Investigating the population structure and genetic diversity of Arabian horses in Oman using SNP markers.

Arabian horses were selected for metabolic efficiency, beauty, efficiency and endurance. Therefore, Bedouins have for centuries traced their prized horses' ancestries. With the establishment of the World Arabian Horse Organization (WAHO), registration of Arabian horses became centralized and countries worldwide registered them in its database. Most existing Arabian horses in Oman today were imported after the 1970s and are predominantly flat-racing Arabians. This work aimed at revealing the genetic background and diversity of Omani Arabian horses by comparing them with Arabian horses from a diverse genetic background. To that end, we genotyped 63 randomly sampled Arabian horses from Oman using the Illumina Equine SNP70. For comparison, SNP genotypes of 12 Saudi Arabian horses, 27 French, 77 Egyptian, 11 Polish and 36 US Arabians were included in the study. We additionally included 17 Thoroughbred horses and 21 horses representing large and small breeds as an outgroup. Our MDS analysis and phylogenetic analysis showed that the Arabian horses in Oman cluster primarily with French Arabian horses, with a few horses clustering within the Polish/US Arabians. The French Arabian horse cluster was the closest to the Thoroughbred horses. Amongst the Arabian horses, plink average genomic inbreeding levels were highest in the Egyptian Arabian (0.169) followed by the Saudi Arabian horses (0.137) and lowest in the Omani and French Arabian horses, -0.041 and -0.079 respectively. To our knowledge, this is the first report on the genetic background and diversity of Arabian horses in Oman. Our results demonstrated a definite subpopulation structure among Arabian horses and this information should advise future decision-making on Arabian horse breeding.

Effect of heat stress on milk production, rectal temperature, respiratory rate and blood chemistry in Holstein, Jersey and Australian Milking Zebu cows.

The effect of heat stress on changes in milk production, rectal temperature, respiratory rate and blood chemistry was evaluated in three groups of six mature Holstein, Jersey and Australian Milking Zebu (AMZ) dairy cows. These animals were subjected to a cool environment when the mean temperature-humidity index (THI) was 72+/-1.4 (dry bulb temperature of 22.2-24.4 degrees C and relative humidity of 100-60%) during the month of December. This experiment was repeated during the hotter month of July of the following year, when the mean THI was 93+/-3.1 (dry bulb temperature of 35.6-43.9 degrees C and relative humidity 95-35%). Holstein cows produced more (p <0.01) milk than AMZ and Jersey cows during the cooler months of the year and all the cows were dry during the hotter months from June until September. Heat stress increased (p<0.01) rectal temperature and respiratory rate in all three breeds. Heat stress had no effect on blood pH in Holstein and AMZ cows but lowered (p <0.01) blood pH from 7.42 to 7.34 in Jersey cows. In addition, heat stress lowered (p <0.01) blood pCO2 (kPa), bicarbonate (HCO3, mmol/L), base excess (BE, mmol/L) and plasma chloride (Cl-, mmol/L) in all three breeds. The total haemoglobin (THb, g/dl) was elevated (p <0.01) in all three breeds when they were subjected to heat stress. Heat stress increased (p<0.01) oxygen saturation (O2SAT, %) in Jersey and AMZ cows but lowered it (p <0.01) in Holstein cows. On the other hand, heat stress increased (p <0.01)pO2 (kPa) in Holstein and Jersey cows but lowered it (p <0.01) in AMZ cows. Heat stress increased (p <0.01) plasma potassium (K, mmol/L) and calcium (Ca, mmol/L) only in Holstein and Jersey cows but lowered them (p<0.01) in AMZ cows. The plasma glucose (GLU, mmol/L) increased (p<0.01) with heat stress in Holstein and AMZ cows but decreased (p <0.01) in Jersey cows. Heat stress increased (p<0.01) plasma creatinine (CR, (mol/L) but lowered (p<0.01) plasma creatinine phosphokinase (CPK, IU/L), aspartate aminotransferase (AST, IU/L) and blood urea nitrogen (BUN, mmol/L) in all three breeds. These results indicate that heat-stressed Holstein and AMZ cows were able to maintain their acid-base balance with a marginal change in their pH of 0.02 when their rectal temperatures increased by 0.47 and 0.38 degrees C, respectively. When heat stress increased the rectal temperature in Jersey cows by 0.70 degrees C, the pH decreased (p<0.01) from 7.42 to 7.34. However, even with this decrease 0.08 the pH is still within the lower physiological limit of 7.31.

