IRANIAN JOURNAL OF VETERINARY RESEARCH (IJVR)
Year:2011 | Volume:12 | Issue:3 (36)|Papers Count:14

The aim of the present study was to investigate the relation between different indices of milk yield and body condition score (BCS) with the commencement of the luteal activity (C-LA) during the postpartum period in high producing dairy cows. Seventy-one multiparous healthy (free of detectable reproductive disorders) Holstein dairy cows (mean peak milk yield=56.7±7.4 kg) were used in the present study. Transrectal ultrasound scanning was performed twice weekly from the 1st to the 8th week postpartum. Blood samples were also collected twice weekly to measure serum progesterone (P4) concentrations. The BCS was monitored weekly after calving. Cows with serum P4 concentrations ³1 ng/ml on at least 2 consecutive blood samplings were considered to have commenced luteal activity. The C-LA was observed in 51 out of 71 cows (71.8%) earlier than 45 days postpartum, while 20 out of 71 cows (28.2%) showed the C-LA later than 45 days postpartum. Among the indices defined for the milk yield pattern in the present study, difference in milk yield between the 1st week and the peak week and the peak of milk yield were significantly (P£0.05) lower in cows that commenced their luteal activity earlier than 45 days postpartum. Cows losing ³1 unit BCS at the 3rd week postpartum showed their C-LA significantly later than those cows losing less BCS during the same interval (P≤0.05). In conclusion, among the different indices defined for the milk yield and BCS in the present study, the higher milk yield at the peak and lower A-BCS (Area under the chart of BCS change) were the main factors associated with delayed commencement of luteal activity in clinically healthy high producing dairy cows.

The aim of this study was to assess the effects of exogenous histamine and H1 and H2 central receptors on electrocardiographic (ECG) parameters, heart rate and mean electrical axis in broiler chickens. For this purpose, Ross broiler chickens (750-800 g weight) received intracerebroventricularly (ICV) histamine. Moreover, to determine the receptors involved in histamine-induced alterations in ECG changes, H1 and H2 blockers were administered to histamine-treated chickens. All ECGs were standardized at 1 mV=20 mm, with paper speed of 50 mm/sec. Leads I, II, III, aVR, aVL and aVF were recorded. Injection of histamine (200 and 300 mg) decreased the duration of T wave and QRS complex and elevated the heart rate as compared to the control group (P<0.05). Chlorpheniramine (100 mg), an H1 receptor antagonist, increased the duration rate of T wave and QRS complex and reduced the heart rate (P<0.05). Cimetidine, an H2 receptor antagonist (100 mg) had no effect on ECG parameters. Pretreatment with chlorpheniramine (100 mg) significantly attenuated histamine effects (200 mg) on the duration of T wave, QRS complex and heart rate (P<0.05). Mean electrical axis, calculated from leads II and III, did not differ between groups and it was between -93o and -99o in all chickens. In conclusion, exogenous histamine intracerebroventricularly results in sinusoidal tachycardia in broiler chickens and central H1 receptors mediate the stimulatory effects of histamine on heart rate, but H2 receptors had no role in this manner.

In pregnant mothers maternal diabetes happens when the pancreas cannot produce enough insulin, so blood glucose increases in the mother and then in the fetus, resulting in several injuries in neonates. This study was conducted to evaluate the effects of maternal diabetes on fetal cerebrum. Sixteen adult female rats were divided in two equal groups. Diabetes was induced in one group by alloxan. Both groups became pregnant by natural mating. At days 17, 18, 19 and 20 of pregnancy, the cerebrum was collected from the fetuses of all rats, also the body weight and number of fetuses was measured. Various histological parameters were determined using routine histological techniques. Results revealed a significant decrease in the ratio of gray matter to white matter and also the number of cells in gray matter and white matter in all days. There was also a significant decrease in thickness of gray matter at day 20 of pregnancy in the cerebrum of fetuses of diabetic mothers (FDM) as compared with the control group. The body weight of FDM was significantly (P<0.05) more than that of the control group and the number of fetuses in FDM was significantly (P<0.05) less than the control group. Maternal hyperglycemia exhibited deleterious effects on cerebrum during fetal life, which affected: cell number, gray matter to white matter ratio and thickness of gray and white matter.

