نشریه علوم دامی (پژوهش و سازندگی)
پیاپی 132 (پاییز 1400)

In the process of sperm storage, production of reactive oxygen species (ROS) and reduction of antioxidant activity cause sperm damage. The most damage related to high ROS production and inadequate antioxidant penetration into mitochondria attacks this organelle. Purpose Combination of antioxidants was used to reduce oxidative damage. This study investigated the effect of different levels of combination of targeted antioxidant 2, 4-dinitrophenol and non-targeting luteolin on semen dilution on sperm parameters under in vitro storage at 4°C for 48 h. Semen samples were collected from 15 rooster at 28 weeks of age. After initial evaluations, semen samples were mixed with each other. After diluting the samples and adding different levels of antioxidants, treatment 1 (0.5 nM 4,2-di-nitrophenol + 1 μM luteolin), treatment 2 (0.5 nM 4,2-di-nitrophenol +3 μM luteolin), treatment 3 (0.75 nM) 4,2-Ditrophenol + 1 μM luteolin), 4 (0.75 nM 4,2-Dithinrophenol +3 μM luteolin) from combined antioxidant and storage of samples at 4°C for 48 h in refrigerator quantitative parameters were evaluated at 1, 24, 48 h after storage at 4°C. The parameters evaluated had a significant decrease over time. But the samples treated with the combination antioxidant significantly increased (P <0.05) in the measured parameters independent of the time and the interaction effect of the treatment on time. Also, addition of 3, 4, 5 and 6 treatments significantly decreased malondialdehyde concentration and treatment's 6 significantly decreased unhealthy spermatozoa (P <0.05).

In order to investigate the effects of different levels of wasted onion (WO) on nutrient digestibility, volatile fatty acids, protozoa population and blood parameters, four Kermani male sheep (BW, 45±1.5 kg) were assigned to Latin square design with four 21-days period. After determining the chemical composition of WO, different levels of it (DM basis) was replaced with barley grain in diets. The experimental diets were: 1) control (no WO), 2) diet containing 8% WO, 3) diet containing 16% WO, and 4) diet containing 24% WO. The dry matter intake, and dry matter and crude protein digestibility of experimental diets were not affected by the WO. The intake and excretion nitrogen and percentage of retained nitrogen were not affected by experimental diets. Also, ruminal fermentation parameters including pH, NH3-N and protozoa population were not affected by addition of WO in diets, but ruminal valeric acid concentration decreased with increasing WO (p<0.05). Furthermore, blood cholesterol decreased linearly (p<0.05) by adding WO. In general, the use of WO up to 24% of the diet instead of barley grain showed no signs of poisoning or anemia (paleness of the mucous membranes, slight discoloration of urine, weakness and lethargy) in sheep. Therefore, due to the fact that the majority of parameters tested in this study were not significantly affected when using WO in diet, WO can be used up to 24% (DM basis) in sheep's diet.

In this study the profitability of male Sistani calf fattening has been investigated in two industrial and traditional systems by estimating financial and economic characteristics. Sample selection was randomly classified and the questionnaire was completed from 16 industrial and 33 traditional Fattening. Criteria for net present value, internal rate of return, cost-benefit ratio, and sensitivity analysis were calculated for these activities. The results of economic analysis of fattening two cows in traditional conditions showed that the ratio of profit to cost of 1.74, Rials, internal rate of return is 96% and the net present value is also positive, which indicates the economic justification of this activity. Sensitivity analysis of this activity showed that if current expenditures increase by 50%, the ratio of interest to expenditure greater than one, the internal rate of return is higher than the bank interest rate, and the current value of interest is also positive. Also, the results of fattening four cows in traditional conditions showed that this activity has a high economic justification. So that the ratio of profit to cost of 1.75, Rials, internal rate of return is 75% and the net present value is also positive. Sensitivity analysis of this activity showed that if current expenditures increase by 50%, the ratio of interest to expenditure greater than one, the internal rate of return is higher than the bank interest rate, and the current value of interest is also positive. Sensitivity analysis showed that if current expenditures are reduced to 139%,

This study aimed to compare experimental treatments containing Leek extract with Phosphoflavomycin growth-promoter antibiotic using 160 Ross-308 day-old chicks in a completely randomized design manner with 4 experimental treatments, 4 replicates, and 10 chicks per replicate for 42 days. Treatments consisted of 1) control group (basal diet); 2) basal diet with Phosphoflavomycin antibiotic growth promoter (0.04%); 3) basal diet with 0.3% Leek ethanolic extract; and 4) basal diet with 0.5% Leek ethanolic extract (P≤0.05). Feed intake, feed conversion ratio, visceral weights, antibody production against Influenza and Newcastle diseases, biochemical parameters of Glucose, Cholesterol, Triglyceride, HDL, LDL, Albumin, Total Protein, and AST were not affected by different treatments (P≥0.05). However, both groups fed Leek extract (0.3% and 0.5% of diet) increased serum levels of liver enzymes of ALT and ALP significantly, compared with Phosphoflavomycin growth promoter (P≤0.05). Based on the findings of the current study, it can be concluded that consumption of Leek ethanolic extract (0.5% of the diet) showed a significant enhancement on the body weight of broilers, with no impact on visceral weights, immune status, and blood biochemical indices.

