فصلنامه پژوهشهای تولیدات دامی
پیاپی 35 (بهار 1401)

Based on the recommendations of some poultry nutrition references as National Research Council (NRC 1994), growth period of growing Japanese quails have been considered to be six weeks and only one dietary protein concentration was recommended for the entire growth period. However, the amino acid requirements of growing quails are similar to those of broilers as the percentage of the diet decreases with age, and applying one level of protein throughout the rearing period may cause deficiency or loss of amino acids compared with daily requirements. Given the high cost of protein in quail diets and the fact that few researches has been done on the effect of dietary protein levels at different phases of growth period on quail performance, this experiment was conducted to investigate different dietary regimens of protein on production and economic performances and also carcass characteristics of Japanese quails.

The experiment was carried out in a 3×3 factorial arrangement (3 protein levels: low (L)=20%, medium (M)=22% and  high (H)=24 percent in grower phase (8-21 days)× the same dietary protein levels, in finisher phase (22-42days)) with 9 treatments, 5 replicates and 8 pieces of quails per each replication. All chicks were received the same starter diet with 2900 kcal/kg Metabolizable energy and 24% crude protein (CP) from time of hatch up to 7 days of age and after that they were received dietary L×L, L×M, L×H, M×L, M×M, M×H, H×L, H×M and H×H protein programs. Production traits such as feed consumption, body weight gain, feed conversion ratio and production index at the whole growth period, as well as some economic traits such as feed cost per gain monetary returns per quail and also some traits related to carcass characteristics and meat quality such as edible carcass percentage, water holding capacity and oxidative spoilage index of meat were measured or calculated.

During 8-42 days of age, different dietary protein levels in growing phase had no significant effect on feed intake, weight gain and feed conversion ratio (FCR). While, higher protein levels (22 and 24%) in finishing phase significantly resulted in a better weight gain, FCR and production index of quails. Protein levels in grower and finisher phases had no significant effect on monetary returns however, increase in dietary protein level in finishing phase resulted in a significant feed cost to the gain at 8-42 days. Different dietary protein programs had no significant effect on carcass part percentages, water holding capacity and oxidative rancidity of meat.

For proper performance and economic production of quails protein regimen with at least 20% protein in grower and 22% protein in finisher phases could be recommended.

a reduced circulatorys lipids influences carduvascular health and therefore it may improves productive performance in birds. This experiment was conducted to investigate the effects the dietary inclusion of the atorvastatin and gemfibrozil drugs into a pelleted diet on productive performance and immune response in broiler chickens.

a total number of 54, 10-day old broiler chicks were used to examine the efftes of the three experimental treatents. The treatments consisted of a basal diet in the pelleted form (control), and addition of atorvastatin (20 mg/kg) and gemfibrozil (1800 mg/kg) in the same diet. Effects of the treatments were evaluated in a completely randomized design in 9 replicates of 2 birds each.

Inclusion of gemfibrozil into the basal diet improved feed conversion ratio during day 14 to 42 of age (p<0.05). Nosignificant effect was found for lipid-lowering drugs on the proportional weight of the immune organs and differential leukocytes counts. Antibody titer against Newcastle virus showed a significant difference among the treatments at day 21 of age. There was a lower antibody titer against Newcastle virus in the birds maintained on the diet containing gemfibrozil (p<0.05). Cutaneous basophil hypersensitivity responses elicited by intradermal injection of phytohemagglutinin were not differing among birds receiving basal diet with lipid-lowering drugs atorvastatin and gemfibrozil.

No significant effect of lipid-lowering drugs atorvastatin and gemfibrozil were found on immune system function in broiler chickens.

This study was conducted to evaluate the effects of different dietary levels of Hemp seed (HS) (Cannabis sativa-L.) on growth parameters of broiler chickens was estimated using Gompertz and Artificial neural network models.

In this study, 192 male broiler chicks (1 d old-Ross 308) were randomly assigned to a completely randomized design with 4 dietary treatments: control (without HS), 2.5, 5 and 7.5% HS in 4 replications (12 birds/pen). The chickens had freely accessed to drinking water and fed ad-libitum. To estimate growth parameters, cumulative body weight of birds was fitted to Gompertz model.

The results showed that different dietary levels of Hemp seed had no significant effect on growth parameters of broiler chickens (p>0.05). But growth rate at first to fifth weeks affected by different dietary levels of Hemp Seed (p<0.05). Results of comparison of models showed that non-linear Gompertz model had higher R2, and lower MSE, MAD, MAPE and bias compared with artificial neural network, that had better estimate of weight of broiler chickens.