Serum vitamin B12 levels in Omani goats.

Blood and faecal samples were studied from 200 Omani goats of both sexes and various age groups, within five different regions in Oman. Survey questionnaires were undertaken on each goat. The serum vitamin B12 values ranged from 105 to >2000 pg/ml, with a mean value of 723.1 pg/ml and a 95% confidence interval of 61-1507 pg/ml. Kids in the age group 1-3 months showed significantly lower levels of serum vitamin B12 than the older animals. Varying levels of serum vitamin B12 were found in different regions of Oman and on farms within the same region. Goats maintained on commercial feed showed higher levels of serum vitamin B12 than those maintained on pasture or fed on household leftover food, as commonly practised in Oman. Coccidial counts were highest in animals with lower levels of serum vitamin B12. The results of this study indicate that there is a wide range of serum vitamin B12 levels in Omani goats and suggests that younger animals, with lower levels of serum vitamin B12, might be more susceptible to vitamin B12 deficiencies than older animals.

Comparative effect of low levels of dietary cobalt and parenteral injection of vitamin B(12) on carcass and meat quality characteristics in Omani goats.

The effect of low levels of dietary cobalt (Co) on carcass and meat quality characteristics were investigated in 36 male goats of three different Omani breeds namely Batina, Dhofari and Jabal Akdhar. Goats were randomly divided into two groups at 10 weeks of age, control (18 animals) and treated (18 animals). Goats from both groups were fed Rhodesgrass hay and a commercially prepared diet containing 0.10 and 0.12 mg Co/kg DM, respectively from 10 to 46 weeks of age. Animals in the treated group were supplemented with subcutaneous injections of 2000 µg of hydroxocobalamin (vitamin B(12)) on week 10 and thereafter for 46 weeks at 8-week intervals. At 46 weeks of age, the animals were slaughtered and their carcass and meat quality characteristics compared. Serum vitamin B(12) levels were significantly higher in goats from the treated group from week 16 till the end of the experiment. The final live and carcass weights were significantly higher (P<0.05) for the treated Batina group by 13.4 and 8.3% compared with the control group, respectively. Shoulder, rack, loin and leg cut weights were also significantly higher (P<0.05) for the Batina treated group compared with the control group by 14.7, 16.8, 12.8 and 13.1%, respectively. Carcass length, leg length, width behind shoulder, maximum shoulder width and longissimus muscle area were significantly higher (P<0.05) for the Batina treated breed than for the control group by 6.7, 5.8, 10.1, 10.1 and 28.5%, respectively. Four muscles (Mm. longissimus dorsi, biceps femoris, semimembranosus, and semitendinosus) from treated and control groups were evaluated for ultimate pH, expressed juice, cooking loss%, colour (L*, a* and b*), and Warner-Bratzler shear force values. There were significant treatment effects on these muscle quality characteristics for the Batina breed only. Muscles from the treated group showed significantly lower (P<0.05) shear force values of between 15 and 27% than those from the control group. Moreover, the treated Batina goats tended to have significantly lower (P<0.05) ultimate pH, expressed juice, L* and higher a* values than those from the control group for longissimus dorsi and biceps femoris muscles only.

The effects of breed, neonatal age and pregnancy on the plasma copper status of goats in Oman.

