فصلنامه پژوهشهای علوم دامی ایران
سال پانزدهم شماره 1 (بهار 1402)

The present study was conducted to investigate the efficacy of adding Oregano L.onites and Althaea offieinalis essential oil into milk on performance, some blood parameters, skeletal growth, and metabolic responses of Holstein dairy calves. Higher milk consumption improves growth performance due to the increase in nutrients available to calves. In this experiment, it is assumed that high consumption of milk with better availability of nutrients and plant essential oils by eliminating pathogens and stabilizing the natural flora of the gastrointestinal tract improves calf function, reduces diarrhea and adequate growth during weaning.

A total of 60 Holstein dairy calves (30 females and 30 males; 7 days) with 42 ± 8 kg of average birth weight were used in a Factorial design (2 × 3) in which calves were randomly assigned to one of six different dietary treatments including 1) 6 L/d milk control without inclusion of any essential oil supplementation, 2) 6 L/d milk with Oregano L.onites essential oil, 3) 6 L/d milk with Althaea offieinalis essential oil, 4) 9 L/d milk control without inclusion of any essential oil supplementation, 5) 9 L/d milk with Oregano L.onites essential oil and 6) 9 L/d milk with Althaea offieinalis essential oil. Calves were individually housed and bedded with straw that was replaced every day. Feed and water were available ad libitum throughout the experiment. Calves were fed colostrum for 3 days and then fed high levels milk with 10% and 20% of their birth weight until 70 days of age. The rations were iso-energetic. Ruminal fluid samples were collected by esophagus tube after morning feeding at the end of study. Starter intake was recorded individually and daily. The amount of feed consumed daily was calculated throughout the experiment from the difference between the feed poured and the remaining feed. The experimental data were analyzed under the SAS 9.1 statistical program with general linear models (GLM). Comparisons of mean was done using Duncan test at a significance level of 5%.

In this study results showed that starter intake was affected by the experimental treatments (p > 0.05). Diet containing Oregano L.onites essential oil reduced feed intake in the period 56 to 70 and in the whole period with using 6 liters of milk (p < 0.05). Dry matter intake (feed dry matter with milk dry matter) in the period of 7 to 56, 56 to 70 days and in the whole period between the group receiving 6 liters and 9 liters of milk was not shown significant difference. Calves consuming 9 L/d milk in control group without inclusion of any essential oil supplementation had higher daily weight gain than other treatments (p < 0.05). The results indicated that calves fed milk without any additives had a higher feed efficiency (p < 0.05). Consuming 9 L/d milk in control group without inclusion of any essential oil supplementation had higher skeletal growth than other treatments (p < 0.05). Hip width, heart girth, body barrel and wither height were affected by the addition of essential oils supplementation (p> 0.05). Rumen parameters were not affected by essential oils (p > 0.05). Ruminal pH value was affected by the experimental treatments and in group of 6 L/d milk with Oregano L.onites essential oil had higher than other treatments (p < 0.05). Addition of Oregano L.onites essential oils to milk of Holstein calves had no detectable effect on the mean concentration of glucose, albumin, urea, aspartate-aminotransferase and alanine-aminotransferase (p > 0.05). The results showed that Feed behavior was affected by the experimental treatments (p > 0.05). Calves consuming Oregano L.onites essential oil supplementation had lowest ruminant and feed consume than other treatments (p > 0.05).

The results of this study showed that the addition of plant essential oils, especially oregano essential oil in high amounts of milk of Holstein calves did not lead to increased feed intake, weight gain and increased skeletal growth compared to the control group. However, the effect of oregano essential oil on feed efficiency was significant. Therefore, increasing the quantitative and qualitative growth of calves per unit time and expressing their genetic predisposition by using plant essential oils as done in this study did not lead to better performance of Holstein calves. In contrast, increasing the amount of milk consumed in infant Holstein calves improved growth performance, although the feed efficiency of the 9-liter milk group was lower than the 6-liter milk group.

