Journal of Animal Production, Print ISSN: 2008-6776., Online ISSN: 2382-994X

Abstract Introduction: 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. Materials and Methods: 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. Results and Discussion: 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. Conclusion: 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.

Abstract Introduction: 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. Material and Methods:  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. Results and Discussion: 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. Conclusion: 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.

Abstract 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.

Abstract The aim of this study was to investigate the effect of emulsifier in diet with with energy reduction on performance, carcass characteristics and some of blood traits of broilers. A total of 540 one-day-old chicks of Ross 308 strain in a 3×3 factorial arrangement with three levels of emulsifier (0, 250 and 500 mg / kg) and three levels of dietary energy (requirement, and 45 and 90 kcal/Kg, 60 and 105 kcal/kg and 75 and 120 kcal/kg less than requirement for the starter, grower and finisher diets, respectively) in a completely randomized design with 9 treatments, 4 replications and 15 birds per replication were used. In total rearing period, feed intake increased by decreasing the dietary energy (P<0.05). Birds fed diets supplemented by emulsifier had higher weight gain and lower feed conversion ratio (P<0.05). The relative weights of the liver, ceca, and abdominal fat were not affected by different levels of dietary energy. The emulsifier × diet interaction had no significant effect on cholesterol, High-density lipoprotein (HDL), Low-density lipoprotein (LDL), cholesterol: HDL, Alanine aminotransferase (ALT) and alkaline Phosphatase. Adding emulsifier to normal diets or diets with more energy deficiency increased blood triglyceride concentration (P<0.05). Supplementing diets with mild energy deficiency by emulsifier increased serum Aspartate aminotransferase (AST) (P<0.05). According to the results, the use of 250 gr/t emulsifier in low energy diets improved the performance of broiler chickens.

Abstract A 42-d study was conducted to investigate the effects of emulsifier and inulin supplementation in diets with different sources of fat on growth performance, carcass traits, immune response, and blood biochemical indices of broilers. A total of 800 one-day-old male broilers in a 2 × 2 × 2 factorial experiment with two fat sources (soybean oil and beef tallow), two emulsifier levels (0 and 0.1% lysophospholipids) and two levels of inulin supplementation (0 and 0.1%) were used in a completely randomized design with eight treatments, five replications and 20 chicks per replicate. Birds fed diets containing beef tallow and emulsifier had a lower feed conversion ratio and abdominal fat percentage than birds fed diets containing soybean oil and emulsifier (P <0.05). The abdominal fat percentage and feed conversion ratio were lower in birds that received fat and inulin diets than other birds (P<0.05). Birds fed the emulsifier-containing diet had higher values of primary and secondary antibody titers against Newcastle disease virus, and secondary titers of total antibody and IgM against sheep red blood cells (SRBC) compared to those fed the emulsifier-unsupplemented diet (P<0.05). Daily weight gain and antibody titer against Newcastle disease and SRBC were higher in birds receiving the inulin-supplemented diet compared to other birds (P<0.05). In conclusion, the use of 0.1 % emulsifier and inulin, either singly or in combination, in the diet of broiler chickens can be useful for improving growth performance and immune response.

Abstract The experiment was conducted to investigate the effects of cell wall carbohydrates with diet supplemented enzyme on the function and expression of glucose transporter genes (SGLT1 and GLUT2), peptide transporter (PepT1) and mucin production (MUC2) in the small intestine of broilers. In this study, 1100 mixeddayold chickens (male and female), Ross 308 were used based on a completely randomized design with 11 treatments and five replications (20 birds per replication) for 42 days. Experimental diets included control diets, diets containing wheat, barley, wheat bran, rice bran, and hull less barley with and without enzymes, respectively. The results showed that the effect of diets containing wheat, barley and hull less barley with enzyme on the total live weight of broiler chickens at 42 days of age was significantly different (P <0.05).Cell wall carbohydrates of wheat, wheat bran and rice bran in diets increased pancreatic amylase activity (barley 3.02, wheat 5.99 U/mg CP of small intestinal tissue) (P < 0.05). The expression of the studied SGLT1 and MUC2 genes in the experimental diets without enzyme showed a significant increase compared to enzymes supplemented diet (P < 0.05). Also, among the groups of enzyme-supplemented diets, only wheat and rice bran groups were able to increase the expression of SGLT1, MUC2 and GLUT2 genes compared to the control group (P <0.05). In conclusion, supplementation of diets containing cell wall carbohydrates with enzyme affects the expression of glucose transport genes (SGLT1 and GLUT2), peptide transport (PepT1) and mucin production (MUC2) in the small intestine jejunum. This indicates the optimal function of the digestive system of broilers in terms of digestion and absorption of nutrients.

