Iranian Journal of Veterinary Research
Volume:7 Issue: 2, Spring 2006

The enzyme rhodanese (thiosulfate: cyanide sulfurtransferase) is a ubiquitous enzyme and its activity is present in all living organisms. Many functions including cyanide detoxification, formation of iron-sulfur centers and participation in energy metabolism have been attributed to this enzyme. The enzyme catalyzes the transfer of a sulfur atom from sulfane containing compounds (such as thiosulfate) to thiophilic anions (such as cyanide). The sulfhydryl group of cysteine-247 in the molecule of rhodanese participates in a double displacement of sulfur transfer mechanism. In this review attempt will be made to summarize the latest information available on the molecular properties and the pattern of distribution of rhodanese in different tissues of domestic animals and to combine these different lines of research to arrive at a plausible explanation regarding the biological function of this important enzyme in living organisms.

In the present study, pancreas glands in Mehraban breed of female sheep were histomorphometrically studied in four different age groups included: fetus, newborn, sexually mature and old ages. The results of histomorphometrical analysis with regard to frequency and percentage of parenchymal and stromal structures such as, exocrine secretory units, secretory ducts, blood vessels, islets of Langerhans and stromal connective tissue showed that minimum and maximum percentages of structures within the whole gland belonged in fetal stage, to blood vessels and stromal connective tissue; newborn stage, to blood vessels and exocrine secretory units; in sexually mature, to islets of Langerhans and exocrine secretory units and in old stage, also to islets of Langerhans and exocrine secretory units, respectively. The diameter changes of islets of Langerhans in different age groups from minimum to maximum were included: fetus, old, sexually mature and newborn stages. In comparison between different age groups, the frequency of exocrine secretory units showed a significant increase from fetal stage to newborn, sexually mature and old stages (P<0.05). On the other hand, there was a significant decrease in frequency of secretory ducts from fetal stage to newborn, sexually mature and old stages and there was also a significant decrease in frequency of blood vessels from fetal to newborn stage (P<0.05). Significant decrease was also observed in frequency of islets of Langerhans from fetal and newborn stages to sexually mature and old stages. In comparison between groups, there was a significant increase in diameter of islets of Langerhans from fetal to newborn and sexually mature stages and decrease from newborn to sexually mature and old stages. Our study revealed that, there was no significant difference in parenchymal and stromal structures and diameter of islets of Langerhans between different parts of the gland in each age group. However, the above mentioned parameters often showed significant differences between different age groups. These differences were more prominent between fetal stage compared to the other age groups. Therefore, it can be concluded that structural changes of parenchyma and stroma of pancreas gland begin from pre-natal period and will proportionally continue during the period of post-natal development.

To study the putative transfer of antibiotic resistance from broiler breeders to human, hen’s eggs and their day-old chicks were examined for the presence of bacteria. The most frequently isolated organisms in decreasing order were: Streptococcus spp., Bacillus spp., Staphylococcus spp., Klebsiella spp., Enterobacter spp. and Escherichia coli followed by Citrobacter spp., Proteus spp. and Pseudomonas spp. from the eggs and E. coli, Enterobacter spp. and Citrobacter spp. followed by Klebsiella spp. and Bacillus spp. from the chicks. Different detection methods were evaluated which use various enrichment and plating media for bacteria in eggs and day-old chicks. Sensitivity tests showed the presence of antibacterial resistant strains of bacteria. In comparison, resistance to all antibiotics in chicks’ isolated bacteria were more frequent than eggs’ isolates, but statistically no significant differences between patterns of antibacterial resistance were seen (P 0.05). Twenty-three, 54, 55, 60, 24 and 10% of chicks’ isolates were resistant to chloramphenicol, enrofloxacin, erythromycin, furazolidone, trimethoprim and tylosin, respectively. Whereas these data about eggs’ isolates were as follows: 1, 12, 18, 18, 10 and 6%, respectively. This study revealed that eggs are often contaminated with different bacteria and could be potential vehicles for transmitting of these bacteria through their broilers. Our findings stress the need for increased implementation of hazard analysis of critical control points (HACCP) and consumer food safety education efforts.

Percentages and yields of fat, crude protein (CP), true protein (TP) and non-protein nitrogen (NPN) were assessed in milk of four groups of Holstein cows, at early, mid and late lactation (days in milk 20-70, 71-110, 111-150 and 151-210), on a diet rich in concentrates during a hot summer. Four milk samples were taken from individual cows at 10-day intervals. Milk fat percentages were close to breed average and increased toward the end of lactation with a tendency (P = 0.055) for significant difference between the early and late lactation. Percentages of CP (P = 0.14) and TP (P = 0.478), however, were low similarly among all groups and did not follow the normal pattern of the breed. Percentage of NPN was significantly higher in groups III and IV (P = 0.005). Yields of fat (P = 0.035), CP (P = 0.002) and TP (P = 0.001), but not NPN (P = 0.589), decreased toward the end of lactation. There was a negative correlation (r = -0.354, P<0.001) between the percentages of NPN and TP. However, no correlation was observed between the percentages of NPN and CP. Despite a very strong correlation between yields of CP and TP (r = 0.983, P<0.001), the correlation between the yield of CP and that of NPN was much weaker (r = 0.473, P<0.001). It is concluded that percents and yields of milk fat, close to breed average are attainable at any stage of lactation on high concentrate diets in hot weather. However, regarding milk protein, cows may not perform well. TP may be more affected than CP.

