فصلنامه پژوهشهای تولیدات دامی
پیاپی 32 (تابستان 1400)

The aim of the present study was to evaluate the effect of zinc oxide on production performance, egg quality and antioxidant status of layer hens. This experiment was performed with 96 Bovens strain layer hens at peak production (28-35 weeks) in a completely randomized design with 3 treatments with 4 replicates and 8 hens each for 3 periods of 28 days. The treatments included control group (without zinc oxide nanoparticles) and two levels of 100 and 200 mg zinc oxide nanoparticles (ZnONPs) /kg of diet. Experimental diets were provided to laying hens for 8 weeks. Zinc oxide nanoparticles increased the egg mass (32-35 wk), and decreased feed intake (28-31wk) compared to control (P<0.05). The ZnONPs did not affect the egg production and egg weight. The haugh unit (31 and 35 wks) and quality traits of egg shell including eggshell stability (31 and 35 wks), and relative weight of eggshell and specific gravity (35wk) increased with increasing ZnONPs supplementation in diet (P<0.05). The concentration of total protein, HDL, and antibody against Newcastle disease were not affected by ZnONPs supplementation level. The use of ZnONPs supplementation reduced the concentration of cholesterol, triglyceride, LDL, concentration of MDA in blood and yolk, and the activity of the enzyme ALT (P<0.05). The ZnONPs supplementation increased the antibody titer against the influenza and increased zinc concentration in the blood. The results of this research showed that supplementation of 200 mg of ZnONPs per kg of layer diet may improve the growth performance indices, hough unit and egg shell quality, and decrease the blood lipids and improve immune response in layer hens at peak production.

In order to study the effect of different levels of zinc and selenium in diets containing oxidized oil on humoral and cellular immunity and relative weight of lymphoid organs in broilers, an experiment performed in a 2×3×2factorial arrangement in a completely randomized design(two Zero and 2% oxidized oil levels, three levels of 0, 40 and 100 mg / kg zinc sulfate, two levels of zero and 0.3 mg / kg selenium) using 480 one-day-old Ross 308 chicks with 12 treatments and 4 replicate per treatment  and 10 chicks per each treatment. To evaluate the immune system, changes in antibody titers were performed by injection of Sheep red blood cell (SRBC) at two times (21 and 28 days) and blood sampling at two times (28 and 35 days). The relative weights of bursa, spleen and thymus were measured at 42 days after slaughter. Cutaneous basophil hypersensitivity (CBH) test was used to evaluate cellular immune system. The results of total antibody titer in first and second times showed significant difference (P <0.05). Maximum grade of primary and secondary total antibodies in chicks fed with 100 mg / kg zinc and 0.3 mg / kg selenium and chicks oil). Containing 100 mg / kg zinc and 0.3 mg / kg selenium and the effect of zinc, Selenium, and their combined supplementation on the initial total antibody grade response was also significant, with 100 mg / kg zinc and 0.3 mg / kg. Selenium significantly increased the initial total antibody titer response. The effect of different experimental groups on IgM antibody response was significant at the first and second time (P <0.05). The cellular immune response of CBH test was not affected by different experimental diets. The effect of treatments on the relative weight of different lymph nodes was not significantly different. The results demonstrated that supplementation of zinc sulfate and sodium selenite improved the immune system of broilers.

The aim of the present experiment was to investigate the effect of diets containing organic and inorganic selenium on growth performance, carcass traits and blood metabolites in geese chickens. A total of 96 one day old native geese were used in a completely randomized design with 3 treatments of 4 replicates with 8 each. The experimental diets were basal diet, basal diet plus 0.3 mg organic Se per kg of diet (Sel-plex) and basal diet plus 0.3 mg inorganic Se per kg of diet (selenite sodium). Growth performance biweekly was calculated by recording during 1-56 days. Phytohemagglutinin test used for the evaluation of cellular immunity at 8 weeks of geese. Bodyweight gain was increased over 2 to 6 weeks and decreased thereafter. Feed conversion rate (FCR) was improved by both selenium sources and the highest FCR value related to the control group in the 8th week. Carcass traits were not affected by various inorganic and organic sources of selenium (P <0.05). Diet supplementation with organic and inorganic Se increased phenolic content and the amount of saturated and unsaturated fatty acids and decreased lipid oxidation after 9 days of storage at 4°C in the refrigerator (P<0.05). Selenium supplementation decreased total blood cholesterol (P <0.05). The cellular immune response was improved in the organic selenium group compared to inorganic selenium and control group (P<0.05). In conclusion, the results of this study suggest that dietary selenium especially organic selenium has desirable potential for improving the performance, immune, and meat quality of goose chickens.

