IRANIAN JOURNAL OF VETERINARY RESEARCH (IJVR)
Year:2013 | Volume:14 | Issue:2 (43)|Papers Count:18

This study was carried out to investigate the relationship between early lactation curve parameters and calving interval in Holstein cows of Iran. In order to describe the lactation curve, the incomplete gamma function was fitted to 5,754,428 test-day milk records corresponding to 766,108 lactations on 315,634 cows in 2,448 herds. Cows with higher milk yield during early lactation had shorter calving intervals; however, longer calving intervals increased the 305-d milk production (P<0.01). Cows with higher yield at the beginning of lactation, steeper ascending, and steeper descending slope had shorter calving intervals (P<0.01). Calving interval was increased by 2.73 (± 0.12) d for every extra kg of milk at peak lactation (P<0.01). The calving interval was directly impacted by the persistency of milk yield, but milk yield persistency was reduced in cows with shorter calving intervals (P<0.01).

This study was designed to examine the effects of intracerebroventricular (ICV) injection of ketanserin (5-HT2a receptor antagonist) and SB242084 (5-HT2c receptor antagonist) on harmaline induced feeding and drinking response in 24-h food-deprived (FD24) broiler cockerels. At first, guide cannula was surgically implanted in the right lateral ventricle of chickens. In experiment 1, birds were injected intracerebroventriculary with 0, 25, 50 and 100 mg of harmaline. In experiment 2, chickens received 10 mg ketanserin prior to the injection of harmaline. In experiment 3, birds were administered with harmaline after 3 mg SB242084 and the cumulative food and water intake was determined at 3 h post injection. The results of this study showed that harmaline decreases food consumption and increases water intake in FD24 broiler cockerels (P£0.05). The effect of harmaline on food and water intake was significantly attenuated with ketanserin and SB242084 pretreatment (P£0.05). These results suggest that there is an interaction between harmaline and 5-HT (via 5-HT2a and 5-HT2c receptors) on eating response in chicken.

Serovar-specific real-time PCR for Salmonella enterica serovar Enteritidis (S. Enteritidis) was conducted to detect the genomic DNA of S. Enteritidis from laying goose after subcutaneous vaccination at different time points. Indirect fluorescent antibody (IFA) technique and immunohistochemical localization were employed to validate the results. The results showed that S. Enteritidis was consistently detected in all the samples. Vagina and uterus were positive at 20 h PI, and the last organ to show a positive result was the largest and third largest preovulatory follicle, at 32 h PI. The copy numbers of S. Enteritidis DNA in each tissue reached a peak at 36-60 h PI, with the vagina and uterus containing higher concentrations than other tissues. However, the number of bacteria started decreasing by 3-4 d, and by 6 d, the concentration of S. Enteritidis DNA was below the detection limits of the PCR assay, except the vagina. The real-time PCR analysis of a variety of tissues is significant for further investigation of the mechanism of vaccine protection and the optimization of vaccination regimes.

Calving records from April 1996 to December 2005 comprising 31863 calving events of 1173 dairy cows in a large commercial dairy herd were used to evaluate the effects of heat stress, using temperature-humidity index (THI) on milk yield and composition and reproductive performance of Holstein dairy cows under humid climatic conditions of Rasht in Iran. THI values were grouped into six groups: 30-40 (THI1), 41-50 (THI2), 51-60 (THI3), 61-70 (THI4), 71-80 (THI5) and 81-90 (THI6). Dairy cows in THI6 had lower milk and fat yields than other groups of THI, but cows in THI1 and THI2 had the greatest amounts of milk and fat yields, respectively (P<0.05). However, dairy cows in the second group of THI had lower percentages of fat than the sixth group of THI (P<0.05). Spring-calved cows had longer days open than cows calved in other seasons (P<0.05). Also, summer-calved cows had greater number of services per conception and lower conception rates than cows calved in other seasons (P<0.05). Dairy cows within the THI5 which calved in spring and/or calving years 2004-2005 had the longest days open (P<0.05). Cows in the second group of THI had the greatest and the lowest number of inseminations and conception rates compared with other groups of THI, respectively. The results of the present study indicated that summer heat stress negatively affected milk yield and composition and reproductive performance of dairy cows. Therefore, application of management interventions to ameliorate the effects of heat load on the performance of dairy cows could be needed in certain periods of the year under the climatic conditions.

The induction and regulation of broodiness is of the most important role of prolactin in avian species. The promoter region of the prolactin gene is an appropriate model for studying tissue-specific and hormonally-regulated activation of gene transcription. In this study, the association between prolactin promoter region alleles and egg production in Fars native chickens was investigated. In total, 100 laying hens, randomly selected from the flock of the Breeding Center for Fars Native Chicken, were genotyped for two single nucleotide polymorphisms (C-2161G and C-2402T), one 24-bp insertion-deletion at the site -358. The observed genotypic frequencies in the C-2161G site were CC (0.437), CG (0.435) and GG (0.101). Two alleles were found for the SNP of C-2402T with frequency of 0.34 for T and 0.66 for C. The 24-bp insertion-deletion at the site -358 was shown to be polymorph in the studied sample, with the observed genotyping frequency of 0.417 in II, 0.457 in ID and 0.126 in DD. Significant relationship was found between the SNPs and insertion-deletion genotypes with egg production (P<0.01).

