فصلنامه پژوهشهای علوم دامی ایران
سال نهم شماره 4 (زمستان 1396)

Introduction Selenium and vitamin E are of the micronutrients that may have an impact on immune functions and health. They protect biological membranes from oxidative damage by acting as scavengers of reactive oxygen species (ROS). Metabolic functions of vitamin E are closely linked to the selenium-containing enzyme glutathione peroxidase (GPx). Optimal serum concentrations of vitamin E are difficult to maintain in the period around lambing due to an increased need for antioxidants during this time. In addition, selenium levels of many soil of Iran are low; this makes the situation gets worse. Therefore, excessive accumulations of ROS affects placental development and function both in early pregnancy and towards lambing, and may subsequently impact both the fetus and dam. Additionally, selenium is also essential for the conversion of T4 to T3, as deiodinase enzymes (those enzymes that remove iodine atoms from T4 during conversion) are selenium-dependent. T3 is the active form of thyroid hormone, and low T3 can cause hypothyroid symptoms. Therefore the aim of this experiment was to investigate the effect of selenium and vitamin E injection times in late pregnant ewes on thyroid hormones metabolism, ewe's blood biochemical parameters and their lambs performance after birth.
Material and Methods To perform this experiment, 9 weeks before parturition, 24 head pregnant ewes of Mehraban breed were allocated to 4 treatments (n=6). Treatments included: Tr1) Did not received any supplement until end of the experiment (Control); Tr2) Received one time an injectable form of vitamin E뇩庞⮦ (E) at 9 week before parturition; Tr3) Received two times E injection at 9 and 6 week before parturition; Tr4) Received three times E injection at 9 and 6 weeks before and 1 week after parturition. During each time of injection, 5 ml E per ewe was injected that each ml contains 0.5mg Se as sodium selenite and 50 IU vitamin E as DL-alpha tocopheryl. Before each time of injection, blood samples of all ewes were collected by jagular vein. Hormones concentration of T4 and T3, lipid parameters such as triglyceride (TG), total cholesterol (CHOL), VLDL, LDL, HDL and also aspartate transaminase (AST), creatine phosphokinase (CPK) and Iron (Fe), copper (Cu) and Zinc (Zn) elements concentrations in serum were determined 6 week before and 1 and 2 week after parturition. Lambs performance parameters were recorded until 45 days of age.
Results and Discussion According to results of this experiment, 6 weeks before parturition, T4 concentration reduced and T3 to T4 ratio and also Zn concentration increased significantly (P

Introduction Aflatoxins (AF) as secondary metabolites are produced by Aspergillus flavus and Aspergillus parasiticus. The most abundant aflatoxin B1 (AFB1) is toxic and carcinogenic to humans and animals. Utilization of mycotoxin adsorbents are noted as the most practical methods for protection of feed ingredients. The purpose of this study was to investigate the effect of organic and inorganic adsorbents for the adsorption of AFB1 and its effects on dry matter digestibility and rumen fermentation characteristics.
Materials and Methods The experimental diet was a mixture of alfalfa silage and concentrate. Procedure of in vitro batch culture was performed according to the Menke and Steingass procedure. In an anaerobic condition, 30 ml of buffered rumen fluid was dispensed with pipetor pump into a 120-ml serum bottle containing 0.5 g DM of the experimental diet. The content of each bottle was contaminated with 0.5 ppm AFB1. Experimental treatments were: the control diet, commercial bentonite, activated bentonite, activated charcoal, the cell wall of Saccharomyces serevisia with 75% purity, bentonite activated charcoal yeast, (0.5 0.4 0.1 percent), bentonite activated charcoal yeast, (0.4 0.45 0.15 percent) and , bentonite activated charcoal yeast(0.3 0.5 0.2 percent) The amount of absorbents for all treatments was 1% of the experimental diets. All bottles were purged with anaerobic CO2, sealed with rubber stoppers and placed in a shaking water bath for 72 h at 38.6 degree centigrade. The amount of produced gas was recorded at 2, 4, 6, 8, 12, 16, 24, 48 and 72 h of the incubation. At the end of incubation, all the bottles were transferred to refrigerator to stop fermentation, and then opened. After pH measurements 2-ml sample of each filtrate bottle was taken and frozen at 20 degree centigrade after acidification with 2-ml of 0.2 N HCl. The biomass residues were centrifuged at 1000×g for 10 min at 4 degree centigrade. The supernatant in each bottle was decanted and the pellet was dried at 65 degree centigrade to a constant weight for the determination of the residues.
