Volume 26, Issue 2, Summer and Autumn 2012, Page 53-113

Effect of some antioxidants on blood picture and antioxidants status in roosters exposed to oxidative stress

A. A. Hassan; M. S. M. S. Al-Ma; atheedi

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 55-61

The present study was designed to investigate the effect of Vitamin E 600 mg/kg diet, Vitamin C 450 mg/kg diet and sodium selenite 0.5 mg/kg diet in adult white Leghorn male chickens (30 weeks), which were concomitantly exposed to oxidative stress induced by hydrogen peroxide (0.5%) supplemented with drinking water for 6 weeks on blood picture. Blood samples were collected at (0, 3, 6) weeks of treatment. Hydrogen peroxide caused a significant increase in the total leukocyte count, heterophils percentage and heterophils /lymphocytes ratio (stress index) accompanied with a significant increase in liver malondialdehyde level associated with significant decrease in hemoglobin concentration, packed cell volume, lymphocyte and esoinophil percentage. It also caused a significant decrease in liver glutathione on the 6th week of the treatment compared with control group. The antioxidants with hydrogen peroxide caused a significant decrease in the total leukocyte count, heterophils percentage and stress index accompanied with a significant decrease in malondialdehyde level in liver tissue compared with hydrogen peroxide alone and control group, beside that a significant increase in hemoglobin concentration, packed cell volume, lymphocyte, esoinophil percentage and liver glutathione level compared with hydrogen peroxide alone which returned to control group values. In general, treatments with Vitamin E, C and Sodium selenite reversed the adverse effects produced by hydrogen peroxide on certain physiological parameters in adult male chickens.

Prevalence and distribution of canine visceral leishmaniasis antibodies in dogs in Mosul City

D.M.T. Jwher

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 63-67

The purpose of the current study to investigate of visceral leishmaniasis antibodies in blood of dogs. One hundred and fifty six samples of blood of stray and domestic dog blood samples of different ages and sexes and from various regions of Mosul city were collected. The study began from July to August 2010. The area of the study (Mosul city) was divided geographically in to two main areas i.e. right and left coasts of Mosul city. Also, another subdivision was followed in which each major areas was divided into six administrative parts, having other residential quarters. A qualitative membrane based immunoassay (rK-39) was followed for detection of antibodies of visceral leishmaniasis. However additional conformation of the parasite was done by blood smears and impressions smears obtained from the liver and spleen of the sacrificed dogs. The finding showed that visceral leishmaniasis antibodies were recovered in the dogs of southern and south eastern parts of Mosul city representing a total infection rate of (14.1%). However, infection rate was higher in the dogs of left coast (16.66%) than that in the right coast of Mosul city (11.11%). It can be concluded that high prevalence rate was found in the southern and south eastern parts of Mosul city.

The analgesic efficacy of xylazine and dipyrone in hydrogen peroxide-induced oxidative stress in chicks

Y.J. Mousa; F.K. Mohammad

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 69-76

The effect of oxidative stress–induced by hydrogen peroxide (H2O2) on the analgesic effect of xylazine and dipyrone in 7-14 days old chicks was studied, compared with the control group that given plane tap water. H2O2, 0.5 % in water, induced oxidative stress in chicks by significantly lowering glutathione, rising malondialdehyde in plasma, whole brain during the day 7th, 10th, 14th of chicks old in comparison with the control group. The analgesic median effective doses (ED50) of xylazine and dipyrone in the control group were determined to be 0.79 and 65.3 mg/kg, intramuscularly (i.m.), respectively whereas H2O2 treated groups decreased these values to be 0.31 and 37.2 mg/kg, i.m. by 61 and 43%, respectively. Intramuscular injection of xylazine and dipyrone at 0.5, 70 mg/kg respectively causes analgesia from electro-stimulation induced pain in 50, 66.67% respectively in control groups whereas H2O2 treated chicks increases the analgesic efficacy to be 83.33 and 83.33% respectively. Xylazine and dipyrone injection at 1 and 100 mg/kg, i.m. 15 minutes before formaldehyde injection in right planter foot of stressed chicks causes analgesia from pain induced by formaldehyde through significant increases in onset of lifting of formaldehyde injected foot, significantly decreases its lifting numbers, decreases the time elapsed of lifting of formaldehyde injected foot in comparison with the stressed control group that injected with saline in right planter foot. The data of this study indicate that H2O2-induced oxidative stress potentiate the analgesic efficacy of the central and peripheral analgesics of xylazine and dipyrone in chicks.