Abstract Effect of red pepper in comparison to commercial growth promoters, Biostrong and Oleobiotec, on growth performance, nutrient digestibility, and other traits of broilers under heat stress conditions using 200 day-old broiler chickens mixed male and female of Arbor Acers strain in a completely randomized design with four treatments, five replications and ten chickens per replicate were evaluated. Treatments included a basal diet without additives and a basal diet containing 10, 0.1, 0.15 g/kg red pepper, Biostrong, and Oleobiotec, respectively. At the beginning of third week, the birds were exposed to heat stress for six hours per day. During the 42 days of the experiment, the mean minimum and maximum temperatures were 25^°C and 33^°C. Feed intake, weight gain, feed conversion ratio, the weight of internal organs, caecal microflora, and precaecal nutrient digestibility were measured for the heat stress period. The use of red pepper improved the feed conversion ratio and daily weight gain in grower and finisher periods and increased protein, lipid, and dry matter precaecal digestibility, the relative weight of bursa of Fabricius, spleen, and gizzard, and decreased the Ecoli population in caecum compared to the control treatment (P≤0.05). Biostrong and Oleobiotec did not affect growth performance, prececal nutrient digestibility, and the E.coli population. Overall, using the red pepper in the diet of broilers compared to commercial growth promoters reduced the adverse effects of heat stress on growth performance, nutrient digestibility, and caecal microflora.

Abstract Effect of different levels of calcium, hydroalcoholic extracts Withania coagulans, and flaxseed oil on performance, mineral retention and bone morphology using with four thousand and eighty male Ross 308 broiler chicks in a 2×3×2 factorial experiment with two calcium levels (Calcium at the recommended level and calcium 30% less than the recommended level), extract Withania coagulans (Zero, 100 and 200 mg / kg in diet) ) and flaxseed oil (0% and 2% diet) in a completely randomized design with four replications and 10 birds per treatment were evaluated for 24 days. Adding 100 mg/kg of extract Withania coagulans to the diet increased feed intake and weight gain. Mineralization of bone growth plate increased in birds fed the extract Withania coagulans supplement (P <0.05). Supplement flax oil in diet did not show a positive effect on performance and bone parameters. Physical properties and mineral retention of calcium and phosphorus were not affected by the supplements. However, the amount of bone ash was affected by the interactions of flaxseed oil and extract, and the amount of ash in chickens fed diets without extract and flaxseed oil decreased. At 24 days of age, blood phosphorus levels in chickens fed a diet containing calcium and 200 mg of extract Withania coagulans increased (P <0.05). Based on the results of this study, adding 100 and 200 ml/kg hydroalcoholic extract of Withania coagulans to the diet of calcium deficient broilers improves performance and some bone parameters.

Abstract The effects of increasing levels of L-leucine supplementation on performance, carcass traits, breast meat production and determination of digestible leucine requirement broilers during the grower period (15 to 30 days) using 240 Ross males broiler chickens in a completely randomized design with six dietary treatments (five repetitions and eight chicks per repetition) was investigated. Treatments include; a basal diet with 1.53% digestible leucine and five diets containing 1.63, 1.73, 1.83, 1.93, and 2.03% digestible leucine by adding synthetic L-leucine to the basal diet. By increasing the levels of digetible Leucin, body wieght gain, carcass and breast muscle percentage were increased, but feed conversion ratio and abominal fat percentage were decreasd (p < 0.05). The response trends to increasing levels of digestible leucine were quadratic for weight gain, feed conversion ratio, the relative weight of carcass, relative weight of breast muscle and relative weight of abdominal fat ( p < 0.05). Due to the better fit of the quadratic model to the response criteria, digestible Leucine requirements were estimated at 1.70, 1.72, 1.724, and 1.735% for body weight gain, feed conversion ratio, the relative weight of carcass and breast muscle; respectively. Based on the average of these estimates, the suggested digestible Leucine requirements of broilers in the grower period is 1.72%.