Prolactin is mainly secreted by the anterior pituitary and is able to stimulate mammary gland development and lactation in mammalians. Although prolactins share a common ancestral gene encoding, they show species specific characteristics and their efficiency may be different in various mammals. The importance of protein structures of all sequences of this hormone have been studied by various bioinformatics algorithms. The results showed bioinformatics tools and modeling methods can be used to identify the species specificity of prolactin hormones in animals with an acceptable precision rate. Based on the author’s knowledge, this is the first report on the structural variation of prolactin hormones by specific structural protein features. Gain ratio model acquired the best accuracy and performance among the algorithms applied here and can be used on similar proteins. The counts and the frequencies of dipeptides were the most important protein attributes in this regard. It has also been reported here that feature selection or attribute weighting can be used to select the most important protein attributes and to reduce the burden of processing equipment. The new findings presented here open up new windows in understanding the characteristics of prolactin hormones and also pave the way to engineer more efficient hormones by using various mutagenesis tools such as site directed mutagenesis.

The objective of this study was to compare the effect of two conventional H9N2 avian influenza (AI) vaccines on replication and shedding of the H9N2 AI virus in broiler chickens. These inactivated oil emulsion vaccines contain either a UAE or an Iranian H9N2 AI isolate. One hundred and fifty one-day-old commercial broiler chickens were randomly divided into six groups. The birds, except for the control group (group 4), were challenged with a low pathogenic A/Chicken/Iran/SH-110/99 (H9N2) virus isolate. Birds in groups 1 and 5 were vaccinated with an Iranian AI vaccine and groups 2 and 6 with an UAE vaccine type. Birds in groups 5 and 6 were also vaccinated with an H120 strain of infectious bronchitis live vaccine. On days 3, 7, 11, and 15 post inoculations (PI) the trachea, lungs, kidneys and faeces were collected for molecular detection and quantitation of the H9N2 AI virus using TaqMan real time PCR assay. The results showed that frequency of virus recovery and viral titration was generally higher for unvaccinated challenged birds (group 3) on all days PI. No virus was detected in the chicks of group 1. The virus was detected in some cases in the tracheas and lungs of chicks in groups 2, 5 and 6. However, there was no statistically significant difference in viral replication in the trachea and lungs between chicks vaccinated with the UAE and Iranian type vaccines. The most frequent detection of the virus was in the kidneys in comparison with the other samples. The viral titer in the kidneys of unvaccinated challenged birds (group 3) on day 3, 7, 11 and 15 PI was higher than those of the same organs in the vaccinated challenged birds (groups 1, 2). The highest titer of the virus was observed in the faeces of unvaccinated challenged and the chicks vaccinated with the IB and UAE type vaccine (group 6) on day 7 PI. There was a statistically significant difference in viral shedding between groups (1 and 3), (2 and 3) and (5 and 6) (P=0.008). Infectious bronchitis live vaccine could increase the AI virus propagation and shedding in co-infected groups (groups 5 and 6). Altogether, both AI H9N2 vaccines could effectively reduce viral replication and shedding in broiler chicken, however, in order to achieve efficient control of the disease, vaccination should be accompanied with other preventive measurements including biosecurity practices.

An in vitro experiment was conducted to study the effect of non-fiber carbohydrates (NFC) on ruminal disappearance kinetics of dry matter (DM) and neutral detergent fiber (NDF) of alfalfa hay, wheat bran and unmolassed sugar beet pulp. Non-supplemented or NFC supplemented samples [70 mg/g DM of each feed sample as sucrose (SU) or starch (ST) or SU+ST as 1:1] were incubated in bottles containing 40% rumen fluid medium for 4, 8, 16, 24, 48, and 96 h at 39oC. After each incubation time, unfiltered content was analysed for DM and NDF. Filtered fluid was analysed for ammonia-N concentration. Kinetic disappearance rate was determined using a first order non-linear model. The source of NFC used in the medium containing alfalfa hay caused a significant decrease in DM disappearance (P<0.01). Feed source, NFC type and incubation time had a significant effect (P<0.01) on NDF disappearance and ammonia-N concentration. In vitro NDF disappearance of unmolassed sugar beet pulp and wheat bran was significantly (P<0.01) decreased by supplementing with ST and SU+ST. The indigestible dry matter fraction of alfalfa hay was significantly increased when it was supplemented by NFC (P<0.05). The rate of DM disappearance of unmolassed sugar beet pulp was also significantly influenced by supplemental NFC (P<0.05). The fractional rate of NDF disappearance of alfalfa hay and wheat bran exhibited an increase (P<0.05) in response to adding NFC when compared with the non-supplemented samples. Generally, the results of the present study suggested that in addition to the amount of supplemental carbohydrate fed, the source of supplemental carbohydrate and the basal feed sources might be effective on the effect of supplemental NFC on fiber utilization.