Results and Discussion Absorbents addition increased the amount of produced gas in all treatments in comparison with the control treatment significantly (P

Introduction Feed represents a major proportion of the overall production cost for livestock industry in worldwide. On the other hand, availability of good quality and unadulterated conventional feed all year round is a major constraint in livestock production. Thus, proper use of inexpensive agricultural by-products is important Goal in livestock production. Appling a new system in olive oil extraction generates large amounts of a new by product, called two-stage olive cake, which includes the remainders of pulp, stones, skin and vegetable waters. Olive cake has high lignin, cellulose and hemicellulose contents. The results of previous experiment showed a high variation on the nutritive value of olive cakes. The chemical composition of by-products is shown olive cake are rich in tannins which can decrease the efficiency of microbial protein synthesis from truly degradable substrate and reducing the amount of ruminal pH and ammonia concentration. The hydrolytic enzymes like carboxymethyl Cellulase, microcrystalline cellulase and degrading activities were estimated in various fractions of rumen contents of Ruminants. Urinary purine derivatives such as allantoin, xanthine and hypoxanthine were estimated to determine the microbial protein supply from rumen. The objective of this trial was to study the effect of replacement Barley grain with olive cake to evaluate the effect of the consuming olive cake on ruminal fermentation characteristics, cellulase enzymes and microbial protein synthesis of lory fattening lambs.
Materials and Methods Fifteen Iranian lory male lambs (27.9 ±3 kg of BW) With the age of 90±10 days were assigned In to a completely ranomized design with 3 treatments and 5 replicates for 84 days 3 dietary treatments and five replications in a completely randomized design. Lambs were grouped based on their age and weight. Weight and experimental trail lasted for 84 days. All lambs were givenfed adlibitum twice daily at 0500 and 1700 h with a Total Mixed Ration (TMR) with 25 to 75% of forage (alfalfa) to concentrate ratio. A TMR composed of 25% forage (Alfalfa) and 75% concentrate. The Dietary treatments were 1) control (without olive cake), 2) 10% olive cake, and 3) 20% olive cake was prepared from animal feed production unite of Jahan Alchohol Co (industrial town of Jamalabad, Gilan, Iran). Approximately all diets were isocaloric and isonitrogenos. Fresh water was also available for lambs at all times during the trail. The NH3-N concentration was determined following the Broderick and Kang (1980) technique. The assay procedure of cellulase enzymes activity was done according to the method of Hristov, et. al (1999). Purine derivatives and was measured by the method of Chen and Gomes (1995).
Results and Discussion The results showed, olive cake caused a significant decrease in the value of ruminal pH the amount of ammonia,concentration of urinary purine derivatives and microbial protein synthesis in the rumen. These results was in accordance with the results have beenreported elsewhere by other workers Overall activity carboxymethyl cellulase enzymes at a level of 10% microcrystalline cellulase enzymes in the diet increase 20% olive cake. It was reported that high fiber diets could increase cellulytic enzymes activity compared to the control diet. Feeding ruminants with olive cake requieres further investigation about its anti nutritional factors. In our study, it would be resulted that feeding of 20% olive cake to lambs diet is possible without any negative effects and it is a good solution for this agricultural by-product usage.
Conclusion This study indicates that lori lambs can be fed with a diet based on olive up to of DMI in tropical areas. According to our findings, using olive cake (up to 20% of DMI) to feed the lambs was decreased pH, ammonia levels and increased the activity of cellulytic enzymes of ruminal.