This study was carried out to evaluate the effect of lecithin emulsifier to diet containing different levels of energy on performance, carcass characteristics, intestinal microflora and nutrient digestibility of broiler chicken. A total of 200 day old broiler chicks (male sex) Ross 308 strain was divided in 4 treatments, 5 replicates and 10 chicks in each replicate in a completely randomized design. Experimental treatments include: diet containing soybean oil with standard energy, diet containing soybean oil with low energy, diet containing soybean oil with standard energy + emulsifier, diet containing soybean oil with low energy + emulsifier. The Results showed that in the case of weight gain throughout the period, the body weight of chickens increased with decreasing energy levels. Also in the case of weight gain in the final period and the whole period, with increasing the level of emulsifier, body weight decreased. Regarding the FCR, in the initial, and whole growth periods, increasing the emulsifier level increased the feed conversion ratio. No statistically significant effects were observed in other experimental traits and different breeding periods by changing the energy level and adding emulsifier (P>0.05). The percentage of thighs in diets with high energy level was higher than other treatments. But other carcass traits did not show any significant effect (P>0.05). No effect of treatments was observed on intestinal microbial population. The results related to digestibility showed that in the case of dry matter, organic matter and fat traits, digestion was reduced in standard diets containing emulsifier and no significant effects were observed in other traits (P>0.05). In general, it can be said that increasing energy levels caused weight loss and reduced nutrient digestion, and adding emulsifier caused weight loss, increased conversion ratio and reduced nutrient digestion.

This experiment was conducted to the comparison of produced acidifier (based on citric acid) with commercial type in the broiler diets on performance, blood metabolites, intestinal morphology and the small intestine pH values of broilers. A total of 400 one-day-old Ross broiler chicks were used in this experiment. A completely randomized design with 5 treatments, 4 replicate and 20 chicks per replicate was performed. Experimental treatments included a control diet with adding 0.5%, 1% and 1.5% produced and 1% commercial acidifiers. The results indicated that feed intake (FI) increased at broiler chickens received 1 and 1.5% acidifier in comparison with the control group at the starter period (p<0.05). The body weight gain (BWG) and feed conversion ratio (FCR) improved by the 0.5% acidifier in comparison with control groups at the starter and the entire rearing periods (p<0.05). The inclusion of 1% produced acidifier decreased BWG and increased FCR compared to the control at the starter and whole periods (p<0.05). Whereas, commercial acidifier improved performance during the grower and whole periods compared to the control (p<0.05). The 1.5% level of produced acidifier increased FCR compared to the control at the starter period (p<0.05). The serum HDL of broiler chicken received acidifier was not significantly different from the control group. But, the lowest LDL was found in the 0.5% acidifier. There was a decrease in serum activity of alkaline phosphatase (ALP) in diets containing 1.5 and 1% of produced and commercial acidifiers compared with control groups (p<0.05). Gastrointestinal pH was not affected in duodenum and jejunum in acid-containing diets compared with controls at 28 and 42 days of age. Also, acidifier improved the traits of intestinal morphology (p<0.05). According to the results of this experiment 0.5% acidifier in feed of broiler chicken to improve performance and positive effect on blood metabolite is recommended.