The results of this study showed that different levels of Hemp seed diets had a significant effect on growth parameters of broilers including relative growth rate, live weight at maturity, turning point of growth curve and body weight at turning point of growth curve. Growth rate in the first to fifth weeks of broiler breeding period was significantly affected by the addition of hemp seed diets. On the other hand, the results of this study showed that the Gampertz model was able to estimate the 42-day-old weight of broilers more accurately than the artificial neural network model.

Cottonseed meal (CSM) is a by-product of the separation of oil from cottonseed, which is limited in poultry feed due to its gossypol, cyclopropenoid fatty acids, high fiber and low protein quality. For this purpose, in the present study, the effect of different levels of cottonseed meal with silymarin on the performance and some blood parameters of broilers was investigated.

Treatments consisted of different levels of CSM (0, 12 and 24 percentage of diet) and 2 levels of silymarin (0 and 600 ppm) that was performed in completely randomized design with 2×3 factorial arrangement with 240 broiler chicks. Experimental diets for starter period (1 to 21 days) and grower period (22 to 42 days) were performed based on the requirements of the National Research Council. Feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR) were recorded weekly. On day 42 of breeding, blood samples were taken to evaluate blood lipid parameters. Breast weight, thighs, abdominal fat, total gastrointestinal tract, liver, spleen and bursa of fabricius were also measured at day 42 and the data were reported as a percentage of live body weight.

The results of this experiment showed that dietary supplementation of silymarin was more effective on increasing FI in birds that consumed 12% CSM at starter period. Supplementation of silymarin to the control diet significantly decreased FI at grower period and whole period of experiment (p<0.05). Improved BWG and FCR was related to the birds fed silymarin at 2 levels (0 and 600 ppm) without cottonseed meal (p<0.05). Highest relative weight of thigh was related to the birds that consumed diet without cottonseed meal and silymarin. Highest value of relative weight of breast was recorded for the birds that received diet with silymarin and without CSM that had significant difference to the diet contains cottonseed meal (with or without silymarin). Also, highest value of relative weight of gastro-intestinal tract was recorded for the birds that received diet with 12% CSM and silymarin. The plasma LDL level of birds fed diet with silymarin and without CSM were lowest that had significant difference to the other treatments (p<0.05). Also, dietary supplementation of silymarin at the lack of CSM increased but in CSM diets decreased significantly plasma triglyceride concentration (p<0.05).

The results of this experiment showed that supplementation of silymarin at 600 ppm to the CSM diets could not reduce negative effects of gossypol in broiler chickens.

Organic acids are one of the alternatives to antibiotics growth promotor which have beneficial effects on animal performance and gastrointestinal microbial population. In general, addition of organic acids into the feed lowers pH of the feed and gastrointestinal tract, stimulates growth, helps beneficial bacteria to overcome pathogenic bacteria, and reduces toxic metabolites produced by harmful bacteria.

A total of 240 day-old Ross 308 male broiler chicks were divided into 4 treatments, 4 replicates, and 15 broiler chickens per replicate in a completely randomized design. Experimental treatments were included 0, 200, 300 and 500 mL of acidifier in 1000 L drinking water.

Feed conversion ratio in broilers that received two levels of 200 and 500 mL of acidifier per 1000 liters in drinking water decreased compared to the control treatment (p<0.01). European efficiency index was higher in the whole acidifier levels than the control and a linear increasing trend was observed (p<0.05). Broilers received 500 mL of acidifier in water had the lowest FCR (1.64 vs. 1.80; p<0.01) and the highest EEF (394 vs. 332; p<0.01) compared with the control. The weight of bursa of Fabricius, spleen and pancreas in broilers received graded levels of acidifier was higher than the control (p<0.05). The pH of the proventriculus, duodenum and jejunum of broilers that received 500 mL of acidifier decreased compared to the control (p<0.05). Administration of graded levels of acidifier in drinking water had no effect on Lactobacillus, coliforms and Escherichia coli count in ileum (p>0.05). The thickness of the lamina propria layer increased in broilers received 300 mL of acidifier (p<0.05). Administration of acidifier in drinking water had no effect on antibody titer against SRBC and Newcastle.

The results indicate that adding 500 mL of acidifier in 1000 L drinking water improves growth performance by increasing the weight of digestive organs such as pancreas and acidifying the initial areas of the digestive tract.

The natural growth and development of the rumen tissue structure and absorption from rumen-reticulum depends on its morphological structure and the change in morphology causes the dysfunction of these tissues. The aim of the present experiment was to investigate the effect of using complete branches of Albizia on histomorphometry and histopathology of the rumen, liver, and kidneys.