Salinomycin is a monocarboxylic polyether ionophore with antimicrobial properties. It is a dietary additive used as a growth promoter for ruminants and as a coccidiostat in chickens. The mechanism of action of ionophores at the cellular level is to selectively bind certain ions creating intra and extracellular biochemical disturbances. Clinical signs of ionophore intoxication are non-specific and similar in all species and include tachycardia, muscle tremor, restlessness, loss of appetite, incoordination, muscular weakness and continual panting. The present study was conducted to determine the changes in ECG parameters and possible arrhythmias and their types due to experimental salinomycin toxicosis in sheep. Acute toxicity with the ionophore (0.5 mg/kg; intravenously) was induced in 6 mixed breed female sheep. A corresponding volume of sterile saline was intravenously injected in each control sheep (n=6). Blood samples were collected before and at various time intervals after the administration of either salinomycin or saline solutions. Following centrifugation, serum biochemical parameters (ALT, AST, CK, LDH and total protein) were measured using conventional laboratory methods. In both groups, the heart sounds of sheep were carefully monitored and the electrocardiogram (ECG) was recorded. Salinomycin caused a significant (P<0.05) increase in the levels of ALT, AST, LDH and CK in the experimental animals. The mean heart rate in the control group was significantly lower than that in the experimental sheep. Numerous arrhythmias such as sinus tachycardia (11 cases), ventricular premature contraction (2 cases) and T-wave inversion (3 cases) were recorded in the experimental sheep. Acute salinomycin intoxication seems to cause numerous arrhythmias in sheep which might be due to the pathological effect of the ionophore on the myocardium.

Previous studies have shown that ascorbic acid (AA) plays a crucial role in mammalian brain as a vitamin and neuronal modulator. There is increasing evidence indicating that dopaminergic system and AA could affect learning and memory processes. In addition, vitamin C acts as a dopamine antagonist in the brain. The aim of the present study was to evaluate the intra-hippocampal co-administration of AA and bromocriptine (Br), a dopamine D2 receptor agonist, on spatial memory and learning. Adult male rats were trained in Morris Water Maze task. Intra-hippocampal injection was performed through an implanted cannula in the CA1 region. Animals were divided into 12 experimental groups (n=7) including: control, AA (6, 12, 24 and 48 mg/rat), Br (0.5, 1, 2 and 2.5 mg/rat), AA plus Br (24 and 2 mg/rat), AA and Br related sham. The results showed that injection of AA caused a significant decrease in both learning and spatial memory. However, administration of Br alone or concomitant with AA caused a significant increase in learning and spatial memory as compared to the control and AA groups. These findings indicate that AA could attenuate the effects of D2 dopamine receptors agonist on spatial memory and learning.

Since sturgeons have no external sexual dimorphism and there are no external markers to determine sex, internal examination of the gonads should be used to sex identification. The present study describes the biopsy method and histological observations of the gonads of great sturgeon (Huso huso) in both sexes at different age classes. Sex and maturity stages of 226 great sturgeons were identified through gonadal biopsy and histological observations. A 20-25 mm incision was made with a sharp scalpel through the ventral midline between pectoral and pelvic fins that allowed gonads to be viewed. Determination of sex and maturity stage was successfully performed in all fish. The sex ratio under culture conditions was 1:0.84 (female: male). Most males and females were at mid-spermatogenesis and pre-vitellogenesis stages, respectively. No apparent mortality and infection was observed after surgery and gonad biopsy in fish. Results of this study showed that sex could be identified by this method when fish are 3-year-old or more. Therefore, biopsy technique is a simple and cost-effective tool in sturgeons and has an important role in aquaculture management and conservation benefits.

Congenital and acquired abnormalities of the reproductive tract of female sheep resulting in subfertility, infertility or sterility cannot easily be detected by routine clinical examination. Morph pathological abnormalities of the reproductive tract of ewes were studied by examining a total of 739 genital tracts in abattoirs of Fars province, Iran. From these, the 648 non-pregnant genitalia were examined grossly. In gross examination, 12.3% of the tracts were pregnant. Out of non-pregnant tracts, 16.6% exhibited abnormalities. Histopathologic examination of these tracts revealed endometritis 2.93%, metritis 0.3%, pyometra 0.15%, hydrometra 0.15%, papillary hyperplasia of endometrial epithelium 0.15%, endometriosis 0.3%, fatty change of myometrium cells 0.3%, multifocal to diffuse hemosiderosis 1.23%, follicular cysts 1.85%, luteinized-follicular cysts 0.6%, paraovarian cysts 0.9%, oophoritis 0.6% and Cysticercus tenuicolis cysts 0.15%. Endometritides were classified as acute or chronic. Acute purulent endometritis and chronic endometritis was diagnosed in 0.75 and 2.18% of the cases, respectively. It was concluded that endometritis and ovarian cysts were the most common abnormalities in the slaughtered ewes.

