Iranian Journal of Animal Science Research
Year:2020 | Volume:11 | Issue:4|Papers Count:10

Introduction: This research was undertaken to evaluate the effects of roasting and extruding heat processes on chemical composition, nitrogenous fractions, urease activity, metabolic protein, properties of degradability, and the ruminal-intestinal digestibility of dry matter and crude protein of raw and processed soybeans. Materials and method: This study was carried out at the Research Farm, Faculty of Agriculture, University of Birjand, Iran. During the extrusion process, soybeans were affected for 20-30 seconds at 150-160° C in the extruder by heat and pressure and finally were dried and cooled. In the process of roasting, the soybean for 15 minutes at temperature of 145° C was heated and for 45 minutes holding tank for heat storage remained. Seeds were dried and cooled by air flow, dry and cold. Approximate analysis of samples including dry matter, crude protein, crude fat and ash was determined by AOAC. The urease activity of raw and processed soybean was determined based on ISO-3896. Degradability parameters of the samples were measured after incubation for 0, 2, 4, 8, 16, 24 and 48 hours in the rumen of two fistulated Brown Swiss cows. Also, ruminal and post ruminal digestibility were determined with the incubation of samples for 12 hours in the rumen by Daisy system. The DM and CP degradation data were fitted by exponential equation: P=a+b (1-e – ct ). Effective degradability (ED) were calculated using of equation ED = a + {(cb)/(c + k)} and taking into consideration passing rate (k) 0. 04, 0. 06 and 0. 08 per hour. Results and Discussion: The findings of the present research revealed that roasting and extruding heat processes lead to increase of dry matter through decreasing water content and that it had no significant effect on other chemical composition. The findings showed that the process of roasting and extruding caused the amount of actual protein of the soybean to increase and was not effective on the amount of insoluble nitrogen in neutral detergent of the soybean. The non-protein nitrogen and nitrogen dissolved in the buffer soybean under the influence of roasting and extruding decreased. The amount of acid detergent insoluble nitrogen soybean decreased which might be due to the removal of some of the shells in the processing soybean has taken place or influence of roasting and extruding decreased. The urease inhibitor of the soybean became inactive by the process of roasting and extruding. Consequently, it caused intestinal protein digestibility to increase and affected by thermal process, the amount of metabolic protein of the soybean increased significantly, too. The process of roasting and extruding reduced the rapid part degradation of dry matter of the soybean (6. 27 and 4. 57 percent, respectively). Also, process of roasting and extruding caused the slow part of degradation to increase (of 63. 75 to 74. 73 and 63. 25 to 85. 82 percent, respectively). In addition, the rate constants degradation of dry matter of the soybean in rumen decreased (of 6. 66 to 4. 21 and 6. 09 to 4. 74 percent) under the influence of roasting and extruding. The process of roasting and extruding reduced the rapid part degradation of crude protein (38. 4 and 68. 4 percent, respectively) and the slow part of degradation to increase (17. 3 and 26. 1 percent, respectively), the rate constants degradation of crude protein of the soybean decreased (ranged from 7. 61 to 3. 79). Also, thermal processes reduced effective degradability of dry matter and crude protein of the soybean. Roasting and extruded with the reduction of the amount of ruminal disappearance and the increase of the post ruminal digestibility of dry matter and crude protein of soybean cased the degradability process of the soybean to be improved so that it transferred the place of the digestion of protein from the rumen to the small intestines and cased the amount of digestible of dry matter and crude protein in the intestine to increases. The increase of digestibility in the total digestive system shows that the reduction of ruminal digestion of soybean affected by the processes of roasting and extruding has been compensated by the increase of post ruminal digestibility. Conclusion: The experiment results indicated that thermal processes of roasting and extrusion were an appropriate strategy for reduction the ruminal degradability of the soybean and the supply of passing protein needed by high milk producing dairy cows.

