Economic assessment of commercial-scale Edwardsiella ictaluri vaccine trials in U.S. catfish industry

Abstract

Enteric Septicemia of Catfish (ESC) is a ruinous bacterial disease affecting the U.S. catfish industry. Previous attempts to develop ESC vaccines have failed to achieve industry acceptance, largely attributed to difficulties in delivering the vaccine to immunocompetent fish. Recently, a live attenuated ESC vaccine has been developed, coupled with a mechanized platform designed to accurately deliver measured doses of vaccine with feed. This delivery scheme for vaccine-feed admixture has shown tremendous promise under controlled research settings. This study evaluated the economic effects of on-going commercial-vaccination trials on catfish fingerling operations in Mississippi. Commercial-vaccination trials for both channel and hybrid catfish demonstrated significant improvement in survival, growth, feed consumption, feed conversion and gross yield. At a realistic vaccination cost of $750/ha, the net economic benefits to channel and hybrid catfish fingerling-production phases were $3199 and $6145/ha, respectively. Whole-farm models showed additional profit ranging from $71,758 to $133,887/400-ha on farms that integrate fingerling production to their production strategies due to appropriation of more of the otherwise incumbent fingerling production acreage into foodfish production. Commercial adoption of the oral-vaccination platform would greatly enhance profitability while laying the foundation for development and delivery of polyvalent vaccines against other catfish diseases.     

Short range dispersal by a rare,obligate freshwater crustacean Triops cancriformis (Bosc)

1. that there are populations of this species that, because of their unusual life history, remain undetected.
2. that this species is able to disperse over distances of several kilometres.

Incubation of sediment samples demonstrated the presence of T. cancriformis at two previously unknown sites. One further serendipitous discovery of adults at another site is also reported, bringing to eight the number of discrete ponds where this species has been recorded on the north Solway coast since 1907.

Only five natural populations are probably extant in the UK (with a sixth introduced population still extant). Four of these are on the Solway coast suggesting that this area is a conservation hotspot.

The inference from the spatial and temporal pattern of records of T. cancriformis from the Solway coast is that this species is able to disperse between discrete habitat patches over distances of at least several kilometres and successfully colonize new sites.

The mechanisms of this dispersal are unknown but transfer of material during floods or on the feet of deer, livestock, humans, waterfowl, or on farm machinery are all highly possible.

Copyright © 2013 John Wiley & Sons, Ltd.     

Evaluation of the potential use of adipose-derived mesenchymal stromal cells in the treatment of canine atopic dermatitis: a pilot study

Stem cells and their potential therapeutic uses in human and veterinary medicine have generated considerable interest. These cells have a number of potentially unique immunologic properties; most notable are their reported regenerative and antiinflammatory capabilities. The aim of this prospective pilot study was to evaluate the efficacy of intravenously administered autogenous adipose-derived mesenchymal stem cells (AD-MSCs) in the treatment of canine atopic dermatitis. AD-MSCs administered intravenously at a dose of 1.3 million cells/kg did not significantly reduce the clinical signs of canine atopic dermatitis or the owner-assessed pruritus level.     

Landscape patterns and diversity of meadow plants and flower-visitors in a mountain landscape

Context

Wild flowering plants and their wild insect visitors are of great importance for pollination. Montane meadows are biodiversity hotspots for flowering plants and pollinators, but they are contracting due to tree invasion.

Objectives

This study quantified flowering plants and their flower-visitor species in montane meadows in the western Cascade Range of Oregon. Species diversity in small, isolated meadows was expected to be lower and nested relative to large meadows. Alternatively, landform features may influence richness and spatial turnover.

Methods

Flowering plants and their visitors were sampled in summers of 2011–2017 in twelve montane meadows with varying soil moisture. All flowering plants and all flower-visitors were recorded during five to seven 15 min watches in ten 3?×?3 m plots in each meadow and year.

Results

A total of 178 flowering plant species, 688 flower-visitor species and 137,916 interactions were identified. Richness of flower-visitors was related to meadow patch size, but neither plant nor flower-visitor richness was related to isolation measured as meadow area within 1000 m. Species in small meadows were not nested subsets of those in large meadows. Species replacement accounted for more than 78% of dissimilarity between meadows and was positively related to differences in soil moisture.

Conclusions

Although larger meadows contained more species, landform features have influenced meadow configuration, persistence, and soil moisture, contributing to high plant and insect species diversity. Hence, conservation and restoration of a variety of meadow types may promote landscape diversity of wild plants and pollinators.

     

Bacterial movement at high matric potentials—II. In fungal colonies

Bacillus subtilis spread readily along water films beside hyphae of killed colonies of Pythium ultimum on membrane filters at a matric potential of —50 cm of water, but movement was restricted at — 150 cm potential. Similar rates of spread occurred when the bacteria were inoculated at a point on the surface of a layer of artificial soil, placed over the killed fungal colony and equilibrated at either of the two matric potentials. This suggests that dead fungal mycelia do not aid bacterial spread to any extent at a matric potential of —150 cm of water.When live colonies of P. ultimum were grown in the artificial soil held at the two matric potentials, the rate of bacterial movement was comparable to that in killed colonies at ?50 cm potential, but was erratic at the lower potential. The accumulation of inhibitory fungal metabolites in the thin water films beside the actively-respiring hyphae probably restricted bacterial spread at some points in the soil. It appears that dead fungal mycelia may aid in the local spread of bacteria at matric potentials higher than —150 cm of water, but live mycelia may not. The ability of bacteria to spread along dead fungal hyphae was explained by a consideration of the thickness of water films imposed by the prevailing matric potential.     

Modeling local terrain attributes in landscape-scale site-specific data using spatially lagged independent variable via cross regression

Precision Agriculture - Analysis methods for landscape-scale site-specific agricultural datasets have been adapted from a wide range of quantitative disciplines. Due to spatial effects expected at...