جوجه های گوشتی

Glutamine represents approximately 30-35% of the total amount of nitrogen in the blood derived from amino acids. The role of glutamine as a nitrogen shuttle helps to protect against the toxic effects of high levels of ammonia in the blood. In addition, glutamine has vital and specific metabolic functions as a vehicle for carbon exchange between tissues, as a fuel for rapid cell division, and as a precursor of many naturally active molecules. It's a great example of how amino acids are used for different purposes in the metabolism and the immune system of the body. Glutamine, a conditionally essential amino acid, seems to be a key nutrient for the gut, as it may be a prominent source of vitality for the enterocytes. Glutamine appears to trigger an increase in the level of intestinal secretory immunoglobulin A, which is essential for mucosal defense. The investigation showed that the use of amino acid supplements in broiler diets improves the performance and the carcass characteristics. Glutamine is one of the most abundant amino acids in blood plasma and is involved in the building of muscle, and tissue, and gaining body weight. Researchers found that adding 10 g of L-glutamine per kg of food increased the weight gain and serum immunoglobulin A and G concentrations in broiler chickens. Therefore, an experiment was carried out in broiler chickens over 42 days of production to determine the effect of L-glutamine on broiler growth, carcass quality, and certain blood parameters.

The experiment was conducted using 300 one-day-old male Ross 308 broiler chickens in a completely randomized design with five treatments and five replicates from the age of 1 to 42 days. The experimental treatments included were: the addition of zero, 0.25, 0.5, 0.75, and 1% of L-glutamine in corn-soybean meal-based diets supplemented with dietary fat. During the experimental period, average daily feed intake (DFI), body weight gain (BWG), and feed conversion ratio (FCR) were measured. At the end of the experiment, two birds were selected from each replicate and slaughtered after weighing, and the weight of the internal organs (thigh, breast, heart, liver, gizzard, fat pad, pancreas, bursa, spleen, and thymus) was measured. Blood samples were collected from two birds per replicate to determine the number of white blood cells (WBC), and heterophile to lymphocyte ratio (H/L). Blood samples were taken from the jugular vein in tubes without anticoagulant and then centrifuged (2000×g for 10 min) to obtain a serum. On the 42nd day of rearing, serum cholesterol (total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL)) and triglycerides were determined by calorimetric examination.

Weight gain during the initial and growth periods was affected by L-glutamine supplementation (P<0.05). Despite higher feed intake for L-glutamine-supplemented diets during the initial period, this effect was significant only during the growth period (P<0.05). FCR and relative weight of internal organs, except liver weight, were not significantly different from the control group in the L-glutamine-supplemented chickens. The addition of 0.5% L-glutamine supplementation reduced cholesterol and triglyceride content and increased HDL in the blood of broilers (P<0.05). The H/L ratio in chickens that consumed L-glutamine was significantly lower than in the control group (P<0.05). L-glutamine has been reported to increase the activity of the intestinal enzyme Na-K ATPase, thereby indirectly increasing the absorption capacity of nutrients such as glucose and amino acids in the intestine. Researchers reported that L-glutamine increases the performance and feed intake of chickens by improving intestinal function and increasing digestibility. Expanding the villi of the small intestine can increase digestion and feed intake by increasing nutrient absorption and thus improving chicken performance. Improving the morphology of the digestive system is one of the possible mechanisms of the positive effect of L-glutamine on improving weight. Since glutamine stimulates anabolic conditions in the body and increases the amount of protein synthesis, therefore, along with muscle growth, it can increase the final body weight. Avian health is directly related to the immune system, and birds with adequate immune systems grow better. The majority of essential amino acids are recognized as critical resources for cytokine production and immune function.

Results from this study indicate that 0.5% dietary glutamine supplementation improved growth performance and had a positive effect on lipid metabolism-related blood parameters.

In broilers, dietary fiber stimulates the production of hydrochloric acid and bile acids and improves amylase activity, leading to better nutrient utilization (Hetland et al., 2002). A well-developed gizzard also enhances reverse peristalsis, which churns food back up the digestive tract. A reduced-crude protein (CP) diet are typically formulated by decreasing soybean meal and increasing feed grains (such as maize or wheat), along with higher inclusions of non-bound (crystalline and synthetic) amino acids to meet nutritional requirements. Studies (Van Harn et al., 2017) have shown that CP reductions (20-30 g/kg) in Ross 308 broiler diets can be achieved without compromising live weight gain or feed intake. Notably, these diets even show a significant improvement in feed conversion ratio (FCR) with a 3.5% decrease. Dietary fiber with increased particle size may enhance foregut development more effectively in poultry fed diets moderately low in crude protein. This study investigates the performance of broilers fed on low-density crude protein diets with increasing particle size of sunflower (Helianthus annus L.) hulls. This experiment aimed to examine the effect of sunflower hull particle size on the performance and physiological response of broiler chickens fed with different protein levels. A completely randomized design based on a 3 × 2 factorial arrangement, comprising 6 treatments (6 replicates per treatment, 10 birds per replicate). The treatments included 3 types of dietary sunflower hull types (without hulls, 4% with 1 mm particle size, and 4% with 5 mm particle size) and 2 crude protein (CP) levels (normal and a 10% reduction). Feed intake (FI) and body weight gain (BWG) were recorded, and the feed conversion ratio (FCR) was calculated. To determine ideal nutrient digestibility, chickens were fed 3 g/kg of chromium oxide from days 21 to 25. On day 25, ileum contents from 2 birds per replicate were collected and stored at -20°C. The cecal microbial population was assessed at 42 days of age. Data were analyzed using SAS software and the GLM procedure. Duncan's multiple range test was used for mean comparison at a 5% significance level. The results indicated that incorporating sunflower hulls (SFH) in the diet increased FI, except during the starter period, and improved FCR in both the starter and grower periods. The high amount of FI in the treatments containing SFH may be related to the high level of lignin and cellulose, because it increases the rate of passage of digestive juice through the digestive tract and ultimately increases FI (González-Alvarado et al., 2010). Broilers fed coarse SFH showed increased relative weights of the carcass, gastrointestinal tract, gizzard. The use of a rich source of insoluble fiber in the diet can increase the growth of the digestive system, especially provetriculus and gizzard (Jimenez-Moreno et al., 2013). The apparent digestibility of crude protein improved by coarse SFH with low crude protein. The positive effect of fiber on the digestibility of raw protein can be attributed to the increase in pepsin activity and the increase in hydrochloric acid production (Gabriel et al., 2003). Both fine and coarse SFH in the diet enhanced the Lactobacillus population. Similarly, other researchers also reported that feeding broiler chickens with dietary lignocellulose leads to an increase in the presence of Lactobacillus species (Bogusławska-Tryk et al., 2015). Overall, the study results indicate that adding coarse sunflower hulls to the diet can enhance broiler growth performance. This improvement is achieved by increasing the digestibility of crude protein, as well as boosting the Lactobacillus population. Additionally, using coarse sunflower hulls led to an increase in the relative weight of the carcass and thighs.