Introduction: Carbohydrates are generally classified as either non-structural or structural carbohydrates. Structural carbohydrates include cellulose, hemicellulose and lignin, and non-fiber carbohydrates (NFC) are present inside the plant cells and are usually more digestible than carbohydrates found in plant cell walls. Dietary non-fiber carbohydrates are the main source of energy for high-producing dairy cows, which provide 30 to 45 percent of the dry matter intake. They are a very diverse group of non-fiber carbohydrates, which include starch, sugars, fructans, and pectin substances. Although the total amount of non-fiber carbohydrates is referred to as a single value, different types of NFC have different effects on digestibility and production properties. The dietary profile of NFC has the potential to alter the supply of metabolizable nutrients to the animal because NFC differ in digestion and fermentation characteristics. Sucrose is rapidly fermented in the rumen compared with corn starch. In vitro fermentation of sucrose, starch, and pectin resulted in different organic acid profiles, digestion characteristics, and maximal microbial protein yields. In addition, these effects may be affected by other feed components, such as the amount of rumen degradable protein. Some researchers have been showed that the impact of starch and sugars on low quality forage utilization may interact with the amount of supplemental rumen degradable protein. This experiment was conducted to investigate the effect of various sources of non-fiber carbohydrates (starch, sucrose, pectin, dextrose) in combination with different levels of rumen degradable protein on gas production and digestibility of fermentation parameters in in vitro condition. Materials and Methods: Soybean meal treated with heating at 160° C-60 min and untreated soybean meal were selected as low rumen degradable protein (RDP) and high RDP sources, respectively. Four types of nonfiber carbohydrates (dextrose, sucrose, starch and pectin) supplemented with two levels of rumen degradable protein (RDP) in a 2×4 factorial arrangement by gas production and batch culture. A basal diet including: alfalfa (30%), corn silage (10%), barley grain (25%), wheat barn (9%), salt (0. 5%), mineral-vitamin supplement (0. 5%), soybean meal (15%) and non-fiber carbohydrate source (10%) was prepared. This study was conducted in two experiments. In the first experiment, the gas production parameters for two levels of high and low rumen degradable protein and four types of non-fiber carbohydrates (starch, sucrose, pectin and glucose) using the gas production technique. In the second experiment, the digestibility of the first experimental treatments were measured in an in vitro batch culture method. In the first experiment, the gas pressure was recorded with the pressure gauge at 0, 2, 4, 6, 8, 12, 24, 36, 48, 72, 96 h after incubation. In the second experiment treatments were incubated in batch culture conditions for 24 hours and the degradability parameters were determined using equations. Results and Discussion: the obtained results showed that sucrose had highest gas production potential, organic matter digestibility (OMD), metabolizable energy (ME) and SHORT CHAIN FATTY ACIDS (SCFAs) than other NFC type in low RDP level. There was a significant difference in digestibility of organic matter and dry matter between treatments (P<0. 05). The highest and lowest ammonia nitrogen concentrations were obtained from treatments with starch in combination with high and low RDP, respectively. Treatments had a significant effect on partitioning factor and production of microbial mass (P<0. 05). Among the lowdegradability protein-based treatments, pectin treatment had the highest amount of microbial production and among the treatments with high degradability protein content, starch treatment had the highest production of microbial mass and partitioning factor. Overall, the results showed that when the RDP level is low, sucrose has a better performance in terms of fermentation parameters, whereas when using the high RDP, there was no significant difference between different types of carbohydrates. It seems that these interactions should be considered in regulating diets. Conclusion: The results of this experiment showed that different types of non-fiber carbohydrates and levels of rumen degradable protein had a different responses to fermentation parameters. When using low protein levels, it seems that there is a greater difference between different sources of non-fiber carbohydrates, while at high levels of protein degradation there is no significant difference between the different sources of non-fiber carbohydrates in terms of digestibility. Based on these results, it can be concluded that the non-fiber carbohydrate sources, along with the degradable protein supplement, has the ability to change the characteristics of ruminal fermentation, the source of food and the production.

Introduction: Buffering and alkalizing supplements have been used in dairy cows in order to increase production and prevention of ruminal acidosis for many years. Magnesium carbonate is typically obtained from magnesite mines and magnesium oxide is produced by the calcification of magnesium carbonate (reduction, oxidation and burning or heating with extreme heat). Some minerals such as bentonite and zeolite have buffering properties and a special role in the buffering capacity of rumen cation exchange. Buffers raise acetate to propionate ratio and improve fiber digestion. The purpose of this experiment was to evaluate the buffering capacity (BC) and buffering value index (BVI) of some native buffer and alkalizer agents including sodium bentonite, magnesium carbonate, magnesium oxide and sodium bicarbonate and their effects on ruminal fermentation and digestion parameters in vitro. Materials and Methods: The first experiment was performed with different types (11 samples) of buffer and alkalizer agents to determine the buffering Capacity (BC) and buffer Value Index (BVI). The experimental samples were including magnesium carbonate A (MgCA), magnesium carbonate B (MgCB), magnesium carbonate C (MgC C), magnesium carbonate D (MgC D), magnesium oxide A (MgOA), magnesium oxide B (MgOB), magnesium oxide C (MgOC), magnesium oxide D (MgOD), sodium bentonite A (SBeA), sodium bentonite B (SBeB) and sodium bicarbonate (SBi). The buffering capacity was defined as the resistance to change in pH from 7 to 5. In order to determine BC, individual samples were dried and ground to pass through 1mm screen. Buffering capacity was determined by titrating the 30-ml solution under continuous stirring from its initial pH to 5 with 1 N HCl and by titrating a similar prepared solution of samples from its initial pH to 7 with 1 N NaOH. In the second experiment in vitro batch culture technique used. The basal diet contains 80 percent of the concentrate and 20 percent of the forage. half-gram (DM) of base ration with magnesium carbonate (MgC), magnesium oxide (MgO), sodium bentonite (SBe) and sodium bicarbonate (SBi) (1 and 3% DM of ration) were added into the culture vials, then incubated with 50 ml of buffered rumen fluid. Rumen fluid was collected from two ruminally fistulated cows. The gas production was estimated. In vitro dry matter disappearance (IVDMD), pH and ammonia nitrogen (NH3-N) was measured after 8 and 24 h incubation times. Results and Discussion: The results showed that the highest pH, buffering capacity and buffering value index were in MgOA and the least of these parameters indicated at MgCD, respectively. Compared to the control lower values were obtained for total gas production (b) of MgO 3%, MgC 3%, MgO 1% and SBe 3% additives. In the present study, addition of MgC and SBi (3% DM diet) also caused a remarkably increase in total gas production. Although the exact mechanisms are not known for the general responses in gas production to supplementation of MgC and SBi, one of the mechanisms of increasing total gas production is considered to be the higher ruminal microbial numbers caused by the SBi and MgC addition. It has been demonstrated that SBi addition increased the number of ruminal total bacteria, cellulolytic and amylolytic bacteria in buffalo. 