Effect of vitamin C on blood picture and some biochemical parameters of quail stressed by H2O2

A.F. Abdulmajeed; H.A. Alkarad; S.Y. Abdul-Rahman

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 77-82

This study was carried out to investigate the Vitamin C protective effect against the H2O2 – induced oxidative stress effects on some hematological and biochemical parameters of female quails (Coturnix coturnix).120 sexed female quails were reared from 21-56 days. Randomly the birds divided into 4 groups (30 birds/group) (2 replicates) as follows: 1st group: T1 (control): reared on standard ration and tap water.2nd group: T2 (H2O2 group): reared on standard ration and tap water supplemented with 0.5% H2O2. 3rdgroup: T3 (Vitamin C group): reared on standard ration supplemented with 300mg/kg ration and tap water. 4thgroup: T4 (H2O2 + Vitamin C): reared on standard ration supplemented with 300mg/kg ration and tap water supplemented with 0.5% H2O2. Results revealed that Vit. C supplementation improve female quails blood picture, this effects were adversive to the H2O2 effects, Vit. C causes a significant increase in lymphocytes % and a significant decrease in hetrophils and hetrophils: lymphocyte ratio (stress index), also a significant decrease in glucose, cholesterol and triglycerides, as well as a significant increase in serum protein when compared with the effect of H2O2 – induced oxidative stress. In conclusion, oxidative stress causes a negative effects on blood picture and some serum biochemical parameters, and Vit. C supplementation reduces and reverses the H2O2 effects.

Neurobehavioral changes associated with chronic treatment of omega-3 in rats

Y. Z. Saleh; F. A. Ahmed

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 83-89

This study aimed to investigate the effect of chronic use for 2 month with omega-3 on the level of neurobehavioral and motor activity in the open field. The study showed an effect for different doses of omega-3 on the nervous system and behavior when drainage drug by mouth, that are easily hand to deal with the rats dosage with 10, 50, 250, 500 mgkg of body weight. Rats in doses 10, 50, 250, 500, 1000 mg/kg recorded a significant decrease in number of crossed squares and the number of rearing comparison with the control group. Pocking test recorded significant increase in the number of times introduction of head in the holes compared to the control group in doses of 50, 250, 500 mgkg of body weight, a dose of 1000 mgkg showed a prolongation in the time required to avoid animal high edge, with a lower score swimming and stretching in a period of rotation in the negative geotaxis test compared with the control group, while the rest of the doses did not show any significant difference compared with control. In test of tonic immobility response all the doses recorded a significant decrease in the stillness and freeze for rats movement, compared with control group. We concluded that omega-3 has beneficial effect on the level of neurobehavioral and motor activity in the open field activity in addition to development cognitive behavior of animals, except dose 1000 mgkg Shaw some behavioral difference compare with control group.

The effect of Bifidobacterium adolescentis on the relative weights of internal body organs and jejunum tissue of broiler chicks

A. A. T. AL-Ani; Z. T. AL-Dhanki

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 91-99

This experiment was conducted to evaluate the effect of Bifidobacterium adolescentis isolated from broiler crops on villus high and crypts depth of jejunum tissues and relative internal organs weight of broiler chicks (Ross 308). Chicks were subdivided into four treatments: the first treatment was considered as control, and other three treatments were treated by inoculating the chicks with 0.25 ml once weekly for (7 week) with normal saline (second treatment); enrofloxacin (third treatment; and liquid culture containing 7.1 × 108 colony forming unit/ml from B. adolescentis (fourth treatment). The results showed that there was a significant increase (P≤0.01) in the villus high in bifidobacteria treatment compared with control and antibiotic treatment, and significant increases in crypt depth of Lieberkuhn in bifidobacteria treatment compared with antibiotic treatment at 1st week of age. At the 2nd week bifidobacteria treatment significantly increases (P> 0.01) in crypt depth of Lieberkuhn and villus high compared with all treatments, and the same significant increases was happened at the 4th treatment in bifidobacterai treatment compared with all treatment in villus high and but only with antibiotic and normal saline treatment in crypt depth of Lieberkuhn. The relative weight of internal organs was not affected by bifidobacterai treatment except the percentage of duodenum weight to its long at the 2nd week in the bifidobacterai treatment compared with normal saline treatment.