Stall-fed lambs, which account for the bulk of mutton production, are one of the main sources of red meat supply in the country. In order to achieve optimal and economical production, sheep breeders must take into account the nutritional needs, food quality and dietary intake time in the diet plan of livestock. However, due to the shortage of forage and pastures in Iran, stockbreeders are forced to include more concentrate in the animals’ diet, while trying to carefully observe the concentrate proportions as well as the necessary points associated with concentrate feeding. Therefore, the purpose of this project is to evaluate the effects of alfalfa removal and reducing forage on the profitability of Afshari fattening lambs. In order to investigate the effects of reducing the amount of forage and also removing alfalfa on performance of Afshari breeding lambs, based on a factorial experiment with a completely randomized design, was done on 36 Afshari male lambs, with a mean live weight of 32.53 ± 1.9 kg and a mean age of 93 ± 6.63 days for 90 days. Experimental diets included: 1) 80 Percentage concentrate and 20 Percentage forage (10 Percentage wheat straw and 10 Percentage dry alfalfa), 2) 80 Percentage concentrate and 20 Percentage forage (20 Percentage wheat straw, 0 Percentage dry alfalfa), 3) 90 Percentage concentrate and 10 Percentage forage (5 Percentage wheat straw and 5 Percentage dry alfalfa), and 4) 90 Percentage concentrate and 10 Percentage forage (10 Percentage wheat straw and 0 Percentage dry alfalfa). Experimental diets were adjusted according to NRC (2007) standard diet tables and the constituents of the diets and their nutritional value were similar. The data were analyzed using SPSS21. The chemical composition of diets was changed with altering of the forage to concentrate ratio, and with increasing the concentrate in the diet, the amount of NFC increased and the percentage of NDF decreased. Increasing the concentrate and removing of alfalfa increased feed intake and daily weight gain throughout the period (P <0.05). Increasing of feed consumption seeks higher concentrate intake is due to faster consumption by animal compared to forage intake. On the other hand, the retention time of the concentrate in the abdominal area is less than the fodder. Therefore, the effect of filling after using of forage, limits the consumption of feed. Result indicated no significant differences in digestibility and feed conversion ratio between experimental treatments. The results of this study showed that the dry matter consumption and daily weight gain for treatment four was significantly higher than other treatments. The fourth treatment had a numerically lower food conversion coefficient (6.1) compared to the other three treatments. Accordingly, increasing the concentrate and removing of alfalfa has caused a significant increase in weight throughout the period. Regarding the interaction effects of concentrate and forage on daily weight gain, it also was shown that the most of the daily weight gain obtained followed by increasing of the concentrate level and then the removal of alfalfa. The most important factor affecting daily weight gain is feed consumption. Regarding to the effect of alfalfa reduction on feed intake, it can be stated that by reducing alfalfa, despite not reducing dietary fiber (treatments two and four), other dietary nutrients supplied through alfalfa were supplied through concentrate, which itself increased the digestibility of the ration. The feed conversion ratio of the four treatments was in the same range. The results of economic comparison showed that lambs fed with 90% concentrate, 10% wheat straw and 0% alfalfa had higher yields compared to other groups. The results of the present study showed that with increasing the percentage of concentrate and removal of alfalfa from the feed, feed intake increases accordingly. Concentrate is palatable and contains more energy and nutrients than forage. Therefore, lambs fed with diets containing higher concentrate levels and no alfalfa experienced faster growth and higher growth efficiency and produced heavier carcasses. Thanks to this diet, stock breeders can save feeding and breeding costs during seasons when feed is more expensive or insufficient. According to the results, diets containing 90% concentrate, 10% wheat straw and no alfalfa can be suggested for optimal yield in stall-fed lambs.

The use of radiation has become a way of life in most countries around the globe. The utilization of nuclear techniques in the area of agriculture, defense, and power generation has increased over the last few decades. Radiation technology is widely used to produce changes in product characteristics leading to the development of new products. Radiation-mediated morphological, structural and/or functional changes in a plant are governed by the intensity and duration of the gamma irradiation. Gamma irradiation was found to increase plant productivity. Gamma rays represent one of the important physical agents used to improve the characters and productivity of many plants (e.g. rice, maize, bean, cowpea, and potato). Gamma irradiation also has been found to be very useful for both sterilization and for the preservation of food and cereal grain in nutrition and agriculture. Gamma rays were also found to cause modulation in protein patterns by inducing the appearance and/or disappearance of some protein bands. It has been shown that large DNA strands were broken into small strands at low irradiation doses but small and large DNA strands were broken at higher irradiation doses. Also it has reported that germination of seeds can be influenced in both positive and negative directions by gamma radiation exposure as a result of mutation inductions depending on cellular abnormalities or stimulatory modifications triggered by radiation doses. In several studies, lethal and stimulatory effects of gamma irradiation on germination percentage, emergence, and survival of seedlings of different plant species have been reported. The present work has been intended to investigate the response of corn seeds exposed to gamma irradiation (25 Gys) in terms of