Pulmonary hypertension syndrome (ascites) is one of the most common metabolic syndromes in today's fast-growing broilers. It is associated with rapid growth and is characterized by the accumulation of fluid in the abdominal spaces. Effective factors in the occurrence of ascites syndrome included free radicals in the body such as superoxide, hydroxide, and hydrogen peroxide. By reducing the capacity of the body's antioxidant systems, free radicals make the bird susceptible to various diseases. Free radicals are produced in the body by damaging the cell membrane leading to cell death and ultimately tissue damage. Therefore, by increasing cell protection from such injuries, one of the common causes of ascites and heart failure abnormalities can be prevented. In addition, reactive oxygen species (ROS) reduce the half-life of nitric oxide (vasodilating agent), causing a decrease in the ability of vasodilation and providing the basis for the occurrence of ascites. B-blockers (or b-adrenergic antagonists) are a group of drugs widely used in the treatment of cardiovascular diseases, namely arterial hypertension, cardiac arrhythmias, and angina pectoris as well as other types of pathologies such as anxiety or glaucoma. Part of the beneficial cardiovascular effects shown by this group of compounds has already been associated with the antioxidant properties that some of them seem to possess. It demonstrated a concentration-dependent membrane anti-peroxidative activity for propranolol, pindolol, metoprolol, atenolol, and sotalol. Of the five b-blockers examined, propranolol was the most potent agent, and the activities seemed to correlate with the drugs’ hydrophobicity. Further studies indicated that the antioxidant activity of propranolol was independent of its pharmacological activity and was related to its intrinsic chemical properties rather than to its quinidine-like membrane stabilization effect. The antioxidant properties of propranolol were later corroborated using membrane and cellular models. More recently, propranolol’s antioxidant-related cardioprotective effects were studied in rats, showing that the chronic treatment with this b-blocker was found able to protect against ischemia-reperfusion injury. Thus, it is now accepted that propranolol is an important therapeutic tool against oxidative stress by stabilizing membranes, including lysosomes, inducing the activity of antioxidant and other beneficial enzymes, increasing endothelial nitric oxide production, and directly protecting isolated membranes, cardiovascular cells, and tissues against oxidative injury. So far, there have been few studies on the effects of propranolol in broilers. Therefore, the current research was designed to evaluate the propranolol on the growth performance, antioxidant status, and the status of some hematological and biochemical parameters of broiler chickens under induced ascites.  The experiment was carried out in a completely randomized design with four treatments in four replicates and 10 chickens in each replicate. Experimental treatments included: 1- positive control group (no induce ascites, basal diet), 2- negative control group (inducing ascites and fed with basic diet), 3 and 4- propranolol groups (inducing ascites, supplemented with 50 and 100 ppm propranolol). To induce ascites, water containing 7 g per liter of salt was provided to the chickens from day 15 of age. Growth performance parameters including feed intake, weight gain, and feed conversion ratio were calculated for the total period. On the last day of the experiment (42 d), two birds were randomly selected from each cage and after sampling from the wing vein, they were killed and the ascites index was calculated as the ratio of the weight of the right ventricle to the weight of total ventricles (RV/TV). The mortalities were collected as soon as they were observed and after weighing to correct the feed conversion ratio, were necropsied to investigate the cause of death. Serum antioxidant parameters include the level of malondialdehyde and the activity of antioxidant enzymes including glutathione peroxidase, superoxide dismutase, and catalase were determined. In addition, the serum enzymes including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were measured. The results showed that induction of ascites increased RV/TV, mortality due to ascites, and feed conversion ratio; while it decreased feed intake, and live weight (P<0.05). Additionally, ascites induction increased the number of white and red blood cells, hematocrit, hemoglobin, heterophile, and decreased lymphocytes (P<0.05). The levels of glutathione peroxidase, superoxide dismutase, and catalase enzymes were decreased in ascites-induced broiler chickens. At the same time, it decreased the level of serum malondialdehyde, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase enzymes (P<0.05). Inclusion of propranolol had no significant effect on growth performance (P>0.05), but it significantly decreased the ratio of right ventricle to total ventricles and ascites related-mortalities (P<0.05). Moreover, inclusion of propranolol reduced the number of white and red blood cells, hematocrit, hemoglobin, heterophile and increased lymphocytes compared to the negative control birds (P<0.05). In addition, propranolol enhanced the levels of glutathione peroxidase, superoxide dismutase and catalase enzymes and reduced the levels of malondialdehyde, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in serum (P<0.05). In conclusion, propranolol inclusion at 100 ppm may be used to alleviation the physiological responses of broilers exposed to ascites. In conclusion, propranolol inclusion at 100 ppm may be used to alleviation the physiological responses of broilers exposed to ascites.

Oxidative stress is inevitable in broiler chicken production, and it affects the physiological, behavioral, and biochemical status of growing chicken which ultimately deteriorates meat quality. The imbalance among free radicals and antioxidant enzymes within living cells or tissues leads to the oxidation of lipids, proteins, and nucleic acids and is a fundamental cause of oxidative stress. When the antioxidant mechanism within living cells weakens, the production of free radicals increases under physiological oxygen metabolism, and reactive species (i.e., reactive oxygen species and reactive nitrogen species) are needed in cells in small quantities because they function as signaling molecules during homeostasis. However, excessive production of these species leads to oxidative stress. There is a mechanism in living cells to reduce the number of oxidative species through physiological scavenging. Numerous reactive oxygen species such assuperoxide and hydrogen peroxide are produced during oxygen metabolism. In addition, some reports showed that after the occurrence of oxidative stress, there are severe inflammatory reactions in the cells involved, which can lead to greater tissue damage and activate tissue apoptosis. Oxidative stress plays an essential role in the emergence of a number of chronic disorders such as diabetes and cancer by inducing inflammation. To protect against free radicals, living organisms have a combined antioxidant defense system including enzymatic system (such as glutathione peroxidase, superoxide dismutase, and catalase enzymes in the cytosol and cell membrane structure) and a non-enzymatic system (such as glutathione, polyphenol, carotenoids, special dipeptides, proteins containing thiol group, polyamines, ubiquinol, flavonoids, bilirubin, uric acid, vitamin E with selenium, and vitamin C) in tissues. Black cumin seeds (Nigella sativa) have been used as alternative medicine for more than 2000 years due to their multisystemic positive effects. Many active components of black cumin have been identified, including dithymoquinone, thymoquinone, nigellone, thymohydroquinone, nigilline, melanthin, nigelamine, damascenone, pinene, and p-cymene. Black cumin contains minerals such as calcium, magnesium, potassium, iron, phosphorus, cobalt, zinc, and manganese, and vitamins A, B, C, D, and E. Moreover, black cumin is rich in essential oils, proteins, alkaloids, saponins, flavonoids, and polyphenols. The black cumin has anti-inflammatory, analgesic, anthelmintic, hypocholesteremia, appetite stimulant, antidiarrheal, diuretic, antiulcer, spasmolytic and bronchodilatory, antimicrobial, antihypertensive, antidiabetic, anticancer, hepatoprotective, and renal protective activities and has antioxidant properties. This study was conducted to investigate the effects of black cumin on growth performance, antioxidant status, inflammatory responses, and biochemical and hematological changes in broilers under oxidative stress induced by hydrogen peroxide.

A total of 200 one-day-old chickens (Ross 308) were reared in the form of a completelyrandomized design with four treatments and five replications (10 chickens per replicate). Experimental treatments included: 1. Control group (fed with basic diet), and groups 2, 3, and 4 had levels of 50, 100, and 150 g of black seed per kg of diet. To induce oxidative stress, all birds received 1% hydrogen peroxide per liter of drinking water from 14 to 42 days of age. At 42 d, two birds were randomly selected from each cage and after blood sampling from the wing vein, were killed and dissected for liver and spleen tissue sampling. Growth performance, blood and biochemical parameters such as the number of red and white blood cells, hemoglobin, hematocrit, heterophil and lymphocyte, serum triglyceride, and cholesterol, as well as serum antioxidant parameters including the level of malondialdehyde (MDA) and the activity of antioxidant enzymes including glutathione peroxidase, superoxide dismutase, and catalase, were determined. In addition, liver enzymes present in the serum including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were measured. Also, to evaluate the effect of black cumin on the inflammatory response of broiler chickens under induced oxidative stress, serum interleukins including IL-10, IL-6, and TNF-α were measured.