The present experiment investigated the effect of pH adjusting additives on meat quality. Twenty-four Arabi male lambs with four months old and initial body weight of 23.9±3.15 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 additive) 2-control + Sodium bicarbonate (1% daily diet in two meals) 3-control + Megasphaera elsdenii and Saccharomyces cerevisiae (bacterial-yeast). At the end of the experiment, five lambs from each treatment that was closer to the average weight were selected, weighed, and slaughtered. The carcass components were separated and weighed. A sample of the Longissimus dorsi muscle between ribs 12 and 13 was prepared to determine the pattern of carcass fatty acids, meat colorimetric measurements. The concentrations of linolenic acid, total W3 fatty acids, stearic acid, docosahexenoic acid (DHA), and W6/W3 ratio were higher in treatments containing pH-adjusting additives than in control treatments (P<0.05). The concentration of eicosapentaenoic acid (EPA) in bacterial-yeast treatment was numerically higher than in control and sodium bicarbonate buffer. The concentration of linoleic acid and the ratio of PUFA/SFA in the control treatment were higher than the treatments containing pH-adjusting additives (P<0.05). The meat protein percentage, Hu angle (H*), carcass weight, and dressing percentage in bacterial-yeast recipient treatment were higher than other treatments (P<0.05). The redness index of meat (a*) and Chroma (C*) were higher in Sodium bicarbonate and control treatments (P<0.05). Therefore, pH adjusting additives, especially bacterial-yeast treatment, could be a way to improve some of the meat beneficial parameters for human nutrition. Because the results of the present experiment show that the additives used to adjust the pH and manipulate ruminal fermentation while feeding the lambs with high concentration diets not only do not adversely affect the chemical composition and quality of the meat but can also benefit the animal and human health that consume the product of these animals.

This study was intended to evaluate the nutritional value, antioxidant activity and digestibility coefficients of Pistacia atlantica seed and meal. The gas production experiment and batch culture degradability test were carried out to investigate the effects of Pistacia atlantica seed and meal on microbial fermentation characteristics, kinetics of gas production, methane and carbon dioxide production, t0.5, and lag time. Also, the calculated parameters e.g. microbial protein, molar proportion of volatile fatty acids, metabolizable energy (ME), short chain fatty acid (SCFA) and organic matter digestibility (OMD %), were evaluated for different treatments. The parameters were analyzed through the completely randomized design with repeated measurements. In this experiment, there was a significant difference in chemical composition (P <0.05). Although no significant difference was observed with respect to phenolic compounds, the amount of condensed tannin in seed was higher than that of meal (P <0.0001). Pistacia atlantica meal had the highest gas production rate (P <0.008). The number of moles of methane produced in 24 hours of incubation had a significant difference between the experimental treatments. Compared to meal, Pistacia atlantica seed had the lowest amount of methane produced (P <0.001). The total concentration of volatile fatty acids in seed decreased. The highest microbial mass was observed in seed (P <0.0003). The separation coefficient in the seed and meal were 6.48 and 2.92, respectively. Research shows that Pistacia atlantica seed and meal have a relatively good digestive potential and can be used in the diet of ruminants if properly planned.

Effects of the Monensin (Monensin sodium 10%, 350 mg/cow daily) on dry matter intake, milk production and healthy during the transition period and early lactation were determined in 360 Holstein cows. Cows were divided into groups of 2 depending on calving date. A total of 100 Holstein cows and heifers were assigned to a control group (n = 50) and administered 350 mg/cow daily of Monensin (n= 50). Cows had unlimited access to fresh water. However, no differences in dry matter intake between treatment groups were noted. Monensin significantly affected daily milk yield (p< 0.05). Significant effects of Monensin supplementation were observed on disease incidence. The open days of Monensin group had a significant difference with the control group (p= 0.0211). The Monensin group, on average, was 16 days in open days less than the control group. The conception rate in the control and Monensin groups was 43.2% and 81.5% respectively (p= 0.0113). The pregnancy rate of Monensin group (34.6%) was significantly higher than the control group (28.4%) (p= 0.0100). Also on the calving to first insemination distance was higher in the control group compared with Monensin (p= 0.0317). Monensin supplementation decreased postpartum BHBA concentration. Results suggest that prepartum and postpartum administration of Monensin increase milk production and healthy and can have beneficial effects on reproductive performance during early lactation.