the nutritional performance of its forage and silage compared with control non-exposed seeds. Corn seeds were obtained from the Vegetable Crop Seed Production and Technology section, Ghezlagh Farm, College of Abouraihan, university of Tehran, Iran. Four kg corn seeds (single cross 704) were divided into 2 groups. The first group did not have any treatment to serve as a control, while the second group was irradiated with Gamma rays (25 Gray) using Gamma cell – cobalt- 60 instruction and with the rate of 0.55 Gr/ min at the Nuclear Agricultural Research School, Nuclear Science and Technology Research Institute, Karaj, Iran. Field experiments were conducted during the summer seasons at Ghezlal farm Research Station located at the southwest of Tehran province, Varamin, to study the effect of gamma irradiation (25 Gray) on the performance of corn forage and silage. After irradiation, control and irradiated seeds were cultivated in 2000 m2. Agricultural practices such as: irrigation, weeding, fertilization, and pest control were carried out as recommended. Samples of corn plants were obtained at the late stage of growth and amounts of proline, soluble carbohydrate, and protein were determined. Performance chrematistics of experimental groups were also recorded. After harvesting, the corn forage was chopped and transferred to an experimental silo made of polyethylene pipe. DM, ash, CP, NDF, and ADF of experimental silages were determined according to standards procedures. The pH of silage also was determined using pH meters. For the determination of gas production parameters, 200 mg of dry samples were incubated at gas production environment and the amount and rate of gas production were recorded at a different time of incubation (0, 2, 4, 6, 8, 12, 24, 48, 72 and 96 h). Using gas production parameters, the amount of OM digestibility, ME, NEL, and SCFA were also determined. Data were analyzed using the t-student test of SAS software (ver. 9.1). Duncan’s multiple range test was used to detect statistical significance between treatments using a significance level of 0.05. Irradiation of corn seeds increased corn performance (wet and dry weight of seed and forage), amount of soluble carbohydrates and protein, and concentration of proline (P<0.05). The exposed treatment showed the highest increase in seed weight, seed number, and weight of 1000 seeds as compared to the control (P < 0.05). Amount of gas, and b and c fractions of gas production, the concentration of short-chain fatty acids (SCFAs), metabolizable (ME) and net energy for lactation (NEL), and organic matter digestibility (OMD) were higher for treated corn forage and silage compared to the control group (P < 0.05). Also, exposed corn silage had a lower level of pH and higher amount of dry matter (DM) and crude protein (CP) than control (P < 0.05). The results of this study show that exposing irradiation of corn seeds to 25 gray gamma-ray improves fermentation parameters and nutrition values of corn forage and silage.

Over the last half century, the shortage of animal feed in many parts of the world, including Iran, has increased the feed costs of animal husbandry and it also has affected revenues from the production of livestock products. Therefore, any improvement in nutritional management and increasing the feed use efficiency in this sector will increase productivity and production. Adding water to ruminant diets is inexpensive physical processing method that has had a positive effect on efficiency of ruminant production. Traditionally, adding water to total mixed diets has been a useful management practice to reduce feed selection behavior by livestock. It has been shown that adding water to the feed of adult cows (decreasing dietary dry matter (DM) from 81% to 64%) reduced the choice of fine components over long particles and also to reduce the preferential consumption of concentrate components (Leonardi et al., 2005). Recent studies have shown that adding water to the starter diet of suckling calves up to 25% during the winter has improved their growth performance (Beiranvand et al., 2018). These positive responses are probably due to the increased adhesion of feed particles, which has led to a reduction of diet dust, condensation of fine particles and increased palatability and consumption. This experiment was conducted in animal house and laboratories of Lorestan University. Twenty-eight Lori male-fattening lambs with120 ± 6 days old and 33.4 ± 3.4 kg of live weight were used in completely randomized design experiment with 4 treatments and 7 lambs per treatment. Dietary treatments in which water was used at levels 10 (control), 20, 30 and 40 % were fed to the lambs for 56 days. Blood and ruminal samples were taken from all of lambs at day 45 and 50 respectively 3 h after morning feeding. A completely randomised design was used to determine the effect of different levels of water on the measured traits. All data were analyzed using the GLM procedure in SAS. Linear (L) and quadratic (Q) contrast statements were included in the model to test the effect of increasing amounts of water. Differences among means were tested using Duncan method. Results showed that increasing the level of dietary moisture up to 30% linearly increased (P<0.05) ruminal ammonia-N, propionate and total VFA concentration, while pH and concentration of other individual VFAs were unchanged among dietary treatments (P>0.05). Increasing the level of dietary moisture up to 30% linearly increased (P<0.05) activity of carboxymethyl cellulase and ɑ-amylase, while activity of microcrystalline cellulase and filter paper degrading activity and blood metabolites (including glucose, total protein and blood urea nitrogen) were similar among treatments (P>0.05). Intake of dry matter (DM) and average daily gain increased linealrly (P<0.05) with elevating dietary water level up to 30%, while NDF and ADF intake and final body weight and feed conversion ratio was unchanged by the level of dietary moisture (P>0.05). Results of present study showed that adding water to the total mixed ration of fattening lambs up to 30% improved ruminal parameters, feed intake and growth performance.