To calculate the thecnical efficiency of broiler meat industry in Golestan Province parametric and non-parametric methods were used. The research tool was a questionnaire completed in production year 2016-2017 by interviewing the mangers of 90 broiler breeding farms. Validity of the questionnaire was confirmed by consulting experts and professors and its reliability was confirmed by using SPSS software and Cronbach's alpha of 0.6%. Based on the capacity of the farm license, all active units were divided into three classes, and the sample size in each class was calculated with the Cochran formula. In the parametric method, the Cobb-Duglass randomization function and Stata software were used. Non-parametric data envelopment analysis method was performed using Excel. The results of the parametric model showed that increasing the input variables area of saloons, treatment and energy costs and number of labors had increased the technical efficiency (P<0.01). There was no significant effect of the number of one-day-old chicks and the amount of food consumption on the farms efficiency. The nonparametric results showed that in the overall efficiency estimation of all 90 units, 14 farms were efficient, but when the classes of capacity were taken into account, the number of the efficient farms increased to 26 units. It can be suggested that inefficient farms take advantage of how labor units, treatment and energy costs are allocated in the efficient farms and try to make optimal use of one-day-old chicks and amount of food consumption to get closer to the efficiency barriesrs.

In this research total of 288 one- day old Ross 308 broiler chickens were used in a completely randomized design with 6 treatments and four replications for 5 weeks. The experimental treatments included 1) Basal diet without additive and normal temperature conditions (negative control) 2) Basal diet without additive and heat stress conditions (positive control) 3) Basal diet with 0.18 mg/kg sodium selenite and normal temperature conditions 4) Basal diet with 0.18 mg/kg sodium selenite and heat stress conditions 5) Basal diet with 0.18 mg/kg nano-selenium and normal temperature conditions and 6) Basal diet with 0.18 mg/kg nano-selenium and heat stress conditions. The results showed that in normal temperature conditions, nano-selenium caused decrease in feed intake in comparison to sodium selenite however in heat stress conditions, both nano-selenium and sodium selenite increased feed intake when compared with control treatment (P<0.01). Also, the results of feed conversion ratio showed that the highest and lowest feed conversion ratios in all rearing periods were related to the control in heat stress conditions and nano-selenium under normal temperature conditions, respectively (P<0.01). The highest and lowest blood serum malondialdehyde, aspartate transaminase and alanine transaminase, concentrations were observed in control treatment under heat stress conditions and treatment containing nano-selenium in normal temperature conditions, respectively. Generally the results of the present study showed that the utilization of nano-selenium in heat stress conditions in diet of broiler chickens improved feed conversion ratio, increased growth and increased cellular oxidation inhibitory enzymes.

The aim of this study was to investigate the effect of different levels of thyme (Thymus vulgaris) extract on growth performance, feed intake, daily weight gain and digestibility of nutrients in fattening lambs and kids. For this purpose, 15 goat kids (average initial BW of 17.3 ± 1.2 Kg, 3 month- old) and 15 Dalagh lambs (average initial BW of 21.4 ± 1.5 Kg, 3 month- old) were randomly assigned to 3 dietary treatments: 1) control (without thyme extract), 2) supplemented with 250 ml thyme extract, 3) supplemented with 500 ml thyme extract. Animals were kept in individual pens with self-mangers for 84 days. Experimental results showed that different levels of thyme extract had a significant effect on daily weight gain and feed intake throughout the period in both species, so that in animals fed 250 ml of thyme extract was higher than other treatments (P <0.0001). Dietary treatments containing 500 ml of thyme extract had the lowest weight gain and final weight and feed intake throughout the period. Also, lambs had better weight gain and more food intake than kids. Thyme extract reduced the digestibility of organic matter and NDFand increased the digestibility of dry matter (P <0.0001) and the effect of the species on nutrient digestibility was not significant.Overall, the results showed that the best level of thyme extract in animals diets was 250 ml, and at this level the best growth performance was achieved. The lambs were also more affected by the thyme extract than the kids.