The aim of this research was to investigate the effect of saponin extract on production performance, some blood parameters and ruminal protozoan in Holstein dairy cows. In this study, out of 20 Holstein cows in second calving,  two groups including, one group with an average milk production of 37.94 kg per day and lactation days was 98.62 and the second group with an average milk production of 38.96 kg per day and lactation days was 98.45,  for a 30-day trial period (Two 15-day periods) was used. Treatments included 1- control (the group that did not use saponin extract) and the second group used 8 ml of saponin extract extracted from mint, licorice and gensing plants. After one period of use, in order to eliminate the effect of the previous treatments, the base diet was used for 20 days and in the second period, the place of the treatments was changed. Feed intake was recorded daily in the last week of each experiment. Milk production per lactation was recorded on days 5, 10 and 15 of the experiment. In order to determine the milk composition, on day 15 of the experiment, a 50 ml sample was taken from the milk of each cow in the morning. To evaluate blood parameters, sampling was performed on day 15 in each period. The results showed that dry matter intake, milk production, milk fat percentage, milk protein percentage, milk somatic cell count and milk urea nitrogen were not affected by the addition of saponin extract (p<0.05). Triglyceride concentration was significantly reduced compared to the control group with the addition of saponin extract (p<0.05). Also, with the addition of saponin extract, acetate concentration, total volatile fatty acids and the number of ruminal protozoa were significantly reduced (p<0.05). In general, saponin extract had no negative effect on the performance of Holstein dairy cows.

In this study, the expression of genes and miRNAs related to differentiation, cell cycle and metabolism was investigated in Zandi sheep mesenchymal cells (ADSC) under fish oil treatment as a source of omega-3 fatty acids. Isolated sheep mesenchymal stem cells were confirmed for pluripotency. ADSCs were treated in the presence or absence of 15 mg / ml fish oil, and cell cycle and apoptosis induction were measured in each group (three independent repeat) via Flow cytometry. In a similar experiment, the expression of downstream miRNAs and genes at the growth and differentiation stages to adipocyte was compared in both groups. Mesenchymal cells treated with fish oil had a higher percentage of late apoptosis, while the percentage of cells in S phase decreased. The expression of miRNAs did not change significantly, however, let-7a was significantly decreased in the fish oil group. Fish oil treatment decreased (0.39) relative expression of peroxisome proliferator-activated receptor G (PPARG) and increased (1.85) Interleukin 1 beta expression. In adipocyte-differentiated cells, PPARG expression was decreased. The results of this study showed the inhibitory properties of fish oil on adipocyte differentiation of mesenchymal cells through direct or indirect effects on PPAR pathway. However, no significant difference was observed in the expression of selected miRNAs.

The light intensity of saloon may affects on production, immunity and economic indices of broiler chickens production that was not enough studied. In the present study the effect of different light intensities of ambient on growth performance, carcass characteristics, blood biochemical and immune parameters as well as economic indices were studied in broiler chickens. Three hundred one-day-old Ross broiler chicks (both sexes) were randomly divided into three treatment groups having five pens as replicates (20 birds in each) in a completely randomized design. Treatments were three light intensities in rearing saloon; conventional (20 lux), low (7 lux) and decreasing (gradually from 20 to 7 lux) that discretely offered in three saloons offered from d 8 to d 42. Chickens were fed with the same starter, grower and finisher diets over the study. Feed intake and body weight gain of chickens were measured weekly. After the end of study, 10 chickens from each treatment group were slaughtered for carcass analysis and blood sampling. Results showed that feed intake, body weight gain and feed conversion ratio of chickens over the study were not affected by ambient light intensity. Carcass parts weights and relative weights of bursa of fabricius and spleen of the chickens were not significantly different among the groups. There were no significant differences in blood biochemical metabolites and hematological parameters of the chicken reared under different ambient light densities. Antibody titer against Gumboro in broiler chickens were affected by light density (p<0.05), where in low-density group it was significantly greater than the conventional group (1.74 vs 1.30 log 2). Antibody titer against Newcastle in low-density group non-significantly tended to be greater than the conventional group. The mortality percentages of broiler chickens in the conventional, decreasing and low light intensity were 1.4, 1.5 and 0.9 percent, respectively. The electricity cost for rearing the broiler chickens in low-density and decreasing groups was as 64.74 and 33.33 percent less than the conventional group. By inclusion of electricity cost, the monetary benefit of production per chicken was approximately 1% more than other groups. Generally, due to the absence of significant differences in the growth performance and carcass characteristics of chickens treated with different ambient light densities and in the other hand, lower mortality percentage and electricity cost in low-density group, using constant 7 lux light intensity for broilers saloon has an economic advantage.

