فهرست مطالب mohammad javad agah

Antibiotics have been used for many years in animal production to treat infectious diseases and as growth promoters. However, the misuse of antibiotics causes problems such as bacterial antibiotic resistance. Also, the possible accumulation of antibiotic residues in livestock products is risky for consumers. After the ban on the use of antibiotic growth promoters in 2006, there was a need to use substitutes in animal feed to replace antibiotics. These alternatives include prebiotics, probiotics, phytobiotics and synbiotics. Probiotics are live microorganisms that, when consumed in sufficient amounts, have beneficial effects on the host by creating a microbial balance in the gut. The purpose of probiotics is to create a competition between the species that are naturally present in the intestinal flora of broilers. The most important advantage of probiotics is that they do not remain in animal products. Prebiotics are feed compounds that are not digested by the host when consumed but can support beneficial bacteria. These compounds are short-chain carbohydrates such as non-digestible oligosaccharides that cannot be digested by animal enzymes. Compounds containing prebiotics and probiotics used in nutrition are called synbiotics. Phytobiotics include a wide range of plant-derived products with bioactive compounds. Plant feed additives (PFAs) are widely effective in improving gut health, increasing digestibility and thus growth performance. These bioactive compounds include secondary metabolites (phenolic and flavonoid). In recent years, various marine organisms have been considered as valuable biological compounds for livestock. Marine algae, due to a wide range of bioactive components such as flavonoid, carotenoid, phenolic compounds, tocopherol, peptide and various sulfated and carboxylated polysaccharides such as alginate and fucoidan with antibacterial, antifungal and antiviruses have beneficial effects on health. Brown macroalgae such as Sargassum angustifolium have beneficial effects on health due to a wide range of bioactive components such as fucoidan, fucose sulfate and polysaccharides. Also, this group of algae is a rich source of sodium alginate oligosaccharides.

The present study was conducted in the form of a completely randomized design, lasted for 42 days at the Ali Abad Kamin research farm of the Fars Agricultural and Natural Resources Research and Education Center, Shiraz, Iran. A total of 240 Ross 308 broilers were distributed in five treatments, four replications and 12 birds per replication. The dietary treatments included: 1 basal diet, without additives, 2 basal diet + 0.05% Oxytetracycline, 3 basal diet + 0.2% brown algae Sargassum and treatments 4 and 5 the basal diet was + 1% and 1.5% of synbiotics Limax, respectively. Ingredients and chemical composition of the ration are presented in (Table 1). At the end of each period, chickens in each group were weighed and the average body weight gain (g/b) in each period was calculated. Feed intake in each period was calculated and expressed as g/b/d. Based on weight gain and feed intake in each period, the FCR values of each group were calculated. Tow representative chickens from each group were selected for carcass analysis representing the average weight and variability of each group. The data obtained on various parameters studied during this experimental trial were analyzed statistically with SAS software.

The results showed that the treatments had no significant effect on the feed conversion ratio of the birds. In the finisher period (25-42 days) and total period (1-42 days), oxytetracycline and Limax 1% treatments had the highest and lowest average daily weight gain, respectively. There wasn't any significant difference between average daily weight gain of the oxytetracycline treatment and other experimental treatments. In the finisher period, the highest amount of feed intake was for the control treatment and the lowest for the Limax 1% treatment (P<0.05). The highest value of production index was belonged to oxytetracycline and Limax treatments was 1.5% (295 and 272, respectively). The highest abdominal fat percentage in the day 42 was related to Oxytetracycline treatment and the lowest was related to Limax treatment of 1.5% (P<0.05). The highest villus width in the day 42 was belonged to Limax treatment of 1 and 1.5% and the lowest was belonged to Oxytetracycline, control and Sargassum treatments (P<0.05). The treatments did not show a significant difference in the feed conversion ratio. The highest value of production index was observed in oxytetracycline and Limex 1.5% treatments (295.25 and 271.71, respectively).

The final result is that the two oxytetracycline and 1.5% of synbiotics Limax treatments shown the highest average daily weight gain and the production index among the experimental treatments. Also, the maximum width of villi and its absorption surface of villus was related to Limax treatment of 1.5%. Therefore, despite the problems of using antibiotics in the diet of birds, Limax synbiotic supplement can be a suitable substitute for oxytetracycline antibiotic.