An investigation was carried out to evaluate the growth performance of six commercial broiler hybrids available in Iran (Arbor Acres, Arian, Cobb 500, Hubbard, Lohmann and Ross 508). Two hundred and fifty fertile eggs of each hybrid were taken from different breeder farms, all over the country. The similarity of flocks ages and their health conditions were considered. After hatching, the sexed chicks were randomly assigned to six replicates of floor pens of 17 chicks, except the male Cobb hybrid which had five replications. All groups were managed in a similar way throughout the 56 days of study. Daily feed intake (FI) and daily body weight gain (BWG) were measured on weekly basis and the European production index (EPI) were calculated at 49 and 56 days of age. There were no significant differences among hybrids in FI during starter and grower periods (P>0.05), although significant differences were observed in finisher period (P<0.01). Differences in daily FI were significant between male and female chicks in grower and finisher periods (P<0.05), but not in starter period. Differences in daily BWG were significant among hybrids throughout the experiment (P<0.01). Sex significantly affected the daily BWG in all periods (P<0.01). The calculated EPI showed significant differences for both 49 and 56 days of age among hybrids and between two sexes (P<0.01). There were no significant differences among hybrids in carcass yield, percentage of breast and abdominal fat to carcass weight at 42 and 56 days of age. On day 42, males had more percentage of carcass and breast yield compared with females (P<0.01). Percent of abdominal fat in females on day 56 was more than that of the males (P<0.01), while on day 42 no significant differences were found in this respect.

The purpose of this study was to identify the anatomic structures of the abdominal region of cat through computed tomography (CT) to be used by veterinary radiologists, clinicians and surgeons. The abdominal region of four cats were scanned twice, with and without using contrast medium in a same position, using high-resolution imaging protocol. Slice intervals were 11 mm and were adjusted so that each vertebra was sectioned at least once. CT cuts taken with and without contrast were compared for accurate identification of specific anatomic structures. Two animals were fixed by routine anatomical method and dissected for use as reference models. Finally, important structures and landmarks were identified and labeled on the CT images.

To develop an ELISA technique for the detection of antibodies against Babesia ovis, the infected erythrocytes were lysed and the supernatant soluble antigen, after sonication and ultracentrifugation of the lysate was used as antigen. Optimal dilution of the antigen was determined by checkerboard titrations, using positive and negative control sera. A correlation of 85% was observed between the results of the developed ELISA and IFA techniques. To study the seroprevalence of Babesia ovis in Khouzestan province, south of Iran, a total of 1000 sheep sera were collected from different areas of the province and tested against Babesia ovis using the ELISA technique developed. The results showed an average seroprevalence of 47.5% in the province. Our results indicated a significant increase of the seroprevalence by advancement of age of the animals. There was no significant difference between the seroprevalence of female and male sheep.

Hydatidosis is a disease caused by infection with the metacestode stage of the dog tapeworm, Echinococcus granulosus. This is recognised as one of the world’s most important zoonoses, affecting both humans and their domestic animals. In the current study, 20 sheep cystic livers or lungs were collected. Hydatid fluid and protoscolices were isolated and the soluble protein was prepared. Polypeptide profile of hydatid fluid and protoscolices was analysed by SDS-PAGE with 12.5% acrylamide concentration. Humoral immunity and antigenic pattern were evaluated by Western blotting. In electrophoresis of hydatid fluid, five bands with molecular weight of 84, 68–70, 55, 27–28 and 16–17 kDa were observed; the 68–70 and 55 kDa bands were noticeably dominant. In Western blot of hydatid fluid protein, only 68–70 and 55 kDa bands had conciderable positive reaction. A total of 12 bands were also observed in protoscolices polypeptide profile. The molecular weight of the bands were 120, 88–89, 84, 66, 55–56, 49–50, 43–44, 36, 30–31, 24, 20 and 15–16 kDa. Seven bands with molecular weight of 66, 55–56, 49–50, 43–44, 36, 30–31 and 24 kDa had positive reaction in Western blot. We concluded that the determination of specific antigenic bands for sheep hydatid fluid and protoscolices was successfully achieved in this study.

Reproduction in domestic animals, as a major source of food and other products for human, has great importance and study of related subjects including sex differentiation and gonadogenesis during fetal life can solve many questions on normal development and various disorders of urogenital system. Since studies on sex differentiation in goat fetus are scarce, this study was performed. Twenty-five goat fetuses with 5–40 mm crown-rump lengths (CRL) were obtained from slaughter-house and fixed in 10% formalin solution immediately. The development and features of external genitalia of these fetuses as well as their sex differentiation were then examined. In externally indifferentiated fetuses, the cranial half of the body was cut away at the diaphragmatic level and serial sections, 6-micron thick, were prepared and the ovarian and testicular differentiation was studied. Results showed that considering the development of the external genitalia, external sex differentiation occurs at 31 mm CRL in male fetuses and at 33 mm CRL in female fetuses. Microscopic studies suggested that testicular tissue differentiation occurs at 23 mm CRL with formation of tunica albuginea and medullary cords. Ovarian tissue differentiation occurs at 38 mm CRL with establishment of cortical and medullary regions.