The aim of this study was to determine the relationship between blood plasma leptin and progesterone concentrations in pre and post sexual maturity in Najdi female calves. For this purpose 7 female Najdi calves of Shushtar Breeding Station of Najdi cattle with average ages of 8 months and the average weight is 85/00±9/72 were used. For determination of the leptin and progesterone concentrations, multiple sampling before and after sexual maturity were performed. The results of this study indicate that in female Najdi calves, 13-16 month with 137.81±13.5 kg body weight was considered the age of sexual maturity. No significant correlation was found between plasma leptin and progesterone concentrations before (r=0.082, p>0.05) and after sexual maturity (r =0.096, p>0.05). There was a significantly positive correlation (r=0.73, p<0.01) between leptin concentration and body weight. Significantly positive correlation (r=0.84, p<0.01) were found between plasma leptin and age. The significantly positive correlation between plasma progesterone concentration and age (r=0.45, p<0.01) as well as body weight (r=0.44, p<0.01) were observed. In conclusion, the results showed that there was no significant relationship between leptin and progesterone concentration, but there was a positive correlation between leptin, progesterone and body weight and bud age of Najdi female calves.

To compare the effect of different levels of monkey flower (MF) (Scrophularia Striata) powder on performance, blood parameter and jejunum histology in growing Japanese quail, the experiment was carried out in a completely randomized design with 400 3d quails was assigned with five treatment and four  replicates  with 20 quail in each replicate. Experimental groups included: 1) basal diet. 2) basal diet with 0.04 g/kg flavophospholipol 3) basal diet with %1 MF powder, 4) basal diet with %2  MF powder, 5) basal diet with %3 MF powder. The use of MF powder had no any significant effect on avergage daily gain and feed conversion ratio, but the feed intake were increased by experimental treatments. Use of different levels of MF powder had a significant effect on jejunum crypt depth. Also, different levels of MF did not significantly affect sexual hormones, but this levels had significant effect on some intestinal histology and feeed intake in both sexes. Although MF powder especially 2 % level, improved live weight and feed intake in mal birds at different periods, but it can could not improved performance in female birds.

This research was carried out to investigate the effects of dietary selenium (Se) sources on hatchability traits in commercial female broiler breeders. The experimental treatment diets were: control (basal diet, none-selenium), basal diet + 0.5 mg sodium selenite (SS), basal diet + 0.5 mg Selenomethionine (S-Meth) and basal diet + 0.5 mg microencapsulated selenium (MS-Met) per kg diet. The total of 100 female and 20 roosters broiler breeder (Arbor Acres® Plus, 38 weeks of age) were considered for present experiment. Semen was collected from roosters by using abdominal massage. Incubation parameters (fertility, hatching, hatch of fertile egg, embryonic mortality, and A-grade chick) were evaluated at 44wk (younger) and 54wk (older) of age. The results indicated that the birds fed an organic sources of selenium (MS-Meth, S-Meth) the percentage of fertility and hatchability was increased (P<0.05) compared to inorganic selenium (SS) and the highest result were obtained in the birds received M-S-Meth diet. Also, the results indicated that embryonic mortality was reduced (P<0.05) in birds fed Se supplemented diet. In conclusion, the use of organic selenium supplementation in diet of could be recommended for improving of hatchability traits in commercial broiler breeders.