3% MgO supplementation increased (P < 0. 05) the final pH and it decreased (P < 0. 05) the IVDMD compared with the control (after 24h incubation). Significant increase in pH by additive MgO and bentonite can be due to the exchange of cations with hydrogen ion as a modifier of hydrogen ion. Also, in this experiment use of SBe decreased digestibility of dry matter. Some researchers reported that 0. 5% MgO (DM diet) does not change the digestibility of dry matter compared to sodium bicarbonate. On the other hand, results of this section of experiment was in agreement with results of gas production, MgC and MgO treatments which had the most and least amount of produced gas (respectively), these also affected digestibility of dry matter. Generally, buffers and alkalizing compounds have no effect on digestibility of dry matter, and probably this reduction in magnesium oxide treatment may indicated a change in the microbial population of ruminal fluid because of the effects of these treatments. In addition, Concentration of NH3-N did not differ (P = 0. 2443) between the treatments. Some compounds, such as bentonites, are believed to be able to absorb and release proteins and other nitrogen substrates, so absorbing it when ammonia is high in the rumen, and when the ammonia concentration is reduced, a large amount of it released and thus increases the efficiency of ammonia and protein in the rumen. Conclusion: In general, the results of this experiment show that magnesium oxide, while increasing the pH of the rumen fluid, also has negative effects on the parameters of gas production, fermentation and possibly microbial activity, and also reduces the in vitro digestibility of dry matter. However, magnesium carbonate and sodium bentonite as a true buffer and due to the preservation and stability of rumen fluid acidity can improve fermentation conditions without having a negative effect on digestibility, so using 1% magnesium carbonate and sodium bentonite as a true buffer is suggested in the livestock diet.

Introduction: Negative energy balance in pregnant ewes during last of gestation could result in fatal pregnancy toxemia and affects ewe and lamb health. Fat supplementation of the diet is an efficient mean to increase energy concentration of diet and modify body weight, body condition score, milk yield, fat content and fatty acid composition in lactating ruminants. Addition of fats to ruminant diets provides preformed fatty acids (FA) which are directly available for milk fat synthesis in dairy cows and small ruminants. Much of the research attempted to obtain milk fat with healthier properties by increasing milk concentration of specific human health promoting fatty acids. Although mechanisms of action are unclear and its use in humans is controversial, CLA is still of particular interest because of its speculated role in preventing human health problems and increasing the nutritive and therapeutic value of milk. Therefore, this study contacted to investigate effects of different fat sources and CLA during late-pregnancy and early lactation on DMI, rumen metabolites and milk fatty acid pattern of Afshari ewes. Materials and Methods: Fifty Afshari ewes were assigned randomly to one of the five experimental diets with ten replicates in a completely randomized design; 1-control (without fat supplement), 2-3% protected fat powder of saturated fatty acids (palm oil), 3-3% Ca salt of omega-6 fatty acids (soybean oil), 4-3% Ca salt of omega-3 fatty acids (fish oil), 5-2% protected fat powder of saturated fatty acids (palm oil) and 1% CLA in a completely randomized design. Diets were fed between 14 days before and 45 days after lambing. Dry matter intake was measured daily, feed compound and milk composition was measured weekly. Milk fatty acid profile was determined using Gas Chromatography. Feeding behaviors were recorded every 5 minutes in 40 day of experiment. Rumen samples were taken directly from the rumen fluid through the esophagus and concentration of volatile fatty acids determined using a gas chromatography. Data were analyzed using SAS statistical software and MIXED procedure. Result and discussion: In prepartum, the addition of saturated fat, omega-6, and omega-3 significantly reduced the dry matter intake, but this effect was not observed in CLA containing treatments (P <0. 01). In the postpartum period, the addition of fat resources caused a significant increase in dry matter intake (P <0. 01). NDF digestion decreased significantly by adding protected fat powder of saturated fatty acids (P <0. 05), but not affected by other treatments. It has been reported that the effect of different fat sources on the dry matter is not constant and depends on various factors such as palatability, amount, source and degree of saturation, chain length and fatty acid stile (triglyceride and free fatty acid). The results showed that adding different sources of fat supplementation to 3% in diet did not have a significant effect on feeding behaviors of Afshari sheep. Animal-derived data showed that ewes were in good condition in terms of comfort. Rumen volatile fatty acid profile and pH after lambing were not affected by feeding different fat sources. In agreement with the results of this study, most studies no reported a significant effects on rumen pH with the addition of fat supplement. Adding protected fat powder of saturated fatty acids alone and, along with conjugated fatty acids, increased a significant increase in milk fat percentage. The addition of omega-6 fatty acids resulted in a reduction in the short, medium, and saturated fatty acid fatty acids, and the increase of medium chain fatty acids. The addition of omega-3 fatty acids did not have a significant effect on the fatty acid model of milk compared to the control treatment. The addition of conjugated fatty acids resulted in a significant increase in the concentration of conjugated linoleic acid in milk. It has been reported that the pattern of milk fatty acids can be affected by the amount and type of fatty acids in the diet. Conclusion: Dry matter was reduced by fat supplementation resources before lambing and increased afterward. Reduction in dry matter digestibility and dietary fiber was observed with saturated fat sources. Rumen pH and VOLATILE FATTY ACIDS (VFA) were not affected by feeding different fat sources. Adding conjugate fatty acids in the diet, increased the conjugate linoleic acid (CLA) concentration in the milk. In general, supplementing fat sources to the prepartum diets increased dry matter intake (DMI) after parturition and conjugated fatty acids resulted in a significant increase in the concentration of conjugated linoleic acid in milk.