Paying attention to antibiotic residues in milk is important due to its health effects on the occurrence of microbial resistance in consumers, as well as its harmful effects on the dairy industry. This study was carried out with the aim of determining the amount of oxytetracycline, enrofloxacin, and penicillin G in raw milk samples produced in Fars province, which were detected as contaminated during screening with a rapid kit.

The samples were first examined with a rapid commercial kit for the presence of antibiotic residues. Then the amount of oxytetracycline, enrofloxacin and penicillin G antibiotics in the positive samples belonging to the middle month of each season was determined using the liquid chromatography-tandem mass spectrometry method.

Antibiotic residues were found in 121 (7.7%) samples by the commercial Eclipse kit. Both season (p<0.001) and region (p<0.01) of sampling had a significant effect on antibiotic residues in raw milk. In the chromatographic method, antibiotic residues of oxytetracycline and enrofloxacin were detected in 6 (27.3%) samples, none of which exceeded the permissible limit determined by the Iranian Veterinary Organization.

Although the amount of antibiotics detected from raw milk from Fars province was much lower than the permissible limit, it is necessary to implement further executive, educational, and research measures to minimize these residues in raw milk due to the possibility of the presence of other antimicrobial substances.

Green fodder is one of the components that is given special attention when preparing animal rations, due to its palatability and high digestibility. Green fodder in the livestock ration has an effect on maintaining health and improving the productive and reproductive efficiency of livestock, and it may also affect the quality of meat. On the other hand, the main problem in fodder production in the world is the lack of access to sufficient water for the cultivation and growth of fodder. The occurrence of continuous drought in recent years in the country has made the production of green fodder a problem and has pushed opinions towards sustainable methods including the hydroponic method. In this method, agricultural soil is not used for growing plants and feeding is done in a solution that contains all the necessary elements for the plant. There is no report regarding the effect of this food source on the quality of meat of livestock. Since at the time of introducing a feed source for livestock, all its dimensions or in fact its nutritional value must be measured, so this study was conducted with the aim of investigating the effect of consumption of different levels of barley hydroponic fodder on the qualitative and sensory characteristics of goat meat.

This experiment was performed with 28 Fars native male goats that were placed in individual cages in four treatments and seven replicates in a completely random design. The experimental treatments included the replacement of barley hydroponic fodder at three levels of 25, 50 and 75% instead of alfalfa (in terms of dry matter) in the diet and a control treatment without replacement. The ration was balanced based on the standard tables of goat nutrients recommended by Nutrient Requirements Council for Small Ruminants. After 90 days from the start of the experiment, six goats from each treatment were slaughtered and after 24 hours of cooling of the carcass at four ºC, the Longissimus dorsi muscle was separated, divided into smaller pieces and labeled to determine physical, chemical, textural and sensory factors. Chemical tests including measurement of intermuscular fat, protein and ash in meat samples were carried out by standard methods and the amount of dry matter of the samples was measured by placing about three grams of the sample at a temperature of 102 ± 2 ºC for three hours. The Keldahl method was used to measure the total content of volatile nitrogen and a digital pH meter set at 25 ºC was used to measure the pH. Fat oxidation rate in meat samples was determined by malondialdehyde method. Digital imaging and plastic bag methods were used to evaluate color and loss weight after storage of meat samples, respectively. The water holding capacity was determined by centrifuging the sample placed in filter paper for 4 minutes at 1500 rpm and recording the weight and then placing it in the oven at 70 ºC for 24 hours. Loss after cooking was calculated by placing the sample for one hour in a water bath at 90 ºC. Texture factors, including hardness, adhesiveness, cohesiveness, springiness and chewiness were measured by preparing cubic pieces with dimensions of one centimeter from the meat samples and using a texture testing machine. This device was equipped with a steel cylindrical probe with a diameter of six mm and a height of 35 mm. The probe of the device was inserted into the tested sample twice at a speed of two millimeters per second and up to 50% of the probe height, and the results were recorded by the device software. Sensory characteristics of meat samples, including color, smell, tenderness and overall acceptance wad evaluated by a panel group who completed a designed questionnaire based on the hedonic test. One-way analysis of variance was used in order to investigate the physicochemical and tissue characteristics in different treatments. In cases where there was a significant difference between the treatments, the averages were compared with Duncan's test. The results of the panel test were analyzed with the Kruskal -Wallis test.