There is a history of copper deficiency in grazing Omani livestock and the copper status of three economically important goat breeds, Jabal Akhdar (JA), Batina (B) and Dhofari (D) were therefore compared in October/November (cool season) and June (dry season) in a penned flock given a plentiful dietary supply of copper. In the cool season, 62 lactating does (5 JA, 12 B and 33 D), their 0-5-day-old kids (17 JA, 19 B and 22 D) and 25 dry does (17 JA, 5 B and 3 D) were blood sampled. In the dry season, the does sampled were either barren (15 JA, 16 B and 13 D) or pregnant (9 JA, 13 B and 33 D). The samples were analysed for total copper (TCu) and trichloroacetic acid (TCA)-soluble copper (TCA-sol Cu). There were no effects of breed on TCu or TCA-sol Cu in the cool season, the overall means being 0.75 (SE 0.049) and 0.59 (SE 0.052) mg/L. The mean TCu was low in kids at birth (0.59 mg/L) but had increased to 0.86 mg/L by 4 days of age (p < 0.001); breed differences were found (p < 0.002), the pooled values for JA, B and D being 0.77, 0.59 and 0.68 (SE 0.033-0.044) mg/L, respectively. By the dry season, the mean TCu had risen in barren does to 0.96 (0.045) mg/L but not in pregnant does (0.76 (0.047) mg/L: p < 0.002) and breed differences had emerged, the mean for D being 20% lower than those for JA and B (p < 0.05). The highest TCu values were found in the 7-month-old kids in June ( 1.17 (0.039) mg/L) but the breeds did not then differ. Some effects on TCA solubility were found but were considered unreliable. Breed effects may have been diminished by the generous supply of copper and early stage of lactation studied.

An outbreak of lymphadenitis associated with Stenotrophomonas (Xanthomonas) maltophilia in Omani goats.

Stenotrophomonas maltophilia is a commonly isolated organism from human clinical specimens and is gaining significance as a pathogen in immunocompromised patients and nosocomial infections. In most cases it is difficult to establish the source of human infections. In veterinary medicine, S. maltophilia is not generally considered a primary pathogen. In the present study, we report the occurrence of 16 cases of caprine abscess from which S. maltophilia was isolated in pure culture from 15 animals. In six animals, the abscesses were confined to the pre-scapular lymph nodes but in the remaining nine, the cutaneous abscesses were multiple and extended from the neck to the inguinal area. The possibility is suggested that goats in Oman, which often live in close proximity to humans, might potentially serve as a reservoir of infection.

Ultrastructural observations on the platelets of the Arabian tahr (Hemitragus jayakari).

The ultrastructure of platelets was studied in specimens of peripheral blood from 18 healthy adult Arabian tahrs (Hemitragus jayakari). The platelets were characterized by their extreme polymorphism. The number of alpha granules, typically one to six per cell, was considerably less than that reported for most animal platelets. Similar to humans, the platelets of the Arabian tahr had nucleoids within the alpha granules. However, nucleoids were not a consistent finding. One or more electron-dense granules, most commonly contained within clear vesicles, was commonly observed. A unique feature was the lack of an open canalicular system, which is considered a hallmark feature of this cell type in most mammalian and reptilian platelets.

Observations on haemoglobin types in three breeds of Omani goats.

Haemoglobin (Hb) types were studied in three breeds of Omani goats, Batinah (n = 22), Jebel Akhdar (n = 27) and Dhofari (n = 85). Type A was the only adult Hb observed in adult Batinah and Jebel Akhdar goats. In contrast, only 34% of the Dhofari goats were homozygous for Hb A, while 66% were heterozygous for Hb A and Hb B. Dhofari goats with type AB could further be differentiated into those with approximately 67% type A and 33% type B and those with approximately 33% type A and 67% type B. None of the goats was homozygous for type B. Seventeen kids observed from birth exhibited different levels of fetal Hb, dependent upon whether they developed the adult phenotype AA or AB. Kids that became homozygous for type A were born with approximately 90% Hb F and 10% Hb A. In contrast, goats that developed the heterozygous AB phenotype were born with only 30-60% Hb F, the remaining Hb being types A and B. These findings are not in accordance with previous reports that kids are born without any adult Hb. Hb F was no longer detectable in any of the three breeds of goats at 49 days of age. There was no evidence of Hb C, the pre-adult form of Hb.

Ultrastructural changes in caprine lungs infected with Mycoplasma capricolum subspecies capripneumonia.