Twenty-four Arabi male lambs with 8 ± 1.3 months old and initial body weight of 28.8±5.34 kg were used in a completely randomized design with three treatments and eight replicates. The lambs were randomly assigned to one of three treatments: 1-control (No Albizia) 2- control + 50 percent complete branches of Albizia replaced with alfalfa 3- control + 75 percent complete branches of Albizia replaced with alfalfa. At the end of the experiment, three lambs from each treatment that was closer to the average weight were selected and slaughtered. Sampling was performed from gastrointestinal, liver, and kidney tissues.

Reticulum wall thickness in treatments containing 50 and 75 percent of All the branches of Albizia was greater than the control treatment And was significant in the 50 percent treatment compared to the control treatment (p<0.05). The thickness of the muscular layer of the reticulum in the recipient 50 percent treatment was higher than the control and 75 percent treatment and was significant compared to the 75 percent (p<0.05). No significant difference was observed between other indicators of the reticulum. The thickness of Rumen tunica muscularis and Rumen wall thickness in 50 and 75 percent treatments were higher than the control treatment (p<0.05). No significant difference was observed between other indicators of the rumen. The treatments didn't affect the villus height of rumen and reticulum, however, the height of ruminal villi in control treatment was numerically higher than 50 and 75 percent of treatments. Liver and kidneys were in better condition in control treatment than other treatments.

In general, according to the results of the present experiment, no significant negative effect was observed on the histomorphometry and histopathology of rumen, liver, and kidneys; even positive results such as reducing the penetration of inflammatory cells were observed during the use of the Albizia plant. Therefore, its use in animal nutrition can be recommended after some performance studies.

In the current state of the country, the shortage of food in animal nutrition can reduce the cost of supplying the nutrients needed by humans and eliminating costly waste from industrial residues from the three aspects of reducing livestock dependency on cereals consumed by humans. The conversion of agriculture and the prevention of environmental pollution from the accumulation of these residues should be considered. Date palp is a product that is obtained after the extraction of the date palm and includes the meaty part of the fruit and the palm kernel. Date palp can be the successor to more expensive carbohydrate sources. The aim of this study was to investigate the effects of adding different levels of date pulp on the quality, fermentation and digestibility of alfalfa silage, and determining the best level of date pulp in alfalfa silage.

This research was conducted in a completely randomized design with 9 treatments and 3 replications. Treatments were: alfalfa (control), alfalfa, 97.5% + date palp 2.5%, alfalfa 95% + date palp 5%, alfalfa 92.5% + date palp 7.5%, alfalfa 90% date palp 10%, alfalfa 87.5% + date pulp 12.5%, alfalfa 85% + date pulp 15%, alfalfa 72.5% + date pulp 17.5%, alfalfa 80% + date pulp 20%. Sample composition was determined using standard methods. Gas production test was used to estimate gas production parameters. The alfalfa silage stabilizer was evaluated at different hours after opening the silage door.

The results showed that there was a significant difference in chemical composition between treatments. Among the treatments, alfalfa silage contained 15% of date palp, which had the lowest amount of ammonia nitrogen compared to other treatments. Adding different levels of date pulp to alfalfa silage significantly decreased pH of silage compared to control (P <0.05). The pH value in the treatment containing 12.5% ​​of the date pulp compared to the control treatment significantly decreased (4.14 vs. 5.31). The date pulp at 10% level in alfalfa silage increased aerobic stability by 188 hours versus 38 hours of silage control. Date pulp did not affect the dry matter of alfalfa silage. The highest amount of crude protein was found in the treatment containing 12.5% ​​of date pulp. The lowest and the highest amount of produced gas were 20 and 10 percent date pulp treatments, respectively. The date pulp at levels of 7.5% and 12.5%, respectively, increased the degradability of dry matter and the crude protein of alfalfa silage.

According to the results of this study, the use of date pulp is recommended to improve nutritional value, fermentation parameters, digestibility and aerobic stability of alfalfa silage.

Agriculture residues are of a good potential for use as the energy source in ruminant diets. Lack of nutrient balance and high lignin rate have restricted the usage of these products in ruminant diets. Nutritional value of lignocellulosic compounds can be improved with the help of proper methods of processing. This research was conducted in order to investigate the effect of chemical processing on the nutritional value of grass pea (Lathyrus sativus) residues.

Grass pea residues were treated with sodium hydroxide (NaOH, 50 g/kg DM), calcium oxide (CaO, 160 g/kg DM), hydrobromic acid (Hbr, 60 ml/kg DM) and hydrogen peroxide (H2O2, 57 ml/kg DM). Chemical composition of the samples was determined using the standard methods of AOAC. Ruminal degradability trial was carried out using the nylon bag technique. Gas production test was used to estimate gas production parameters. In vitro digestibility of the samples was determined through the batch culture method.