Introduction: Cereals are the major part of a poultry diet and primary sources of feed energy Because of the worldwide high cost of corn, the use of barley and wheat grain in broiler diets has become more appealing. However, the use of barley in poultry diets because of its high content of non-starch polysaccharides (NSP) is limited. NSP increased intestinal viscosity, reduced litter quality and poor productive performance. Most of the adverse effects of barley in poultry feed have been attributed to the content of β-glucans. The NSP fraction of the cereal protects lipids, starch, and protein, thereby compromising the access of digestive enzymes to dietary components. Therefore, the processing of barley grain to remove anti-nutritional factors and improve its nutrient bioavailability before including it in the diets of one-stomach animals is beneficial. However, information concerning the effect of electron beam radiation on nutritional and anti-nutritional components of barley grain are scarce. Therefore, this study was carried out to evaluate the effects of electron beam radiation on the chemical composition and metabolizable energy of barley grain. Materials and Methods: The barley samples (cultivar Fajr) were packed in nylon bags and exposed to electron beam irradiation (Rhodotron TT200 accelerator, IBA Co., Belgium) at the Yazd Radiation Processing Center (AEOI, Yazd Center, Iran) at doses of 10, 20, 30, and 40 kGy at room temperature. Chemical composition of the raw and electron beam irradiated barley grain was determined. In order to estimate AMEn Chicks were fed a standard broiler diet for a 15-d pre-experimental period and, after four h of feed deprivation, were randomly distributed into experimental groups (16 treatments, 4replicates and 5 birds in each) in such a way that all groups had a similar average weight. All diets were given in mash form with birds having free access to water and feed throughout the experiment. The basal diet used during the experimental period was based on corn and soybean meal as major ingredients. The raw and electron beam irradiated barley grain (as test ingredient) was included in the basal diet at levels of 7, 14, and 21% to form test diets. The 16 experimental diets, evaluated in a balance trial to determine the AMEn content which contained 0. 3% chromium oxide as an indigestible marker. The precision-fed cockerel assay of Sibbald was used for determining the TMEn of the raw and electron beam irradiated barley grain. The birds were housed in individual metabolism cages, following a period of 24 h without feed, 30 g of the different ground barley samples were fed by intubation to 20 (4 per treatment) adult cockerels (Rhode island reds). At the same time, another 4 cockerels were deprived of feed to estimate the endogenous energy losses. Total excreta over the following 48-h period were dried and ground for subsequent analyses, Roosters were assigned to treatments at random. Results and Discussion: The results showed that percentage of dry matter, crude protein, ether extract, ash, β-glucan, ADF, and starch of barley grain were not affected by radiation. However, electron beam irradiation in all doses significantly decreased (P<0. 05) the NDF of samples compared to raw barley grain. The AMEn of barley was calculated by extrapolation of the linear regression equation to a 100% of barley inclusion. These equations indicated that with increasing dose of irradiation, AMEn of barley increased. The AMEn value of raw and irradiated barley at doses of 10, 20, 30 and 40 kGy were 2593. 80, 2628. 30, 2663. 10, 2730. 70 and 2795 kcal/kg, respectively. The electron beam irradiation numerically increased (P>0. 05) AME, AMEn, TME and TMEn of barley grain in cockerels at doses above 20 kGy. Previous studies using gamma or electron irradiation show a reduction in anti-nutrient content of canola meal, barley, and cottonseed meal and an improvement in their utilization increase in broilers. Gamma and electron radiation can denature proteins, decrease starch crystallinity and increase digestibility of barley and canola meal. Therefore, increased AMEn and TMEn of barley grain were expected in this experiment. Conclusion: The present study showed that electron beam irradiation reduced NDF and increased AMEn and TMEn of barley grain. It seems that radiation is an effective processing method for improving the nutritive value of barley, but more experiment is needed to evaluate radiation.