Using species-specific PCR technique to detect Toxoplasma gondii in broiler chickens

R.A. Al-Sanjary; T.H. Hussein

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 53-56

Two groups of broiler chickens were used in this study. One was reared under typical conditions at the animal house of Veterinary Medicine College/Mosul University- Iraq, while the other group was reared under common commercial farm conditions. Fifty and 80 birds from the two respective groups were sacrificed at 49 days of age for detecting Toxoplasma gondii by using Species-specific PCR technique. Results of Latex agglutination test indicated, principally, that 29.3% and 49.2% of the serum samples were positive for the birds of both groups, respectively. Titer figures ranged between 1:20 to 1:320 where the highest value was 1:160 (39.3%) and the lowest was 1:20 (5.8%). Confirmation of 38 and 64 serum samples, using Latex agglutination test was performed by PCR technique, from the two respective groups of chickens. Of those, 8 samples from the college birds and 35 from the commercial farm birds were confirmed positive by giving band of 133 bp, according to specific primers designated on gene B1.Based on these results, pursuing the PCR technique is considered, so far, a most sensitive method for Toxoplasma gondii detection. Also, positive PCR results are counted on as an early marker for reactivation and useful means in monitoring therapies.

Comparative morphometric study of shank bone in the tom (Meleagris gallopavo) and local cock (Gallus banikaval)

S. Al-Sadi

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 57-64

The study was carried out on 20 legs of ten adult clinically and healthy local and Tom were obtained from Mosul local market, were divided into three groups; the first and second groups were subjected to gross feature regarding to shape, position, relationship of tibiotarsal and fibula in both birds also the length and diameters of shank bone while third group study morphological of muscles, blood and nerve supply of leg. The purpose of this study, this part of the limb is popularly known as the (drum stick), the bird in lowering its body flexes knee and hock joints and this passively tenses these tendons of leg which clamp the digits about the perch, and that is the much longer than the femur and, in spite of importance study to parameters of leg are more economic to choose breed of fertilization depend on the measurement, the outcome of this investigation may served as a guide for successful study of domestic birds in Iraq. The results include in both birds, the leg is consist of tibia fuses with tarsal element, forming tibiotarsus and fiblula articulates with the femur that in contrast to mammals. In Tom the tibia has two cnemial crest in proximal extremity and the distal extremity has tendinal groove, but in local cock it has one cnemial crest of proximal extremity, and it has two tendinal groove in the distal extremity, while hock joint in the Tom and local cock is an intertarsal joint that unites the tibiotarsus with the tarsometatarsus but the stiff joint is similar to that seen in mammals. The mean length of tibiotarsal in Tom 17.99±0.44 cm and the mean length of tibiotarsal in local coke 11.74±0.31 cm, the mean diameter of tibiotarsal in Tom 3.02±0.0021 cm proximal part, 2.21±0.005 cm middle part, 1.94±0.0021 cm distal part, but the mean diameter of tibiotarsal in local coke 2.86±0.048 cm proximal part, 2.02±0.067 cm middle part, 1.51±0.0022 cm distal part. While the mean length of fibula in Tom 11.62±0.21 cm and the mean length of fibula in local coke 7.27±0.32 cm, the mean diameter of fibula in Tom 1.51±0.0021 cm proximal part, 0.81±0.0033 cm middle part, and 0.33±0.0043 cm the distal part,also the mean diameter of fibula in local coke 1.12±0.0025 cm proximal part, 0.51±0.007 cm middle part, and 0.23±0.0054 cm distal part. Tendon of muscles of shank bone in Tom generally ossification but remain that tendon in local cock. Also cranialis tibialis muscle has two head, femoral head is usually smaller than the tibial head and gastrocnimeus muscles is composed of three part into two birds which passes through the planter aspect of the tarsometatarsal joint, as soon as flexor digitorium muscle of both species can be grouped into three morphological level (superficial intermediate and deep), the muscles in turkey are very clearly distinguished are read deep color than it is rose color in local cock, blood, nerve supply and venous drainages of the shank bone in both birds by cranial tibial artery is passage with cranial tibial vein and common fibular nerve.