Chemical processsing was effective on changing the chemical composition of residues (p<0.05). The treatments of CaO, H2O2 and NaOH increased the Ash. Except for Hbr, the other treatments reduced the amount of crude protein (CP). Chemical compounds reduced the amounts of neutral detergent fiber (NDF and acid detergent fiber (ADF). Gas production potential (p=0.0005) and rate, and related estimated parameters were lower in treated samples than control (p<0.0001). Dry matter digestibility (DMD) in HBr and CaO treatments, and organic matter digestibility (OMD) in CaO treatment decreased compared to the control (p<0.0001). The pH of culture medium was increasd by the treatments (p<0.0001), however ammoniacal nitrogen (NH3-N) was the same among the different treatments. The treatments of NaOH, H2O2 and HBr incresed the microbial biomass (MB) and its efficiency (p=0.0001, p=0.0018 respectively).

Overall, although processing decreased the cell wall compounds of grass pea residues, it did not have a positive effect on gas production parameters and in viro digestibility of the samples.

Conjugated linoleic fatty acid (CLA) in milk fat has a positive effect on cardiovascular health, so efforts have been focused on increasing this fatty acid in cow's milk. Ionophores, including monensin, have been shown to increase milk production performance and immune capacity in the diet of lactating cows. In addition, monensin may have beneficial effects on milk production and the body's immune system, as well as milk composition and the pattern of milk fatty acids in dairy cows. Therefore, the main purpose of this experiment was to investigate the effect of monensin on the production, composition and pattern of milk fatty acids in Holstein cows

4 lactating Holstein lactating cows (mean calving 3.5) with an average weight of 507±14 and lactation days 91±16 days in a rotating Latin square design (rotating) 4× 4 randomly Four experimental diets were allocated. Experimental diets included levels of 0, 250, 350 and 450 mg monensin per kg of dietary dry matter. Each cow received all experimental diets over 4 periods. The length of each experimental period was 21 days, of which the first 14 days of each period were considered for adaptation of cows and the last 7 days were considered for data collection. Diets were balanced using NRC (2001) software. The ratio of forage to concentrate in all four diets was 44 to 56%. The cows were milked twice a day and the record of both meals was recorded as a daily record. Feed and manure samples were analyzed for dry matter, organic matter, crude protein, crude fat, NDF. Milk production was also recorded daily in a 7-day data collection period. Milk sampling was performed on days 17 and 18 of each experimental period. The pattern of milk fatty acids in the nutrition laboratory of Ilam Veterinary Office was determined by gas chromatography.

The results of this study showed that the addition of monensin significantly increased the production of raw milk and corrected milk for 4% fat (p<0.05). Monensin also reduced the concentration of short-chain fatty acids in milk fat, but had no significant effect on the concentration of medium-chain and long-chain fatty acids. The addition of monensin decreased the concentration of saturated fatty acids and increased the unsaturation of 18: 1 (omega-9) and 18: 1 (trans-9) and conjugated linoleic acid (cis-9, trans-11) in milk

In general, this study showed that monensin increases milk production, concentration of unsaturated fatty acids, conjugated linoleic acid in milk fat and decreases the concentration of short chain fatty acids and saturated fatty acids in milk fat.

Flax seed meal (FSM) is rich in various nutrients, especially CP and energy, and can be used as animal protein feed. Flax seed meal is a by-product of flax seed oil extraction. It has approximately 13.3 MJ DE/kg DM and 32% to 37% CP. It has a balanced amino acid profile and relatively low-rumen effective degradable protein. Additionally, it has been reported that FSM has greater content of phenolics and flavonoids than that in its seed. Moreover, it exhibits high antioxidant activity, which is beneficial for the growth and health of animals. These qualities are desirable in feedstuffs for ruminants. However, studies on the effects of replacing SBM with FSM in fattening ewes are limited. The aim of this experiment was to study the effects of replacing a portion of cottonseed meal with flax meal) Linum usitatissimum( on blood parameters, rumen fibrolytic enzyme activity metabolites, the immune system and growth performance in ewes.