The results showed that black seed supplementation in chickens under induced oxidative stress significantly improved the growth performance, increased the activity of antioxidant enzymes, and decreased MDA in serum, liver tissue, and spleen (P<0.05). Black seed supplementation significantly decreased serum levels of inflammatory cytokines of IL-6 and TNF-α, and increased anti-inflammatory cytokine of IL-10 (P<0.05). Also, black seed supplementation did not affect red blood cells, hematocrit, or hemoglobin, but increased white blood cells, lymphocytes, and decreased blood heterophils (P<0.05). Serum levels of triglycerides, cholesterol, ALT, AST, and ALP also decreased significantly under the influence of black seed.

Based on the results of this experiment, it appears that black cumin (Nigella sativa) seed supplement can improve the growth performance of broiler chickens due to its antioxidant and anti-inflammatory effects.

The aim of this study was to investigate the effects of guanidinoacetic acid (GAA) supplementation to reduced protein diets on performance, carcass characteristics and blood parameters of broiler chickens. For this purpose, 240 male Ross 308 broilers were allocated to 6 treatments with 4 replications and 10 birds per replication. The dietary treatments consisted of a 3×2 factorial arrangement of reduced dietary CP (100%, 90 and 80% of Ross 308, 2009 recommendation), with or without GAA (0.06%). Body weight gain was significantly reduced when dietary ideal protein was reduced by 20%, during 11-24 and 25-42 days of age (P<0.05). The transition from 100 to 80% CP, increased feed conversion ratio significantly during grower period. An interaction was found between CP level and GAA for feed intake during 11-24 and 25-42 days of age. GAA addition reduced feed intake of treatments with reduced protein diet (80% of management guide recommendation). Body weight gain and FCR were not affected by dietary GAA supplementation. Addition of guanidine acetic acid in the diet resulted in relatively higher carcass performance and significantly lower heart weight (P<0.05). It was concluded form the result of the current experiment that reducing the ideal protein to 80 % of management guide recommendation resulted in inferior growth performance and dietary GAA supplementation did not improve the bird’s performance.

The aim of this study was to investigate the effect of ammonium acetate on reducing the amount of fungal toxins in feed and its effect on performance, carcass characteristics and some blood parameters of broiler chickens. For this purpose, 300 one-day-old broilers (Ross 308) were used in a completely randomized design with 6 treatments and 5 repetitions and 10 birds in each repetition. Corn-soybean meal based experimental treatments included negative control (without fungal toxins), positive control (basal diet containing corn contaminated with aflatoxin B1, ochratoxin A and zearalenone) and positive control diets containing 0.04, 0.06, 0.08 and 0.1 g/kg of ammonium acetate. Performance traits were measured during the starter, grower, finisher and whole the experimental period. Carcass characteristics and blood parameters were determined at day 42 of age. The results showed that the birds treated with negative control diet and positive control diet containing 0.08 and 0.1 g/kg of ammonium acetate had higher daily feed intake, weight gain, carcass yield and breast weight as compared to the positive control treated birds. Birds receiving the negative control diet and positive control diets containing different levels of ammonium acetate had lower AST and ALT concentrations than the birds in positive control treatment. In general, it was found that the consumption of 0.08 and 0.1 g/kg of ammonium acetate in the contaminated feed with fungal toxins improves the performance and carcass characteristics of broiler chickens through removing the negative effects of the toxins.

The effect of utilization of feed disinfected with ozone gas on performance, carcass characteristics and blood parameters of broilers was investigated using 432 Ross 308 male broilers in a 3×2 factorial arrangement with three levels of ozone gas (zero, 20, and 30 parts per million) and two levels of fat including low (1.5 and 2% vegetable oil for grower and finisher periods, respectively) and high (3 and 4% of vegetable oil for grower and finisher periods, respectively) in a completely randomized design with 6 treatments and 4 replications of 18 birds in each. At 42 days of age, two birds were selected from each replication and slaughtered after weighing and the weights of the carcass, heart, liver, small intestine, and ceca were measured precisely. The results showed that the weight gain of chicks fed a high-fat, ozone-free diet was significantly higher than that of chicks fed a high-fat, gassed with a 20 ppm ozone diet (P <0.05). The ceca weight of chicks fed low-fat diets was higher than that of birds fed high-fat diets and birds fed diets gassed with 20 ppm ozone had higher ceca weight (P <0.05). According to the results of this experiment, it seems that the utilization of ozone gas for the disinfection of diets containing high levels of fat has a negative effect on feed quality and reduces the performance of broilers.

Aflatoxin B1 is the most dangerous form of aflatoxins that could be produced by Aspergillus flavus and Aspergillus parasiticus molds. Contamination of feedstuffs with aflatoxins is problematic during the manufacturing, processing, storage, and transportation stages, and it has adverse effects on the health and productivity of poultry and human health. By using inorganic and organic toxin binders in poultry feed, aflatoxins are not allowed to be absorbed through the animal's digestive system, and it is considered a good solution to reduce their negative effects.

In this research, the effects of adding a multi-component toxin binder to diets containing aflatoxin B1 were investigated on growth performance, carcass traits, and immune parameters of broilers, by using 180 one-day-old male broilers (Ross 308) in a 3×3 factorial arrangement in a completely randomized design with three levels of toxin binder (0.0, 0.5, and 1.0 kg/ton) and three levels of aflatoxin B1 (0.0, 0.5, and 1.0 mg/kg) in nine treatments, four replications, and five chickens in each replicate.

The results showed that the using of 1.0 kg/ton of toxin binder significantly reduced the negative effects of 0.5 mg/kg of aflatoxin B1 on the average daily feed intake and weight gain in the finisher and entire production periods and the final live weight in whole production period (P<0.05). The regression equations (Y= -25.033x+ 65.734) with (R2= 0.97), (Y= -23.961x+ 64.844) with (R2= 0.91), and (Y= -15.133x+ 64.319) with (R2= 0.75) were obtained to predict the average daily weight gain of birds fed with treatments containing 0.0, 0.5, and 1.0 kg/ton of "Delta bond®" toxin binder and different levels of aflatoxin B1, respectively. Feeding chickens with diets containing aflatoxin B1 significantly increased liver and spleen weights (P<0.05). All treatments containing 1.0 mg/kg of aflatoxin B1 and treatments containing 0.5 mg/kg of aflatoxin B1 and 0.0 and 0.5 kg/ton of toxin binder showed a significant decrease in the bursa of Fabricius weight compared to the other treatments (P<0.05). In addition, the treatment containing 1.0 mg/kg of aflatoxin B1 without a toxin binder increased heart weight compared to the other treatments (P<0.05). In the case of immune parameters, the amount of heterophils and the ratio of heterophils to lymphocytes were significantly increased and the number of lymphocytes was significantly decreased as the aflatoxin B1 level increased (P<0.05). Furthermore, there were no significant effects for the main and interaction of aflatoxin B1 and the toxin binder for the Newcastle antibody titer.

Based on the results, the addition of 1.0 kg/ton of a multi-component toxin binder to diets containing 0.5 mg/kg aflatoxin B1 can improve the average daily feed intake and weight gain in the finisher and entire production periods, final live weight, and bursa of Fabricius weight of broilers.

Ascites is one of the most common metabolic syndromes in today's fast-growing broilers and is associated with rapidly growing and characterized by accumulation of fluid in the abdominal spaces. Effective factors in the occurrence of ascites syndrome, can mention free radicals in the body such as superoxide, hydroxide and hydrogen peroxide. By reducing the capacity of the body's antioxidant systems, free radicals make the bird susceptible to various diseases. Free radicals produced in the body by damaging the cell membrane lead to cell death and ultimately tissue damage. Therefore, by increasing cell protection from such injuries, one of the common causes of ascites and heart failure abnormalities can be prevented. In addition, free radicals from oxygen derivatives reduce the half-life of nitric oxide (vasodilating agent), causing a decrease in the ability of vasodilation and providing the basis for the occurrence of ascites. Therefore, it is suggested that antioxidants can prevent ascites and improve performance in broilers. Medicinal plants are among the rich sources of natural antioxidants that do not have the harmful effects of antibiotics and synthetic antioxidants. For this reason, the use of medicinal plant extracts is an important step in animal nutrition to increase the immunity of poultry. The mentioned extracts have strong antioxidant, antibacterial and digestive properties. Probably, the positive effects of medicinal plants are due to the active compounds found in plant extracts such as menthol, thymol, carvacrol. In order to investigate the effects of aqueous ethanol extract of Vinifera Vitis (V.V) on the performance, antioxidant status and blood parameters of broiler chickens under induced ascites. 