Sex allele homozygosity as an indicator of inbreeding could effects on the performance of honey bee colonies. Then sex allele homozygosity is essential to evaluate apiaries situation in the country, as well as designing breeding strategies. In order to investigation of sex alleles homozygosity percentage and number of allele in honey bee populations of West-Azerbaijan and Kurdistan provinces and its correlations with honey production and adult population, 320 honeybee colonies were used. Data analysis was performed using SAS software (Version 9.4). The results showed that sex alleles homozygosity and number were 12.7 % and 9.02 for West Azerbaijan province for apiaries of Kurdistan province were 13.82% and 8.15, respectively. The results of variance analysis showed that the province had significant (p<0.05) effect on all studied traits. The county in provinces had significant (p<0.01) effect just only honey production. The sex alleles number effects on colony population and honey production, and also effect of colony population on honey production were significant (p<0.01). The results of correlation analysis showed negative and significant (p<0.001) between sex alleles homozygosity percentage with sex alleles number (-0.92), honey production (-0.79) and colony adult population (-0.86). Also, regression analysis results showed that sex alleles homozygosity percentage had negative and significant (P<0.001) effect on colony adult population (-0.17) and honey production (-0.44). Thus, with an increase of one percent homozygosity, the colony adult population decreases about 0.17 frame (units), and honey production decreases about 0.44 units, or in other words, 440 grams. Therefore, only with attention of beekeepers on the homozygosity and number of sex alleles, it is possible to prevent a decrease in honeybee population and consequently a decrease in honey production in the countrychr('39')s apiaries.

Historically, both significant decline of genetic diversity and simultaneously increasingly rate of inbreeding are two serious threaded factors in worldwide dairy industry. With this motivation, the aim of present report was to investigate the intra genetic diversity criteria (linkage disequribrium, observed and expected heterozygosity, Fis statistics, MAF distribution, autozygosity rate and population stratification using principal component analysis) in Holstein cattle population using dense markers. An Illumina Bovine 50k SNP Chip (V2) ready genotyped file for 25 Holstein cows obtained for further investigation. Here, we used Plink software for statistical analysis and measurement of molecular diversity indices. Observed outcomes results addressed average of MAF (0.28), mean frequency of observed and expected heterozygosity (0.38, 0.37), Fis statistic (– 0.032), Fhom statistic (-0.028-0328. In addition, PCA graph showed a significant indicating high population diversity, which was in accordance with all other calculated parameters. As a final conclusion, high-density SNP markers seems be as an accurate tool applicable for high-precision intra-diversity analyses.

Selection to increase the frequency of new mutations useful only in some subpopulations leaves markers at the genome level. Most of these regions are related to genes and QTLs associated with significant economic traits. The aim of this study was to identify selection traits related to functional traits in the number of world's sheep using modern methods. For this purpose, genotyping files were used using genomic chips related to 1591 sheep from different breeds of the world, (Dryad ،Frontiresin ،Zenodo ،Animal Genom، Hapmap( including 52 breeds from 20 countries on all continents, and 13 studies were stored in various genomic databases. First, to determine the population mixing between different breeds from regions with different climatic conditions, population structure analysis or population stratification was carried out. Fst, hapflk, iHs, Rsb, XpEHH tests were used to identify the selection signatures, and finally, a meta-analysis of the above methods was used. The population was divided into three groups by PCA analysis: AIT: Asian, Turkish and African breeds, AUNZ: Australian and New Zealand breeds, and EU: European breeds. Based on the meta-analysis test, 10 genus regions were identified on chromosomes 2, 3, 4, 5, 6, 7, 9, 12, 20, 22. For example, the MC1R gene is associated with skin color, the DSG2 gene with the quality and quantity of wool, and the AICDA gene with the production of immunoglobulin. Bioinformatics analysis showed that some of these gene regions are directly and indirectly associated with genes affecting environmental adaptation (ADAMTS9), reproduction (GNAQ), melanocyte regulation (KITLG), and immunoglobulin production (BATF, TNFSF13, AICDA, MZB1), Cell differentiation (TNFSF13, TGFB1), Immune process (AGBL5, ATG7, PRDX1, CCL26, IL17RC, TNFSF12, TGFB2, PTGS1), Cellular response to external stimulation, NKK1, PRF3 (PR) Interferon alpha (DDX58), defense response process (CCL24, FAM13B, LDLR, CLDN7), cellular homeostasis (BAMBI, DVL2), regulation of mitogen-activated protein kinase (PLCE1) and regulation of stress response (FXR2, HSPH1). Comparative analysis of meta-analysis of selection cues based on bioinformatics databases can identify selected genomic regions for traits of economic and biological importance in sheep.