Introduction The protein sources in poultry nutrition are the most expensive parts of rations. Today, soybean meal is the major protein source that using in poultry nutrition. The cost of soybean meal is expensive and search to find new source of protein for poultry diet is important. Nigellasativa meal is a protein that could be used in poultry nutrition. The Nigella sativa or cumin seed meal has an acceptable percentage of crude protein, crude fiber, ether extract and metabolizable energy. The amino acid profile of nigella sativa meal is better than soybean meal with the exception for lysine. The percentage of lysine in soybean meal was higher than nigella sativa. Broilers that fed nigella sativa had better performance, and immune system. Therefore, the main objective of the present experiment was conducted to determine metabolizable energy of Nigella sativa or cumin seed meal by adult cockerels.
Materials and Methods The nigella sativa meal samples were provided from three industries. The major components of samples involved gross energy, crude protein, crude fiber, ether extract, ash, calcium, available phosphorous were analyzed by AOAC method. The AME of nigella sativa samples were determined by cockerels. A total of sixteen leghorn cockerels were used. The age of cockerels was 31 weeks old. This experiment was done in a completely randomized design with 4 treatments involved 0, 10, 20 and 30 percentage of nigella sativa with 4 replicates (1 cockerel each).The cockerels were adapted to new diets for 3 days, and then they were hunger for 24 hours. Cockerels were fed experimental diets for 72 hours and the excreta were collectedat whole of this period. The excreta and diets samples were analyzed for gross energy, crude protein, crude fiber, ether extract, ash, calcium, available phosphorous were analyzed by AOAC method. The AME of experimental diets were computed by the models of AME (Kcal/kg)= [Fi×GEf)-(E×GEe) ]/ F. Then, AME of experimental feed were calculated by the equations of AMEn(Kcal/kg)=AME of basal diet – [(AME of basal diet – AME of experimental diet)/ levels of replacement].Then, the digestibility and metabolizable energy of diets were determined. The predicted apparent metabolizable energy was corrected for nitrogen (AMEn) was calculated with suggested equations of Nascimento et al. (2007 and 2009).
Results and Discussion The cumin seed meal had 92.24 ± 0.723 % dry matter, 30.749 ± 1.151 % crude protein, 7.487 ± 1.129 % ether extract and 7.884 ± 0.813 % crude fiber, 52.871 ± 0.955 % neutral detergent fiber (NDF), 4.999 ± 0.227 % Ash. These findings were in agreement with results of previous researches. Abdo (2004) reported that Nigella sativa had 5.59, 86.8, 31.36, 12.27, 16.52, 7.61, 26.65, 1.16 and 0.7 % moisture, organic matter, crude protein, ether extract, crude fiber, ash, nitrogen free extract (NFE), calcium, and available phosphorous respectively. The apparent metabolizable energy (AME), and nitrogen-corrected apparent metabolizable energy (AMEn) forcumin seed meal were 2234.21 ± 89.596, and 2233.52 ± 89.594, kcal/kg, respectively. Abbas Ali et al., (2012) also reported that nigella sativa is an enrichment of minerals involved sodium, potassium and calcium. The true metabolizable energy (TME) and nitrogen-corrected true metabolizable energy of cumin seed meal were 2298.79 ± 76.254 and 2298.38 ± 76.25 kcal/kg, respectively. There are several equations for predicting the AMEn. Some of this equations that proposed by Nascimento et al., (2007 and 2009) are: 1)AMEn = 2707.71 5.863EE− 1.606aNDFom,(R2 = 0.81; RSD = 0.4847; P-value

Introduction In view of rising concerns on the extensive use of antibiotics in animal production, there is an increasing interest for developing alternative disease control strategy to enhance animal health and to reduce the use of antimicrobials. One promising new possibility to achieve this goal is the use of natural foods and herbal products to enhance feed efficiency, gut health, and innate immunity. In clinical medicine, plant-derived products are increasingly being used as feed supplements to enhance immunity to diseases and cancers. Among these products, the dietary effects of the mixture of three plant derived phytochemicals, carvacrol, cinnamaldehyde, and Capsicum oleoresin as anti-bacterial and anti-fungal agents have been reported. Carvacrol is a component of numerous aromatic plants, such as Origanum vulgare, thyme, and wild bergamot. The anti-microbial functions of these herbs are associated with carvacrol since carvacrol vapour has been shown to inhibit Salmonella growth in chickens. Cinnamaldehyde is a constituent of cinnamon and widely applied as flavoring. It has been proven to have strong anti-bacterial activity against Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Salmonella sp., and Vibrio parahemolyticus. Capsicum oleoresin, prepared by organic extraction of pepper fruits, contains anti-bacterial activity. It contains the pungent principles, capsicin which has effects on the resistance to Salmonella enteritidis infection by altering pH and histological changes.