Introduction: Antibiotics as growth promoters in poultry feed are posing serious health risks to human health. Because of their residual effects in poultry meat and eggs, as well as result pathogens develop resistance to antibiotics. Currently, poultry scientists are challenged to find out alternatives to antibiotic growth promoters with no side effects for poultry that could be more or as effective against harmful microorganisms in the gastrointestinal tract and to stimulate the growth by increasing the efficiency of feed utilization and to enhance the immunity. Regarding to this subject, supplementing the dietary herbs or plant extracts would stimulate the productive performance of poultry. In recent years, products containing essential oils derived from several spices and herbs could be used feed additives as growth promoters in animal nutrition. These phytogenic additives may have more than one mode of action, including improving feed intake and flavor, stimulating the secretion of digestive enzymes, increasing gastric and intestinal motility, endocrine stimulation, antimicrobial, anti-viral, anthelminthic and coccidiostat activities, immune stimulation, and anti-inflammatory and anti-oxidative activity and pigments. Many studies have also been conducted on the effects of dietary essential oils or combinations thereof on the performance of poultry but with varying and conflicting results. While one report demonstrated that essential oils improved animal performance, some researchers reported that these additives were not effective in this regard. Salmonella and Escherichia Coli bacteria have become the major cause of foodborne diseases which has raised a great safety concern to public health. In several geographic regions, a large proportion of foodborne diseases are confirmed by the hazardous salmonellosis caused by infectious Salmonella. The antibacterial effects of essential oils have received widespread attention and numerous reports exist in the literature. The essential oil of oregano has been shown to inhibit Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes. The aims of this study were to investigate the In-Vitro and In-Vivo effects of 5 dietary essential oils, marjoram, tanacetum balsamita, Artemisia annua, Fennel and Pinus, on minimal bactericide concentration (MBC) and minimal inhibitory concentration (MIC) of 5 bacteria strains including Escherichia coli (PTCC 1399), Klebsiella pneumonia (PTCC 1053), Salmonella typhimurium (PTCC1609), Staphylococcus aureus (PTCC 1764) and Streptococcus pyogenes (PTCC 1447) and performance and intestinal microflora of broiler chickens challenged with Salmonella typhimurium and Escherichia coli. Materials and Methods: The disc diffusion method, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) were applied for the determination of antimicrobial activities of essential oils. In vivo study, a total of three hundred eighty four 1-d-old broiler chickens were assigned to 8 dietary treatment groups: 1) Control= basal diet, 2) Control + Virginiamycin (200 mg/Kg), 3 and 4) Control+ Marjoram Hydro alcoholic essential oil (200 and 400 mg/Kg), 5 and 6) Control+ Fennel hydro alcoholic essential oil (200 and 400 mg/Kg) and 7 and 8) Control+ Tanacetum Balsamita Hydro alcoholic essential oil (200 and 400 mg/Kg). At the second week of life (8-14 d) the broilers of each replicate in all of the treatments divided to 3 part (4 broilers in each treatment) and one group had no challenge, and the 2 other groups were challenged with challenged with Escherichia coli and Salmonella typhimurium. Essential oils were provided by Giah-Essanse Company in Golestan Province. The diets were formulated to meet the requirements of broilers as established by the Ross 308 broilers feeding guide in starter (1-14 d). The birds were kept under conventional conditions for vaccination, temperature, ventilation, and lighting based on Ross 308 catalogue recommendations. Standard management practices of commercial broiler production were applied. The broiler diets were formulated based on standardized ileal digestible amino acids and other requirements were obtained from Ross catalogue recommendations. Broiler chicken performance (feed intake, body weight gain, feed conversion efficiency at the end of the first and second week of age), blood cell count and ileal morphology were measured. Finally population of Lactobacillus and Escherichia coli of ileum were detected. Results and Discussion: The results showed that fennel, tanacetum and marjoram essential oils inhibited the growth of Escherichia coli and Salmonella typhimurium and the greatest MBC belonged to tanacetum essential oil as compared to virginiamycin. Inclusion of essential oils improved feed intake and body weight gain of broiler chickens changed with Escherichia coli and Salmonella typhimurium. Escherichia coli-challenged broiler chickens fed diet supplemented with essential oils had higher lymphocyte percentage and lower heterophil to lymphocyte ratio as compared to control group. Essential oils significantly increased Lactobacillus and decreased Escherichia coli count of healthy and Escherichia coli challenged broiler chickens compared to control group respectively. Conclusion: In conclusion, supplementation of essential oil had MIC and MBC effects and improved growth performance of broiler chickens challenged with Escherichia coli and Salmonella typhimurium. It is suggested that these essential oils can be supplemented to broiler chickens diet as substitution of antibiotics.