The aim of the present study was to find the effects of pre and post vitrification taxol treatment on bovine immature cumulus oocyte complexes (COCs). Bovine ovaries were collected from the local slaughterhouse in a container with 30-37oC physiologic saline and supplemented with antibiotics. The grade A aspirated COCs were assigned to 6 experimental groups, The 1st group was control (n=100) in which the COCs were subjected to in vitro maturation (IVM) in oocyte maturation medium (OMM). The 2nd group was the COCs (n=51) that were exposed to vitrification and warming solutions and then subjected to IVM. The 3rd group was the COCs which were incubated in OMM contained taxol (1 mM, n=51) for 20 min then transferred to IVM. The 4th group was the COCs (n=50) that were vitrified, warmed and transferred to IVM. The 5th group (n=57) was the COCs which were incubated in OMM containing taxol (1 mM for 20 min), vitrified (solutions with 1 mM taxol), warmed and transferred to IVM. The last group was the COCs (n=58) that were vitrified and warmed, then were incubated in maturation medium containing taxol (1 mM for 20) and, finally, were transferred to IVM. The COCs of all groups were incubated in OMM for 24 h under a humified (95%) condition with a temperature of 39oC and 5% CO2. Oocyte maturation was not affected by exposing the COCs to vitrification solution or taxol groups compared to control (P>0.05). Vitrification reduced the oocyte maturation rate compared to control (P<0.05). Taxol treatment (before and after vitrification) did not improve the bovine oocyte maturation rate compared to control (P<0.05). The results have shown no beneficial effect of taxol on vitrification of bovine immature oocytes.

Mastitis continues to be one of the economically most important diseases in dairy farming. Forty-six licensed dairy farms in the central region of Fars province were randomly selected in order to participate in a seasonal prevalence study. A cross-sectional study was designed to determine prevalence at cow and quarter level based on clinical signs for clinical mastitis and indirect tests for subclinical mastitis. 6180 quarters from 1545 dairy cows were tested by clinical examination and California mastitis test (CMT). Milk samples from both clinical and subclinical quarters were collected for bacteriological culture. 4714 (76.28%) quarters were healthy, 1335 (21.6%) quarters were positive by results of CMT (as indicated to subclinical mastitis), 44 (0.71%) quarters showed clinical mastitis signs and 87 (1.41%) quarters were blind. The clinical and subclinical mastitis prevalence at cow level was 2.2 and 42.5%, respectively. There was no significant difference in the prevalence of mastitis between different quarters, seasons and cities. The most prevalent isolated bacteria were coagulase positive staphylococci followed by Streptococci, Escherichia coli and coagulase negative staphylococci. Insufficient control measures such as pre and post milking hygiene and dry cow therapy in dairy farms and limited knowledge of farmers on the importance, identification and control of mastitis, especially subclinical forms, can be the main causes for the high prevalence of mastitis in Fars province.

Feline herpesvirus 1 (FeHV-1) and feline calicivirus (FCV), associated with upper respiratory tract disease, are highly prevalent in cats worldwide. With the aim of investigating the importance of FeHV-1 in a population of cats, samples were taken in a hospital in Ahvaz, south-west Iran, between June 2007 and June 2008. Oropharyngeal, nasal and ocular swabs were collected from 65 domestic cats, including 52 stray and 13 household animals and were tested for the presence of FeHV-1 DNA by polymerase chain reaction (PCR). The overall prevalence rate of FeHV-1 was 35.38%. There was a statistically significant association between the prevalence rate of FeHV-1 and the presence of respiratory signs. High prevalence of FeHV-1 infection strengthens the importance of applying hygienic and preventive measures in cats in the study area.