Materials and Methods In this study, 160 Ross 308 male broiler chicks were allocated in a completely randomized design with 5 treatments, 4 replicates of 8 chicks in each replicate for 42 days. Treatments contained 1 level of oxytetracycline antibiotic and 3 levels of extract supplementation (50, 100 and 200 mg/kg of feed). The rearing and management conditions were equal for all groups. Experimental diets were formulated to meet the nutrients requirements of the Ross broiler chicks. Chicks had full access to feed and water during the experimental period. Performance parameter such as body weight gain, feed intake and feed conversion ratio were recorded at 1-10, 11-24 and 25-42 d of age for each replicate. At the end of the experiment, two birds of each replicate were slaughtered and blood was collected to determine hematological parameters, and carcass characteristics were analyzed.
Results and Discussion Based on the results, in 1-10 d period supplementing the broiler diet with 100 mg/kg herbal extracts decreased significantly feed intake (P

Introduction Egg quality related traits are economically important in laying hens Egg quality is one of the important factors in the process of hatching. So, economical success of commercial and local flocks of hens depends on the quality of eggs produced. Increased egg quality results in higher marketability of the egg. Having eggs with higher quality is possible through improving nutrition, management and genetics. Understanding genetic structure of these traits with high accuracy will help us to design a desirable breeding program. Maternal effects can be caused by genetic or environmental differences between mothers or by the combination of the genetic and environmental differences. Advantages of Bayesian technique as a method of choice would be a promising method for providing high accurate genetic parameters estimations and having eggs with higher quality in next generations.
The purpose of current study was to estimate and compare variance components and heritability for egg quality traits in Khorasan Razavi native fowl using different animal models.
Materials and Methods The records for egg quality traits were collected from native fowl of Khorasan Razavi breeding center located in east north of Iran. In this experiment, 1000 eggs from 775 hens of 9th generation at the age of 28 to 29 weeks were collected and measured for internal and external traits. An electronic scale with an accuracy of 0.01 g was used to weigh the eggs (EW). The short and long lengths of each egg (SL and LL, respectively) were measured using Egg Form Coefficient Measuring Gauge. The eggs were broken using an Egg Shell Strength Tester to measure shell strength (SS). The height of yolk and albumen (YH and AH, respectively) were measured using a tripod micrometer (calibrated in mm) and a dial caliper to the nearest 0.01 mm was used to measure albumen and yolk diameters (AD and YD, respectively). Subsequently, yolk and albumen were carefully separated and yolk weight (YW) and albumen weight (AW) were measured. Shell weight (SW) was measured after 72 hours’ exposure to dry air. Shell thickness (ST) was measured with a Shell Thickness Meter (calibrated in mm) at the pointed end, equator and blunt end of shells and average values were used. These traits were evaluated by six different animal models through Bayesian method using Gibbs3f90 software. The most suitable model was determined by deviance information criterion (DIC) for each trait.
Results and Discussion The mean value of egg weight in this local breed was 49.66 gr. The mean value for specific gravity in present study was 1.089. Specific gravity is an important indicator to determine the quality of shell and the amount of shell to the other members. The mean values of shape index, shell strength, shell weight and shell thickness obtained in this study were 76.92, 4.24 kg/cm2, 5.19 g and 0.43 mm, respectively. The mean values of albumen weight, albumen height, yolk weight and yolk height were 28.11 g, 6.41 mm, 14.07 g, and 17.53 mm, respectively. For egg weight, specific gravity, egg length, shape index, yolk diameter and Haugh unit, a model consisted of maternal permanent environmental effects in addition to direct genetic effects was the most suitable. For egg width, shell strength, shell thickness, shell weight, yolk weight and yolk height, model including maternal genetic and permanent environmental effects in addition to direct genetic effects was the optimal model. For albumen index and albumen diameter, only direct genetic effects were affective. The estimates of direct heritability were from 0.08 (albumen height) to 0.28 (egg weight and shell weight) and maternal heritability ranged from 0.03(yolk index) to 0.13 (yolk height and albumen height). Observed differences in genetic and non-genetic parameters estimations determined by different models indicated that model choice is an important aspect for obtaining accurate estimates, which are going to be used when deciding on a breeding scheme. Generally, this study indicated that considering maternal effects in the models resulted in unbiased estimations of direct genetic variance and heritability for most of the studied traits.