Milk production is one of the most important economic traits in the dairy cattle industry, which is controlled by a large number of genes and is a function of the activity of epithelial cells that are influenced by several biological pathways and the interaction of different genes and gene expression. Gene expression is a process in which information within a gene is used to obtain a functional product. It is also one of the fundamental issues that helps the genotype to appear as a phenotype. The aim of this study was to identify the genes affecting milk production and to construct the gene interaction network of the studied genes to identify the major genes of the effect to better understand the mechanism of milk production using the gene expression pattern during bioinformatics studies. in this study, in order to identify genes with different expression in dairy cow breast tissue, gene expression data related to breast tissue with access number GSE33680 were download from the GEO section of the NCBI database. Data quality was assessed using the limma package available in R software and the basic component analysis method. DAVID software was used to evaluate the function of genes with different expression. After identifying the target genes, they were presented to STRING databases. Cytoscape software was used to explain the role of genes. In this study, the results of analysis of gene expression differences led to the identification of 14020 genes, which according to fold change and adj P-Value statistics, 409 gene increased expression and 326 genes decreased expression. Among the known biological pathways affecting milk production are NF-KB signaling, Glycerolipid metabolism, EGFR1, IL6, B cell receptor. The most important genes are based on the degree of association with other genes and the internal and external centrality of MYC, KRAS, HSPA8, ATP5B, SRC, JAK1 and FOXA2 genes, which play a role in regulating milk production in several reports.

In this study, in order to genetic and economic evaluation of the progeny testing selection program and the usual selection program of buffaloes in Khuzestan, 3000 buffalo cows were simulated using R program. In each progeny test programs, different levels of milk recording (100, 80, 50 and 20%) and artificial insemination (100, 80, 50 and 20%) were used and in usual program, the selection was based on pedigree information of male calf and its mother milk production. In the selection index, two traits of milk production and fat percentage were considered. The studied programs were compared based on genetic improvement, production changes, total genotypic value and costs and revenues of programs. In study of selection programs, it was observed that with increasing the proportion of herds covered by artificial insemination, genetic progress and changes in total genotypic value were increased in progeny testing programs. This increasing was also observed for the cost and revenue of each of considered programs. In addition to artificial insemination, the milk recording system was also effective in increasing the two parameters of cost and revenue. However, the additional costs of using milk recording system and artificial insemination were offset by increased revenue from performance of better buffaloes. In general, based on changes in total genotypic value, genetic improvement of milk production and minimum cost and maximum income of the programs, the progeny testing selection program with 20% of milk recording and 100% of artificial insemination was selected for buffalo herds as the suitable progeny testing program.

In order to investigate the management factors affecting the mortality rate in broiler farms in Ramyan and Azadshahr cities in Golestan Province, Iran, the necessary information was collected in form of questionnaire from 65 active broiler farms between years 2018 to 2019 breeding period. To compare the means of studied traits (first week mortality and whole breeding period mortality) at different levels of management factors GLM procedure of SAS software was used. The results showed that the mortality rate in broiler farms in Ramyan was lower than Azadshahr city (p<0.05). Large hall area, high density of chickens and times of breeding per year increased mortality rate. The distance of the broiler farm from the nearest city, village and other poultry farms did not affect the mortality rate. Also, chick strain, breeding season, manager age and experience had no significant effect on mortality rate. Farms that their managers had higher educational level experienced lower mortality (p<0.05). The presence of any kind of disease significantly increased the mortality rate (p<0.05). Diet type (mash or pellets) had no significant effect on mortality but the effect of feed preparation source on mortality was significant and farms that prepared food from the factory had lower mortality rate (p<0.05). Generally, the results of this study showed that chicken density, farm area, breeding frequency during a year, manager educational level and disease are the most important managerial factors affecting mortality rate and should be considered to increase the survival of chicks.