The objective was to quantify and compare cow cervical morphology on oestrus vs. non-oestrus days using a new farm technology. The cervical tissues were videotaped using a cervixscope involving new camera equipment in four Holstein cows on multiple oestrus and non-oestrus days to score tissue morphology as altered by oestrus. The non-oestrous days were in diestrus phases. The videotaped records were processed in a computer installed with image processing software. Cervix central positioning, movements, mucosal secretions, and clarity in the captured images were scored visually, each on a 5-point basis. Cervical regions were significantly more discrete, more mucosal, more central, and more stable on standing oestrus days than on non-oestrus days. During standing oestrus, the cervix was lucidly visible and rigidly positioned in the central end of vagina, whereas non-oestrus cervices were unstable and hardly separable from surrounding tissues. Findings demonstrate the on-farm feasibility of the novel inexpensive cervixscope as a farm management tool for quantifying cervix morphology.

This study was conducted to determine the electrophoretic pattern of serum protein in goats infected with Babesia ovis. Serum total protein was calculated and serum electrophoresis from 15 goats naturally infected with B. ovis as well as same number of healthy goats was performed. Microscopic examination of Giemsa-stained peripheral blood smears revealed B. ovis infection. The parasitological diagnosis was confirmed using polymerase chain reaction (PCR) assay by using a pair of B. ovis-specific primers. Mean values total protein and a and g globulin fractions in infected goats were significantly higher (P<0.05) than those observed in the healthy group.

Although the high infection rate of microscopic sarcocyst occurs in cattle, to the best of our knowledge, there is no report about the identification of macroscopic sarcocyst in Iran. In this work, Sarcosystis hirsuta was first isolated from slaughtered cattle. In a 2-year-old slaughtered cattle, morphological examination revealed 3-5 mm in length cysts distributed in different striated muscles, particularly intercostalis and diaphragm. In electron microscopy study, ultramicroscopic structure of primary cyst wall based on the presence of cone-shaped villar protrusions confirmed the occurrence of S. hirsuta.

Persistent patent urachus with other accompanying anomalies like urethral obstruction and uroperitonium quickly deteriorates animal conditions which necessitate prompt surgical intervention and animal salvage. A 10-day-old calf was referred to clinic with mildly distended abdomen, history of umbilical dribbling and no signs of normal urination since birth. On clinical laboratory results and ancillary tests persistent patent urachus complicated with imperforated urethra and uroabdomen was diagnosed. After abdominocentesis under ultrasonography, exploratory laparotomy was performed. Persistent urachus was removed and attempts failed to insert a catheter into urethra. Then, a Foley catheter was placed into bladder and passed through subcutaneous tissues and exited lateral to the umbilical region from skin. The calf voided via the catheter right after standing up and showed clinical improvement for the two months after-discharge follow up.

Overall 10389 snails were collected from four study areas of Punjab from November 2005 to October 2006. The highest prevalence (38%) was found for Indoplanorbis followed by Physa (17%), Bellamaya (10.3%), Gyraulus (10%), Lymnaea (9.2%), Oncomelania (9%) and the lowest was found for Bulinus (6.7%). Only Indoplanorbis snails were found to be positive for Schistosoma bovis cercaria. Correlation between snails’ infection and meteorological factors like relative humidity (%) and rainfall (mm) were significant (P<0.05) while this correlation was not significant for temperature (oC) and pan evaporation (mm).

A 3-year-old wild gray wolf was referred to the Department of Veterinary Clinical Sciences of Shiraz University with a history of car accident. The radiographic examination showed supracondylar distal femoral fracture in right leg. The wolf was pre-medicated by acepromazine followed by induction of anesthesia using a combination of diazepam and ketamine. Anesthesia was maintained by halothane. The fracture was reduced; the first pin was bent based on anatomical curvature of the femoral shaft and inserted from lateral epicondyle and drove proximally. The second one was inserted from medial epicondyle as a cross pin. For further stabilization, a bone plate was contoured to curve from the shaft onto the condyle and applied on lateral surface of the distal femur. The joint capsule and incision site was closed. Postoperative radiograph showed good pin placement and bone reduction. Cage rest and restricted activity was accomplished for 8 weeks. Postoperative follow up revealed no complication and the wolf was allowed to return to its domain area of wilderness four months after surgery. In conclusion, using a combination of different fixation techniques can result in successful fracture repair in wild animals.