There was not significant difference in the amount of fat (range of 10.08-13.87%), dry matter (range of 29.08-31.55%), ash (range of 0.93-1.15%) and total volatile nitrogen (range of 20.25-25.33 mg/100g) between the control group and experimental treatments. The results showed that the replacement of barley hydroponic fodder by 25% instead of alfalfa in the diet caused a significant increase in the amount of meat protein (P=0.0136) and oxidation (P=0.0497) and a significant decrease (P=0.0132) in loss of cooking compared to control treatment and other experimental treatments. There was no statistically significant difference in the recorded values for the texture evaluation and sensory scores of the meat between the experimental treatments and the control group. The overall acceptance of the meat samples in all the investigated treatments had a score of more than five and were placed in the moderately favorable level.

Finally, it can be concluded that the replacement of hydroponic barley fodder instead of alfalfa in the ration of fattening goats up to the level of 75%, did not have negative effects on the chemical, physical and oxidative stability of the meat during storage in the refrigerator or freezer. Also, the use of barley hydroponic fodder in proportions of 25, 50, and 75% (instead of alfalfa and 10, 20, and 30% of dry matter of the ration) did not have adverse effects on the redness, tenderness, and smell of meat. The scores obtained for overall acceptance showed that there was no significant difference in terms of sensory characteristics between the meat of the experimental treatments and the control.

In the past, vitamins were considered as unknown growth factors, but during the twentieth century, their structure and nature were gradually discovered. These compounds are necessary to maintain the integrity of the tissues and general health of the body. Broiler chickens are unable to synthesize vitamins (except vitamin C) or have the ability to make limited amounts of them (group B and K2). For this reason, vitamins should be added to broiler feed as a supplement. Vitamins interact with other nutrients in various ways. The main reference for vitamin requirements in broilers is the National Research Council (NRC, 1994). The recommended amounts ensure conditions where there are no severe deficiencies. Applying the NRC recommendations cannot guarantee the genetic potential of today's birds. Because these values were taken from old studies and using pure feeds in laboratory conditions. Due to the dependence of Iran's poultry industry on the import of vitamins, unfortunately, in recent years, few studies have been conducted in the country on the appropriate pattern of adding vitamins to the diet of broiler chickens. Therefore, it is necessary to examine the lower levels than the recommendation of the Ross 308 strain catalog (Aviagen, 2019) as the dominant strain of the country and to propose an optimal model for different regions that does not have a negative effect on the performance and safety traits and to reduce the need to import this strain. It will also follow the products.

The aim of this study was to determine the optimal pattern of vitamin supplementation in diets based on corn, wheat waste and soybean meal on production traits, carcass characteristics and immune responses of broilers from 1 to 42 days of age in Fars province. A total of 500 Ross 308 broilers with similar mean weight (mixed sex) were distributed in a completely randomized design with five treatments, five replications and 20 chickens per replication. Experimental treatments included five levels of vitamin supplementation: 1) control (100% of the recommended values of Ross 308, 2019 strain catalog), 2) 90% of the recommended values of Ross 308, 2019 strain catalog, 3) 80% of the recommended values of Ross 308, 2019 strain catalog, 4) 70% of the recommended values of Ross 308, 2019 strain catalog and 5) 60% of the recommended values of Ross 308, 2019 strain catalog. At the end of each period, the feed consumption and body weight of the birds were recorded with a digital scale with an accuracy of ±0.01. At the age of 39 days, blood was drawn from the vein under the wing of two birds from each experimental unit, with a syringe containing EDTA anticoagulant, and the blood sample was quickly transferred to the laboratory in a flask containing ice for differential counting of white blood cells. At the end of the 42nd day of rearing, two birds from each experimental unit were slaughtered to measure the relative weight percentage of carcass components. To measure the humoral immune response, the injection of 0.5 ml sheep antigen (SRBC) at the age of 21 days was used. CBH skin hypersensitivity test was also used to measure cellular immune response.