The experimental design was a replicated 4 × 4 Latin square with the following treatments: (1) 0% flax meal, (2) 33% flax meal, (3) 66% flax meal and (4) 100% flax meal. The ewes were fed in individual pens for periods of 21 days, with the first 14 days for adaptation to diets and daily meal two hours of 08:00 am and 04:00pm were administered orally. The measurement of blood parameters (Glucose, triglyceride, Blood urea nitrogen, Cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL- cholesterol) and immune system (Leucocytus, Lymphocytes,   Monocytes, Granulocyte, Red blood cells , Hemoglobin, Hematocrit, The average volume of hemoglobin, The average weight of hemoglobin, The average concentration of hemoglobin in the cell, Red cell scattering amplitude, Platelets, The average size of platelets, The volume of platelets) at the end at the end of the 21-day period. To measure ruminal parameters (pH, ammonia nitrogen and micro-crystalline cellulose and carboxy-methyl cellulose) at the end of each sampling period was 20 days.

The results show that increasing the amount of blood urea nitrogen, cholesterol and HDL- cholesterol and LDL- cholesterol reduced. The immune system parts value hemoglobin and mean hemoglobin concentration have difference significant in treatment and the most amount was of 100% cotton meal treatment. Micro-crystalline cellulose enzyme activity to every three enzymatic activity (intracellular, extracellular and attached to particles) declined.

Overall, the results indicated that cottonseed meal can be effectively replaced by flax meal in the diets of ewes and the optimal proportion was 100% under the conditions of this experiment and without health impact.

Oxidative stress is an important factor in poor sperm function that causes morphological changes and oxidative damage. Various studies have shown that antioxidants can reduce oxidative damage during freezing. In fact, antioxidants reduce, eliminate, and inactivate free radicals. Many compounds, such as some plant extracts, some industrial chemicals, and some amino acids, can act as active antioxidants and neutralize free radicals. luteolin is an important member of flavonoids which is present in glycosylated form in plants and studies have shown that luteolin has antioxidant properties. The aim of this study was to reduce lipid peroxidation and minimize oxidative stress by adding different levels of luteolin in the freezing medium.

Semen samples were collected from 15 roosters at 28 weeks of age. Sperm collection from roosters was performed by back-abdominal massage method. To eliminate individual effects after initial evaluations, the samples were mixed together and used for cryopreservation. After extending the samples and adding the levels of 0 (control), 0.25, 0.5, 0.75, 0.1 and 1.25 μM luteolin to the base extender (lake extender), sperm were added at 1:20 ratio. The test samples were cooled to 4 ° C and then frozen in liquid nitrogen. The samples were thawed at 37 ° C and then the motility parameters were measured by CASA computer system, survival by eosin nigrosine test, plasma membrane integrity by host test, morphology by Hancock test and the amount of produced malondialdehyde. Then the data were analyzed by completely randomized design.

The results showed that the addition of 0.75, 1 and 1.25 μM levels significantly increased the total motility and the levels of 0.75 and 1 increased the progressive mobility and VAP. In addition, 1 μM of luteolin caused a significant increase in VSL parameter (p <0.05). The results showed that levels of 0.75 and 1 μM significantly increased membrane integrity, and also level of 0.75 μM of luteolin decreased malondialdehyde content and sperm percentage with abnormal morphology (p <0.05).

The results of this study showed that the addition of luteolin in the extender during freezing and thawing can have a positive effect on improving the quality of rooster sperm and subsequently increase the total and progressive motility after freezing and thawing and also the level of 0.75 μM could be the best performance among different levels added to the extender.

The Broiler breeders use diets with different characteristics to feed the chickens based on the price of feed items in the market and the availability of them, their experience and taste. The aim of this experiment was to evaluate the effect of different energy level on blood metabolites, bacterial population of small intestine and performance of Arian broiler chickens.

In this study, 200 commercial broiler chickens of Arian commercial breed were used in a completely randomized design with four treatments, five replications and 10 chickens per replication. Treatments included, 1: control treatment with the recommended energy level of the guideline;2: 50 kcal / kg less energy than the control; 3: 100 kcal / kg less energy than the control and, 4:150 kcal / kg less energy than the control.

The results of the experiment showed that reduce the energy level of the diet on weight gain, feed conversation ratio and were ineffective (p>0.05) but at 24 and 35 days of age, it increased feed intake also increased the level of breast in treatment 3 and 4 and increased blood glucose and HDL (p<0.05). No effect of treatments was observed on intestinal microbial population.

The results of this experiment show that energy reduction has no effect on poultry performance and shows that dietary energy in Arian breeds can be reduced to levels even less than 150 kcal / kg compare to control diet, which requires further supplementary testing.  Also, the percentage of breasts increased with decreasing energy level, which requires the ratio of energy to protein in the guide of this breed should be reviewed.

In the present study, the effect of solanum melungena extract on the semen characteristics of Farahani ram under short-term storage preservation was investigated.