Heavy metal pollutions of aquatic ecosystems have already raised many concerns on aquatic organisms’health and survival especially on their sperm. The effects of a single metal on sperm may be totally different from cocktail of several metals because of their interactions, so the effects of zinc, cadmium and calcium on the trout and carp sperms and their competition have been examined by incubation of different concentrations of cold heavy metals with a radioactive competing metal. The results showed that radioactive 65Zn and 109Cd were not displaced from the trout sperm by calcium even at 3000 ppm concentration but radioactive cadmium was displaced equally well by cadmium or zinc, with a decrease in pellet activity to 38 and 37% of control values (0 ppm concentration) at 3000 ppm concentration, respectively in trout. Calcium was replaced by non-radioactive and radioactive zinc and cadmium as well as by calcium. The findings confirmed that at least part of heavy metals toxicity (especially cadmium) on fish sperm could be due to displacement of essential zinc and calcium. Both trout and carp sperms showed a similar pattern.

To investigate the prevalence of Mycobacterium paratuberculosis (M. avium subsp. paratuberculosis) infection among cattle slaughtered in Ahvaz abattoir, samples were taken from 250 cattle. Before slaughter, sex and age were assessed. Thereafter, samples were taken from ileocecal valve, rectum mucosa, ileocecal lymph node and stool. All smears which taken from these samples were stained by Ziehl-Neelsen method and examined by light microscopy. At first, ileocecal samples were examined; other samples were examined when ileocecal sample was positive. Out of the 250 cattle, 5 (2%) were positive. With the exception of one sample in which the organism was observed in both ileocecal valve and ileocecal lymph node, in other positive samples the bacteria was observed in only ileocecal valve smear.

Faecal samples from 291 dairy calves from 10 dairy herds in Kerman were examined to investigate the prevalence of Cryptosporidium infection. Cryptosporidium spp. oocysts were identified by using the modified Ziehl-Neelsen staining technique in 63 (21.65%) calves. Calves were grouped according to their age as follows: <3 months, 3–6 months and 6–9 months. Cryptosporidium infection was detected in 28.2, 20.6 and 15.09%, of the calves in the respective age groups. A significant age-associated decrease in the detection rate of Cryptosporidium infection (P<0.05) was found. Cryptosporidium infection was detected in 11 of the 30 (36.66%) diarrhoeic and 52 of the 261 (19.92%) non-diarrhoeic calves. There was a significantly (P<0.05) higher prevalence of Cryptosporidium infection in diarrhoeic than in non-diarrhoeic calves.

An experimental inactivated oil-emulsion H9N2 avian influenza vaccine was formulated with 3 parts of inactivated avian influenza antigen A/Chicken/Iran/101/1998(H9N2) emulsified in 7 parts of oil adjuvant. Twelve week-old specific pathogen-free (SPF) chickens were divided into seven groups of 10 birds. Six groups were vaccinated with 1, 1/10th, 1/50th, 1/100th, 1/200th and 1/400th field dose of the experimental avian influenza vaccine (EAIV). The last group, was injected with saline and served as the control group. The mean titer in haemagglutination inhibition (HI) test (log 2) on the vaccinated groups, 21 days post-vaccination were 6.0, 4.4, 3.83, 3.3, 3.0 and 2, respectively. Prevention of virus shedding through cloaca was used as the potency test which revealed that the protective doses 50% (PD50) of full, 1/10th and 1/50th of the field dose of the experimental vaccine were 100, 100 and 96.25%, respectively. Those groups that received <1/50th dose could not prevent virus shedding. So it can be concluded that EAI vaccine could even be entirely protective and efficient in 1/10th dose and got a desirable immunity in experimental SPF chickens.

Infectious bronchitis (IB) is a very contagious disease caused by a coronavirus (IBV). In chickens, the virus affects the respiratory, reproductive, and urinary systems. This study was carried out to determine the seroprevalence of anti-IBV antibodies in domestic village chickens. Serum samples of 300 domestic village chickens from Esfahan (centeral Iran) were collected and examined for the presence of anti-IBV antibodies by commercial ELISA kits. The results showed that 85.3% of the domestic village chickens had high titers of anti-IBV antibody without any clinical signs. It was concluded that the rate of IBV infection in these chickens is very high that could be a potential hazard for commercial poultry.

Rupture of the peroneous tertius was diagnosed in a 7-year-old stallion, based on clinical examinations. The stifle joint flexed as the limb was advanced forward without flexing the hock. When the limb was pulled backward, the hock joint extended but the stifle was in the normal position. The recommended treatment included complete stall rest for 6 weeks followed by limited exercise for 2 months. The animal, ultimately, returned back to its normal exercise.