The highest and lowest mean body weight gain and feed intake belonged to the vitamin pattern of 100 and 60% of the recommendation of Ross 308 strain, respectively (P<0.01). The best feed conversion ratio and production index belonged to the vitamin pattern up to 90% of the Ross strain recommendation (P<0.01). The highest and lowest percentages of pectoralis muscle (22.2% and 19.2%) were related to the pattern of 100 and 60% of vitamin supplementation recommended by the Ross strain (P<0.01). The effect of reducing vitamin supplementation on cutaneous basophil hypersensitivity (CBH), serum antibody level against SRBC and percentage of heterophils, lymphocytes and heterophil to lymphocyte ratio was not significant.

There was no significant difference between the functional indices and most importantly the production index of treatment 1 (100% vitamin pattern) and treatment 2 (90% vitamin pattern). Carcass traits and indicators related to humoral and cellular immune systems did not show significant differences too. As a result, a 10% reduction in the level of vitamin supplementation compared to the recommended level of the Ross 308 catalog is possible and suggested for raising broiler chickens. The final result is that in the breeding conditions of Fars province poultry farms, it is possible to reduce the level of vitamin supplements in diets containing wheat waste up to 90% of the recommendation of Ross 308 strain compared to the control diet.

Reproductive performance of dairy cows plays an essential role in the efficiency of the herd and its economy, and indices have been defined to evaluate it. These indices can be affected by various conditions such as the climatic conditions and herd density. Although a large number of dairy cows in Fars province are kept in small farms, but information about their reproductive performance is not available. The purpose of this study was to assess reproductive traits in smallholder dairy farms in Fars province and investigate effects of climate and herd size on it. Reproductive events of 586 cows in selected farms in the cold, temperate and warm climates of Fars province which categorized base on herd size were recorded during one year (from 2017 to 2018) and using them, reproductive traits including the length of pregnancy, Voluntary waiting period (VWP), the numbers of open days (DO) calving interval (CI) and the numbers of service for each conception were calculated. Also, by calculating the number of calves per number of productive cows in herd (including pregnant heifers and dairy and dry cows) and the total number of cows in the herd, the reproductive efficiency of productive cows and the whole herd were calculated. Using analysis of variance tables, the effects of climate, herd size and their interaction on the calculated indices were investigated. The overall mean±standard deviation (SD) of the length of pregnancy, VWP, DO and CI were 278.97±4.70, 83.62±20.12, 104.35±30.04 and 383.34±30.73 days and the numbers of service for each conception was 1.56±0.71 times. The GL, VWP and CI differed significantly (p < 0.05) between warm and cold regions. The herd size alone was not influenced studied traits but in interaction with geographical regions, significant differences (p < 0.05) were observed in VWP, DO and CI between warm and cold regions in herd size 15-21 cows. Means±SD of reproductive efficacy were 54.32±21.27 and 38.20±19.30 % in productive and total cows, respectively, which were not significantly affected by climate and herd size. Unlike climate, herd size has no effect on reproductive performance indicators of small farms in Fars province and although these indicators are not ideal, but they are more desirable than the other reports from Iran.

Over the past ten years, some regions of the world have faced a significant decline in honey bee colonies. In fact, honey bee losses are not an unusual phenomenon, but recently, in many countries of the world, a significant decrease in bee colonies has been observed. Cases of this type of death in the United States of America, many European countries and the Middle East have attracted a lot of attention, mostly due to the lack of an identifiable cause. Due to the diverse social behavior of honey bees, it is difficult to determine the main factors in causing colony losses. In addition, honey bees are in contact with many environmental factors in their daily activities and they are exposed to a multitude of human activities and their consequences. However, various factors have been considered in bee losses and recent research has identified some of the most important of them, which include pests and diseases, bee management, beekeeping practices and bee breeding, climate change, agricultural activities, and pesticide use. Global studies have reported Varroa as the main factor in honey bee colony losses, followed by Nozma ceranae. It is clear that many factors influence honey bee colony losses worldwide. Increased monitoring and scientific research should shed new light on the factors involved in recent bee colony losses. The present review focuses on the main factors that influence the increase in bee colony losses.

