Arbuscular mycorrhizal fungal association in Asteraceae plants growing in the arid lands of Saudi Arabia

The present research was undertaken to explor the possibility of arbuscular mycorrhizal(AM) association with Asteraceae plants in the arid lands of Saudi Arabia(Al-Ghat, Buraydah, Thumamah and Huraymila). AM fungal colonization in the roots, spore numbers in the rhizosphere soil, fungal species diversity and correlation between AM properties and soil properties were determined. The highest colonization was in Conyza bonariensis(65%) from Al-Ghat, Anthemis cotula(52%) from Buraydah and C. bonariensis(53%) from Thumamah. The lowest was in Vernonia schimperi(41%) from Al-Ghat, Pulicaria undulata(25%) from Buraydah, Acanthospermum hispidum(34%) from Thumamah, Asteriscus graveolens(22%) and V. schimperi(22%) from Huraymila. Vesicular and arbuscular colonization were also presented in all plant species examined. The number of spores were 112–207 in Al-Ghat, 113–133 in Buraydah, 87–148 in Thumamah and 107–158 in Huraymila. Funneliformis mosseae, Glomus etunicatum, G. fasciculatum and G. aggregatum were identified. Relative frequency of AM fungal species varied widely and was irrespective of location and plant species. Diversity index varied with the rhizosphere soils of different plant species at various locations. Soil properties varied with locations and no distinct correlations were observed among the soil properties, root colonization and the number of spores. The results of the present study specified the association of AM fungi in different plants of Asteraceae and its significance in the ecological functioning of annual plants in the punitive environments of the rangelands in Saudi Arabia.     

Patterns of disease and host resistance in spatially structured systems

We use data from species of the anther-smut fungi and the host plants Lychnis alpina and Silene dioica to show that spatial structuring at different scales can influence patterns of disease and host resistance. Patterns of disease and host resistance were surveyed in an archipelago subject to land-uplift where populations of S. dioica constitute an age-structured metapopulation, and in three contrasting areas within the mainland range of L. alpina, where population distributions range from continuous, through patchy but spatially connected to highly isolated demes. In S. dioica, disease levels depend on the age, size and density of local patches and populations. Disease is most predictably found in larger dense host patches and populations of intermediate age, and more frequently goes extinct in small old populations. The rate of local disease spread is affected by the level of host resistance; S. dioica populations showing an increase in disease over time are more susceptible than populations where the disease has remained at low levels. Among-population variation in resistance is driven by founding events and populations remain differentiated due to limited gene flow between islands. As observed in the L. alpina system, when populations are more connected, a greater fraction of populations have disease present. Results from a simulation model argue that, while increased dispersal in connected systems can increase disease spread, it may also favour selection of host resistance which ultimately reduces disease levels within populations. This could explain the observed lower disease prevalence in L. alpina in regions where populations are more continuous.     

Canine mammary gland tumours; a histological continuum from benign to malignant; clinical and histopathological evidence*

This study describes the clinical and histopathological findings in dogs with mammary gland tumours, and compares the histopathological and clinical evidence consistent with progression from benign to malignant to human breast cancer epidemiology. Clinical and histopathological data on 90 female dogs with 236 tumours was included. Dogs with malignant tumours were significantly older than dogs with benign tumours (9.5 versus 8.5 years), P = 0.009. Malignant tumours were significantly larger than benign tumours (4.7 versus 2.1 cm), P = 0.0002. Sixty‐six percent had more than one tumour, and evidence of histological progression was noted with increasing tumour size. Dogs with malignant tumours were significantly more likely to develop new primary tumours than dogs with benign tumours, P = 0.015. These findings suggest that canine mammary tumours progress from benign to malignant; malignant tumours may be the end stage of a histological continuum with clinical and histopathological similarities to human breast carcinogenesis.     