Abstract This experiment was conducted to investigate the effect of processed date pit on broiler performance. In this experiment, 280 broiler chicks were used in a completely randomized design with seven treatments and four replicates. The experimental treatments were: 1- control (diet without date pit), 2- 10 percent raw date pit, and treatments 3 to 7- were 10 percent date pit that processed with steam pressure, NaOH, and fermented with Lactobacillus fermentum, Bacillus subtilis, and Aspergillus niger respectively. The crude protein content of processed date pit was higher, and the ether extract content was lower (exept NaOH) than raw date pit (p < 0.05). The feed intake, body weight gain, feed conversion ratio and cecal microbial population of broiler chickens were not affected by experimental treatments. The small intestine length of birds that fed diets containing processeddate pit with steam pressure and NaoH was significantly reduced in comparison with birds resived diets containing fermented date pit with Aspergillus niger and without date pit (p < 0.05). The highest amount of litter dry matter and lowest amount of excreta ash was observed in groups fed diet containing raw date pit (p < 0.05). According to the results of this study, the processing methods of date pit has no effect on broiler performance and cecal microbial population. Therefore, due to the high cost of processing, and the favorable effects of feeding raw date pit on broiler litter quality, the use of raw date pit in broilers diet is recommended.
 

Abstract In order to evaluate the effect of different levels of corn gluten feed on performance, immune responses, intestinal morphology and some blood serum biochemical parameters of broiler chickens, an experiment was conducted using 500 male Ross 308 broiler chickens in a completely randomized design with four treatments, five replicates and 25 birds per replication. The experimental treatments included levels  of zero (control), 2.5, 5 and 7.5 percent corn gluten feed in the diet which fed to broilers from 15 to 42 days of age. The results showed that dietary inclusion of corn gluten feed up to 7.5 percent had no significant effect on average weight gain, feed intake and feed conversion ratio
compared to control treatment. Also, jejunal morphological indices and blood biochemical parameters including triglyceride, cholesterol, albumin, phosphorus and alkaline phosphatase concentrations, livability, European broiler index and feed cost per kg of weight gain were not affected by dietary treatments. Antibody titer in response to sheep red blood cell (SRBC) injection was higher in treatment containing 2.5 percent corn gluten feed comparing to other treatments (P<0.05). Based on the obtained results, corn gluten feed can be included in grower and finisher diets of broilers (15 to 42 days of age) up to level of 7.5 percent without any adverse effect on performance.

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

Abstract The effect of medicinal plant of Cynara scolymus (artichokes) were studied on ascites syndrome, systolic blood pressure and blood parameters in broiler chickens using a total of 400 one-day-old Ross 308 in a completely randomized design with 5 treatments, 4 replicates and 20 chicks for each replicate, up to 42d under cold temperature condition. Experimental treatements were control (basal diet), antibiotic (basal diet plus 0.0015 percent antibiotic virginiamycin), aspirin (basal diet plus 0.2 percent aspirin powder) and two basal diets containing 1 and 2 percent artichoke powder. The results showed that feed intake and body weight were increased and feed conversion rate was decreased in artichoke powder received groups in comparison with other treatment (P

Abstract The effect of two types of dietary acidifier; Globacid®, Greencab® and their mixture on growth performance, carcass characteristics, nutrient digestibilities and intestinal microflora in broilers were studied by using hundred and twenty eight one-day old Cobb 500 broiler chickens of either sex, four treatments and four replicates of eight chicks in each in a completely randomized disign. The experimental treatments consisted of a basal diet; diet containing basal diet + 0.085 percent Globacid®; diet containing basal diet + 0.035 percent Greencab® and diet containing basal diet + mixture of 0.085 percent Globacid® and 0.035 percent Greencab®. The effect of treatments on growth performance, carcass characteristics and intestinal microflora was not significant and the higher digestibility of dry matter, organic matter and crude protein in comparison to control diet were seen in treatment containing the mixture of Globacid® and Greencan® acidifiers. According to the results of this study, the dietary mixture of Globacid® and Greencan® acidifiers can be useful in broilers by improving dry matter, organic matter and crude protein digestibilities and decreasing feed intake trend.