This study was performed to investigate the effect of organic and inorganic selenium supplementation on laying hens' performance, quality traits and peroxidation of egg yolks and whites. The experiment was carried out in a completely randomized design with 300 laying hens (W-36) from 23 to 35 weeks of age with 5 treatments and 6 replications and 10 laying hens in each replication. Experimental treatments include: treatment one or control (basic diet without selenium), The second treatment of 0.5 selenite-sodium (base diet+0.5 mg/kg selenite-sodium), the third treatment selenite-sodium 1 (basic diet+1mg/kg selenite-sodium), the fourth treatment selenium-methionine 0.5 (basal diet + 0.5 mg/kg seleno-methionine) and the fifth treatment was seleno-methionine 1 (basal diet +1 mg/kg seleno-methionine). The results showed that experimental treatments had no significant effect on egg weight, weight mass, production percentage, feed intake, feed conversion ratio and egg yolk and egg white characteristics (P<0.05). Peroxidation of egg yolk and egg white fats in 1 mg/kg seleno-methionine treatment showed the lowest rate compared to other experimental treatments (P<0.05). The results of the present study showed that among the sources of selenium, 1 mg/kg of selenium-methionine more effectively reduced the peroxidation of fats and increased antioxidant activity.

In order to estimate some population parameters in sheep flocks of Khuzestan province, information of 100 flocks from rural rearing systems with two breeds of Arabic and Lori-Bakhtiari sheep were used during the years 2017 - 2019. The data were collected through a questionnaire and interview with the farmers. Data was analyzed by SAS 9.1 software. The average of the number of breeding ewes, the number of breeding rams, duration of ram stay in the flock and ram to ewe ratio were achieved 173.67 heads, 9.56 heads, 5.96 years and 5.65%, respectively. Accordingly, the average of effective size and the rate of inbreeding of flocks were 34.9 heads and 3 percent per generation, respectively. In general, the results showed that the estimated effective size was less than the minimum size recommended by FAO (50 heads) for having less than 1 percent inbreeding per generation. So, it may result in having flocks with inbreeding rate which is 3 times more than the permissible rate. Increasing of inbreeding in the flocks can decrease production performance, reproductive performance and increase genetic abnormalities. Therefore, based on the estimated inbreeding rate for sheep flocks in the province (3 percent per generation), it is necessary to prevent further increasing in inbreeding rate and its negative consequences by training farmers about issues such as suitable ram to ewe ratio, supplying breeding rams from out of the flock and keeping rams in flock for a shorter period of time, as well as, using rotational mating scheme

In this experiment, nano DL-methionine was synthesized from commercial DL-methionine and used in broiler diets to evaluate the effects on growth performance, carcass characteristics, blood parameters and small intestine morphology. A total of 200 one-day-old broilers (Arian) were used in a completely randomized design with five treatments and four 4 replicates of 10 birds for a period of 40 days. Experimental treatments included: 1) a control diet consisted of DL-methionine, 2) a diet included 75% of DLM of the control+2.5% nano-methionine, 3) a diet included 50% of DLM of the control+5% nano-methionine, 4- a diet included 25% of DLM of the control+7.5% nano-methionine, and 5- a diet included 10% nano-methionine. The results showed that replacing DLM with NM caused no significant difference between treatments for live responses, carcass characteristics and activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase. There was no significant difference between treatments for serum uric acid, height and width of villi in duodenum and jejunum. However, groups with 7.5% and 10% NM manifested a significant increase (P < 0.05) in breast weight and villus height and width and its absorptive surface area compared to the control. In conclusion, the use of NM could save up to 90% of DLM requirements.

This study was carried out to investigate the effects of pre-slaughter feed withdrawal (0, 2, 4, 6, 8 h) and thermal treatments (-4 to -6, 22 and 38 to 40 ºC) on carcass features as well as certain blood parameters using 450 male broiler chickens during days 35 to 42 of age. Effects of the 15 experimental treatments evaluated in a 3×5 factorial fashion in 3 replicates of 10 birds each in a completely randomized design. Water uptake significantly reduced when birds subjected to eight hours of pre-slaughter feed withdrawal (P<0.05). Heat stress before slaughter increased weight loss and decreased thigh meat pH at 24 h postmortem compared with the birds kept in normal ambient temperature (P<0.05). Cold and heat treatments resulted in significant decrease and increase, respectively, in the rectal temperature of the birds (P<0.05). Blood potassium concentration decreased in the birds subjected to 8 h pre-slaughter feed removal (P<0.05). Acute heat exposure during pre-slaughter period significantly decreased blood concentration of phosphorus compared with the birds kept in normal ambient temperature (P<0.05). It was concluded that pre-slaughter starvation up to six hours exert no significant effect on water uptake and other variables concerned in broiler carcass. Exposure to a high ambient temperature imposes a greater negative impact than cold stress on pre-slaughter feed deprived broiler chickens.