Intestinal function in nutrient uptake depends on its morphology, and any change in villi structure, as well as changes in the differentiation and development of absorbent cells, can alter digestion and absorption capacity and thus function. Increasing the height and surface of Villus in the gastrointestinal tract of animals consuming high concentrates increases the absorption capacity and in turn, protects the animal from the accumulation of volatile fatty acids and a noticeable decrease in pH. In fact, it helps the lining of the gastrointestinal tract absorb volatile fatty acids faster and stabilize the pH. High starch in diets, followed by a decrease in pH, affects the morphology of the rumen and intestine. Any change in this morphology may predispose the intestines to dysfunction. Megasphaera elsdenii prevents a sharp decrease in ruminal pH due to lactic acid accumulation by consuming lactic acid, and in cases of subacute acidosis by converting lactic acid to propionic acid may provide an opportunity to reduce inflammation and improve energy balance in livestock. Saccharomyces cerevisiae also contributes to the growth and activity of cellulose-degrading bacteria, lactate consuming bacteria, and rumen protozoa and the concomitant use of lactate consuming bacteria with Saccharomyces cerevisiae has been confirmed. Therefore, the aim of this study was to investigate the effect of chemical and microbial buffer additives on histomorphometry and histopathology of the small intestine and large intestine during high concentrate feeding.  Twelve Arabi male sheep at 9 ± 1 months old and initial body weight of 35.95±3.55 kg were used in a completely randomized design with three treatments and four replicates, and the duration of the experiment was 35 days. The experimental treatments consisted of a 1- control diet, 2- control diet + sodium bicarbonate buffer, 3- control diet + Megasphaera elsdenii, and Saccharomyces cerevisiae (bacterial-yeast), which fed ad libitum. At the end of the experiment, the lambs were slaughtered and the small and large intestines were sampled for histomorphometry and histopathology studies. Each sample was placed separately in closed-sealed containers containing 10% formalin, and tissue changes were examined microscopically. No significant difference was observed between the experimental treatments for the tissue indices studied in the duodenum and jejunum. However, the ratio of villus height to crypt depth in the bacterium-yeast recipient treatment was numerically higher than other treatments. In ileum section, villi height, crypt depth and villi area in control treatment 653.33; 506.67; 258.42 compared to buffer treatment 430.00; 328.33; 161.40 and treatment containing bacterial-yeast 445.00; 365.00; 178.04 respectively were significantly higher (P <0.05). In the present experiment, due to the consumption of a diet with high concentrate and possibly increased production of volatile fatty acids in the rumen and their transfer to later parts of the gastrointestinal tract, increased villi height, crypt depth, and villi area in different parts Intestine was observed especially in control treatment; In fact, one of the reasons for increasing the villi height and Villus surface in acidosis, is increased the absorption capacity of volatile fatty acids and help maintain pH of the rumen, Therefore, reducing these indices in chemical buffer and bacterial-yeast treatments can be the result of the positive effects of buffer and microbial additives such as improving the pH of ruminal fluid transferred to different parts of the intestine, as a result of increased activity of cellulolytic bacteria and more acetate production, which has caused relative control of acidosis in the control treatment. Improving the Villus height to crypt depth ratio in the duodenum and jejunum in treatments receiving chemical or microbial additives can be considered as positive results of using pH-adjusting additives in the present experiment. In different parts of the small intestine, in all three treatments, inflammation of the intestinal mucosa was observed in the form of infiltration of mononuclear inflammatory cells, including lymphocytes, plasma cells with different degrees of eosinophils. In the large intestine in the control treatment, hyperemia, the infiltration of inflammatory cells of lymphocytes, plasma cells, and eosinophils in small numbers in Lamina propria and labyrinth of Lieberkohen glands as well as necrosis of the villi was observed. In general, changes in intestinal tissues are to counteract the inflammation caused by acidosis. In general, although the use of chemical buffering or microbial additives had a positive effect on the histomorphometry of the ileum, but did not have a positive effect on the histopathology of the small and large intestine. It is suggested that the present experiment be examined in the early stages of livestock growth when the microbial flora is not fully established.