A total 300 one-day-old chickens (Ross, 308) were done in the form of a completely randomized design with 4 treatments and 5 replications (15 chickens in each replication). Experimental treatments include: 1- positive control group (without inducing ascites and fed with basal diet), 2- negative control group (inducing ascites and fed with basal diet), 3 and 4- Vinifera Vitis groups (ascites induction with 1000 and 2000 ppm of Vinifera Vitis extract). To induce ascites, water containing 1200 mg of sodium (3 grams per liter of salt) was provided to the chickens from the 15th day of the experiment. Growth performance parameters including feed intake, weight gain and feed conversion ratio were calculated for the total period. On the last day of the experiment (42 d), two birds were randomly selected from each cage and after sampling from the wing vein, killed and the ascites index was calculated as the ratio of the weight of the right ventricle to the total ventricles. The mortalities were collected as soon as they were observed and after weighing to correct the feed conversion ratio, were necropsied to investigate the cause of death. Serum triglyceride and cholesterol levels, as well as serum antioxidant parameters including the level of malondialdehyde and the activity of antioxidant enzymes including glutathione peroxidase, superoxide dismutase and catalase. In addition, liver enzymes present in the serum including alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT), and alkaline phosphatase (ALP) were also measured. 

The results showed that induction of ascites increased the ratio of right ventricle to total ventricles, mortalities due to ascites, feed intake, feed conversion ratio and body weight (P <0.05). The administration of Vinifera Vitis extract improved the growth performance index and reduced the ratio of the right ventricle to the total ventricles and mortalities (P <0.05). Vinifera Vitis extract moderated the increasing effects of ascites induction on triglyceride and cholesterol compared to the negative control treatment (P <0.05). In addition, the induction of ascites caused a decrease in the activity of glutathione peroxidase, superoxide dismutase and catalase enzymes and an increase in serum malondialdehyde, the experimental treatments improved the antioxidant status compared to the negative control treatment (P <0.05). Also, induction of ascites increased the serum levels of aspartate aminotransferase, alanine aminotransferase, gammaglutaryl transferase and alkaline phosphatase enzymes. The supplementation of the experimental supplements decreased the serum level of the mentioned enzymes (P <0.05). The results of this research showed that the use of ethanolic extract of Vinifera Vitis has positive results on the performance and stress reduction of broiler chickens affected by ascites and it can be effectively used from the level of 2000 ppm of the ethanol extract Vinifera Vitis was used in the diet of broiler chickens to reduce stress and improve performance.

Knowledge about the association between single nucleotide polymorphisms (SNPs) and important economic traits is one of the crucial tools in breeding programs within the poultry industry. Genome-wide studies for discovering SNP variations related to these traits are often conducted using simple linear models. However, due to certain assumptions of these models, some SNP markers may not be identified. This study aimed to evaluate the performance of random forest and gradient boosting methods compared to linear models in identifying SNP markers associated with body weight traits at 6 and 9 weeks of age in F2 broiler chickens resulting from crosses between the commercial Arian line and native Urmia birds. The results showed that the machine learning approaches were able to identify important markers, such as GGaluGA308573, GGaluGA255033, Gga_rs13614212, Gga_rs13743072, GGaluGA258772, Gga_rs14034395, and Gga_rs13858398, associated with body weight traits, which were related to genes MAP2, ACSL1, CAMSAP2, FAM117B, SLC4A4, TIMP4, and LncRNA, respectively. These genes are primarily involved in cellular division, growth control, regulation of cellular skeleton structure and microtubules, and transcription activity, constituting the most important biological processes. The identification of these novel genes using machine learning methods, which were not detected by linear models and previous studies in this population, could provide new insights into genetic control of growth traits in broiler chickens. Moreover, the discovered significant markers can be utilized in genetic improvement programs for broiler chickens.

During the last stages of incubation, avian mortality commonly happens due to the lack of enough nutrients and amino acids (Fardoost et al. 2019). However, in ovo injection or in ovo feeding is considered a new technique for improving growth of chickens (Ebrahimi et al. 2017). Most studies indicated improving effect of in ovo feeding of nutrients (especially amino acids) on small intestine growth and histology as well as higher absorptive capacity of digestive system (Ebrahimi et al. 2017, 2018a,b; Elwan et al. 2019; Fardoost et al. 2019). Previous studies indicated an improving effect of excess feeding of arginine on growth performance, carcass traits, blood metabolites, and intestinal histology of broilers (Ebrahimi et al. 2013, 2014, 2016b). However, there are few records regarding the impact of in ovo injection of arginine on intestine histology of chickens. Accordingly, the present study was designed to evaluate the effect of in ovo injection of different levels of arginine on carcass traits, blood metabolites, and small intestine histology of broiler chickens.

For this reason, 300 fertile broiler breeder eggs were divided into three treatment groups: 1- 0.5% L-arginine in ovo injection group (100 eggs), 2- 1% L-arginine in ovo injection group (100 eggs), 3- control group included distilled water injected (sham-control subgroup, 50 eggs) and non-injected (control subgroup, 50 eggs). Eggs were then set into the incubator for the first 18 days with the temperature of 37.8°C and six rotations per day. At d 14 of incubation, eggs were injected into the amniotic fluid (Ebrahimi et al. 2017) as follows: 1- in ovo injection of 5 mg L-arginine/ ml distilled water, 2- in ovo injection of 10 mg of L-arginine/ml distilled water, 3- control group included sham-control (in ovo injection of 1 ml distilled water) and control (received no injection). For in ovo injection, solution pH was set at 7.0. At d 18 of incubation, eggs were moved into hatchery boxes. After hatching, chicks were reared for 24 days. During the experiment, chicks received standard commercial diets based on Ross recommendations as starter (0-10 days) and grower (11-24 days), (Table 1). At d 24, blood samples of three chickens per each replicate were collected, centrifuged (3000 rpm for 20 minutes), and serum was separated to evaluate cholesterol, glucose, triglyceride, uric acid, and total protein by the Enzymatic Colorimetric method (Ebrahimi et al. 2017). Then, all birds were weighed, slaughtered, some carcass traits (scalped carcass, eviscerated carcass, breast, thigh, gizzard, proventriculus, pancreas liver without gall bladder, heart, duodenum , jejunum, and ileum were weighed, and their relative weight to chicken body weight were calculated. Also, length of duodenum , jejunum, and ileum was evaluated and their samples were stored in 10% formalin for fixation to evaluate histological parameters (crypt depth, villus height, villus thickness, mucosal thickness, and crypt diameter) using Hematoxylin - Eosin staining method (Ebrahimi et al. 2017). Then, villus height to crypt depth ratios were calculated. Afterwards, data were analyzed based on a completely randomized design by the Proc GLM of SAS software (Ver 9.2). Also, Tukey-Kramer test was used for comparing treatments and results presented as least square means ± standard error.