Introduction: Horses (Equus ferus caballus) have always been alongside humans and played an important role in the formation of human civilization. Horses are vertebrates that belong to the Mammalia class, the Equidae family, and the Equus genus. There are free and wild horses in Africa, Asia, Australia, Europe, North and South America, and some oceanic islands. Because of the long-standing relationship with human civilization, horses are considered as companions, a symbol of power and predilection, human assistant, and rival of other animals. The origins of domesticated horses have always been interesting to humans, and studying them is very important. Archaeological evidence and analysis of the horse's body color indicate that the first horses were found in the Eurasian steppes between 5th and 4th millennia BC. Among the genetic studies, simple repeat sequencing can be implied. Random repetitive sequences are scattered throughout the genome and show high polymorphisms that are harbored consecutively and repeat almost every 3-5 Kbp of genome. These sequences comprise a total of 20% of the mammalian genome sequence. Material and methods: Blood samples were obtained from Arabian horses and their DNAs extracted using salting out method. Extracted DNAs was run in an agarose gel and concentration and quality of DNAs were measured by Nano-drop. Four microsatellite markers were used that all have been recommended by International Society for Animal Genetics (ISAG) for testing the parentship. These markers included ASB17, LEX3, HMS1 and CA425. These loci were amplified by multiplex polymerase chain reaction (PCR) with fluorescent dyelabeled primers. PCR was performed using total volume of 25 ml for each sample and PCR products were separated and analyzed with capillary electrophoresis and the products were evaluated using GenMapper software. Results and discussion: According to the results obtained, the smallest allele was found is 88 bp at the position of ASB17 locus, as expected. Moreover, the largest allele observed in this population was 110 bp. The most frequent allele observed in the population was also 110 bp, with an allele frequency of 0. 46%. For LEX3, the smallest allele observed is 144 bp, which was expected. The largest allele observed in this population was 166 bp, which was more than expected range. The most frequent allele observed in the population was 160 bp, with an allele frequency of 0. 32%. However, the smallest allele observed in the population at position HMS1 was 172 bp, which was expected to be within the normal allele frequency range. The largest allele observed in the population was 182 bp, which was expected to be in the allele range. The most abundant allele observed in the population was the 174 bp allele, with a frequency of 0. 41%, which has a high prevalence in other races. For CA425, the smallest size of the allele observed for this site was in the population of 242 bp, which was smaller than the expected allele size and had a significant frequency of 0. 11%. The largest allele size observed in this site was 248 bp, which was expected to be above the expected allele range. The largest allele observed in the population was 182 bp, which was expected to be in the allele range. The most abundant allele observed in the population was the 174 bp allele, with a frequency of 0. 41%, which has a high prevalence in other races. For CA425, the smallest size of the allele observed for this site was in the population of 242 bp, which was smaller than the expected allele size and has a significant frequency of 0. 11%. The largest allele size observed in this site was 248 bp, which was expected to be higher than the expected allele range. Conclusion: According to the results obtained from the observed alleles in the studied population of Arabian horses, there is a relatively high genetic variation among this population. It can also be said that for some alleles, there is a high prevalence in the Arabian horse population, while they were not seen in other breeds of horses. In general, several alleles in the Arabian horse population of Iran have been observed with different frequencies that were not present in rest of the races, which implies to the differentiation of this race from horses of other races.

Introduction: The Kermani sheep breed is one of the most important native breeds in Iran. It is well adapted to the harsh and undesirable environmental conditions of the southeastern part of the country. Therefore, consideration to the breeding of Kermani sheep and the improvement of the environmental and genetic conditions of this breed can contributed greatly to providing a part of the livelihood needs of the people. The longevity in the ewe is a high economic trait, because increasing the longevity will lead to a reduction in the culling rate as well as replacement costs in the herd and increasing of number of lambs. Considering that the investigation and identification of the important factors influence culling of ewes from the herd, which leads to a decrease in the yield and longevity of the animal, can be used to provide and develop a suitable strategy to promote the survival and longevity of the ewes. In addition, due to the absence of genetic parameters of production life length in Kermani sheep, the aim of this study was to study changes, prediction of components of variance and genetic parameters of survival distribution function in Kermani ewes. Materials and Methods: In this research, longevity records of 772 heads of Kermani ewes (collected from 1989 to 2008) at the Kermani sheep station (Shahr Babak, Kerman province) were studied. The overall production life length was equal to the time between births to ewe culling. Frequency distribution for causes of culling and survival distribution function for ewes were estimated using R software. The Weibull model and Matvec software were also used for estimating variance component and genetic parameters of longevity traits as survival. Results and Discussion: The results showed that the mean of ewe’ s longevity was 4. 72 years with average lambing of 3. 4 in life time. The most important cause of culling was disease (53%), especially in the first three parity of the ewe. After disease, oldness, reproductive problems, low production, physical phenomenon, experimental slaughter, selling additional ewes and bad type (0. 5%) are the accounted causes for remaining ewe culling, respectively. Considering that culling due to disease accounts for more than half of the deaths, prevention and treatment of diseases are important in this breed. Therefore, the type and timing of the prevalence should be investigated and preventive and therapeutic proceeding should be taken for diseases. The total amount of nonoptional culling (illness, physical incidence, and aging) was about 83% of total casualties. It can be concluded that the deletion due to the low production was very small. At the age of two and three, the mortality rate was low, reaching its peak at the age of four, has declined since this age, with partial fluctuations between the ages of 5 and 6, and at the age of 7 and 8 years decline have happened. Therefore, most ewes were culled from the herd before reaching the age of 8. Most culling has occurred in pre-maturity ages, so it should be taken into consideration because it indicates that the ewes were eliminated before they reach the peak of production. The conditional culling probability increases with age, while cumulative survival rate decreased with age of ewe. The hazard ratio of death increased with age up to 6 years of old steadily and then increased strongly, and reached two at 7 to 8 years of old. The high hazard ratio indicated an early death or short longevity. Normally, inverse of this ratio expresses useful information. The reversal of this ratio at a certain time interval, provided that the hazard level remains constant at this interval, will indicate the time it takes to occur (death). For example, at a time interval of 3 to 4 years, the ewe's longevity will be equal to a reversal of 0. 5298, equivalent to two years. But, for 7 to 8 years old, the reciprocal of two will be 0. 5 years that indicating if the dangers remain constant at this interval, the ewe's life will be only 6 months, and ewes remaining in this group will be lost after 6 months. Trend of survival and hazard ratio at different ages of ewes can be provided as a model to breeders of this breed. Heritability on the logarithmic scale, the original scale and effective heritability of the risk ratio obtained from the sire model with the Weibull function was predicted at low to high (0. 002-0. 145). Although heritability estimates for longevity are low, but genetic improvement may be increased by selecting animals with higher inbreeding values. Conclusion: The results of this study showed that the most effective factor in shortening the longevity and decreasing survival in Kermani ewes is culling due to disease, especially in pre-maturity. Therefore, in order to improve the longevity, necessary studies and necessary preventive should be taken regarding the type and timing of the disease. Genetically, if possible, it would seek to create genetic resistance to diseases and environmental conditions. On the other hand, the results of models with the Weibull function indicate that in order to improve the survival rate and longevity, in addition to improving the non-genetic factors, the selection should be considered within the breed. Also, high heritability traits with high genetic correlation with longevity traits are identified and indirect selection be done based on them.