This study was conducted to evaluate the effects of feed form (FF) and dietary supplements on performance, immune system, cecal microflora, and intestinal morphology in broiler chickens. A total of 960 one-day-old Ross 308 mixed-sex chickens were distributed to 8 treatments consisting of 6 replicates (20 birds/pen). The experimental design was a 2×4 factorial arrangement of treatments evaluating two feed forms (mash or pellet) and dietary supplements [without a supplement, Lactobacillus acidophilus (L. acidophilus), Bacillus subtilus (B. subtilus), and Avilamycin (an antibiotic)]. Considering the main effects, dietary supplements and pellet diets significantly improved growth performance parameters (FI, BWG, and FCR) compared to the other treatments. Birds fed with a pellet diet had a reduced relative weight of the gizzard and pancreas, increased villus height, and gained the relative weight of the liver and small intestinal. Regardless of the FF, B. subtilis supplementation tended to greater villus height, lower crypt depth, and higher villus height to crypt depth ratio compared to other groups. Birds fed with mash diets supplemented with L. acidophilus and B. subtilis and a pelleted diet supplemented B. subtilis had higher villus height, goblet cell, and Lactobacillus population in the gut compared to the other treatments. Probiotics supplementation reduced the percentage of heterophils compared to other diets. The significant interaction between FF and dietary supplements showed that L. acidophilus in the mash diet tended to enhance the percentage of lymphocytes and reduce the heterophil to lymphocyte ratio compared to the pelleted diet. The main factors had no significant effect on anti-SRBC antibody titer. The results from this study indicated that the probiotic L. acidophilus and B. subtilis used in the mash diet may serve as alternatives to an antibiotic.

In this study, the effect of probiotic supplements (Protexin® (PR) and Multi Behsil® (MB)) and oxytetracycline antibiotic was evaluated on performance, egg and carcass quality, immune response and acidity of the small intestine contents of laying Japanese quails from 7 to 13 weeks of age. A total of 240 laying Japanese quails were used in a completely randomized design with 6 treatments, 4 replications and 10 birds in each replication. The experimental treatments included 1- basal diet without additive (negative control; NC), 2- basal diet+ 50 mg/kg Oxytetracycline (positive control; PC), 3 and 4 were basal diet+ 50 and 100 mg/kg of MB probiotic, and treatments 5 and 6 were basal diet+ 50 and 100 mg/kg PR probiotic, respectively. The results showed that the diets containing MB and PR probiotics improved feed conversion ratio (2.96 and 2.77 vs. 3.05), feed intake (29.49 and 29.13 vs. 30.56 gr) and egg mass (10.47 and 10.66 vs. 10.37 gr), respectively in comparison to NC treatment (P<0.05). The utilization of PR probiotics decreased the feed cost per each kilogram of egg when compared with NC treatment (P<0.05). The treatment containing 100 mg/kg PR probiotic had the maximum shell thickness (P<0.05). The utilization of probiotic had no significant effect on immune response and pH of small intestine and cecum contents of laying quails (P>0.05). Generally, the use of probiotic in the diet of laying quails was able to show the ability to compete with Oxytetracycline growth promoter antibiotic by improving performance and egg qualitative traits.

The aim of this study was to investigate the effect of physical form of the diet and the type of probiotic on performance, carcass characteristics and acidity of the small intestine and cecum contents of broilers (from 1 to 42 days of age). Seven hundred and twenty day old Ross broilers were randomly distributed to 24 experimental units and 6 dietary treatments (4 replicates with 30 birds in each). The completely randomized design with factorial arrangement 2×3 with two forms of feed (mash and pellet) and three modes of using probiotic (without probiotic, probiotics Protoxin and Multi Behsil) were used. The results showed that pelleting diets resulted in greater feed intake (FI), weight gain (WG) and improved feed conversion ratio (FCR) during starter, grower and overall period (p < 0.01). The use of Protexin compared to the absence of probiotics resulted in a significant increase in WG (56.31 vs. 53.78 g/bird/day) and improved FCR (1.61 vs. 1.73) (p < 0.05). The use of probiotic supplementation in the diet caused a significant increase in the breast percentage (22.62 and 21.5 vs. 20.63) and decrease in the pH of duodenum (5.57 and 5.59 vs. 5.83), jejunum (5.95 and 5.92 vs. 6.16) and ileum (6.58 and 6.91 vs. 6.98), respectively (p < 0.05). Based on the results of this study, it can be concluded that the use of probiotic in pellet diets has led to improved breeding performance of broiler chickens compared to mash form diet. In this regard, Protexin compared to the Multi Behsil probiotic showed higher efficacy.