Based on the results, in ovo injection of different levels of L-arginine did not affect hatchability, day-old chick weight, chick weight to egg weight ratio, 24-day-old chicken weight, feed conversion ratio, relative weight of all carcass traits, cholesterol, glucose, total protein and blood urea nitrogen (P> 0.05), (Table 2). However, serum triglyceride was significantly affected by experimental treatments (P <0.01) and the highest amount was observed in 0.5% L-arginine in ovo injection group (Table 2). In a similar study, Gao et al. (2017) indicated that L- arginine in ovo injection increased weight gain of broiler chickens. Furthermore, Abdolalizadeh Alvanegh et al. (2017) reported the improving effect of in ovo injection of different ratios of L- arginine to L- lysine on chick weight and their carcass traits. Also, they reported higher serum total protein level, while lower blood urea nitrogen of broiler chicks with in ovo injection of different ratios of L- arginine to L- lysine (Abdolalizadeh Alvanegh et al., 2017).Present results indicated no significant effect of in ovo injection of L-arginine on most weight and length parameters of small intestine length (P>0.05); however, relative weight of jejunum was significantly affected by in ovo injection of L-arginine (P<0.05) and the highest amount was observed in 0.5% L-arginine in ovo injection group (Table 3). Present results indicated no significant effect of in ovo injection of L-arginine on duodenal crypt diameter; jejunal villus height, crypt depth and diameter, and mucosal thickness; and ileum villus height, crypt depth, villus height/crypt depth ratio, and mucosal thickness (P>0.05), (Table 3). However, significant effect of in ovo injection of L-arginine was observed on duodenal villus height, villus thickness, crypt depth, villus height/crypt depth ratio, and mucosal thickness; jejunal villus thickness and villus height/crypt depth ratio; and ilium villus thickness and crypt diameter (P<0.05), (Table 3). Also, the highest amount in most histological parameters was observed in 1% arginine treatment (Table 3). In a similar study, it was reported that in ovo injection of L- methionine had a positive impact on small intestine length and weight with improvement in villus height, crypt diameter, crypt depth, and villus height/crypt depth ratio of duodenum and jejunum (Fardoost et al. 2019). Also, in ovo injections of L- lysine improved histological parameters of duodenum, jejunum, and ileum (Ebrahimi et al. 2017). Ebrahimi et al. (2018b) with in ovo injection of different DL- methionine to L- lysine ratios reported higher small intestinal weight and length along with higher Villus height and Villus height to crypt depth ratio.

Based on the overall results of the study, injection of 0.5% arginine showed a positive effect on the growth and small intestine morphology of broiler chickens.

Guanidinoacetic acid (GAA), a creatine precursor, is synthesized from L-arginine and glycine. The capacity for de novo synthesis may be limiting in high-yielding farm animals, especially in those fed all-vegetable diets. As the precursor to creatine, dietary GAA can also effectively “spare” arginine from being used for GAA synthesis, so that the arginine may be used for muscle accretion and other physiological functions. It has been reported that arginine affects bone development by its involvement in the formation of collagen and connective tissue. It also has been shown that reducing the protein level in broiler diets reduces the concentration of manganese and copper in the tibia. Therefore, low-protein diets probably decrease bone density in broilers. This study was conducted to investigate the effects of GAA supplementation to low protein diets on performance, calcium and phosphorus and the strength of the tibia of broiler chickens.

  The 240 male broilers of Ross 308 strain were assigned to 6 dietary treatments in a 3 × 2 factorial arrangement with 4 replications and 10 birds in each replication. Dietary treatments included diets containing 80, 90 and 100% of the breeder recommended ideal protein each containing 0 and 0.06% of GAA. Feed intake, body weight gain and feed conversion ratio (FCR) were measured for the grower (11-24 days), finisher (25-42 days) and the overall period (11-42 days). On d 42, two birds from each experimental unit were killed, and the ash, calcium and phosphorus content and the strength of the tibia of the chickens were measured.

The results showed that by reducing the ideal protein to 80% of the breeder recommendation, body weight gain and feed intake was reduced significantly (P<0.05). Reduction of the dietary CP from 100 to 80%, resulted in inferior FCR during grower period. The inferior performance of broilers fed reduced protein diets is attributed to a limited availability of amino acids (AA). The supplementation of essential AA alone has failed to increase performance in reduced protein diets. The addition of GAA decreased feed intake of treatments (P<0.05) with reduced protein diet (80% of management guide recommendation). Body weight gain and FCR were not affected by dietary GAA supplementation. By reducing dietary protein to 80% of the recommendation, the strength of tibia decreased significantly (P<0.05). A low-protein diet may be associated with a hypocalciuretic effect, increased Ca retention and requirement for available P to avoid Ca:P imbalance, hormonal flux, and bone mobilization. Addition of GAA to the diet did not affect the parameters of bone strength. Tibia ash, Ca and P content were not significantly affected by dietary treatments.

According to the results of this experiment, reducing the dietary ideal protein to 80% of the breeder recommendation, resulted in inferior growth performance and tibia strength of broiler chickens, and dietary addition of GAA did not ameliorate those effects.

A total of 240 male Ross 308 broiler chicks were allocated in completely randomized design, including six experimental diets with 4 replicates and 10 chicks per replicate. Experimentaldiets include 1- a control diet based on corn and soybean meal, recommended according to the guide of Ross strain (308) 2- a control diet with the addition of protease enzyme with recommended levels (0/02 %) 3- low protein diet (five percent reduction) 4- Diet with low levels of protein and essential amino acids (five percent reduction) 5- Diet with low levels of protein (experimental diet three) with the addition of protease enzyme with recommended levels (0/02 %) 6- Diet with low levels of protein and essential amino acids with the addition of protease enzyme with recommended levels (0/02 %).The highest amount of feed consumption in the starter  period and the highest feed conversion ratio  in the growth period, as well as the highest percentage of abdominal fat, were related to the diet with low levels of protein and amino acids. Protease enzyme increased the body weight and decreased the feed conversion ratio during the growth period in diets with low levels of protein and amino acids (P<0.05).The use of protease enzyme in diets with low protein levels improved the digestibility of dry matter and organic matter, and the highest percentage of thigh and spleen and blood HDL concentration was related to the diet with low protein levels with the addition of protease enzyme (P<0.05). Based on the results, use of protease enzyme in diets with low levels of protein and amino acid improved the performance of broiler chickens.

In the past studies, the beneficial effect of insoluble fiber in broiler feed has been well demonstrated. Studies have shown that moderate amounts of fiber in poultry diets lead to significant improvements in nutrient utilization efficiency. Depending on the type of dietary fiber (soluble or insoluble), the particle size plays a role in the growth and development of gizzard and improves the mixture of digestive substances with digestive secretions. On the other hand, nutritionists are trying to respond to the rapid growth needs of birds by increasing the energy concentration of diets. Fats are considered for this purpose, as their energy value is at least twice that of carbohydrates and proteins. At a young age, the secretion of bile acids and the activity of pancreatic lipase are low, and therefore, the ability to digest fat in young broilers is compromised. Some studies have shown that cellulose and oat hull as a source of insoluble fiber (3%) in the diet of broiler chickens have increased the apparent digestibility of crude fat in the ileum and increased the availability of energy for the bird. Therefore, the purpose of this research is to investigate the effects of sunflower hull with different particle sizes in diets containing different sources of fat on growth performance, digestibility of nutrients and the microbial population of the caecum of broiler chickens.

This experiment was conducted using 360 one-day-old Ross 308 broiler chickens in a completely randomized design with a 2×3 factorial arrangement for 42 days. Experimental treatments included: sunflower hulls (SFH) (without hulls, 3% with 1 mm particle size and 3% with 5 mm particle size) and different fat sources (3% tallow, 3% canola oil). Feed intake (FI) and body weight gain (BWG) of birds were recorded and feed conversion ratio (FCR) was calculated. To determine the ileal digestibility of nutrients, 3 g/kg of chromium oxide was fed to chickens on days 37-42 of the rearing period. On the 42nd day of rearing, the ileum contents of 2 birds were collected and stored in a freezer at -20◦C. To investigate the morphology of the small intestine, 5 cm of the duodenum, jejunum and ileum were taken. Cecal microbial population also determined at 42 days of age. The data obtained from the experiment were analyzed using SAS statistical software and GLM procedure. To compare means, Duncan's (1955) multi-range test was used at a significant level of 5%.