On the contrary, the grain-fed steers received a grain-based regime that served as an efficient source of high-digestible energy. Rumen may function differently in the grass- and grain-fed regimes. Therefore, grain-fed cattle suffer stronger metabolic stress than pasture-fed steers; and they tend to easily have metabolic and infectious diseases. In this study to gain insights into transcriptional regulation in spleen and rumen tissues under two different regimes include grass and grain, the first high expression genes in two different conditions were identified by RNA-seq data analyses. Promoter analysis was performed using a bioinformatics database of Genomatix. Moreover, in this study to the visualization of regulatory networks containing transcription factors and that regulate the genes in the rumen and spleen, were used Cytoscape software. Then, promoter analysis leads to the identification of 31 novel transcription factor activating in the rumen and 10 novel transcription factors candidates in the spleen in cow fed with grass and grains. Results revealed that 10 genes with the highest expression were identified in both rumen and spleen. According to the analysis of the results in the David Database, the processes: reduction of oxidation, regulation of cell proliferation, ion transport, epididymal development ,and ectoderm development were evaluated as significant. The results in this study provide valuable insights into molecular mechanisms in spleen and rumen tissues under two different regimes include grass and grain.

The effect of L-carnitine in omega-3 rich diets on the production performance and immune system of One hundred tewnty 34-week-old Lohmann LSL-Lite laying hens were used in 2 × 3 factorial arrangement with two types of diets (without omega-3, Enriched with Salomega at the rate of 3%) and three levels of L-carnitine (0, 100 and 200 mg / kg) were evaluated in a completely randomized design with 6 treatments and 5 replications and 4 birds per replication for 70 days. The Egg Production Percentage percentage of birds fed with diets enriched of salomega increased compared to diets without omega-3 (P <0.05). Egg shape index in birds fed with diets containing 200 mg / kg L-carnitine increased compared to diets without L-carnitine (P <0.05). Egg mass of birds receiving omega-3 without diets and L-carnitine or 100 mg / kg L-carnitine and/or diets enriched of salomega containing 200 mg / kg L-carnitine increased compared to other groups (P <0.05). The height of yolks and whites and haugh unit eggs of birds fed with diets containing 100 mg / kg L-carnitine increased compared to diets without L-carnitine and 200 mg / kg L-carnitine (P <0.05). HET:LYM ratio in the blood of birds fed with diet enriched of salomega decreased compared to diet without omega-3 (P <0.05). It seems that the use of 200 mg / kg L-carnitine with 3% omega-3 fatty acids with salomega source can improve productive performance and quality traits of eggs. Further studies in this area are recommended.

In order to investigate the rates of inbreeding trend and also the effect of inbreeding on milk, fat and protein yields, the pedigree data of 2,394,517 Iranian Holstein cattle from 1986 to 2019 which collected was used. CFC software was utilized to calculate the inbreeding coefficients, and WOMBAT program was applied to estimate the inbreeding depression by determining regression coefficient of production traits on inbreeding coefficient. The average of inbreeding coefficients in the whole population and inbred animals were estimated as 0.777 and 1.681 percent, respectively. In general, the rate of inbreeding trend was positive and for recent years it was 0.17 percent per year. However, this rate was estimated as -0.29 percent per year for inbred animals, the number of inbred animals was increasing. Examination of the effect of inbreeding on production traits showed that per 1 percent increase in inbreeding coefficient resulted in 11.87, 0.39 and 0.29 kg decrease in milk, fat and protein yields, respectively. The use of domestic sperms and cows has limited the population and increased relative mating. However, close relative mating has been controlled. The existence of negative effect of inbreeding on production traits and on the other hand, increasing the number of inbred animals indicates that breeding and mating strategies of animals need to be continuously reviewed, and if it is necessary close relative mating can be limited using imported sperms.

The present study aimed to determine the proper weaning age of Zel lambs. For this purpose, ninety male and female lambs (average live body weight =2.57±0.41 kg) selected and were divided into three groups (each group = 30). The experimental treatments were; 1. weaning at an average age of 60 days, 2. 75 days, or 3. 90 days. The lambs were introduced to fattening program and were fed with iso-energetics and iso-nitrogenous diets until 6 months of age. The dam’s ewe of all groups enters to mating program two months after parturition and ewe lambing data contain dam’s weight, lamb’s mortality, litter size, lamb’s birth weight, and sex were recorded. Results showed that dry matter intake (DMI) and feed conversion ratio (FCR) did not affect by weaning age of lambs. The lambs that weaned at 60 days old, had higher average daily gain (ADG) at fattening period, then lambs were weaned at 75 and 90 days old, significantly. The parturition rate, prolificacy rate, lambing rate, and litter size of groups weaned at 60, 75, and 90 days of age were 88, 81, and 85; 119, 118, and 117; 104, 96, and 100; and 19, 18, and 17% respectively, and did not observed significant between the treatments. It concluded that Zel lambs weaned at 60 days old, could increase growth performance compared to elder lambs, and improves the reproductive performance of ewe.