Abstract The effect of peanut pod as insoluble fiber source in diets on growth performance, small intestine morphology and nutrient digestibility of broilers was evaluated. This study was conducted using 320 Ross-308 broiler chickens in a completely randomized design with four treatments diets (containing 0 (control), 2.5, five or 7.5 percent peanut pod), with five replicates and 16 birds in each from 11 to 42 days of age. At the growth phase (11 to 24 d) dietary peanut pod decreased feed intake and feed conversion ratio, however, the birds that fed the diet containing 7.5 percent had higher daily weight gain (P<0.05). Peanut pod improved the digestibility coefficients of dry matter and ether extract and the diets containing 2.5 or 5.0 percent peanut pod had more organic matter digestibility than the control diet (P<0.05) Chicks that fed the diets containing 5.0 or 7.5 percent peanut pod, the villous was (P<0.05) longer than control birds. The results of present study suggest that using peanut pod up to 7.5 percent of diet did not adversely affect chickens growth performance and can improve feed conversion ratio at the grower phase.

Abstract In the current study, growth parameters of broiler chickens fed with rice hull were estimated and their final body weigh was predicted using non-linear, spline regression and neural networks models. The experimental treatments were control and dietary inclusion of rice hull at the levels of 2.5, 5 and 7.5 percent. Predicted final body weight estimated by non-linear regression models in the current study was higher in control chicks compare with those fed rice hull containing diets (P<0.05), but similar among the other birds. Inflection point of growth curve occurred earlier in in control chicks than those fed hull rice containing diets (P<0.05), but increasing hull rice in the diet level had no effect on this parameter. The highest and lowest body weight at inflection point observed in birds fed control and those fed diet containing 5 percent of rice hull, respectively (P<0.05). Feeding chicks with diets containing rice hull decreased parameters b of spline regression model compared with control birds, while parameter c was only lower in birds fed diet containing 7.5 percent hull rice compared with birds on control diet (P<0.05). According to our results, spline regression model is more efficient than the non-linear and artificial neural network models to predict body weight of broiler chicks fed with diets containing rice hull at day 42 of age.

Abstract To investigate the effect of cinnamon, turmeric and carnation powders on growth performance, carcass characteristics, morphological and pH changes of intestine and blood serum oxidation status in broilers, 450 unsexed Ross 308 day-old broiler chicks were randomly allotted in a completely randomized design with six treatments, five replicates and 15 birds per each replicate, for 42 days. The broilers were fed either a basal diet (without feed additive as control) or basal diet supplemented with 3 g/kg of cinnamon, turmeric and carnation powders and 0.6 g/kg of their mixture (2 g/kg of each) as well as 0.5 g/kg of flavophospholipol. Feed intake, weight gain and FCR as well as carcass characteristics were not affected by experimental diets. The jejunal villi height to crypt depth ratio was turned out to be significantly higher in the diet containing the mixture of cinnamon, turmeric and carnation than those of control, flavophospholipol and cinnamon diets (P<0.05). In addition, the feed additives appeared to reduce the pH of duodenal digesta compared to the control (P<0.05). Moreover, blood serum MDA of chickens fed basal diet and diet containing carnation was significantly higher than the other experimental diets (P<0.05). In conclusion, turmeric powder alone or in combination with cinnamon and carnation can be considered as an appropriate alternative to antibiotics in broiler diets, and used for improving the pH and morphological traits of intestine as well as blood serum oxidative stability.

Abstract An experiment was conducted to determine of the effects of vitamin E and C supplementation in diet based on different source of oils on performance and serum parameters of broilers. A total of 320 broiler chicks (Strain Ross 308) used in a 2×2×2 factorial arrangement in the form of completely randomized design with eight treatments, four replicates and 10 chicks in each replicate. Experimental factors included: two different oil sources (soybean and canola), two levels of vitamin E (zero and 200 mg/kg), and two levels of vitamin C (0 and 1000 mg/kg). Oil sources and vitamin E and C had no effect on performance of broilers. Supplementation of vitamin E or C increased serum total cholesterol and HDL (P<0.05). Source of oil had no significant effect on glucose and total serum cholesterol. Broilers fed diet containing canola oil had higher HDL and lower serum malondialdehyde than those fed diets with soybean oil (P<0.01). Supplementation of vitamin C to the diets containing canola oil decreased serum triglyceride compared with diets include soybean oil and vitamin C (P<0.05). Supplementation of vitamin E decreased serum malondialdehyde and increased activity of glutathione peroxidase (P<0.05). Results of this study indicate that dietary supplementation of canola oil, vitamin C or E to broiler diet increased serum HDL and vitamin E decreased oxidation of serum lipids by improving antioxidant system.

