dehydrogenase in comparison with the control treatment (P<0.05). The results showed that the consumption of a mixture of plant extracts had no significant effect on the amount of phosphorus and iron in the blood serum of broilers (P>0.05). On the other hand, consumption of 200 g/ton of mixed plant extracts compared with the control treatment increased the amount of calcium and magnesium in the blood of broilers (P<0.05). From this study, it is concluded that up to 150 g/t of a mixture of Cinnamomum verum, Origanum vulgare and Capsicum annuum extract in broiler diet without changing feed intake led to improved weight gain and increased relative length of ileum and jejunum in broilers. Liver enzymes were at normal levels and even showed a decreasing trend; The blood calcium and magnesium levels of broiler chickens also increased. Therefore, up to this level, a mixture of cinnamon, marjoram and pepper extract can be used in broiler diets.

To investigate the effect of Orgasid supplementation under heat stress conditions along with standard and diluted diets on performance, carcass characteristics and blood metabolites of Ross 308 broiler chickens for 42 days. The experiment was conducted from the age of 10 days in the form of a completely randomized design with 6 treatments, 8 replications, and 10 chicken pieces per replication. The experimental treatments were: 1- Standard ration (control), 2- Diluted ration + Orgasid supplement, 3- Standard ration + heat stress conditions, 4- Standard ration + Orgacid supplement, and 5- Standard ration + Orgasid + stress conditions. Heat and 5- Diluted ration + Orgasid supplement + heat stress conditions. The results showed that the use of Orgasid supplement in the heat stress condition kept the feed consumption, weight gain, and feed conversion ratio within the standard range. The use of ergacid improved the carcass quality and the relative weight of the thigh compared to heat stress conditions. The use of ergacid in heat stress conditions led to an increase in the relative weight of the duodenum, jejunum, and ileum compared to no use. The use of orgacid under stress conditions caused an increase in the relative length of the ileum, while the relative length of the duodenum, and jejunum was not affected. The consumption of orgacid led to the preservation of the acidity of the scrotum, stratum corneum, duodenum and jejunum in the treatments that were under heat stress compared to the control treatment. According to these findings, it can be concluded that the use of orgacid supplement in the conditions of heat stress in diluted rations leads to the improvement of the health and condition of the digestive system, leading to the maintenance of the bird's performance in the standard range.

This study was performed to investigate the effect of organic and inorganic selenium supplementation on laying hens' performance, quality traits and peroxidation of egg yolks and whites. The experiment was carried out in a completely randomized design with 300 laying hens (W-36) from 23 to 35 weeks of age with 5 treatments and 6 replications and 10 laying hens in each replication. Experimental treatments include: treatment one or control (basic diet without selenium), The second treatment of 0.5 selenite-sodium (base diet+0.5 mg/kg selenite-sodium), the third treatment selenite-sodium 1 (basic diet+1mg/kg selenite-sodium), the fourth treatment selenium-methionine 0.5 (basal diet + 0.5 mg/kg seleno-methionine) and the fifth treatment was seleno-methionine 1 (basal diet +1 mg/kg seleno-methionine). The results showed that experimental treatments had no significant effect on egg weight, weight mass, production percentage, feed intake, feed conversion ratio and egg yolk and egg white characteristics (P<0.05). Peroxidation of egg yolk and egg white fats in 1 mg/kg seleno-methionine treatment showed the lowest rate compared to other experimental treatments (P<0.05). The results of the present study showed that among the sources of selenium, 1 mg/kg of selenium-methionine more effectively reduced the peroxidation of fats and increased antioxidant activity.

This experiment was conducted in a completely randomized design with 5 treatments, 6 repetitions and 10 chicken in each repetition in order to evaluate the effect of selenium supplement immune system related treats, egg qualitative characteristics, blood parameters and antibody titers against Newcastle disease and influenza, laying hens w36 strains. Experimental treatments include: (1) basic diet, (2) basic diet plus 0.5 mg/kg of Sodium selenite (3) basic diet plus 1 mg/kg of Sodium selenite, (4) basic diet plus 0.5 mg/kg of selenium-methionine and (5) base diets plus 1 mg/kg of selenium-methionine. The results show egg traits were not affected by experimental treatments (P>0.05). treatment of 0.5 and 1 mg/kg of selenium-methionine significantly reduced the enzyme Aspartate Amino Transferase (P<0.05). Also, treatments containing organic selenium significantly reduced the enzyme Alanine Amino Transferase (P<0.05). The results showed that 0.5 mg/kg of selenium-methionine significantly increased the levels of immunoglobulin G, M and A compared to other experimental treatments (P<0.05). However, the levels of immunoglobulins A and M in organic and inorganic sources were not significantly affected by selenium levels (P>0.05). Newcastle antibody titers did not significantly differentiate between experimental treatments (P>0.05). However, 1 mg/kg of selenium-sodium significantly reduced the antibody titer of influenza (P<0.05). In general, although the consumption of organic and inorganic sources of selenium was ineffective on egg characteristics, organic sources of selenium more effectively stimulate the immune system and increase blood immunoglobulins than non-organic sources.