Maternal stimuli, such as nutrition, result in developmental adaptations by the fetus which changes physiology and metabolism of offspring. In ewe energy level and source during gestation have been shown to impact lamb performance. Supplementation of fatty acids during gestation has been shown to affect offspring in dairy cattle and sheep. The omega-3 (n-3) fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are particularly bioactive and can alter physiology and metabolism by increasing the transcription of lipolytic genes and decreasing the transcription of lipogenic genes, potentially increasing the utilization of fatty acids for energy, which yields more energy than other metabolizable nutrients. The bioactive properties of EPA and DHA allow them to affect offspring development through changes in metabolism in non-ruminant species. Therefore, we hypothesized that supplementation of EPA and DHA will alter metabolism of pregnant ewes, which in turn will modulate growth and metabolism of the offspring.Antioxidants protect the body against free radicals that are responsible for causing more than 100 diseases. Among the most important natural antioxidants are retinol (vitamin A), carotenoids, tocopherol (vitamin E), ascorbic acid, butyric acid, EPA and DHA. Long-chain unsaturated fatty acids have high antioxidant power, as it is reported that EPA and DHA have the same antioxidant capacity as vitamins. It has also been reported that supplementation of EPA, DHA in the diet of dairy cows has increased the concentration of antioxidants in milk. 45 ewes were selected while were in the last two months of pregnancy and randomly assigned to three treatments, including control (first treatment) second treatment which received EPA and DHA supplement and third treatment received a basal diet with one percent calcium fat supplement. Plasma samples were collected to measure glucose, triglycerides, cholesterol, total protein, albumin, globulin, urea nitrogen, non-esterified fatty acids, beta-hydroxybutyrate and antioxidants. The amount of milk production and milk composition were also determined. There was a significant difference in birth weight between different treatments. In a study conducted on dairy cows in the last weeks of gestation with long-chain unsaturated fatty acids, the birth weight of calves born on long-chain unsaturated fatty acid supplementation was significantly different compared to other treatments. In another study, the birth weight of lambs whose mothers received fat supplement was not significantly different from the control group. Plasma concentrations of glucose, non-esterified fatty acids and beta-hydroxybutyrate were significantly different between treatments. Supplementation of ewes in the last two months of pregnancy with eicosapentaenoic acid and docosahexaenoic acid fatty acids increased glucose and decreased non-esterified fatty acids and beta-hydroxybutyrate compared to other treatments, which releases fatty acids from the tissue to reduce energy balance to provide the energy needed for breastfeeding. In a study it was found that addition of trans fats to the diets of pregnant cows reduced glucose levels and increased NEFA, possibly due to increased circulating fat. There was no significant difference in the amount of blood metabolites such as triglycerides, cholesterol, total protein and urea between treatments.Milk production in 3 hours showed a significant difference between treatments, as EPA and DHA supplemented group produced more milk than other groups, which can be attributed to the higher amount of blood glucose in this treatment. Experimental diets had no effect on the amount of protein, fat and total SNF of milk. It was also observed that consumption of 18 mg per kg metabolic body weight during pregnancy did not show any change in milk parameter.The use of EPA and DHA supplements in the diet of pregnant ewes increased the total antioxidant capacity of milk and colostrum. Omega-3 fatty acids reduce the effect of free radicals. In this way, omega-3 fatty acids may increase the level of catalase in the peroxisomes and cytoplasm and, thus, improve the defense against free radicals. The use of EPA and DHA supplementation in pregnant ewes caused significant changes in the birth weight of lambs, milk production and the amount of antioxidant production in milk and colostrum. It also altered glucose, non-esterified fatty acids and beta-hydroxybutyrate in the plasma metabolite on lambing in ewes.

Today, livestock and poultry health in an advanced production system is a major challenge affecting human health and the global economy. Antibiotics have been used in poultry nutrition for many years. Chickens are raised with the assistance of the regular use of antibiotics, not only for the prevention and treatment of diseases but, also, for body growth. Overuse and misuse of antibiotics in animals are contributing to the rising threat of antibiotic resistance. In recent years, as a result of increasing concerns about the possibility of developing antibiotic-resistant strains, as well as the fact that they remain in animal tissues and eventually ban their use, the use of compounds such as organic acids, probiotics, prebiotics, enzymes, etc. as safe alternatives have been widely considered in poultry nutrition. Organic acids are a good alternative to antibiotics in poultry diets. These are improving the immune system of broilers by acidifying the gastrointestinal tract and improving the intestinal microflora. Organic acids cross the bacterial membrane; inside the bacterial cell, it produces hydrogen ions and bicarbonate, which eventually increases the acidity. Therefore, they force the bacteria to consume energy in order to keep the acidity constant, which leads to their death. Coating of organic acids prevents its dissociation and digestion in the stomach so that the biological effect of organic acids reaches the distal parts of the gastrointestinal tract and is effective in intestinal microflora and mucosal morphology. This study was performed to investigate the effect of encapsulated organic acids on microbial population, intestinal acidity, blood indices, nutrient digestibility, and viscosity of digestive contents, carcass characteristics and performance of broilers. 