Introduction: Lysine is one of the essential amino acids not synthesized biologically in the human body and mammals so should be supplied through diets. Among the industrially important amino acids, L-lysine is in 1st position, which is used in pharmaceuticals, animals, human feeds and precursors for the production of peptides or agrochemicals. As L-lysine has large applications, the demand for it is increasing constantly year by year. To minimize the gap between increasing demand and production of L-lysine, it has to be produced in large scale. Corynebacterium species especially Corynebacterium glutamicum is widely used for the industrial production of amino acids especially L-glutamate and L-lysine. The C. glutamicum from long period has been used for the industrial production of various amino acids, primary metabolites and nucleotides. This organism is an aerobic gram positive, rod shaped and non-sporulating bacteria which used for the industrial production of amino acids of L-lysine and L-glutamate. This bacterium uses a variety of carbohydrates, alcohols and organic acids as single sources of carbon and energy for growth and also for the amino acid production. The quantity of lysine production by wild (natural) type of Corynebacterium glutamycum is very low, and its cultivation and propagation cannot provide the amino acid required by markets, therefor the wild type of this bacterium is not suitable and cost-effective for industrial purposes. To minimize the gap between increasing demand and production of L-lysine, it has to be produced in large scale. Aspartate kinase (AK) is one of the key enzymes in the biosynthesis of aspartate-derived amino acids such as lysine. This enzyme catalyzes the transfer of the Cphosphate group of ATP to aspartic acid. In most bacteria, the reaction is the first step of branched biosynthetic pathway for lysine, threonine, isoleucine and methionine and is known to be regulated by the end metabolites through feedback inhibition. For example, aspartate kinase from Corynebacterium glutamicum is concertedly inhibited by lysine and threonine, while aspartate kinase I and III from Escherichia coli is inhibited by threonine and lysine, respectively. Due to industrial production of lysine amino acid by using Corynebacterium species, a lot of researches have been done to improve the genetic modification of these microorganisms. Today, bioinformatics tools are available as online access through web-based databases and software, which can be used to study best structures of aspartate kinase enzyme with the least cost and time. Also due to high laboratory costs, the use of bioinformatics methods will be important in obtaining the final result. The aim of this study was to investigate the bioinformatics structure of aspartate kinase enzyme in different species of Corynebacterium by authenticated bioinformatics databases to suggest best bioinformatics structure of the aspartate kinase enzyme for applying in laboratory cloning and production of lysine amino acid for industrial purposes. Material and methods: The amino acid sequences of the aspartic kinase enzyme from 33 species of the Corynebacterium was obtained from the NCBI (https: //www. ncbi. nlm. nih. gov/protein) and stored as FASTA. In order to study the genetic distances and similarities in 33 species of Corynebacterium a phylogenetic tree was constructed using the Neighbor Joining method using the Mega software (MEGA 6). (A bootstrap check with 1000 replications was also conducted to obtain a confidence level for the branches) ClC main work bench5 software was used to investigate genetic similarities using protein sequences. The Evolutionary properties, physiological and physicochemical properties of aspartate kinase enzyme were studied and investigated in 33 different species of Corynebacterium through valid databases and software of NCBI, MEGA, ProtScale and ProtParam. In order to predict the second structure, two proteins selected from the psipred server were used (http: //bioinf. cs. ucl. ac. uk/psipred). For this purpose, the protein sequences of aspartate kinase enzyme in Corynebacterium glutamicum with access numbers of CAO00530. 1 and SJM57548. 1 introduced into the psipred and their second structure was mapped. Afterward, three-dimensional structure of mentioned protein was modeled using Swiss-model server (https: //swissmodel. expasy. org) Then the quality of the two predicted models evaluated by the Rampage server (http: //mordred. bioc. cam. ac. uk/ ~ rapper / rampage2. php), and in the next step its ramachandran plot mapped. Results and discussions: The results of evolutionary tree analysis in Corynebacterium species showed that derivation time of aspartate kinase protein in these 33 species is very close. The results of the ProtScale and ProtParam databases showed that the aspartatekinase enzyme of Corynebacterium glutamicum with the access number of CAO00530. 1 and SJM57548. 1 have the best physicochemical and maximum stability among 33 different species of study. Afterward, with further in silico investigation by the Swiss-Model server and Rampage tool, it was found that the two access numbers of CAO00530. 1 and SJM57548. 1 had the best threedimensional structure. From the results of in silico analyses, it can be inferred that the aspartate kinase enzyme with the two access numbers of CAO00530. 1 and SJM57548. 1 have the best physicochemical properties, the most stable and also the best three-dimensional structure and therefore could be offered for laboratory cloning and production of lysine amino acid for industrial purposes. Conclusion: Due to wide applications and importance of lysine production in our country and also the necessity of selecting appropriate strain of Corynebacterium for genetic engineering and industrial production, this bioinformatics study was done to predict best structure of aspartate kinase enzyme and best strain of Corynebacterium. Based on the results of our in silico analysis, it is suggested that corynebacterium glutamicum has the best protein structure of aspartate kinase enzyme and may be beneficial to increase Industrial lysine amino acid production.