Abstract This study was conducted to investigate the effect of adding olive leaf (OL) and coriander seeds (CS) powder to the diet on performance, jejunum morphology and nutrient digestibility of broiler chickens. Seven hundred and twenty Cobb 500 broilers (mixed sex) were randomly distributed to 36 experimental units and 12 dietary treatments (3 replicates with 20 birds in each). The completely randomized design with factorial arrangement 4×3 with 4 levels of OL (0, 2, 2.5 and 3 percent of diet) and 3 levels of CS (0, 0.3 and 0.6 percent of diet) were used. The results showed that the simultaneous consumption of olive leaf and coriander seeds did not have a significant effect on the performance of broilers.. Broilers that received OL with CS had significantly higher crypt depth, villus length, width and surface area than control treatments. Broilers that used OL and CS simultaneously showed higher digestibility of protein and fat. According to the results of this study, although the use of OL and CS did not have a significant effect on weight gain, feed intake and FCR, may be recommended for improvement of small intestinal morphology indices and increased digestibility of lipid and protein.

Abstract This research was conducted with the aim of evaluating the performance of Twenty-second generation improved indigenous hens in rural areas of Fars province in two hot and cold climates. For this purpose, two counties per climatic region, 3 villages per county and 4 families per each village were covered for a period of 72 weeks. Each family received twenty one 45-day old chickens. During the experiment period, mortality and egg production were recorded daily. Live body weight mean of hens was measured at 8, 12, 24, 48 and 72 weeks of age. The results showed that chickens raised in hot climate produced more eggs than those in cold climate during the experiment (P<0.01). Average egg mass in months and in entire experimental period, was significantly lower (P<0.01) in cold climate (Dasht Arjan and Sepidan Counties) than hot climate (Darab and Zarindasht Counties). Average live body weight was significantly lower in Dasht Arjan compared to other Counties at 72 weeks of age (P<0.05), but no significant difference observed between climates. Durability percentage in hot climate was significantly higher that cold climate during the experimental period (P<0.01). The mortality rate in indigenous hens was relatively high (%46). The cause of most mortality was disease. The mortality rate in this generation of indigenous hens at the station for up to 72 weeks, 14.8 percent was reported.

This study was done to determine the most efficient estrus synchronization method for fixed timed artificial insemination of Torki-ghashghaie does during the non-breeding season. Treatment groups were: 1) CIDR; the animals were treated with intravaginal devices impregnated with 0.3 g of progesterone for 16 days. 2) Treatment 1 and IM injection of 400 IU eCG in CIDR removal. 3) Sponge; the does were treated with sponge impregnated with 40 mg flugestone acetate for 16 days. 4) Treatment 3 and IM injection of 400 IU eCG in sponge removal. 5) Implant; 1.5 mg norgestomet implant was inserted in subcutaneous ear for 10 days and injected IM with 1.5 mg norgestomet and 2.5 mg estradiul valerate in first day. 6) Treatment 5 and IM injection of 400 IU eCG in implant removal. 7) Two IM injection of 10 mg PGF2α eCG with 10 days interval and 8) Treatment 7 and IM injection of 400 IU eCG in tenth day. The injection of eCG was not effective on estrus response in progestagens base treatments, but increased significantly (p

The effects of different dietary levels of olive leaf powder (OLP) as a natural antioxidant on growth performance, carcass traits, some blood parameters, small intestinal morphology and feed digestibility in broiler using a total of 300 one-day-old Cobb500 broilers were studied in a completely randomized design with 5 treatments, 3 replicates and 20 chicks for each replicate, up to 42d. The experimental diets included: corn-soybean meal basal diet (negative control), basal diet supplemented with 250 mg/kg of alpha-Tocopheryl acetate (positive control) and three basal diets containing 2, 2.5 and 3 percent OLP. The results showed that during total experimental period (1-42d), weight gain was decreased (P