To evaluate the effects of a mixture from Cinnamomum cassia (L.) J.Presl, Mentha pulegium L., and Capsicum annuum L. extracts on the relative weight of visceral and gastrointestinal organs, gastrointestinal tract acidity, blood parameters, and tibia characteristics of Ross 308 broilers, an experiment was conducted in a completely randomized design with five treatments, four replications, and eight chickens per replication. The experimental treatments included basal diet (BD), BD+500 mg kg-1 oxytetracycline, BD+50 mg kg-1 mixed extract, BD+100 mg kg-1 mixed extract, and BD+200 mg kg-1 mixed extract. After 42 days of raising the broilers with the mixed extract, the sampling was performed to evaluate the desired traits. The results showed that the consumption of 100 mg kg-1 mixed extract increased the pancreas and heart weight, relative length of ileum and jejunum, and relative weight and length of tibia and reduced the acidity of duodenum and jejunum compared to the control (p < <0.05). The results showed that the experimental treatments did not affect the concentration of blood elements of broilers, but the amount of magnesium and phosphorus in tibia was affected by 50 and 100 mg kg-1 mixed extract (p < <0.05). Based on the findings of this study, it could be concluded that the use of 100 mg kg-1 mixed extract improved the performance of broilers by increasing the relative length and weight of gastrointestinal organs and reducing the acidity of gastrointestinal tract.

This experiment was conducted to investigate the effect of use of the blend of medicinal plants extract in starter (1-10 days) on performance, carcass characteristics, weight of internal organs and blood parameters at the end period (42days) broiler chickens. Experiment was conducted in a completely randomized design with 4 treatments, 4 replications and 8 chicken in each replication. The experiment treatments included: (T1) Control diet, (T2) Control diet+50 g/ton blend of medicinal plants Extract, (T3) Control diet+100 g/ton blend of medicinal plants Extract and (T4) Control diet+200 g/ton blend of medicinal plants Extract. Using of medicinal plants extract caused a significant increase in body weight of broilers compared to the control treatment (p < 0.05). The results showed that the relative weight breasts and wings treatments received 100 and 200 and relative weight pancreas and heart by 100 g/ton blend of medicinal plants extract were Increased significantly (p < 0.05). Blend of medicinal plants extract significantly reduces cholesterol and increases HDL in blood serum (p < 0.05). Globulin, urea, protein, glucose, and serum albumin in broilers were not affected by experimental treatments (P>0.05). While 100 g/ton of blend of medicinal plants extract significant increased creatinine (p < 0.05). Based on the findings of this study can conclude that the use of 100 g/ton blend of medicinal plants extract at the first of the can have beneficial effects on the internal organs weight, broiler performance and blood parameters period.

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, plant-derived 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 anti-bacterial and anti-fungal agents have been reported. Carvacrol is a component of numerous aromatic plants, such as Origanum vulgare, thyme, and wild bergamot. The anti-microbial 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 anti-bacterial activity against Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Salmonella sp., and Vibrio parahemolyticus. Capsicum oleoresin, prepared by organic extraction of pepper fruits, contains anti-bacterial 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 1-10, 11-24 and 25-42 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 1-10 d period supplementing the broiler diet with 100 mg/kg herbal extracts decreased significantly feed intake (P

This experiment was conducted to evaluate the effect of organic acid supplementation on some characteristics of gastrointestinal tract and small intestinal morphology in male Ross 308 broiler chicks for 42 days. The study was completely randomized design with 4 treatments, 4 replicates and 8 chicks per each replicate. The treatments consisted of: T1: basal diet, T2: basal diet + 0.1% organic acid supplementation, T3: basal diet + 0.2% organic acid supplementation, T4: basal diet + 0.3% organic acid supplementation. The results showed that the relative weight and relative length of different parts of gastrointestinal tract were not significantly affected by experimental treatments (P>0.05). About acidity of different parts of gastrointestinal tract, the result showed that pH of proventriculus by treatment receiving 0.1% organic acid supplementation and pH of duodenum by treatment receiving 0.2% organic acid supplementation were, significantly decreased (P<0.05). Villous height in jejunum and ileum by use of 0.2% organic acid supplementation were significantly increased (P<0.05). Villous height to crypt depth ratio, in jejunum and ileum were significantly increased by consumption of 0.2% organic acid supplementations (P<0.05). Muscularis thickness in jejunum by treatment receiving 0.2% and 0.3% organic acid supplementations were significantly decreased (P<0.05). The results obtained from this experiment showed that the use of 0.2% organic acid supplementation have beneficial effect on small intestinal morphology of broiler chickens.

This experiment was carried out to determine the effect of organic acid (OA) on some serum metabolites, plasma minerals and some tibia characteristics of Ross 308 broiler chicks. A total of 128 broiler chicks were used in a completely randomized design with four treatments, four replications and eight chicks per each replicate. The treatments were: T1: basal diet (no additives; BD). T2: BD + 0.1% OA, T3: BD + 0.2% OA and T4: BD + 0.3% OA. The results showed that serum concentrations of metabolites including urea, cholesterol, total protein, albumin, globulin and also plasma minerals, including calcium, phosphorus, magnesium and iron at 21 and 42 days of age were not significantly affected by organic acid. Blood triglyceride concentration at 42 days of age significantly affected by treatments so that treatment containing 0.2% organic acid had the highest levels of blood triglyceride and control and treatment containing 0.3% organic acid had lower blood triglyceride level and this difference was statistically significant (P<0.05). Calcium, phosphorus and magnesiumpercentage of tibia of broilers were not significantlyaffected by dietary treatments. Percentage of ash, relative weight, relative length, internal diameter and thickness of the tibia in broiler chickens were not significantly affected by dietary treatments. The results obtained from this experiment indicated that use of organic acid was not able to influence blood parameters and tibia characteristics of broiler chickens.