Semen samples were collected by five rams. We assessed different four long-term liquid storage times after: 0, 24, 48, 72 and 96 h pre-freezing with levels of: control or without additives extract (control), 2, 4, 6 and 8 mg/ml SME in Tries-based extender at 5℃ before freezing.

In this experiment our finding indicated that the interaction of SME and storage time was significant on sperm motility, membrane integrity, viability and progressive sperm motility (p<0.05). In the sperm membrane integrity, the concentration of 2% SME had the highest percentage (p<0.05) and the spermatozoa progressive motility was shown at a concentration of 2% SME higher than other groups. However, the addition of 2% SME had a better effect than other treatments (p<0.05).

In conclusion, in vitro addition eggplant peel extract to ram semen at chilled-stored conditions could be improved sperm parameters in during assessments.

Burkholderia mallei, is the etiologic agent of the glanders disease. Clinical and bacteriological diagnosis of glanders is difficult in the early stages of the disease. Some methods such as Complement fixation test (CFT) due to false positive results and troublesome for veterinary authorities and cause financial losses to animal owners, The other one is Malleination test, which requires appropriate equipment and efficient laboratory personnel. Therefore, in order to quickly and accurately diagnose the disease, especially in areas that cannot be kept animals, new methods should be used to identify the disease. The Western blot is a serological diagnostic test and has been recommended by the World Organization for Animal Health (OIE). In this study, a Western blot assay making use of a purified lipopoly-saccharide (LPS) containing antigen of Burkholderia mallei was designated.

in this study, a total of 75 sera were collected from different horse populations from several geographical areas of Iran. Specificity and sensitivity of the Complement fixation test, ELISA and a Western blot were compared for serodiagnosis of glanders. ELISA test was based on B. mallei antigens and Western blot made use of a purified LPS-containing B. mallei-antigen.

The Western blot and ELISA, were more specific than the Complement fixation test. ELISA based on B. mallei antigens had more sensitivity compared to Complement fixation test and Western blot. Finally, sensitivity and specificity were obtained for Complement fixation test (92.31% and 98.38%), Western blot (92.31%, 100%) and (100% and 100%) respectively.

Complement fixation test for glanders is still the prescribed serological method for commercial purposes, which is used to confirm the health of animals. However, in order to maintain the biosafety of valuable and expensive horse colonies, it is important to implement a more accurate and intelligent disease control and eradication program. This enhances the laboratory diagnostic capabilities to better understand the cause of the disease and to use and optimize the diagnostic methods of glanders in the country. Therefore, efforts to further improve and optimize ELISA and Western blotting should be continue.

Genotype imputation in genomic selection schemes has been considered by researchers in recent years because it can reduce the costs of genomic selection without having a negative impact on the accuracy of genomic selection. In the genotype imputation process, markers that their genotypic information has been missed for any reason are imputed using various statistical methods.

To constructe genotypic matrix, a one morgan genome including one chromosome for 250 and 1000 individuals was simulated on which in different scenarios 250, 500, 750, 1000, 1500 and 2000 single necleotide polymorphismes (SNP) was distributed. In order to create genomic matrix including missing genotypes, genotypic information of respectively, 5%, 10%, 25%, 50%, 75% and 90% of SNPs was masked and then imputed with KNN. The percent of genotypes correctly imputed (the ratio of genotypes correctly imputed to total masked genotypes) as well as the correlation between primary genotypic matrix (no missing genotype) and imputed genotypic matrix were used as imputation accuracy.

In the population including 250 individuals, the accuracy of imputation in the scenarios of 5%, 10%, 25%, 50%, 75% and 90% missing genotypes, were 0.82, 0.82, 0.80, 0.76, 0.62 and 0.40, respectively, but by increasing the size of the population to 1000 individuals, the imputation accuracies as 0.83, 0.83, 0.82, 0.82, 0.71 and 0.54 were obtained which in the scenarios of 75% and 90% of missing genotypes the increase in imputation accuracy was noticable. The correlation between the primary genotype matrix and the imputed genotypic matrix also decreased with increasing percentage of missing genotypes. In a fixed population size, by increasing the number of SNP from 250 to 2000, imputation accuracy increased from 0.67 to 0.84. In addition, an inverse relationship was observed between MAF and imputation accuracy in a way that by increasing MAF from 0.01 to 0.5, imputation accuracy decreased by 15%. Computation time increased following increase in dimension of genotypic matrix. Bu increasing the percent of missing genotypes, the accuracy of predicted genomic breeding values decreased. In the scenarios of 5 and 10% of missing genotypes, no change in accuracy was observed, but in the scenarios of 75 and 90% of the missing genotypes, the accuracy of prediction of breeding values decreased by 16 and 32%, respectively.