The results showed that, using of the coarse and fine SFH in the diet of broiler chickens increased FI and improved the FCR in the whole period of experiment (P<0.05). Canola oil improved FI and BWG compared to tallow (P<0.05). Apparent digestibility of crude protein and crude fat also increased by using of coarse SFH in the diet (P<0.05). The use of coarse SFH increased the villus height of duodenum and the villus height and thickness of ileum (P<0.05). Canola oil increased the villus height of ileum, but decreased the villus thickness compared to tallow treatment (P<0.05). The use of coarse SFH in the diet reduced the population of Escherichia coli bacteria in the cecum, and coarse SFH with different sources of fat increased the population of Lactobacillus (P<0.05).

In general, the results of the present study showed that the addition of coarse sunflower hull to the diet could improve the growth performance of broilers by increasing the digestibility of crude protein, crude fat, Lactobacillus population, and reducing the cecal population of E. coli. Although its interaction with canola oil also had positive effects on the population of beneficial gut bacteria.

Effect of different sources of probiotic and prebiotic on growth performance, carcass characteristics, intestinal microflora, and blood metabolites using 720 Ross 308 commercial male broiler chickens in a 3×3 factorial experiment with three levels of probiotic (without probiotic, probiotic type I and type 2) and three levels of prebiotic (without prebiotic, prebiotic type 1 and type II), in a completely randomized design with nine experimental groups (four replications and 20 birds were studied in each replication. Birds that were fed with diets containing type 2 probiotics had a lower conversion factor (P<0.05). Diets containing prebiotic type 1 as well as diets containing probiotic type II and diets containing probiotic type II and two prebiotics under test reduced serum cholesterol and LDL concentrations (P < 0.05). The effect of the experimental treatments on carcass fat was not significant, but the birds fed diets containing prebiotic type 1 had less abdominal fat (P<0.05). At 21 days old, the population of E. coli in the ileum and ceca of birds that received probiotics, prebiotics, and their combinations decreased (P < 0.05). At 38 days of age, feeding the birds with probiotics and prebiotics and a combination of them reduced the population of E. coli in the ceca and increased lactobacillus in the ileum (P < 0.05). The results of this experiment showed that probiotics or prebiotics assayed in this study have positive effects on the increase of beneficial intestinal bacteria (Acid lactic bacteria), blood biochemical traits, and FCR in broiler chickens.

Ascites is one of the most common metabolic syndromes in today's fast-growing broilers and is associated with rapidly growing tissues and characterized by accumulation of lymph fluid in the peritoneal spaces. Effective factors in the occurrence of ascites syndrome include free radicals in the body such as superoxide, hydroxide, and hydrogen peroxide. By reducing the capacity of the body's antioxidant systems, free radicals make the bird susceptible to various diseases. Free radicals produced in the body by damaging the cell membrane lead to cell death and ultimately tissue damage. Therefore, by increasing cell protection from such injuries, one of the common causes of ascites and heart failure abnormalities can be prevented. In addition, free radicals from oxygen derivatives reduce the half-life of nitric oxide (vasodilating agent), causing a decrease in the ability of vasodilation and providing the basis for the occurrence of ascites. Therefore, it is suggested that the use of antioxidants can prevent ascites and improve performance in broilers. Medicinal plants are among the rich sources of natural antioxidants that do not have the harmful effects of antibiotics and synthetic antioxidants. For this reason, the use of medicinal plant extracts is an important step in animal nutrition to increase the immunity of poultry. The mentioned extracts have strong antioxidant, antibacterial, and digestive properties. Probably, the positive effects of medicinal plants are due to the active compounds found in plant extracts such as menthol, thymol, and carvacrol. This study aimed to investigate the effects of ethanolic extract of sage on the performance, antioxidant status, and blood parameters of broiler chickens under induced ascites.
A total of 450 one-day-old chickens (Ross 308) were reared in the form of a completely randomized design with six treatments and five replications (15 chickens in each replication). Experimental treatments include 1. Positive control group (without inducing ascites and fed with basic diet), 2. Negative control group (inducing ascites and fed with basic diet), 3 and 4. Vitamin C group (inducing ascites with levels of 1000 and 2000 ppm vitamin C), 5 and 6- Sage group (ascites induction with 1000 and 2000 ppm of sage extract). To induce ascites, water containing 1200 mg of sodium (three grams per liter of sodium salt) was provided to the chickens from the 15th day of the experiment. Growth performance parameters including feed intake, weight gain, and feed conversion ratio were calculated for the total period. On the last day of the experiment (42 d), two birds were randomly selected from each cage and after sampling from the wing vein, killed and the ascites index was calculated as the ratio of the weight of the right ventricle to the total ventricles. The mortalities were collected as soon as they were observed and after weighing to correct the feed conversion ratio, were necropsied to investigate the cause of death. Blood and biochemical parameters such as the number of red and white blood cells, hemoglobin, hematocrit, heterophil and lymphocyte, serum triglyceride, and cholesterol, as well as serum antioxidant parameters including the level of malondialdehyde and the activity of antioxidant enzymes including glutathione peroxidase, superoxide dismutase, and catalase were measured. In addition, liver enzymes present in the serum including alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), and alkaline phosphatase (ALP) were also measured.
The results showed that induction of ascites increased the ratio of the right ventricle to total ventricles, mortality due to ascites, feed consumption, feed conversion ratio, and body weight loss (P<0.05). Administering sage extract improved the mentioned traits and vitamin C also reduced the ratio of right ventricle to total ventricles, losses due to ascites (P<0.05). Sage extract and vitamin C moderated the increasing effects of ascites induction on heterophiles, triglyceride, and cholesterol and increased red blood cells, hematocrit, and hemoglobin compared to the negative control treatment (P<0.05). In addition, the induction of ascites decreased the activity of glutathione peroxidase, superoxide dismutase, and catalase enzymes and increased serum malondialdehyde, experimental treatments, especially sage extract, improved the antioxidant status compared to the negative control treatment (P<0.05). Also, the induction of ascites increased the serum levels of aspartate aminotransferase, alanine aminotransferase, gammaglutaryl transferase, and alkaline phosphatase enzymes. The addition of experimental supplements, especially sage, decreased the serum level of the mentioned enzymes (P<0.05).
The results of this research showed that the use of sage extract compared to vitamin C has better results on performance, increasing antioxidant power, and reducing stress of broilers with ascites.