Conclusion It can be concluded that all egg quality traits in Khorasan Razavi native fowl are influenced by maternal genetic and environmental effects. Therefore, including maternal effects in statistical models is essential for estimation of genetic parameters; the models included direct and maternal effects result in more accurate genetic parameters estimations for most of the studied traits.

Introduction Mastitis is recognized as one of the most costly diseases of the dairy industry. Somatic cell count (SCC) is a widely used indicator trait for mastitis, which in many countries is used as an indirect selection criterion for improving mastitis resistance. This is based on the positive genetic correlation between clinical mastitis (CM) and SCC. Recent estimates of the genetic correlation between mastitis and SCC range between 0.53 and 0.77 and the heritability is estimated between 0.05 and 0.31. Individual test day SCC are influenced by systematic environmental effects, such as stage of lactation, lactation number, season of calving, and season of recording. The aim of this study was to investigate factors affecting milk somatic cell score (SCC) and estimation of its heritability and correlation with the other productive traits.
Materials and Methods A total of 185688 test day records of production and pedigree from 54 herds in Khorasan Razavi State were used. To normalize SCC, log transformation of natural records were considered from cows, which had at least one calving up to 10th. Environmental effects such as herdyear of record (247 levels), stage of lactation (15 levels), lactation number (10 levels), month of recording (12 levels), year of calving (9 levels) and season of calving (4 levels), and the 1st and 2nd regression coefficient of milk production were included in the model. Heritability of SCS was estimated by animal model test-day random regression and correlations between traits were analyzed by bivariate animal model of Wombat. Fixed effects in model included herdyear of record, Holstein gene percentage, and stage of lactation as covariate, as well as additive genetic effect and common permanent environmental effects as random effects with 5-degree of Legendre.
Results and Discussion Analysis of variance revealed that all factors in models were significant (P

Introduction Pseudogenes are copies of the ancestral genes which have undergone changes that were constructed based on gene duplications and reverse transcription in the genome. They have been reported in all types of organisms ranging from bacteria to mammals. Pseudogenes increase the genetic diversity of a plethora of genes and they do so through gene conversion and recombination. Three classes of pseudogenes are known to exist: duplicated pseudogenes; processed or retrotransposed pseudogenes; and unitary or disabled pseudogenes. Pseudogenes have long been considered as nonfunctional genomic sequences. However, recent studies reported that many of them might have some form of biological activity. Recently, it has reported that pseudogenes represent a conspicuous part of the human transcriptome and proteome, as thousands of them are transcribed and hundreds are also translated. Also, it has been demonstrated that pseudogenes exert important coding-dependent and coding-independent functions that are involved in complex regulatory networks. Hence, the possibility of functionality of these genes, has increased interest in their accurate annotation. According to the best of our knowledge, there is no available report on the high-throughput pseudogene identification in sheep. Therefore, in the present study, to improve the annotation of sheep genome, we present the first genome-wide pseudogene identification for protein-coding genes using a homology-based computational approach.
Materials and Methods The pseudogene content in the sheep genome was estimated using an in-house computational annotation pipeline, named PseudoPipe. The PseudoPipe pipeline predicts pseudogenes in the genome using homology-based method (BLAST and a clustering algorithm). In the present study, repeat-masked sheep genome reference (Ovis_aries.Oar_v3.1), genome annotation gtf file (version 77) and all of the protein coding genes sequences were downloaded from ENSEMBL database. To identify pseudogenes, the sheep genome was searched in a comprehensive and consistent manner. The key steps in the pipeline involved using BLAST to rapidly cross-reference potential ‘‘parent’’ proteins against the intergenic regions of the genome and then processing the resulting ‘‘raw hits’’ such as eliminating redundant ones, clustering together neighbors, and associating and aligning clusters with a unique parent. Then, pseudogenes were classified based on a combination of criteria including homology, intron/exon structure, and existence of stop codons and frameshifts. Finally, we investigated the results manually and false positive results were removed. Also, the gene ontology (GO) of the parental genes that pseudogenes derived from them, have been investigate by DAVID software. Furthermore, different characteristics of the identified new candidate pseudogene were compared with known pseudogenes in the human, mice and cattle species.