In general, imputation accuracy of KNN was acceptable in such a way that up to 50% of missing genotypes, KNN imputed missing genotypes with 80% accuracy and therefore one could recommend this algorithm for genomic selection schems.

Accurate estimation of genetic variance components is essential for the correct prediction of breeding values. The discovery of SNP markers and advances in molecular genetics and the discovery of new methods for sequencing the entire genome of living organisms and the development of bioinformatics methods and computer science, etc. have provided a great deal of molecular data and created a branch of genetics called genomics. This study aimed to estimate the genomic variance components of Border sheep using SNP data.

For this study, the SNP panel, which was genotyped with a 50k marker chip from Illumina, was used. Data were collected at Falkiner Farm in Australia. The studied traits were birth and weaning weights, diameter, and length of wool yarn. To study the relationship between allelic frequency and the amount of justified genetic variance justified, SNPs were classified into five different groups of rare allelic frequency (MAF), with approximately equal numbers in each group. The analyses were performed with the approach of limited genomic maximum likelihood and the method of analysis of complex genome traits with GCTA software.

Genomic heritability estimated by SNPs with a rare allelic frequency of more than one percent for birth weights, weaning, diameter, and length of wool were 0.58, 0.47, 0.59, and 0.2, respectively. The contribution of different groups of SNPs with rare allelic frequencies in justifying genetic variance for different traits was different and in general a significant part of genetic variance was justified by SNPs with

Although the number of SNPs was different in different groups, the amount of genetic variance justified by different MAF groups was different. According to the results, a very large, ideal sample size and better coverage of low-frequency variants are needed to obtain a stronger and more reliable inference.

Breeding between Indus cows and Taurus cows in the Sistan region of Iran has been done in recent years through the use of liquid sperm, frozen sperm, or foreign bulls. There are few studies in Iran on the effects of interbreeding programs on Sistani cattle. The present study was performed to identify mononucleotide polymorphisms (SNPs) based on RNA-Seq data in purebred Sistani cows and its crosses with three foreign breeds of Holstein, Simmental, and MonteBilliarde cows.

In this study, RNA-Seq data were used for pure Sistani, Sistani and Holstein, Sistani and Montebeliarde, Sistani and Simmental cattle. For this purpose, first of the tail vein of purebred cattle mixed with Holstein, Simmental, and MonteBilliarde. (4 treatments and for each treatment two biological replications) in the same environmental, nutritional, and managerial conditions located in the breeding center of Sistani cattle in Zabol. blood was drawn.

SNP discovery analysis was performed on transcriptome using SAMtools software package, which led to the discovery of 152496, 177042, 134285, and 163362 SNPs in pure Sistani breeds and its crosses with three foreign breeds of Holstein, Simmental, and Montebeliarde bulls. In this study, there was no direct relationship between the number of SNPs identified and the length of chromosomes. Also, 12 types of SNPs were identified, of which four types were transition and eight types were transversion. The most common known SNPs were transition which was 71.84% in pure Sistani, 72.65% in Sistani and Holstein, 72.60% in Sistani and Simmental, and 71.94% in Sistani and MonteBilliarde.

Overall, the results of this study confirmed that RNA-Seq technology is an effective, economical, and efficient method for identifying SNP loci. Factors influencing RNA-Seq evaluation are such as the number of samples.

Whereas high levels of inbreeding in domestic animals reduce genetic diversity and increase the probability of animals being homozygous for deleterious alleles. Therefore, the longevity of inbred animals is decreased due to reduced genetic merit. Therefore, in designing breeding programs, preknowledge about the level of inbreeding is essential to control the increase in inbreeding and thus control the inbreeding depression in animals. In this regard, genomic data can be used to estimate inbreeding coefficients. The aim of this study was to investigate the rate of inbreeding using SNP marker data available throughout the genome from the Illumina OvineSNP600K array in Iranian native sheep.

In this study, the genomic inbreeding of 154 samples including 11 Iranian sheep breeds (Kermani, Baluchi, Afshari, Karakul, Sanjabi, SiahKabud, LoriBakhtiari, Shal, Ghezel, Chios, GrayShiraz) was studied. For this purpose, five different methods were used by using Plink software: molecular indices of inbreeding coefficient based on observed and expected heterozygosity (FIS), inbreeding coefficient based on “runs of homozygosity” (FROH), inbreeding coefficient based on genomic relationship matrix (FGRM), inbreeding coefficient Based on the number of observed and expected homozygous genotypes (FHOM) and the correlation between uniting gametes (FUNI).