The effects of two Iranian medicinal plants including Zataria multiflora and Geranium pelargonium were evaluated on growth-inhibiting of some toxigenic fungi such as Aspergillus flavus, A. parasiticus, A. ochraceus and Fusarium verticillioides. In this study, standard Z. multiflora and G. pelargonium essential oils (EOs) were diluted in 0.01% dimethyl sulfoxide. Different dilutions of Z. multiflora (500, 1000, 2000 and 4000 ppm) and G. pelargonium EOs (1000, 2000, 4000 and 8000 ppm) along with 0.1 ml of each fungal suspension were inoculated onto sabouraud glucose agar and incubated at 25°C for 7 days. Zataria multiflora (³2000 ppm) and G. pelargonium (³8000 ppm) EOs completely inhibited all the tested fungi. Aspergillus species were more susceptible than F. verticillioides to two EOs. The EOs considerably exhibited inhibitory effects against these important toxigenic fungi and their different concentrations demonstrated various degrees of growth inhibition. This study showed inhibitory effects of Z. multiflora and G. pelargonium EOs against some toxigenic fungi including A. flavus, A. parasiticus, A. ochraceus and F. verticillioides.

The aim of this study was to determine the frequency of enterotoxigenic and enteroaggregative strains of Escherichia coli in chicken carcasses by polymerase chain reaction (PCR). In this study 63 strains of E. coli were isolated from 110 samples of chicken carcasses during processing after chilling in the poultry slaughter house of Shahrekord. Polymerase chain reaction assays were used to detect the presence of the genes encoding heat-stable enterotoxin a (STa), heat-stable enterotoxin b (STb), heat labile toxin (LT) and Enteroaggregative heat-stable toxin 1 (EAST1). Sixty three out of 110 (57.27%) carcasses were contaminated with E. coli. Six out of 63 (9.52%) harbored the gene for LT, 1 (1.58%) STb, 21 (33.3%) EAST1 and 8 (12.69%) contain both LT and EAST1 genes. None of the strains contain the STa gene. The results indicated that contamination of the chicken carcasses with E. coli in such a level could be a potential hazard for consumers.

In order to study the role of the kidney in fish osmoregulation, freshwater acclimatized juvenile spotted scat (Scatophagus argus L.) were subjected to four different salinities and observed for histomorphometric changes of the kidney at 1, 2, 10 and 15 days post transfer time points. The overall morphological changes displayed by fish kidney included significant decrease in the density of collecting tubules and glomeruli when subjected to higher salinity levels (10, 20 or 30 g/l) in comparison to proliferated, extensive, dense and muscular ones retained in the kidney of residents in freshwater and also of 5 g/l adapted animals. In conclusion, the observed histomorphological changes in the current study agree well with previously established physiological differences in the function of teleost kidney in freshwater and in the seawater.

An aborted female Holstein foetus with marked generalized anasarca was referred to the Excellence Centre for Ruminant Abortion and Neonatal Mortality, Ferdowsi University of Mashhad. On postmortem examination, red-tinged ascites, pale and firm liver with extreme irregularity and numerous round to oval slightly raised foci on the capsular surface were seen. Histological examination revealed widespread fibrosis, linkage of periportal areas to the central vein region and proliferation of bile ductules forming a branching network within the fibrous tissue. The lesion was diagnosed as congenital hepatic fibrosis.

In this paper, the metazoan parasite community system of Capoeta damascina in the Tigris basin (Mesopotamian region) in the Middle-East is presented. Overall, 54 species have been identified. Between 2005 and 2008, Iranian surveys of Capoeta damascina found a total of 47 metazoan parasites species, most identified to species level. In addition, 6 parasite species from Iraq and 1 species from occupied Palestine have been reported. Among these, 16 species belong to Monogenea (30%), including Dactylogyrus 9, Gyrodactylus 4, Paradiplozoon 1 and Dogielius 2 species. The remaining 70% belong to: Cestoda (7.4%) including Ligula, spp Caryophyllaeus and Coelobothrium 1 species each; Crustacea (5.55%) comprising Lernaea, Argulus Ergasilus 1 species each; Digenea (11.11%) containing Allocreadium spp, Diplostomum, Clinostomum tylodelphis, 1 species each; Acanthocephala (5.55%) 3 species; Nematoda (14%) 8 species; Myxozoa (18%) including Myxobolus with 9 species, Myxidium with 1 species and, Hirudinea 3 species; and at last, Bivalva, Unio as 1 species.