Comparative study of the auricle and external acoustic meatus of the cattle and buffalo

S. Al-Sadi; A. A. Hasso

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 65-72

The present work was design to study the anatomical features and radiographic appearance of auricle and external acoustic meatus of cattle and buffalo, collected from (12) sample of heads were used in this study, there were equally divided into three groups: first group to study the shape, position and relation of cartilage, muscles and ligament of auricle in both animals, second group to study the measurements of external acoustic meatus, and the third group study morphological and radiographical of external acoustic meatus in both animal, the study revealed that the auricle is a flapy flashy appendage attached to the side of the skull by muscles and ligaments, the auricle is funnel shape, distally is wide open, but more proximally, it is rolled up to form a tube that bend medially to be connected to the external acoustic meatus, the auricle in both animals is composed of three cartilage: the part auricular, scutiform and annular cartilage also auricular muscle and ligament which support the external ear. The result of this study shows that intrinsic auricular muscles is more developed in buffalo, while the greater parts of the extrinsic auricular muscles are developed in both animals. The present work shows that the frontoauricular muscles are distinguish into two parts in buffalo and cattle on the other hand the interscutularis muscle thin fibers and attached with scutuloauricularis prefunds muscle in buffalo, also the parotidauriculares narrower and thicker in cattle, but a ribbon -like muscle thin and wide in buffalo. The external acoustic meatus begins where the rolled up part of the annular cartilage narrows and ends, the meatus has cartilaginous and osseous parts it is lined with skin the study provided that acoustic meatus about 5.667±0.0816 cm of length in cattle and 6.500± 0.126 cm in buffalo, the aim of present work is to report more detailed information about the auricle and meatus in both animal for value importment can easily examined by the speculum the shortness of the meatus should be courses of the risk of injuring of the tympanic membrane and to be able to pass the otoscope tube through the external meatus and to recognize the eardrum when it is seen, to know the surgical anatomy of auricle and acoustic meatus and to know the relationship of vessels and nerve that must be avoid during surgery and to be able to recognize all parts of the temporal bone on radiographs.

Effect of Gundelia tournefortii on some biochemical parameters in dexamethasone-induced hyperglycemic and hyperlipidemic mice

O. H. Azeez; A. E. Kheder

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 73-79

The aim of this study was conducted to evaluate the effect of Gundelia tournefortii on some biochemical parameters in hyperglycemic and hyperlipidemic mice. Male albino mice were induced hyperglycemic and hyperlipidemic by daily injection of dexamethasone 1 mg/kg of body weight intramuscularly (i.m.), the mice randomly divided into five groups (6-8 mice in each group). The group 1: served as negative control group; the group 2: injected with dexamethasone at dose 1 mg /kg.b.w.i.m and served as positive control group; the groups 3, 4, 5: treated with extract of G. tournefortii at doses: 75, 150, 300 mg/kg.b.w. orally respectively companied with injection of dexamethasone 1 mg/kg.b.w.i.m. All treatment were once daily for 22 days. Dexamethasone treatment lead to significant increase in levels of glucose, cholesterol, and triglyceride, and significant decrease of body weight, without any effect on level of total protein. G. tournefortii extract treatment at doses: 75 mg/kg.b.w. resulted significant decrease levels of glucose, and body weight. Beneficial effect were seen when mice treated with G. tournefortii at dose of 300 mg/kg.b.w. that lead to significant decrease in levels of glucose, triglyceride, and cholesterol. These results indicate the usefulness of G. tournefortii extract as hypoglycemia and hypolipidemia in dexamethasone treated mice.