Results and Discussion It is vital to identify pseudogenes to better understand genome annotation and disease-related molecular mechanism. Identification of pseudogenes is an ongoing effort, and there are several groups continuously working on identification of pseudogenes. The complexity of the identification of pseudogenes can be addressed by in silico analysis and using a homology-based whole genome identification approach. Here, using a computational method, we identified 4,098 high confidence pseudogenes including 1,102 duplicated and 2,996 processed pseudogenes in sheep genome. The results of the GO analysis showed that identified pseudogenes are significantly enriched in various biological processes, such as mRNA splicing, ribosome structure, binding rRNA, mitochondrial electron transport, translation and etc. Interestingly, a growing body of evidence suggests parental genes of pseudogenes roles are associated with ribosome, rRNA and translational biological processes. Detailed comparison of our results with other species showed that our results are in consistence with previous studies. For example, pseudogene distribution on the sheep chromosomes was in consistence with human and mouse genome. Moreover, it is reported that, duplicated pseudogenes are commonly found on the same chromosome as their parent genes.
Our results showed that about 28% of the identified duplicated pseudogenes were on the same chromosome with their parent genes. The results of the study will help to improve the annotation of the sheep genome. The coincidence of the results of this study with previous studies indicates accuracy of the method used in this research.
Conclusion This study, for the first time, has generated the catalog of 4,098 sheep putative pseudogenes. Our findings provide an evidence for pseudogene content in sheep which is a starting point for understanding of their regulatory mechanism. The identification of the novel pseudogenes have greatly improved the genome annotation of sheep. The results of this study will help to better annotation of sheep genome. By using such methods, we can also improve annotation genomes of various organisms.

Introduction Lithium as a toxic and heavy metal and environmental contaminant could be a risk factor for male fertility. Lithium can induce male reproductive toxicity through damage in testes structure, sex hormones imbalance and decrease in testes and accessory sex organ weights as well as reduction in epididymal sperm count, normal morphology, viability and motility. Lithium is proposed to exert its cytotoxicity by free radicals generation and the activation of oxidative sensitive signaling pathways. Oxidative stress is metabolic and physiologic status caused by imbalance between free radical production and antioxidant defense of body. Therefore, the use of natural antioxidants could be a possible strategy for reducing oxidative stress in body. Silymarin is extracted from milk thistle (Silybum marianum) seeds. This compound is a polyphenolic flavonoid with a potent antioxidant property which not only acts as free radical scavenger but also increases the capacity of cell antioxidant enzymes. This study aimed to evaluate the harmful effects of lithium on sperm of Farahani’s ram and to know the protective effect of silymarin on protection against to toxic effects of lithium.