Introduction: Mastitis refers to inflammation of the mammary gland and is a common and costly bacterial disease in the dairy industry that causes direct economic losses (reduced milk production, early culling of cattle from the herd and high costs of treatment) and indirect (reducing the quality of milk production). The disease is divided into two types of acute and subclinical, which the clinical type is associated with clear clinical symptoms. Infection can have different origins and can be caused by various pathogens such as E. coli, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Streptococcus dysgalactiae, Streptococcus obris and Klebsiella Pneumoniae. Management Improvement is not being alone able to control the disease of mastitis, because the environmental organisms causing the disease cannot be eliminated. As a fact, there are genetically different factors affecting on susceptibility to mastitis. Therefore, breeding in order to increase resistance to mastitis is a powerful tool to reduce the incidence of this disease. In most countries, this disease simply does not record like as the other health traits. On the other hand, there is an unpleasant correlation between milk production and the number of somatic cells count as an indirect indicator of mastitis. Due to the low heritability of mastitis, a direct selection is very difficult to reduce the disease, and most countries that have a genetic evaluation for mastitis resistance, generally use the number of milk somatic cell as an indirect indicator. Considering the positive correlation between mastitis and somatic cell count, in the genetic evaluation of mastitis, a somatic cell count is used. On the other hand, the heritability of somatic cell is more than mastitis, and it has been estimated from 0. 04-0. 16 in the first lactation by test day method The aim of this study was to investigate the factors affecting the incidence of mastitis, estimation of variance components and frequency of pathogens. Materials and Methods: A total of 22722 records of Holstein cows’ mastitis in 6 herds in Khorasan Razavi province. Environmental effects of mastitis were analyzed by the logistic procedure of SAS software. These effects included of the herd, year and month of calving, lactation number, stage of lactation, the first and the second degree of regression coefficients of days in milk and SCC, respectively. Variance components of mastitis were estimated by considering effects of herd, year and month of calving, lactation number, milk production, Somatic cell count, days in milk and pedigree in a logistic model of ASREML software. Sixty milk samples were collected to culture the most frequent pathogens of mastitis. Results and Discussion: Our study showed that 12% of cows showed mastitis at least once during their lactation, which was the most likely outbreak in 9-12 months of lactation; however, 5% of all cows had mastitis during the first 150 days of lactation in all lactation periods. Analysis of variance revealed that all factors of the model were significant (P<0. 01). Mastitis was reduced by the 4 th lactation number and increased then after. Mastitis rate showed a decreasing trend in February and during the studied years, which interpreted improvement in this trait. The heritability of mastitis, somatic cell score and their genetic and phenotypic correlations were estimated 0. 037± 0. 0008, 0. 055± 0. 008, 0. 712± 0. 112 and 0. 062± 0. 009, respectively. The microbial culture showed different patterns of pathogen-related mastitis during the stage of lactation. The highest cultured bacterial strains were Streptococcus aureus (20%) and Staphylococcus agalactiae (12%). The E. coli bacteria, which mainly cause environmental mastitis, accounted for 6% of all samples. it was found by the interval between calving and microbial culture time, the highest amount of E. coli was observed in the second half of lactation, while the streptococcus from the eighth month and staphylococcus from the fifth month to the end of the period was observed. Based on the classification of milk production per 10 kg, it was found that by increasing production, the risk of Streptococcus increased, but no change was observed for staphylococci. All E. coli contamination was observed in cows producing range between 30 and 40 kg, which may be due to the long openness of the nipples after being milked and entering the pathogens during the resting time of cattle. Conclusion: This study revealed that there was a high genetic correlation between the somatic cell count and mastitis infection (0. 71). Hence, there is a possibility to genetically improve dairy herds by selection of resistant cows with lower somatic cells. Therefore, it is strongly suggested that the industrial herds take into account the milk somatic cell records. On the other hand, The National Animal Breeding Center and Promotion of Animal Products, should report the breeding values of this trait every six-month. Since the information of mastitis outbreak is highly scattered and done by herds individually, it is suggested that a central database of this information be provided by National Animal Breeding Center and Promotion of Animal Products.