The use of medicinal plants and their derivatives can stimulate feed consumption, increase daily weight, feed conversion ratio, increase shelf life, improve the health and function of the digestive system. It seems that the use of an optimal mixture of several medicinal plants in the diet has positive effects on performance and carcass quality of broiler chickens in comparison to each one. Nowadays, with the popularization of ready-made feed in raising broiler chickens, many breeders tend to add food additives in drinking water. Therefore, it is a question that adding these compounds in feed or drinking water makes a difference. Three commercial plant additives that are used today are Coxan, O.X. Plant, and Entex. Coxan contains oregano (with the active ingredient of menthol) and garlic (with the active ingredients of allin and allicin), O.X. Plant contains savory (with the active ingredients of carvacrol and thymol), thyme (with the active ingredients of thymol and carvacrol) and red pepper oleoresin (with the active ingredient of capsaicin), Entex contains cinnamon (with the active ingredient of cinnamaldehyde), and garlic and eucalyptus (with the active ingredient of cineol). The aim of this research was to compare the effects of using these commercial plant additives (in water and feed) on growth performance, intestinal microflora and morphology and immune response of broilers.
A total of 336 Ross 308 broilers were examined in a completely randomized design with seven treatments, four replications, and 12 chickens per replication. Experimental treatments included: control (without phytogenic in feed or water), Coxan in feed (300 mg/kg) and in water (200 mL/1000 L), O.X. Plant in feed (200 mg/kg) and in water (135 mL/1000 L) and Entex in feed (500 mg/kg) and water (350 mL/1000 L). Daily weight gain, daily feed intake, daily water intake and feed conversion ratio were measured. At 42 days of age, two birds were selected from each experimental unit and after slaughter, the length of the intestinal components was measured separately (duodenum, jejunum, and ileum). To determine the microbial population, samples were taken from the ileum of chickens. EMB culture medium was used to determine Escherichia coli population and MRS culture medium was used for Lactobacillus bacteria. To check the humoral immune response, 0.1 mL of 25% sheep red blood cell solution in PBS was injected into the breast muscle of chickens on the 12th and 29th days of rearing. Blood was taken from the chickens on the 28th, 35th and 42nd days of breeding and the levels of Anti-SRBC, and immunoglobulins G and M were calculated. Antibody titer against Newcastle disease was measured by HI method.
The effect of additives in water and feed on average daily feed consumption, daily weight gain, feed conversion ratio and daily water consumption was not significant in the whole period. Since the amount of water consumed by the chickens did not change, it can be concluded that the additives added to the water in the examined amounts do not have a spicy or unpleasant taste that would cause the birds to refuse to drink water. The relative length of duodenum, jejunum, cecum and colon was not affected by experimental treatments. However, the relative length of the ileum was lower in the chickens that received Entex in the feed compared to the control group. No significant difference was observed in the relative length of different parts of the intestine in the treatments that received herbal additives either in feed or water. The relative length of duodenum, jejunum, cecum, and colon, villus length, villus area, crypt depth, thickness of lamina propria, thickness of muscular layer, and thickness of advantis layer were not affected by experimental treatments. The chickens that consumed 500 mg/kg of Entex herbal additive of feed had a lower villus width in the ileum region compared to the control group chickens. The population of Escherichia coli bacteria in the ileum of chickens that had received the addition of O.X. Plant and Entex in the feed decreased compared to the control group. The population of Escherichia coli bacteria in the Entex treatment in the feed was also reduced compared to the Coxan treatment in the feed. The population of Lactobacillus bacteria in the ileum of chickens that received Coxan in water, O.X. Plant in feed and water, and Entex in feed increased compared to the control group. There was no significant difference in the population of Escherichia coli and Lactobacillus bacteria in the treatments that received herbal additives either in feed or in water. The use of plant essential oils in poultry feed, while improving the microbial population by increasing the number of lactobacilli, by improving the morphological characteristics of the intestine, probably improves the ability of digestion and absorption in the digestive system and improves the growth efficiency of broiler chickens. Antibody levels against SRBC were higher at 28, 35, and 42 days in all chickens consuming herbal additives in water. The performance of animals is significantly influenced by the state of health and safety of the animal. A weak or stressed immune system causes weight loss when dealing with infectious diseases, so the use of immune system stimulating substances can increase performance by improving the immune status. In raising poultry, it is important to strengthen the immune system to prevent the occurrence of diseases.
The results of this research showed that the commercial plant additives of Coxan, O.X. Plant, and Entex had no significant effect on growth performance, relative length and intestinal morphology. The population of opportunistic bacteria Escherichia coli was significantly reduced compared to the control group with the addition of O.X. Plant and Entex in the diet. In general, it can be concluded that adding tested herbal additives not only did not have a negative effect on the drinking water consumption of broiler chickens, but also using them in water improved the immune responses of broilers more than adding them in feed. A total of 336 Ross 308 broilers were examined in a completely randomized design with 7 treatments, 4 replications, and 12 chickens per replication. Experimental treatments included: control (without phytogenic in feed or water), Coxan in feed (300 mg/kg) and in water (200 mL/1000 L), O.X. Plant in feed (200 mg/kg) and in water (135 mL/1000 L) and Entex in feed (500 mg/kg) and water (350 mL/1000 L). Daily weight gain, daily feed intake, daily water intake and feed conversion ratio were measured. At 42 days of age, 2 birds were selected from each experimental unit and after slaughter, the length of the intestinal components was measured separately (duodenum, jejunum, ileum). In order to determine the microbial population, samples were taken from the ileum of chickens. EMB culture medium was used to determine Escherichia coli population and MRS culture medium was used for Lactobacillus bacteria. To check the humoral immune response, 0.1 ml of 25% sheep red blood cell solution in PBS was injected into the breast muscle of chickens on the 12th and 29th days of rearing. Blood was taken from the chickens on the 28th, 35th and 42nd days of breeding and the levels of Anti-SRBC, immunoglobulin G and M were calculated. Antibody titer against Newcastle disease was measured by HI method. The effect of additives in water and feed on average daily feed consumption, daily weight gain, feed conversion ratio and daily water consumption was not significant in the whole period. Since the amount of water consumed by the chickens did not change, it can be concluded that the additives added to the water in the examined amounts do not have a spicy or unpleasant taste that would cause the birds to refuse to drink water. The relative length of duodenum, jejunum, cecum and colon was not affected by experimental treatments. However, the relative length of the ileum was lower in the chickens that received Entex in the feed compared to the control group. No significant difference was observed in the relative length of different parts of the intestine in the treatments that received herbal additives either in feed or water. The relative length of duodenum, jejunum, cecum, and colon, villus length, villus area, crypt depth, thickness of lamina propria, thickness of muscular layer, thickness of advantis layer were not affected by the experimental treatments. The chickens that consumed 500 mg/kg of Entex herbal additive of feed had a lower villus width in the ileum region compared to the control group chickens. The population of Escherichia coli bacteria in the ileum of chickens that had received the addition of O.X. Plant and Entex in the feed decreased compared to the control group. The population of Escherichia coli bacteria in the Entex treatment in the feed was also reduced compared to the Coxan treatment in the feed. The population of Lactobacillus bacteria in the ileum of chickens that received Coxan in water, O.X. Plant in feed and water and Entex in feed increased compared to the control group. There was no significant difference in the population of Escherichia coli and Lactobacillus bacteria in the treatments that received herbal additives either in feed or in water. The use of plant essential oils in poultry feed, while improving the microbial population by increasing the number of lactobacilli, by improving the morphological characteristics of the intestine, probably improves the ability of digestion and absorption in the digestive system and improves the growth efficiency of broiler chickens. Antibody levels against SRBC were higher at 28, 35 and 42 days in all chickens consuming herbal additives in water. The performance of animals is significantly influenced by the state of health and safety of the animal. A weak or stressed immune system causes weight loss when dealing with infectious diseases, so the use of immune system stimulating substances can increase performance by improving the immune status. In raising poultry, it is important to strengthen the immune system to prevent the occurrence of diseases. The results of this research showed that the commercial plant additives Coxan, O.X. Plant and Entex had no significant effect on growth performance, relative length and intestinal morphology. The population of opportunistic bacteria Escherichia coli was significantly reduced compared to the control group with the addition of O.X. Plant and Entex in the diet. In general, it can be concluded that adding tested herbal additives not only does not have a negative effect on the drinking water consumption of broiler chickens, but using them in water improves the immune responses of broilers more than adding them in feed.

Lipids (fat and oil) are the most concentrated sources of energy for animals, which are usually added to poultry diets to meet energy requirements for better performance (Abudabos 2014). However, there are problems with dietary lipid levels and digestibility in poultry, especially in young birds due to low bile secretion (Ravindran et al 2016). This physiological limitation of the poultry digestive system can be solved by using exogenous emulsifiers. Emulsifier can help increase the active level of lipids, stimulate the formation of micelles, and then increase the digestibility of dietary lipids and other nutrients in broilers (Siyal et al 2017). Upadhaya et al (2017) showed that 1, 3-diacylglycerol as an exogenous emulsifier can improve growth performance and increase nutrient digestibility in broilers. In addition, a large number of studies have also shown that exogenous emulsifier can improve meat quality and regulate fat metabolism of broilers (Zhao and Kim 2017). Bile acids are the main pathway of cholesterol catabolism in mammals. Cholesterol is converted into bile acids by changes in ring structure, oxidation and side chain shortening (Li and Chiang 2019). The chemistry of bile acids is complex due to the large variety of chemical structures in natural compounds such as cholic acid, kenodeoxycholic acid, deoxycholic acid, and lithocholic acid. Bile acids of birds are mainly composed of kenodeoxycholic acid and cholic acid (Hoffman and Hagee 2018). Recently, bile acids have been considered as an emulsifier to increase digestibility (Upadhaya et al 2019) and improve the performance of broiler chickens (Parsai et al 2007). Supplementation of bile acids in the diet of broilers significantly improves fat digestibility (Lammasak et al 2019). The effect of bile salts on performance, carcass characteristics and blood parameters of broiler chickens were investaigeted.