150 male broiler chickens of Ross 308 commercial strain as one-day-old were allocated in a completely randomized design with 5 treatments, 3 replications and 10 chickens per replicate. Experimental treatments included: 1. Basal diet 2. Basal diet + commercial Organic acid 3. Basal diet + Non-encapsulated organic acid 4. Basal diet + Encapsulated organic acid 5. Basal diet + encapsulated organic acid + Non-encapsulated organic acid. On day 42 of the experiment, one chickens from each experimental unit, which were close to the weight average of that unit, were selected and blood samples were taken from their wing veins. AT 42d, from each replication, a chick with the same weight as the average weight of the experimental unit was taken and their live weight was recorded and slaughtered. Also, from each replication, a chick with a weight similar to the average weight of the experimental unit was selected and their live weight was recorded and slaughtered. Then, different parts of the carcass were weighed by peeling and emptying the viscera. In order to evaluate the microbial population of the intestines of the tested broilers, at the age of 42 days, one chick from each experimental unit was selected with conditions close to the weight average of the relevant unit and after weighing, it was slaughtered. The microbial population of Lactobacillus and gram-positive and gram-negative bacteria were studied.The data were statistically analyzed by statistical software using GLM procedure. The means were compared by Duncan method at the significance level of 0.05%. The result showed that in growth cycle, weight gain during the growth period and the whole period in the treatments containing encapsulated organic acid showed improvement and a significant difference with the control treatment. The addition of organic acids to the diet during the growth period reduced the conversion coefficient compared to the control group. Feed intake in the treatments containing capsular organic acid showed a significant decrease compare to the control group. The acidity of the duodenum and jejunum showed a significant decrease compared to the control group. The addition of encapsulated organic acids significantly reduced the total number of coliforms in the ileum and duodenum and increased the number of lactobacilli in the ileum. Also, experimental treatments increased the apparent digestibility of crude fat compared to the control group. The weight of the lymph nodes (bursa and spleen) also showed a significant increase under the influence of organic acids. The results of current experimental study showed that the usage of encapsulated organic acids in broiler chicken diets, reduces the acidity of the digestive tract, reduces the intestinal microbial contamination, creates favorable conditions in the digestive system, improves digestibility of the nutrients, and performance of the bird's growing birds.

Antibiotics have been routinely supplemented in diets of poultry to maintain their health, reduce stress, and enhance productivity. However, due to the development of resistance of bacteria to antibiotics and the possibility of these pathogens to be zoonotic, the use of various antibiotic products in livestock and poultry production is gradually being banned around the world. With the possibility of further ban in more regions of the world, research interest into alternatives to in-feed antibiotics has increased. One alternative to in-feed antibiotics that has gained research interest for use in poultry is yeast (Saccharomyces cerevisiae). Yeast in both probiotic (live) and prebiotic (dead) forms has been reported to provide several benefits to both healthy of animals, including poultry. The ability of yeast and its components to act as growth promoter could be associated with different mechanisms that it exhibits individually or synergistically. For instance, yeasts have been reported to favor the proliferation of beneficial microbes by serving as substrates for these microbes in the gut. These beneficial microbes, such as Lactobacillus, have been reported to improve gut health as well as exhibit growth-promoting effects in broiler chickens. Specifically, yeast cell wall that is extracted from whole yeast consists mainly of α-mannans and β-1–3-glucans, which are reported to prevent or eliminate bacterial infections. In order to study various levels of autolyzed yeast (Privita) on performance, quality characteristics of egg, cecal microbiology and intestinal histomorphology of laying hens (Hy-line W-36) (64 weeks), an experiment was done with 192 birds for 10 weeks. Treatments were various levels of autolyzed yeast (control, 250 ml/1000l, 500 ml/1000l, and 750 ml/1000l) that conducted in completely randomized design with 8 replications. Egg production (EP) and egg weight (EW) were recorded daily and feed intake (FI) and feed conversion ratio (FCR) were evaluated weekly. Quality characteristics of eggs were evaluated 2 times per period. Iintestinal histomorphology was determined at the end of experiment. At the end of the study, one birds per replicate were killed by cervical dislocation and blood was drawn from the jugular vein. Serum was separated after centrifugation at 4500 g and 4°C for 10 min, and frozen at −20°C until further analysis was conducted for blood biochemical parameters. Serum samples were analysed for concentrations of low-density lipoprotein (LDL), cholesterol, and triglycerides using standard kits (Zist Shimi, Tehran, Iran) with an autoanalyser (Autolab PM 4000; Medical System, Rome, Italy). Then, caecal digesta (1 g) from each bird were aseptically transferred into 9 ml of sterile saline solution and serially diluted. Lactobacilli, Coliforms, and E.Coli were grown on Rogosa–Sharpe agar, MacConkey Agar, and Eosin Methylene Blue Agar, respectively. Plates for Lactobacillus were incubated anaerobically for 48 h at 37 °C. Microbial populations for E. coli and Coliforms were counted after aerobic incubation at 37°C for 24 hours. All samples were plated in duplicate. This study results showed that addition of autolyzed yeast could not change performance parameters. Yolk color was highest at 