1, 25-dihydroxycholecalciferol [1, 25 (OH)2 D3], the major biologically active metabolite of vitamin D3 is produced by two sequential hydroxylation reactions. The first hydroxylation occurred when vitamin D3 is transported to the liver, forming 25-hydroxycholecalciferol [25-(OH) D3] and the second in the kidney, by the enzyme 1-alpha-hydroxylase (VD3 1 hydroxylase) forming 1, 25 (OH)2 D3. Vitamin D3 may have a role in regulating the morphological and functional development of intestinal villus mucosa. Calcium ions have an essential role function in activation and maturation of lymphocytes. Previous studies have demonstrated that the intracellular concentration of free Ca2 increases in several types of cells during stress. For example, acute restraint stress enhances Ca2 mobilization in lymphocytes from mice. In addition, Ca2 ions are essential for production of interleukin-2 by T cells (22). Withania somnifera (WS) is an annual herb and a rich source of bioactive compounds. Several pharmacological activities of the plant have been attributed to its roots. Oral administration of root extract of WS at 10, 30 and 300 mg/kg body weight for 15 days stimulated B and T cells proliferation, induced type 1 immunity, increased the activity of machrophage and levels of immunoglobulin which indicated the potent role of extract on humoral and cellular immunity. The present study aimed to evaluate the main effects and interaction of calcitriol and WS root extract in either low or adequate Ca diets on immune response and small intestinal morphology of broiler chickens.
Material and Six hundred male day old Ross 308 broilers obtained from a commercial hatchery, and reared in 60 floor pens with wood shavings litter at a stocking rate of 10 birds per pen (1×1 m). Feed and water were provided ad libitum throughout the 6–wk experimental period. The experimental design was a 2×3×2 factorial comprising of two dietary concentration of Ca (negative and positive control), three concentrations of WS root extract (0, 75 and 150 mg/kg diet), two concentrations of 1, 25 (OH)2 D3 (0 and 0.5 g/kg diet). SRBC test was used to measure humoral immunity response. So, at 25 and 32 days of age chicks were injected to evaluate the primary and secondary antibody response. On d 21 and 42, one bird per replicate was killed to determine small intestinal morphology and lymphoid organ weights. Sample sections (2.5 cm in length) were taken from the middle region of the jejunum. The tissues were stained for measurement of villus length, villus width, crypth depth and thickness of muscle layer. The General Linear Models of SAS were used to analyse all the data.
The results of humoral immune response showed that reduction of dietary Ca level by 30% resulted to depression of immunoglobulin M and total antibody levels. Supplementation of WS at 150 mg/kg significantly improved the level of immunoglobulin G only in primary test. Calcium ions have an essential role function in activation and maturation of lymphocytes (10). Previous studies have demonstrated that the intracellular concentration of free Ca2 increases in several types of cells during stress. For example, acute restraint stress enhances Ca2 mobilization in lymphocytes from mice. In addition, Ca2 ions are essential for production of interleukin-2 by T cells. It was found that supplementation of calcitriol resulted in shorter villus length at 21 d and shorter villus width at 42 day of age, respectively. Reduction of dietary Ca level by 30% resulted to shorter crypth depth compared to positive control diet. A researcher reported that supplementation of 25-OH-D3 decreased the length and weight of small intestine. The duodenal putrescine content was enhanced in parallel with the increase in intestinal calcium absorption, suggesting that polyamines, in particular putrescine, may be involved somehow in the intestinal calcium transport mechanism. The aliphatic polyamines, putrescine, spermidine, and spermine, are considered to be essential cell constituents that play an important role in modulating cell proliferation and differentiation.
The results of humoral immune response showed that decreasing of dietary Ca level to 30% resulted to reduction of total antibody response. The findings showed that supplementation of calcitriol did not exert beneficial effects on intestine morphology. Supplementation of WS root extract did not affect intestine characteristics.