Serum total thyroxine and thyroid stimulating hormone concentrations in dogs with behavior problems

The aim of this case controlled study was to determine whether dogs with behavioral problems have evidence of abnormal thyroid function on routine screening tests for hypothyroidism. The hypothesis of the study was that thyroid function, as assessed by serum total thyroxine (TT4) and serum thyroid stimulating hormone (thyrotropin) (TSH) concentrations, is normal in most dogs with behavioral problems. Concentrations of TT4 and TSH in 39 dogs with behavior problems presenting to a veterinary behavior referral clinic (abnormal behavior group), were compared with TT4 and TSH concentrations in 39 healthy control dogs without behavior problems presenting to 5 community veterinary practices (control group). Dogs in the control group were matched for age and breed with the abnormal behavior group. Dogs with behavioral problems had higher TT4 concentrations than dogs without behavioral problems (t-test: t = 2.77, N = 39, P = 0.009), however none of the TT4 values were outside the reference range. There was no significant difference in TSH concentration between the 2 groups. Two dogs with behavior problems and 1 dog without behavior problems had results suggestive of hypothyroidism. All other dogs were considered to be euthyroid. There was no evidence to support a diagnosis of hypothyroidism in the majority of dogs with behavior problems in this study. The higher concentration of TT4 in dogs with behavior problems suggests, however, that alteration in thyroid hormone production or metabolism may occur in some dogs with behavior problems. Further studies that include additional indicators of thyroid status such as serum total triiodothyronine, serum, free thyroxine, and anti-thyroid antibody concentrations are necessary to further evaluate the significance of this finding.     

中国生猪健康养殖业发展的战略思考

作者在分析生猪健康养殖业发展背景的基础上,以实现动物健康、人类健康、环境健康、产业链健康为目的,从质量保障和价值保障2个方面构建了生猪健康业发展的目标体系及其实现途径,重点从技术体系、组织结构、运行机制、适度规模等方面提出了生猪健康养殖业发展的保障策略。     

A retrospective study of wildlife rabies in Zimbabwe,between 1992 and 2003

To assess the epidemiological features of wildlife rabies in Zimbabwe, a retrospective study covering a period of 12 years (1992–2003) was conducted using rabies records of the Central Veterinary Laboratories (CVL), Department of Veterinary Technical Services at Harare. Records of monthly and annual wildlife rabies were perused with regard to total samples submitted to the CVL and corresponding positive cases. Positive cases were analyzed in relation to the animal species involved, seasonal trends, and land-use categories. A total of 2107 samples were submitted and 1 540 (73.1%) were positive. Jackals (Canis mesomelas and C. adustus), with a peak occurrence of rabies between January and March were the major maintenance host, representing approximately 91% of the total rabies cases confirmed. The Canidae family recorded the highest number of cases followed by the Viverridae, Mustelidae, Felidae, Herpestidae and Hyaenidae families in that order. During the present study rabies cases were confirmed in 7 additional wild animals. The majority of the positive cases (83.7%) were recorded in commercial farming areas in the northeast parts of the country.     

Deformation of the equine pelvis in response to in vitro 3D sacroiliac joint loading

Reasons for performing study: Sacroiliac joint injuries can cause poor performance; however, the interaction between pelvic mechanics and the sacroiliac joint is poorly understood. Objective: To measure pelvic displacement during 3D sacroiliac joint loading. Methods: Nine reflective triads were attached rigidly to bony prominences in sacropelvic specimens harvested from 14 horses for stereophotogrammetric analysis of triad displacements and joint kinematics. The sacrum was coupled to a load cell and mounted vertically within a material testing system (MTS). A pneumatic actuator was used to apply 90 Nm moments to the ischial arch to simulate nutation‐counternutation and left and right lateral bending of the sacroiliac joints. Axial rotation of the sacrum was induced by torsion of the upper MTS fixture. Vectors of marker displacement within orthogonal planes of motion were measured during loading of the sacropelvic specimens. Comparisons in the magnitude and direction of triad displacements were made between paired left‐right markers and paired loading conditions. Results: Nutation‐counternutation of the sacroiliac joint caused vertical displacement of the ischial tuberosities and cranial‐caudal displacement of the wings of the ilium. Lateral bending induced rotational displacement within the horizontal plane of all pelvic landmarks, relative to the sacrum. Axial rotation of the sacrum caused elevation of the wing of the ilium ipsilateral to the direction of sacral rotation and depression of the contralateral ilial wing. Significant paired left‐right differences occurred during most sacroiliac joint loading conditions. Comparable magnitudes of pelvic displacement were measured during nutation‐counternutation, left and right lateral bending, and left and right axial rotation. Conclusions: The equine pelvis is not a rigid structure and asymmetric pelvic deformation occurs during most sacroiliac joint movements. Clinical relevance: Bony pelvic deformation should be considered a normal response to any sacroiliac joint movement.     