Three hundered one-day-old broilers (Ross 308) were divided into 5 treatments and 6 replications with 10 birds in each replication. Five experimental treatments included the control diet (corn soybean based diet), emulsifier (added to control diet) and three levels of 0.05%, 0.1% and 0.2% of poultry bile salts (added to control diet). All the dietary treatment were fed to the birds from day one to day 42 of age. The experiment lasted for 42 days and were performed during the starter (1-10 days), grower (11-24 days) and finisher (25-42 days). Performnce indices were measured during the difeferned periods and carcass characteristics and blood parameters were determined on day 42 of age. The data obtained from the present study were statistically analyzed using SAS statistical software and GLM procedure. To compare the means, Tukey's test was used.

The results showed that consumption of different levels of bile salts had no significant effect on feed consumption (P<0.05). However, consumption of 0.1% bile salts improved body weight gain and feed conversion ratio during the starter period (P<0.05). Previous studies have shown that the consumption of 0.05% commercial emulsifier can improve the growth performance of broiler chickens (Wang et al 2016). In addition, in the present study, 0.05% poultry bile acids supplement significantly improved daily weight gain and feed conversion ratio during 1 to 10 days, which is consistent with the results of Alzawqari et al (2011) regarding bile. These researchers observed improvement in daily weight gain with 0.05% bovine bile acid supplementation. Arshad et al (2020) reported that feed intake was not affected by bile acid supplementation in the initial, growth, finisher and overall periods. In the newly hatched chick, the ability to digest and absorb dietary fat is poor as a result of limited bile secretion (Tancharonrat et al 2013). For this reason, artificial bile acid and bile salts have shown the greatest effect in young broiler chickens to improve fat digestion, and the improvement in the performance of birds receiving bile in the initial period of recent research was for this reason. The results of Maisonnier et al (2016) showed that 0.5% of pig bile acids can increase fat digestibility and body weight in broilers. These results may imply that the supplementation of bile acids in diets improved the growth performance of broiler chickens by increasing the solubility and digestibility of dietary fat and fat-soluble nutrients in this study. Abdominal fat decreased significantly by consumption of 0.1% bile salts (P<0.05). Subcutaneous fat and abdominal fat are considered as the main factors influencing the performance of poultry carcasses (Tůmová and Teimouri 2010). In agreement with our results, many researchers have pointed out the positive effects of emulsifier on reducing fat status and improving carcass quality in broiler chickens (Zhao and Kim 2017). Blood triglyceride concentration was decreased in 0.05% bile salts fed birds wherease cholesterol and uric acid concentrations decreased in the birds fed emulsifier (P<0.05). Triglyceride, cholesterol, HDL and LDL blood are key indicators of lipid metabolism balance (Helkin et al 2017). In agreement with our results, researchers reported that bile acids increased hepatic AST and ALT activity in broilers and reduced serum triglyceride levels, which could be due to the participation of these enzymes in the lipogenesis process (Ge et al 2019). In addition, Siyal et al (2017) showed that feed emulsifier can reduce serum triglyceride concentration in broilers. It can also be stated that bile acids may enhance fat catabolism and inhibit fat synthesis by regulating the expression of genes related to lipid metabolism which may play a pivotal role in improving serum lipid profile and reducing fat deposition in broiler chickens (Ge et al 2019).

Totally, it was found that dietary bile salts supplementation improves the performance of, carcass characteristics and blood lipids in broiler chcikens.

Heat stress is one of the serious issue in poultry industry which causes significant economic losses. Decreasing feed consumption, increasing excretion and decreasing the bioavailability of nutrients during heat stress reduces the performance and immune response. Selenium is an essential trace element for humans and animals that plays a role in improving the antioxidant status and the immune system and inflammatory response. The goal of this study was to investigate the effects of different selenium sources [2-hydroxy-4- methyl seleno butanoic acid, selenomethionine and sodium selenite) on performance, carcass characteristics, antioxidant and immune response and blood characteristics in broiler under heat stress condition.

This experiment was conducted in a completely random designs with 240 Arbor Acres (Male) broilers chicks. Chicks were randomly distributed in 4 treatments and 6 replicates (10 chicks in each replicate). The experimental treatments include that: (1) basal diet + 0.3 mg 2-hydroxy-4- methyl seleno butanoic acid; (2) basal diet + 0.3 mg selenomethionine per kilogram of diet; (3) basal diet + 0.3 mg sodium selenite per kilogram of diet; (4) The basal diet that did not have any additives. The birds were kept at 32-340C (10.00 to 16.00; for 6 hours) from 22 to 42 days.

The results of this experiment showed that feed intake, body weight gains and feed conservation ratio were not affected by the experimental diets. The use of different sources of selenium had no significant effect on blood biochemical factors in broiler chickens under heat stress. dding selenium source with 0.3 mg/kg 2-hydroxy-4- methyl seleno butanoic acid significantly affected immunoglobulin G in comparison to other treatments. Diets containing selenium sources significantly increased the relative weight of the spleen compared to the control treatment (P < 0.05). The treatments of 2-hydroxy-4- methyl seleno butanoic acid and selenomethionine significantly decreased liver weight percent. The concentration of glutathione peroxidase, superoxide dismutase and catalase enzymes in blood were significantly increased by selenium sources in different treatments.

The use of selenium source improved the immune system and blood antioxidant status in broiler chickens.

Silver nanoparticles are one of the new achievements in nanotechnology, which are used in medicine, veterinary medicine, agriculture, and pharmaceuticals due to their antimicrobial activity. Silver nanoparticles can react with biological macromolecules and induce apoptosis by disrupting intracellular homeostasis. Hence, the aim of this study was to the effect of zeolite, organic acid and silver nanoparticles coated on zeolite on the expression of BAX and Bcl2 apoptosis genes in broiler chickens.

The number of 450 one-day- old broiler chicks (Cobb 500) were used in five treatments and six repetitions with 15 chicks per replicate in the form of a completely random design. Experimental diets were: control or basal diet (1), a basal diet supplemented by 1% zeolite (2), a basal diet supplemented by 1% zeolite coated with 0.5% nanosilver (3), a basal diet supplemented by 0.15% organic acid (4) and a basal diet supplemented by 1% zeolite coated with 0.5% nanosilver and 0.15% organic (5). The experiment was conducted with broiler chicken from 1 to 42 days old. The expression of the BCL2 and BAX apoptosis genes, liver sampling was done on the 21st and 42nd days of the breeding period.

The results of this experiment showed that in broiler chicks receiving zeolite treatment (Z) on d 21 and silver nanoparticles coated on zeolite treatment (NS) on d 42 of the breeding period the expression level of Bcl2 gene in liver tissue was significantly increased (P<0.05) compared to the control treatment (C Also, the expression of the BAX gene in the liver tissue in NS and NSOA treatments on d 42 of the breeding period increased significantly compared to the control treatment (P<0.05).

In conclusion, the results of this experiment showed that zeolite and NS and NSOA treatments have an increasing effect on the expression of Bcl2 and BAX genes, while this effect was not observed in organic acid treatment.