Oral imipramine and intravenous xylazine for pharmacologically-induced ejaculation in donkeys

U.T. Naoman; A.J. Ali

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 81-83

The aim of this study is to evaluate using chemical method by oral imipramine and intravenous injection of xylazine for semen collection from donkeys in a field condition. Five mature male donkeys were used in this study weighting 120-150 Kg, aged 2-4 years, kept in the animal house of the Veterinary Collage, University of Mosul. Semen collections were performed by administration of a combination of imipramine hydrochloride 3 mg/kg. BW orally then 2 hours later, intravenous xylazine hydrochloride was injection as 1.1 mg/kg BW then semen was collected in ballistic tube. A total of 29 ejaculates from 30 trials were collected successful with a successful rate up to 96.6%. Semen characteristics of these donkeys were volume 60.1±2.9 ml, individual motility 53.5±2.0%, sperm concentration 60.2±1.7×106/ml sperm abnormalities 9.5±3.3%, live sperm 57.2±4.5% and PH 7.3±1.8. It could be concluded that, chemical method could be used successfully for semen collection from donkeys.

Reproductive performance improvement in primiparous lactating Holstein cows by different hormonal treatments

T. M. Al-Hamedawi

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 85-87

This study was aimed to evaluate different hormonal treatments during early postpartum period on reproductive efficiency on 42 primiparous Holstein cows in the experimental farm of college of Agriculture, University of Baghdad, aged 3-3.2 y. during the period from 2010-2012. These cows were divided randomly into four groups according to hormonal treatment at day 50 postpartum. The 1st group included 11 cows and was injected with GnRH 0.0126mg/IM, the 2nd group (10 cows) injected with eCG 1000 IU/IM, the 3rd group (11 cows) administrated by hCG 1500 IU/IM and the 4th group (10 cows) without treatment as a control group. The results of this study revealed that the responsive cows (estrus behaviors) were 10 (90.9%), 8 (80%), 9 (81.8%) and 9 (90%) in the 1st, 2nd, 3rd and 4th group respectively and these results were recorded superior significant (P<0.01) for group 2 compared with group 1 and 3 related with duration from initiation of estrus, but no significant differences (P<0.01) between all groups about services per conception and number of conceived animal while the days open and calving interval was recorded significant differences (P<0.01) between the 1st, 2nd and 3rd groups compared with control group (4th group). It could be concluded that using hormonal treatment which indicated to produce improvement in certain parameters of reproductive performance provided early post partum breeding.

Effect of induced epilepsy on some biochemical parameters in female rats

J.S. H. Ali; L.I. Matty; S.S. Yahya

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 89-92

The activity of cholinesterase and some biochemical parameters of blood such as glucose, cholesterol and phospholipids were estimated in 52 epilepsy induced females of Wister albino rats. Animals of this experiment were divided into two groups, group (I) regarded as control and group (II) administrated subcutaneously by pentylenetetrazole 100mg/kg and divided in to three sub-groups according to the time of samples collection 3 hrs, 24 hrs and 1 week. The results revealed that epilepsy induction caused a significant inhibition of serum cholinesterase activity 3 hrs after induction while in the brain, the activity of cholinesterase was significantly increased after 24 hrs Serum glucose level was significantly elevated after 3 hrs and 24 hrs of induction, total cholesterol and phospholipids were not changed. From the results obtained in this study, it can be concluded that epilepsy caused significant changes in cholinesterase activity in brain and serum in addition to the glucose level in the serum.