Ultrastructural examination of the lungs from goats with natural infections with Mycoplasma capricolum subspecies capripneumonia, the causative agent of contagious caprine pleuropneumonia, revealed extensive hyperplasia of type II pneumocytes. Typically, these type II cells contained abundant numbers of osmiophilic lamellar bodies that had lost most of their characteristic lamellar ultrastructure. These findings were absent in healthy control goats.

Hypospadias in a Himalayan cat.

A one-year-old male Himalayan cat was presented with a history of chronic cystitis. Physical examination revealed that the cat had hypospadias. It was postulated that the abnormal urethral opening on the ventral aspect of the penis permitted faecal contamination of the preputial area and gave rise to the ascending infection. The hypospadias was surgically corrected and a complete recovery was achieved.

Sudden cardiac death from thrombotic thrombocytopenic purpura.

Clinical thrombotic thrombocytopenic purpura (TTP) is characterized by a pentad of microangiopathic hemolytic anemia, thrombocytopenia, neurological symptoms, renal involvement, and fever. A case of TTP in which early symptoms and signs were suggestive of ischemic heart disease, renal failure, and severe thrombocytopenia developed to a rapid outcome of death. The postmortem examination revealed coronary artery microthrombi, typical of TTP. The clinical presentation of this TTP was atypical: severe thrombocytopenia, striking renal and CNS symptoms were present, but fever and anemia were not present. Thrombotic thrombocytopenic purpura is an uncommon condition that carries a high fatality rate if untreated. Awareness of this syndrome and its high risk of sudden death underlines the importance of rapid diagnosis and treatment.

An abattoir survey of caprine liver diseases in the sultanate of Oman.

The examination of 675 caprine livers from a slaughterhouse in the Greater Muscat area in the Sultanate of Oman revealed that 63 (9.3%) exhibited gross pathological changes leading to condemnation of this organ. Forty of these livers (71.4%) exhibited one major abnormality, whereas the remaining 28.6% had two or more lesions. The most frequently occurring disorder was diffuse hepatic lipidosis (4.0%), followed by bacterial associated abscesses (2.4%), cysticercosis (1.9%), and eosinophilic granulomata (1%). Although the cause for the hepatic lipidosis was not determined it appeared to be a reversible condition based on the absence of degenerative nuclei within the affected hepatocytes. Conditions observed in only a single liver were subcapsular (non-parasitic) cysts, focal necrosis, micronodular cirrhosis, extensive bile duct proliferation and diffuse haemorrhage.

Atypical outbreak of caprine cryptosporidiosis in the Sultanate of Oman.

An outbreak of cryptosporidiosis occurred in goats ranging in age from two days to adult, on a well-managed closed farm. None of the other animals on the farm, including sheep, cows and buffalo, were affected. Morbidity approached 100 per cent in goats less than six months of age. Despite intensive supportive care, 238 goats died, ranging in age from two days to over one year. Cryptosporidia were detected in large numbers in the intestinal contents of dead animals and in faecal smears of animals with diarrhoea. Massive numbers of the organisms were also demonstrated histopathologically and by electronmicroscopy, and no other significant pathogens were detected. The outbreak was unique in terms of the extreme virulence of the organism, its apparent species-specificity, and the shedding of the organism by animals over four weeks of age.

Hepatic lipidosis associated with cobalt deficiency in Omani goats.

Livers from 36 of 684 (5.3%) apparently healthy goats examined at an abattoir in the greater Muscat area of Oman exhibited gross pathological findings characterized by extremely pale, friable, fatty livers encompassing the entire organ. Histopathologically, diffuse hepatic lipidosis and occasional bile duct proliferation were observed. Periodic acid Schiff-positive, diastase-resistant pigment was observed in the macrophages lining the sinusoids. These histopathological lesions were consistent with those characteristic of ovine white liver disease. Cobalt analysis revealed that normal livers had six times more cobalt and a 3-fold less fat content than those measured in the fatty livers. This is the first report of an association between cobalt deficiency and hepatic lipidosis in Omani goats.