Antibiotic feed additives have long been used as growth promoters (10). However, consumers and health authorities increasingly dictate that the use of synthetic food additives should be phased out and, where possible, only natural products should be used. Hence, alternatives from natural sources with potential antioxidant activity are investigated (16). Olive leaves are a good source of several antioxidants including oleuropeoside compounds such as oleuropein and verbascoside, and flavonoid compounds such as luteolin, luteolin-7-glucoside, apigenin-7-glucoside, diosmetin, diosmetin-7-glucoside, rutin and catechin, and simple phenolic compounds such as tyrosol, hydroxytyrosol, vanillin, vanillic acid and caffeic acid. Oleuropein, the most prominent compound, may reach concentrations of 60 - 90 mg/g dried leaves (8). Most of these phenolic compounds have been shown to possess substantial antimicrobial and antioxidant activities in vitro. However, in vivo investigations on the antioxidant and antimicrobial activities of olive leaves as a dietary supplement to food producing animals have not been conducted (33). The present study was designed to evaluate the effects of dietary α-tocopheryl acetate, olive leaf powder (OLP) and olive leaf extract (OLE) as feed additives on the growth performance and small intestinal morphology of male broilers. The experimental protocol was approved by the Animal Care Committee of the Ferdowsi University of Mashhad, Iran. The chickens (120 Ross 308 male birds) were placed at one day old in a single colony in a floor pen containing fresh wood shavings to a depth of 10 cm, and all were fed on a starter ration. At 7 d old, 6 replicate cages containing four chicks selected at random were assigned to each of 5 dietary treatments using a completely randomized design, giving a total of 30 experimental cages. The study was completed at 28 d of age. Dietary treatments included a negative control group (NC) fed a corn soybean meal based diet without feed additive supplementation, a positive control (PC) group fed a diet with 250 mg of α-tocopheryl acetate/kg, a test group OLP fed with 10 g of olive leaf powder/kg, and two test groups remaining OLE fed with 120 or 240 mg of olive leaf extract/kg. The birds were provided with one hour of darkness following a period of 23 h light, from the start to the finish of the study. Each cage was provided with a single feed trough and nipple line, with three nipples per cage, to provide ad libitum access to feed and water. On day 7, 14, 21 and 28, body weight and feed intake were measured after a 6-h fast to determine average daily gain, average daily feed intake, and feed conversion. On d 28, one bird per cage randomly selected and killed to determine small intestinal morphology and lymphoid organ weights. Sample sections (2. 5 cm in length) were taken from the middle region of the jejunum. The tissues were stained for measurement of villus length, villus width, crypt depth and thickness of muscle layer. The General Linear Models of SAS (17) were used to analyze all the data. Chicks fed with diet containing 240 mg of OLE/kg had the highest average daily gain. ِِDressing percentage and the percentage of breast muscle in the carcass were significantly higher for chicks fed diets supplemented with OLP and OLE compared with those fed NC diet. Similar to our results, Chinese herbal medicine supplementation enhanced BW gain of female broiler chicks at 7 to 21 day of age, when compared with the non-supplemented group. There were no significant differences in daily feed intake between the different treatments from 7 to 21 day of age (17). Also Christaki et al. (12) found that laying Japanese quails diet supplementation with olive leaves (10 g/kg or 20 g/kg) resulted in a tendency (p = 0. 054) for higher egg production percentage. The benefits of dietary olive leaves are possibly due to the presence of polyphenols and particularly oleuropein, the main active component in this material (12). The inclusion of OLP and/or OLE in diet significantly decreased the relative lengths of duodenum. Villus height, crypt depth, epithelial thickness and surface area for absorption villi were significantly increased in diets containing OLP and/or OLE compared with NC fed birds. Intestinal morphology can reveal some information on gut health. A shortening of the villus reflects villus atrophy and a decrease in surface area for nutrient absorption. The crypt can be regarded as the villus factory, and a large crypt indicates fast tissue turnover and a high demand for new tissue (21). The gastro protective potential of OLE is probably related to its ability to maintain the cell membrane integrity, by its ant lipid per oxidative activity that protects the gastric mucosa against oxidative damage and by its ability to strengthen the mucosal barrier, the first line of defense against exogenous damaging agents (14). The use of OLP and/or OLE as feed additives in diet may affect chick performance and gut health. Although, it seems that further experiments are needed to elucidate the mechanisms underlying the enhanced growth of chickens by OLP and/or OLE.