250 ml/1000l which had a significant difference with 750 ml/1000l (P <0.05). Addition of autolyzes yeast at levels of 500 and 750 ml/1000l significantly increased cecal Lactobacillus and decreased Coliforms of cecum (P < 0.05). Addition of autolyzed yeast at level of 750 ml/1000l significantly decreased cecal Ecoli compared to the other treatments (P < 0.05). The possible reason for the observed response could be the ability of the yeast to maintenance of normal gut microflora as well as preventing the proliferation of pathogenic microbes. This action may partly contribute to increased nutrient digestibility, reduced competition for nutrients, increased nutrient utilization as well as absorption. Villus height of the e duodenum increased in layers fed on 750 ml/1000l compared to the birds fed 250 ml/1000l (P < 0.05). While crypt depth and villus height-to-crypt depth ratios of the duodenum in birds fed 750 ml/1000l compared to the birds 250 ml/1000l decreased and increased, respectively. Crypt depth of jejunum significantly decreased in birds fed highest level of autolyzed yeast compared to the other treatments. Results of this experiment showed that supplementation of autholyzed yeast could not significant change in qualitative and quantitative parameters. But, levels of 500 and 750 ml/1000l autholyzed yeast increased cecal microbial of Lactobacillus and decreased Coliform and the level of 750 ml/1000l decreased Ecoli of cecum and increased villus height and villus height-to-crypt depth ratios of the duodenum.

Due to the high importance of egg shell quality in terms of hardness, extensive transportation with high volume of this product between different countries, the importance of shell quality in terms of protecting the internal content from extra-shell contamination and also one of the ways to improve traits, relying on The genetic structure of a trait is the application of genetic selection. Therefore, the aim this study is to use transcriptome data obtained from uterine tissue of two groups of laying hens with hard and weak eggshell, in each of the three stages of the calcification period (initiation, growth and termination). Gene expression profile was determined and differential expression of genes is analyzed so that different index genes can be expressed and their ontology can be studied to help the results. As a result, the genetic structure of the trait and the list of index genes have been regularly completed, and with the information obtained from the present study, the correct and practical genetic selection can be made in laying hen breeds. The aim of this study was to investigate the gene expression profile between two groups of chickens with hard and weak eggshells in three stages of calcification period (initiation, growth and termination), to identify significant index genes with different expression and analysis. Ontology and the paths involved are related to them. Therefore, in this study, transcripts (total mRNA sequences) of 18 samples of uterine tissue including three replicates in each stage of each group were prepared. The process of converting the initial format of readings was done using SRAtoolkit software, measuring the quality of readings with fastQC software, editing readings with Trimmomatic software and re-measuring the quality of readings after editing with fastQC software; Also, the alignment and mapping of the readings were done using Hisat2 software and format conversion and sorting of results was performed using Samtools software. Finally, the differential expression analysis of genes was performed using Cufflinks software package (Cufflink, Cuffmerge and Cuffdiff software) and Then, considering p-value <0.00025 and the criterion for comparing the value of differential gene expression, log2 (fold_change) less than -4 and greater than +4 were identified as the most significant genes with different and significant expression. Histogram of the results was performed using CummeRbund package in R software environment and ontological analysis was performed using DAVID and Ensembl databases. According to the results of gene expression profile, 28833 genes were identified on the transcript of the samples. Finally, by analyzing the differential expression of genes, 1338 genes at the initiation stage, 81 genes at the growth stage and 190 genes at the termination stage were identified with significantly different expressions, that Considering log2(fold_change) > +4 and log2(fold_change) < -4, 51 genes at the initiation stage, two genes at the growth stage and four genes at the termination stage had different and significant expression. The largest difference in gene expression between the two groups at the initiation stage, ENSGALG0000000044418 gene with log2 (fold_change) equal to 8/63 and at the growth stage, ENSGALG0000000049618 gene with log2 (fold_change) equal to 6/82 and at the termination stage, ENSGALG0000000049618 gene with log2 (fold_change) equal to 5/14 was observed. Ontological analysis of index genes showed that they are mainly involved in protein binding activities (ENSGAL000000444418, NMRAL1, SLITRK4, CHL1, ENSGAL00000009041, PHACTR3 and CORIN genes), DNA transcription regulation (LHX1, TFAP2A, RUNX3, ETV1, NR4A3 and RUNX1 genes), immune response (ENSGAL0000000043996, TMEM117, AvBD9, GCNT3, ENSGAL00000046947 and ENSGAL00000051617 genes), fat metabolism (PNPLA3, NR4A3, CD36, FFAR4 and DGKB genes) and calcium ion binding (ANXA10, CAPN8, CDH18 and DGKB genes), respectively. In the differential expression analysis of genes, considering log2 (fold_change) more than +4 and less than -4, in the initial stage, 51 genes, in the growth stage, two genes and in the termination stage, four genes were identified. The highest differences in gene expression between the two groups were observed in the initial stage, ENSGALG00000044418 and PDZK1IP1 genes, in the growth stage, ENSGALG00000049618, ENSGALG00000048945 and TMEM63C genes and in the termination stage, ENSGALG000000004400 and ENSG26 genes; The results of ontological analysis of index genes showed that they are mainly involved in protein binding, DNA transcription regulation, immune response, lipid metabolism and calcium ion binding, respectively.