The average minor allele frequency in Iranian native sheep was 0.268. Also, the mean of observed heterozygosity and expected heterozygosity was 0.341 and 0.360, respectively. The lowest rate of inbreeding according to FIS was related to Baluchi breed and the highest was related to Shal breed.  The highest amount of FROH (0.129) was observed in Kermani breed and the lowest amount (0.019) was observed in Baluchi breed. Also, the highest amount of FGRM, FHOM and FUNI indices was observed in Kermani breed and lowest amount was related to Baluchi breed. The highest ROH coverage was observed on chromosome 26 (20.23%), while the lowest was on chromosome 2 (6.62%).

The genetic diversity of Iranian native sheep was moderate and ranged from 0.315 to 0.354. ROH was found in all breeds, so that the average length of ROH was between 48 to 318 Mb, while the average number of ROH was between 8 to 53. The mean of genomic inbreeding coefficients for the whole population of native sheep were similar (0.05). The results of this study indicate that there is no high level of genomic inbreeding in most of the native sheep populations of Iran.

Unlike evaluation of male fertility which is done based on the phenotype records of females e.g., conception rate, semen traits are directly measured in bulls. The objective of this study was to identify genomic regions associated with sperm traits in Holstein bulls using the genome wide association based on gene set enrichment analysis.

For this purpose, phenotype records included 1508 genotyped Holstein bulls were used for ejaculate volume, sperm concentration, number of motile sperm, progressive sperm motility, and number of progressive motile sperm in each ejaculation. The evaluation of genome-wide association was carried out PLINK software (v. 1.90). In the next step, using the biomaRt2 R package R the SNP was assigned to genes if they were within the genomic sequence of the gene or within a flanking region of 15 kb up- and downstream of the gene. For the assignment of the genes to functional categories, the GO, KEGG, DAVID and PANTHER databases were used.

In this research, 11 SNP markers on chromosomes 1, 2, 5, 7, 8, 15, 18, 20, 21, 25, and 27 associated with SPEF2, SEPT12, SLC24A, BSP3, ETNK1, ERBB4 (sperm motility and number of progressive motile sperm), DSCAML, MYH3, RPM1 , RPM2, CAPSL (number of sperm and sperm concentration), DMRT1, and PPARγ genes (ejaculate volume) were identified. Some of these genes in the significant regions were consistent with some previous studies. In pathway analysis, 15 pathways from gene ontology were associated with the sperm traits. Among those pathways, the purine nucleotide metabolic process, cellular calcium ion homeostasis and regulation of fertilization biological pathway had an important role in the progressive sperm motility and number of progressive motile sperm. Also, the calcium channel regulator activity, PPAR signaling pathway, steroid hormone mediated signaling pathway and focal adhesion had significant association with ejaculate volume and sperm concentration.

The Identification of these candidate genes and selection bulls using genomic selection can considerable to improve male fertility and benefits of animal breeding centers and decrease production prices for consumers.

Understanding the losses caused by animal and poultry diseases is important by recognizing the share of indirect costs such as infrastructure and services as well as the direct costs of breeding and losses to improve the economic efficiency and proper managment. Therefore, the aim of current study was to estimate the financial losses due to coccidiosis in broiler and broiler breeder farms.

Collected data was from 16 broilers (12 farms) and broiler breeders’ (4 farms) farms in Gilan province. Williams model was used to calculate the economic losses of coccidiosis with a few changes based on Irans’ breeding systems.

The results of this study showed that the average loss due to coccidiosis in a broiler farm with 50,000 pieces of broiler and a broiler breeder farm with 30,000 active capacities was estimated about 225 and 333 million Rials, respectively. In commercial broiler farms, losses from mortality, reduced weight gain and increased feed conversion ratio had the greatest impact on coccidiosis losses. However, in the broiler breeder farm, the highest loss due to coccidiosis was related to losses from mortality (54.41%). After mortality, the parameters of vaccination, treatment, reduced egg production and reduced hatchability accounted for 22.63, 10.51, 7.86 and 4.57% of total losses, respectively. In small farms, due to the reduction of overhead costs, losses due to mortality is less than large farms. On the other hand, the management is more accurate in small farms than large farms.

Due to the financial losses associated to coccidiosis, using natural products including fungal, plant extracts and probiotics is necessary to reduce the problems from coccidiosis. In addition, where coccidiosis is more prevalent it is necessary to have coccidiostats and vaccinations in the management programs. In future research, segregation of type and source of infection, the number of herds studied to calculate financial loss due to Coccidiosis muse be increased, also the collected data should be related to different climates of the country.