Synbiotic effect of Bacillus mycoides and organic selenium on immunity and growth of marron,Cherax cainii (Austin, 2002)

The present feeding trial examined the effect of synbiotic use of Bacillus mycoides and organic selenium (OS) as Sel‐Plex on marron immunity, growth and survival. The marron were cultured in recirculated tanks and fed test diets consisting of a basal diet; basal diet supplemented with B. mycoides (10⁸ CFU g^?1 of feed); basal diet supplemented with OS (Sel‐Plex) (0.2 g kg ^{? 1} of feed) and basal diet supplemented with synbiotic (B. mycoides at 10⁸ CFU g^?1 and OS 0.2 g kg ^{? 1} feed) diet, in triplicate. The effect of the prebiotic OS (Sel‐Plex) on the growth rate of B. mycoides was also studied in vitro. The results suggested that synbiotic use of B. mycoides and OS significantly improved some immune parameters of marron, particularly the glutathione peroxidase, and to some extent total haemocyte counts. However, the synbiotic feed did not synergistically improve marron growth, in fact the use of B. mycoides‐supplemented diet alone demonstrated significantly higher growth in marron compared with the growth of marron fed on other test diets. Supplementation of the basal diet with host origin B. mycoides significantly increased the intestinal bacterial population (3.399 ± 825 CFU g ^{? 1} of gut) in marron compared with other diets. Organic selenium as Sel‐Plex in Trypticase Soya Broth also confirmed that OS did not increase the amount of growth of B. mycoides and resulted in a lower intestinal bacterial population in the synbiotic diet‐fed marron. In conclusion, synbiotic of OS and B. mycoides may improve a particular immune parameters of marron and to a lesser extent their growth.     

Encapsulation capacity of Artemia nauplii with customized probiotics for use in the cultivation of western king prawns (Penaeus latisulcatus Kishinouye, 1896)

The encapsulation capacity of Artemia nauplii with customized probiotics Pseudomonas synxantha and Pseudomonas aeruginosa for use in the cultivation of western king prawns (Penaeus latisulcatus) was investigated. Seven trials were conducted to investigate this encapsulation capacity in terms of Artemia survival and probiotic load in Artemia. Newly hatched Artemia nauplii at 250 nauplii mL^?1 were fed individual probiotics at 0, 10³, 10⁵ and 10⁷ colony‐forming units (CFU) per millilitre, and mixtures of these two probiotics (10⁵ CFU mL^?1) at 30:70, 50:50 or 70:30 v/v in a medium of ozonated water (OW), tryptone soya broth (TSB), and a mixture of these media. The appropriate medium for encapsulation of probiotics by Artemia nauplii was the mixture of OW and TSB at 75:25 v/v; whereas, the use of OW or TSB alone was not effective. Artemia nauplii most effectively encapsulated the customized probiotics at 10⁵ CFU mL^?1. The results indicates that the encapsulation of Artemia nauplii is optimized by using a combination of P. synxantha and P. aeruginosa at 50:50 v/v in a media mixture of OW and TSB at 75: 25 v/v. Artemia should be harvested at 48 h when survival is still high (78%) and the probiotic load in Artemia is high (3 × 10⁴ CFU nauplius^?1).     

Traditional Mobile Pastoralism in a Contemporary Semiarid Rangeland in Namaqualand,South Africa

Pastoral systems are regarded as complex social-ecological systems with components that interact and change over a range of spatial and temporal scales. As such, herd mobility has traditionally been used to respond to the dynamic nature of these systems. However, mobile pastoral systems around the world are becoming more constrained and increasingly fragmented with important implications for herd mobility. This study assessed the spatial distribution of 256 herds and their mobility patterns over a decade in the 10 villages that comprise the spatially constrained Leliefontein pastoral area in South Africa. We developed a hierarchical model of rangeland use, which showed that several stratified and connected socioeconomic, climatic, and environmental factors determined the spatial and temporal use of grazing areas in this 192 000-ha semiarid environment. At the highest level of use, access to the Leliefontein pastoral area is formally regulated. At the next level, the place of residence of herd owners largely defined which village commons was used by their livestock. At the third level of rangeland use, the wealth status of owners determined where in relation to human settlements their herds were located. At the lowest level in the hierarchy, the locations of water and croplands delineated seasonal grazing areas and the movement of stockposts. These stratified factors, together with the overall variability in grazing resource availability and the different decision making processes involved, resulted in high flexibility and diversity of herd mobility patterns at the lowest level of rangeland use. This, in turn, ensured heterogeneity in resource use over a range of spatial and temporal scales. It was concluded that policies should embrace the complexity of the pastoral system and enable the adaptive management of herds. This could reduce the level of vulnerability experienced by pastoralists to climate variability and wider societal change.     

COMPUTED TOMOGRAPHIC AND RADIOGRAPHIC CHARACTERISTICS OF AORTIC LESIONS IN 42 DOGS WITH SPIROCERCOSIS

Spirocerca lupi is a common cause of vomiting, regurgitation, and sudden death in dogs that live in tropical or subtropical regions. Sudden death due to aortic rupture may occur with no preceding clinical signs. The purpose of this prospective study was to compare radiographic and computed tomographic (CT) characteristics of aortic lesions in a cohort of 42 dogs with endoscopically confirmed spirocercosis. Dorsoventral and right lateral recumbent thoracic radiographic findings were compared with pre‐ and postcontrast thoracic CT findings. Aortic mineralization was detected using CT in 18/42 dogs (43%). Three dogs had faint diffuse aortic wall mineralization. Using CT as the reference standard, radiographs had a sensitivity and specificity of 6% and 96%, respectively, for detecting aortic mineralization. A total of 20 aortic aneurysms were detected using CT in 15/42 dogs (36%). Using CT as the reference standard, radiographs had a sensitivity and specificity of 86% and 56%, respectively, for detecting aortic aneurysms. Respiratory motion, aortic displacement by esophageal masses and Spirocerca nodules adjacent to the aorta mimicked aneurysm formation on radiographs. Aortic thrombi were seen in two dogs in postcontrast CT images. Findings from this study indicated that aortic mineralization and aneurysm formation are common in dogs with spirocercosis. Findings also supported the use of pre‐ and postcontrast CT as effective methods for detecting and characterizing these lesions.