Estrus synchronization is a valuable management tool that has been employed in enhancing reproductive efficiency in ewes. Synchronization of estrus and ovulation for fixed-time artificial insemination in sheep is mostly based on the insertion of intravaginal devices containing either progesterone CIDR (Controlled Internal Drug Release) inserts or progestagens (sponges impregnated with fluorogestone acetate (FGA) or medroxyprogesterone acetate (MAP)). Intravaginal sponges are usually inserted over periods of 12 to 14 day and used together with eCG, particularly out of season, administered at the time of sponge withdrawal or 48 hours prior to sponge removal. It has now been indicated that shortening the duration of progesterone treatment with intravaginal instruments, while being effective in inducing estrus and ovulation, reduces the incidence of vaginal infections and consequently improves fertility. On the other hands, it has been reported that pregnancy rates of progestagen-synchronized ewes were lower during anestrus than during the breeding season. Therefore, this study was conducted to investigate the reproductive performance of indigenous ewes in Khanmirza city with short-term and long-term estrous synchronization programs accompanied by eCG during breeding and anestrous season. Moreover, efficacy of estradiol injection instead of gonadotropin during short-term progesterone treatment was evaluated in both seasons. The experiment was performed at two periods, during the breeding and the anestrus seasons on 2 different groups of 400 ewes. During each season, ewes (2 to 5 years of age and average body weight of 45±2.5 kg) were allocated to 4 groups of 100, in the way that each experimental group contained an equal number of ewes of a particular age. Experimental groups were: Control (without any synchronization program), Short term-estradiol group (ewes received 12 days progesterone treatment and intramuscular injection of 1mg estradiol benzoate at the time of sponge removal), Short term-eCG group (ewes received 12 days progesterone treatment and intramuscular injection of 400 IU eCG at the time of sponge removal) and Long term-eCG group (ewes received 14 days progesterone treatment and intramuscular injection of 400 IU eCG at the time of sponge removal). The progesterone treatment consisted on a vaginal sponge which contained 60 mg Medroxyprogesterone Acetate. Then, the ewes were placed in pens and one healthy ram was introduced for every 5 ewes, in order to detect heat and mating. Estrus signs were detected and recorded every hour for 5 days. The percentages of ewes that showed overt signs of estrus during a period of five days (estrus rate), estrus onset (the time elapsed between sponge removal and the first accepted mating) and pregnancy rate (The number of ewes without showing signs of estrous after 42 days of mating/total number of ewes×100) were recorded. Fecundity and prolificacy rate was calculated based on the number of lambs born. Lambs were monitored for 30 days after birth and deaths among them during this period were recorded against the ewes which were their mothers, and the survival rate was determined. The multiple birth rate was calculated by combining the twin and triplet birth rates. The results showed that reducing the duration of treatment with progesterone sponge in both trial period (autumn and spring) led to a significant reduction in estrus rate (P ≤ 0.05), but had no significant effect on other reproductive parameters (P > 0.05). Regardless of the season, injection of estradiol instead of eCG on sponge removal day, while increasing the estrus rate of ewes, led to a sharp increase in the rate of return to estrus (P ≤ 0.05) and caused decreases in the percentage of pregnant ewes, percentage of parturition ewes and lambing rate (P ≥ 0.05). In the breeding season, the mortality rate of lambs born from progesterone-synchronized ewes decreased and fecundity increased numerically compared to the corresponding group in breeding season group. Lack of possible effect of the anestrus season during synchronization programs on estrous rate and fertility of ewes can be attributed to optimal nutritional conditions of ewes in this season. Short term progesterone treatment (12 day) as well as injection of estradiol benzoate instead of eCG is not recommended to synchronize the estrous of ewes during both reproductive and anestrus seasons. In other words, short-term progesterone treatment (12 days) was not effective to synchronize estrus in breeding and anestrous sheep which can be attributed to follicular dynamics.