A cerebral primitive neuroectodermal tumor in a squirrel monkey (Saimiri sciureus).

An adult squirrel monkey with a history of long-term exposure to microwave radiation was found at necropsy to have a malignant tumor of the right cerebral cortex. Gross examination revealed a mass with expanding borders in the right frontoparietal cortex with compression of the adjacent lateral ventricle. Microscopy revealed a tumor composed of sheets of moderate-sized cells, resembling an oligodendroglioma, with clear cytoplasm and central nuclei interrupted by delicate vasculature. Malignant features were present in the form of marked nuclear pleomorphism, frequent mitotic figures, and focal necrosis. A neuronal cell origin for this tumor was supported by immunohistochemical analysis, which revealed immunopositivity for neurofilament proteins and neuron-specific enolase. Staining for vimentin and glial fibrillary acid protein was negative, except in reactive astrocytes at the tumor margins and adjacent to intra-tumoral blood vessels. Antibody activity against Ki-67 antigen, a marker of rapidly proliferating tumor cells, and p53 oncoprotein was strongly positive, indicative of the aggressive and malignant nature of this tumor. The tumor was diagnosed as a cerebral primitive neuroectodermal tumor.

The ultrastructural morphology of the camel eosinophil.

The ultrastructural morphology of the eosinophil was studied in specimens of peripheral blood from normal adult camels and those with eosinophilia. Specific granules were extremely polymorphic. The specific granules exhibited the basic structure of an electron-dense crystalloid core surrounded by a lighter, homogeneous matrix. The crystalloid cores were extremely variable in size and shape, often were segmented and demonstrated a variety of lamellated patterns that were transverse, longitudinal or concentric to the long axis of the core. It was not uncommon to observe multiple crystalloid cores in a single granule. In addition to large specific granules, microgranules and specific microgranules were observed. The extreme polymorphism of the specific granules and variety of lamellated patterns differentiate camel eosinophils from those of other species.

Dientamoeba fragilis: the unflagellated human flagellate.

Dientamoeba fragilis is a pathogenic protozoan parasite with a world-wide distribution. Although originally described as an amoeboid organism, it has been reclassified as a flagellate, on the basis of a number of electron microscopic and immunological findings. Except for its lack of a flagellum, D. fragilis closely resembles Histomonas and Trichomonas. Interestingly, a resistant cyst stage has not been demonstrated and it is unlikely that its trophozoites can survive successfully outside the human host. As a consequence of its higher than anticipated coincidence of infection with Enterobius vermicularis, transmission may occur via ova of this pinworm. D. fragilis infection may be acute or chronic, and has been reported in both children and adults. The most common clinical symptoms include abdominal pain, persistent diarrhoea, loss of appetite, weight loss and flatulence. Occasionally, eosinophilia, urticaria and pruritus have been described. Demonstration of the characteristic nuclear structure of D. fragilis, needed for a definitive diagnosis, cannot be achieved in unstained faecal material; therefore, permanently stained smears are essential. Treatment is recommended in symptomatic cases, and iodoquinol, tetracycline and metronidazole have been used successfully.

A light and ultrastructural study of rice bodies recovered from a case of date thorn-induced extra-articular synovitis.

Rice bodies are most commonly found in inflammatory joints of patients with rheumatoid arthritis and have traditionally been considered to be a nonspecific response to inflammatory synovial disease. In the present study 18 rice bodies were found in the tibialis tendon sheath of a nine-year-old Omani boy subsequent to a date thorn injury. The rice bodies consisted of three major components: fibrin, collagen, and fibroblasts. In contrast to the findings of other authors there were no type A, B, or C synoviocytes, cartilage, or vascularisation of the rice body. At this extra-articulate site it would appear that rice bodies are composed chiefly of fibrin and that the fibrosis of the rice body occurs as a result of the entrapment of fibroblasts, which subsequently produce collagen. These findings shed doubt on the synovial origin of rice bodies and suggest that rice bodies may have multiple origins, depending on their location. This is the first ultrastructural study of rice bodies associated with a date thorn injury.