Abstract Effect of adding Melissa officinalis aqueous extract was studied on immune response and performance in 200 Ross 308 broiler chicks in a completely randomized design with five treatments and four replicates and 10 observations per replicate. The amounts of 0 (control), 0.5, 1, 1.5 and 2 ml/L Lemon balm extract were added in drinking water for 42 days. Humoral immunity was evaluated by injection of 0.1 ml sheep red blood cell (SRBC) 25 percent on days eight and 22 of age and measurement of serum antibody levels produced in response to SRBC on days 21, 28, 35 and 42. Cellular immunity was assessed by injection of phytohemagglutinin intradermally on day 16. The consumption of Lemon balm extract had no effect on daily feed intake and daily body weight gain (P>0.05). The birds that received 1.5 and 2 ml Lemon balm extract in drinking water had lower feed conversion ratio in grower and whole period (P<0.05). The birds that received Lemon balm aqueous extract in drinking water had  higher  total Anti-SRBC titer than control birds on days 28, 35 and 42 (P<0.05). IgG titer of birds that received Lemon balm extract was higher than control group on day 28 (P<0.05). IgM titer of birds that received 1, 1.5 and 2 ml of Lemon balm extract was higher on days 28 and 35 (P<0.05). It is concluded that inclusion of 1.5 ml Lemon balm extract in drinking water decreased feed conversion ratio and improved humoral immunity in broilers.

Abstract This study was conducted to evaluate the share of cost factors affecting on final cost of broiler live weight per kilogram in Tehran province. Data were collected through questionnaires. Farms were divided to three cost ranges: less than 35,000, between 35,000 to 40,000, and over 40000 Rails based on production cost per kg of live weight. In this study, water and additives, staff, vaccines, transportation, laboratory, chicks, feed, insurance, letter, personal cost and fuel were investigated.Share of cost-effective price per kilogram of broilers by using a multi-criteria decision analysis were determined. Performance parameters, including body weight and feed conversion ratio were not different among three groups (P>0.05). Water and additives, staff, vaccines and fuel were the factors that influenced the difference among the three groups, so they made a significant difference in final live weight cost. Insurance and feed had the lowest effects on final price. The group with over 40000 Rails cost for kg of live weight production had less productivity of cost factors. In conclusion, in order to reduce production costs in poultry farms should consider the entire costs factor. For example, the food and insurance costs are the highest and lowest total cost of production that had a minor role in the creation of a difference between different groups of broiler cost in this study.

Abstract 400 one day-old broiler chicks were allocated on a randomized complete design experiment with five treatments consisting of four replications for 42 days. Experiment treatments were included: 1 . based diet consist 20 percent barley (barley control), 2 . barley control + 0.1 percent of mixed essential oil (Antibiofin), 3 . barley control + 0.2 percent organic acid, 4 . barley control + 15 ppm of antibiotic (virginiamycin) and 5 . corn-soybean based diet as corn control. In addition, Basal diet supplemented with commercial enzyme preparation. There was significant difference within treatments for 42 age's body weight and FCR. No significant differences in FI were noted among treatment during experiment. Antibody titer against (SRBC) among groups in secondly immuno response had a significant effect (P< 0.05). The villus height of deudenum and Jejunum was significant differences among the treatment groups. It can be concluded that by using additives such as medicinal plant and organic acids in diets containing barley, can be achieved to similar performance of corn based diets.

Abstract This experiment was conducted for determining the best level of substitution of fish meal with blood meal in broiler chicks. In a three × five factorial experiment with three sources of blood meal (blood meals of Mashhad, Yasoj and Talesh) and five levels of substitution (zero, 30, 40, 50 and 60 percent). A Total of 600 one-day-old chicks were randomly allocated to 15 treatments with each treatment having four replicates. The results indicated that there were not significant difference between sources of blood meal on the weight gain, feed intake, feed conversion rate and percent of breast, thighs and abdominal fat. All the carcass traits were expressed as percentages of live weights. Levels of substitution had significant effect (P< 0.05) on weight gain, feed intake and feed conversion rate. 30 percent substitution had the most feed intake that its difference was significant (P< 0.05) with other treatments. Least feed intake was for 50 percent substitution that its difference was significant (P< 0.05) with other treatments. Most weight gain was for 30 percent substitution which except with 40 percent substitution represented a significant difference (P< 0.05) with other treatments. Type of blood meal and level of substitution and interaction between them had not any significant effect on percent of breast, two thighs and abdominal fat. These results demonstrated that 50 percent substitution of fish meal protein with blood meal of Mashhad improved feed conversion ratio in broiler chicks. Therefore, 50 percent substitution of Mashhad blood meal is recommended.