Impact of oxidative stress on pregnancy outcome in albino rats

R.S. Al-Naemi; Q.H. Abdullah; S.A. Ibrahim

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 93-99

Accumulative reports documented that oxidative stress is implicated in many human and animal diseases. However, the reports concerning the effect of oxidative stress on pregnancy outcome are limited and scarce. The objective of this study was to determine the impact of oxidative stress on pregnancy outcome and to assess the antioxidant effect of vitamin C and E on oxidative stress parameters in blood and placental tissue samples in experimental pregnant animals model exposed to oxidative stress. Wister Albino rats were used in this work to investigate the effects of oxidative stress exposure (addition of H2O2 to the drinking water) on pregnancy outcome. Rats were divided into 5 groups, as follows: Group I (included 7 normal pregnant rats which served as control group). Group II (exposed to 1 % H2O2) included 7 pregnant rats, the rats were allowed to become pregnant and received (1% H2O2) in drinking water from day 7th till the day 19th of pregnancy. Group III (exposed to 3% H2O2) included 8 pregnant rats. Same as group 2, but the rats were exposed to a higher concentration of H2O2 (3%) in drinking water. Group IV (included 8 pregnant rats). Pregnant rats received vitamins C and E without induction of oxidative stress. Group V (included 8 pregnant rats).induction of oxidative stress by 1% H2O2 with vitamins supplementation in the pregnant rats. Serum total antioxidants capacity (TAC), serum and placental tissue oxidative stress biomarker; 8-iso prostaglandin F2α (8-Isoprostane) were measured using specific ELISA kits. Also placental tissues of pregnant rats were isolated and put directly in 10% formalin prepared for histopathological examination. Results revealed a significant decrease in the median values of the body weight and total serum antioxidants capacity (TAC) in groups II and III of rats compared with the control group. A significant higher median value of TAC obtained in the groups IV and V when compared with the control group. Significant higher levels of serum and tissue Isoprostane observed in both groups II and III compared with control group. Histopathological, oxidative stress induced macroscopically degenerative with microscopical appearance of vasculitis and hemorrhage within decidua. Data of the present study demonstrated that imbalance oxidative stress status in pregnant rats occurred due to exposure to oxidant, which played an important role in the pathogenesis of abnormal pregnancy outcome. In addition antioxidants supplementation (vitamins E and C) were valuable in reducing this stress.

Misoprostol treatment of dystocia due to ringwomb in Awassi ewe: a case report

I.Y. Ibrahim; E.S. Hussain; E.H. Lazim; O.I. Azawi

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 101-102

Two years old Awassi ewe was brought by the owner to the clinic of the College of Veterinary Medicine, University of Mosul and he claimed that his animal had dystocia 12 hours ago. Fetal fluid was escaped since 3 hours ago. On clinical examination, the ewe was at term, as denoted by mammary changes and relaxed edematous vulva. The ewe was in a standing position and restlessness due to abdominal discomfort, without any abdominal contractions. Vaginal examination indicated that the cervix was dilated about 1 finger and the fetal membranes ruptured. No any medications were previously given to the ewe in the near past.

A serological study of brucellosis in camels south of Kirkuk, Iraq

M. Yawoz; S. E. Jaafar; A. I. Salih; M. H. Abdullah

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 105-107

A study of the prevalence of antibodies to camel brucellosis has been carried out in the south of Kirkuk city during March 2011. A total of 66 camels (6 male, 60 female) involved in this study with age between 6 months to 22 years. Blood samples were collected from jugular vein and the sera samples were screened by using Rose Bengal Plate Test (RBPT). The sera that were positive by using RBPT have been tested again by using the 2-Mercaptoethanol (2ME) test. The results of this study revealed that two camels from 66 camels (3.03%) were seropositive for brucella antibodies in South of Kirkuk city.

Synergism of the analgesic activities of tramadol with α2 adrenoreceptor agonist xylazine in mice

G. A. Taqa

Iraqi Journal of Veterinary Sciences, Volume 26, Issue 2, Pages 109-113

The present study was undertaken to evaluate the antinociceptive interaction between tramadol and xylazine. The antinociceptive effect of intraperitoneal (I.P) administration of the drug alone or in combination was evaluated using the mouse hot-plate test. Administration of tramadol in fixed dose (20mgkg) I.P with different doses of xylazine (0, 2, 4, 8) mgkg I.P significantly referred synergism of the antinociceptive effect of tramadol depending on the dose of xylazine. There was an increased the antinociceptive maximum possible effect (%MPE) from (27.08%) to (85.4%). The effective dose that produce 50% antinociceptive (ED50) were evaluated for each drug alone or in combination. The present study found that the administration of tramadol and xylazine markedly reduced the median effective dose (ED50) of both drugs for antinociceptive effect in mice. The result of this study demonstrated that there was synergism (super-additive) interaction between tramadol and xylazine.