Histological and immunohistochemical evaluation of duodenal and colonic biopsies after oral bovine lactoferrin supplementation in beagle puppies

Lactoferrin is a natural compound in the milk of mammals and was shown to influence the intestinal micro‐flora and the immune system in mice, calves, dogs and man. The present study was carried out to investigate the effect of orally administered bovine lactoferrin (0, 30, 60 and 120 mg/kg DM feed) on the intestinal morphology and lymphocyte colonization in 36 motherless raised puppies. Endoscopic biopsies from duodenum and colon, taken in week 14, were scored histologically after staining with haematoxylin and eosin (H&E) and lymphocytes (CD3⁺, CD4⁺, CD8⁺) and plasma cells (IgA⁺, IgG⁺, IgM⁺) were enumerated after immunohistochemical staining by computer‐aided quantification. Histological scoring revealed no significant differences amongst the groups. IgG⁺ plasma cells were reduced (p < 0.05) in the lamina propria of the colon of the 30 and the 60 mg group. The number of CD8⁺ lymphocytes was higher (p < 0.05) in the epithelium of the colon of the lactoferrin groups. In conclusion, this study indicated only minimal effects of bovine lactoferrin on the population of selected immune cells in the gut mucosa of puppies. More investigations are needed to describe the impact of lactoferrin on the digestive physiology of puppies.     

Response of broiler finishers to diets containing graded levels of processed castor oil bean (Ricinus communis L) meal

A 4‐week feeding experiment was conducted to determine the effects of graded levels of dehulled and cooked castor oil bean (Ricinus communis L) meal on the performance of broiler finishers. Castor oil bean seeds were dehulled and detoxified by cooking in two stages at 100 °C for 50 min per cooking. Sixty 6‐week‐old broiler birds (Anak strain) were randomly divided into four groups of 15 birds each. The groups were fed four isocaloric (2.90 Mcal of metabolizable energy/kg) and isonitrogenous (21% crude protein) diets containing 0%, 10%, 15% and 20% dehulled and cooked castor oil bean meal (CBM) for 4 weeks. Results showed that there were significant (p < 0.05) differences among treatments in average daily feed intake, final body weight, average daily weight gain (ADWG), feed conversion ratio (FCR) and protein efficiency ratio (PER). Birds fed diets containing 0% and 10% CBM had significantly (p < 0.05) higher feed intake than birds on 15% and 20% CBM diets. The lowest feed intake was recorded at the 20% CBM inclusion level. The highest ADWG was observed in birds fed 0% CBM diet, but this was not significantly (p > 0.05) different from the ADWG of birds on 10% CBM diet. Birds fed diets containing10% and 15% levels of CBM had similar and non‐significant (p > 0.05) ADWG. Birds fed 20% CBM diet had the least (p < 0.05) ADWG. Birds fed 0%, 10% and 15% CBM diets had similar FCR and this was significantly (p < 0.05) lower and better than that of birds on 20% CBM diet. The least (p < 0.05) PER was observed in birds fed 20% CBM diet. Birds fed 20% CBM diet had significantly (p < 0.05) higher packed cell volume (PCV) than birds on 10% and 15% CBM diets. Birds fed 0%, 10% and 15% CBM diets had similar (p > 0.05) PCV values. Birds fed diets containing 0%, 10% and 15% levels of CBM had similar and significantly (p < 0.05) lower heamoglobin than birds fed 20% CBM diets. There were also significant (p < 0.05) differences among treatments in dry matter (DM), nitrogen, ether extract (EE) and nitrogen‐free extract (NFE) retention. Birds fed 0% CBM diet had significantly (p < 0.05) higher retention of DM, nitrogen and NFE than birds on 10%, 15% and 20% CBM diets. Birds fed 10% CBM diet had significantly (p < 0.05) higher DM, nitrogen and NFE retention than birds on 15% and 20% CBM diets. The lowest retention of DM, nitrogen and NFE was recorded at the 20% CBM inclusion level. Birds fed 0% CBM diet had significantly (p < 0.05) higher EE retention than birds on 15% and 20% CBM diets. The lowest EE retention was observed at the 20% CBM inclusion level. The results of the study indicate that up to 10% dehulled and cooked CBM can be included in broiler finisher rations for optimum performance.