Materials and Methods In this experimental study, Farahani's ram testes were received from Arak slaughterhouse and transferred to the research laboratory under standard conditions. The experiment funding was approved by the ethical committee at Arak University. A few incisions were made in the caudal epididymis and spermatozoa were then washed into a sterile Falcon tube by Ham's F10 medium (Sigma, USA). Firstly sperm number and sperm motility were determined, according to World Health Organization protocol (WHO), to estimate sperm quality. High quality sperm samples were then used for experiments. The sperm samples were separated in eppendorf tubes as each tube contained 5×106 spermatozoa and divided into four groups to assess sperm viability. The MTT, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay was used to assess viability. In brief, 10 μl of MTT (Sigma, USA) stock solution (5 mg/ml ham's F10) was added to each tube containing sperm suspension and incubated at 37PoPC in COR2R incubator for 1 hr. The tubes centrifuged at 6000 rpm for 6 min and the precipitate was dissolved in 200 μl dimethyl sulfoxide (DMSO). The solution was then centrifuged at 4000 rpm for 4 min. 100 μl of the purple solution were transferred into a 96-well plate and absorbance was measured using ELISA reader (SCO diagnostic, Germany) at 505 nm. Optical density of sample was then used for calculating sperm viability percentage Evaluation of sperm motility was done according to WHO guidelines. Minimum of five microscopic fields was evaluated to estimate sperm motility on at least 200 spermatozoa for each sample. The percentage of sperm motility was evaluated for following motion patterns: progressive motile sperm (PMS), non-progressive motile sperm (NPMS) and non-motile sperm (NMS). Evaluation of sperm motility was done according to WHO guidelines. In brief, 10 μl of sperm suspension was placed on semen analysis chamber. Minimum of five microscopic fields was evaluated to estimate sperm motility on at least 200 spermatozoa for each sample. The percentage of sperm motility was evaluated for following motion patterns: progressive motile sperm (PMS), non-progressive motile sperm (NPMS) and non-motile sperm (NMS). One-Way analysis of variance (ANOVA) followed by Tukey's test was used to assess data statistical significance. p

Introduction Animal performance can be affected by the weather condition. Nowadays, study the effect of weather conditions on plants, animals and all living being is an interdisciplinary science, which has a great effect on the quality and quantity of their products. In order to survive and maintain their physiological activities, body temperature of warm-blooded animals should remain in a specific range. Therefore in warm days, in order to restrain their body temperature in an optimized range, their transpiration, breathing and heart beat raises, while the feeding rate decrease. Meanwhile, if the relative humidity was high, the cooling reaction does not response well and therefore animals’ body temperature raises, which puts animals under the heat stress. Subsequently, problems such as feeding rate and animal production reduction, reproductive problems, and increase in the rate of getting sick occur. In this regard, researches have shown that air temperature and environmental humidity are two key parameters in cows’ heat stress. To evaluate and assess the heat stress, most of the researchers use Temperature Humidity Index (THI). Numerous equations have been proposed for THI calculation, each having coefficients to be calibrated in different regions, which in return make their application confusing. The aim of this study is to determine the best THI equation for dairy industry in Mashhad region, and also find the reduction in milk production during the heat stress period.
Materials and Methods The meteorological data (daily wet and dry bulb and relative humidity records) were obtained from Iran meteorological organization. THI was calculated by 8 common equations for seven consecutive years (2007-2013). The daily milk production data was also obtained from improvement center of milk production in Karaj. Then the relationship between daily milk production and 8 obtained THI were calculated for both annual and seasonal time scale. At that point by using the correlation coefficients and P-value the best equation to determine THI was chosen. Finding the best THI equation for the study area, led to find a warning heat stress point. At the end, daily milk production during the heat stress was calculated and milk production reduction was estimated during the heat stress time.
Results and Discussion Results indicated that there was no significant correlation between annual milk production and obtained THI. Also the relationship between THI and milk production in seasonal scale (spring, fall and winter) was not significant. Nevertheless, only daily milk production in summer had a significant relationship with temperature-humidity index, which was negative. This means that daily milk production decreases as THI increases. Among 8 investigative equations, the forth equation (which calculate THI by using dry bulb and dew point temperature) had the best correlation coefficient and P-value with daily milk production. By definition the break point in summer daily THI and milk production, the heat stress warning point for Mashhad dairy industry was found. The results showed that when THI rises above 75, the milk production significantly decreases. To calculate the milk reduction corresponding to THI increase, the relationship between milk production and THI was estimated more than 75. Then by subtracting the calculated THI from average milk production in a non-stress day, the loss of milk production were calculated for each cow. Then by multiplying one cow milk lost, by the number of cows, the final milk production loss were calculated for each year. The results showed that the temperature humidity stress had a greatest effect on milk production, so that during a summer time, each cow averagely produce 138.8 liter milk less than usual. This amount is also equal to 1.5 liter milk per a day. During a 7 years period investigation, the total milk loss was calculated 401 ton.
Conclusion In conclusion, raising air temperature can cause a heat stress and a reduction in milk production. When the heat comes with high relative humidity, these effects highlighted and cows were under enormous stress therefore their body temperature transpiration, breathing and heart beat raise, while the feeding rate decrease, and as a result of that milk production reduced which can cause a great damage in diary industry.