A demographic survey of unwanted horses in Ireland 2005-2010

Background

The Irish Horse Industry expanded during the Celtic Tiger boom years, then contracted in the current economic recession. High value horses were traditionally controlled through sale at public auction, private sales and sales to dealers; these are now also being reduced by decreases in production (> 40%), and increases in retirement, re-homing, euthanasia and disposal through Category 2 plants and abattoirs. The absence or banning of horse abattoirs has been shown to have very significant welfare social and economic consequences in the USA. This study described the currently available data on the demographics of unwanted horses in Ireland from 2005 to 2010.

Results

The majority of horses euthanised by practicing veterinarians are destroyed on medical grounds but the number euthanised at the request of welfare groups and the state, as well as welfare related calls and the number of horses involved in these calls and subsequent visits is increasing reflecting the increasing involvement of the veterinary profession in equine welfare. Welfare groups have limited resources and do not have a tradition of recording data, but they too have reported increasing calls, visits and numbers of horses per visit. Welfare groups provide significant service to equine welfare and the community. Local Authorities report similar trends. Over 300 horses were found dead or required immediate or subsequent euthanasia following welfare group and local authority visits in 2010, which is of national concern. The majority of local authority interfaces with unwanted horses are with urban (60%) rather than rural (40%) horses. Mortality figures are poor indicators of non-fatal neglect. More horses were admitted into the care of local authorities than welfare groups, reflecting significant state and taxpayer investment in the control of low value horses. Category 2 plants and abattoirs represent a significant state investment in licensing and control in the national interest. Abattoirs provide an increasingly important and essential service for the disposal of unwanted horses. Despite the increase in unwanted horses, Ireland is a minority contributor to the EU slaughter total.

Conclusions

There is a need for annual demographic data compilation and review of the numbers of unwanted horses and ponies within the horse industry to assist policy makers and legislators.     

Density‐dependent growth and survival in salmonids: Quantifying biological mechanisms and methodological biases

Understanding the complex variation in patterns of density‐dependent individual growth and survival across populations is critical to adaptive fisheries management, but the extent to which this variation is caused by biological or methodological differences is unclear. Consequently, we conducted a correlational meta‐analysis of published literature to investigate the relative importance of methodological and biological predictors on the shape and strength of density‐dependent individual growth and survival in salmonids. We obtained 160 effect sizes from 75 studies of 12 species conducted between 1977 and 2019 that differed in experimental approach (sensu Ecological Monographs, 54, 187–211; 65 laboratory experiments, 60 observational field studies, and 35 field experiments). The experimental approach was the strongest factor influencing the strength of density dependence across studies: density‐dependent survival was stronger than growth in field observational studies, whereas laboratory experiments detected stronger density‐dependent growth than survival. The difference between density‐dependent growth and survival was minimal in field experiments, and between lotic and lentic habitats. The shape of density dependence (logarithmic, linear, exponential or density‐independent) could be predicted with 66.7% accuracy based solely on the experimental approach and the density gradient (highest/lowest*100) of the study. Overall, the strength and shape of density dependence were primarily influenced by methodological predictors, while biological factors (predator presence, food abundance, and species) had predictable but modest effects. For both empirical studies and adaptive fisheries management, we recommend using field experiments with a density gradient of at least 470% to detect the proper shape of the density‐dependent response, or accounting for potential biases if observational or laboratory studies are conducted.     

Growth of Juvenile Scup,Stenotomus chrysops,Fed Three Commercial Diets

Juvenile scup, Stenotomus chrysops, 0.5–1.5 g weight were fed three different commercial diets for six weeks to determine growth rates. Diets were hand-distributed to triplicate groups of 30 fish, four times a day. Survival for all treatments was 93%. The diets used were INVE Aquaculture NRD marine diet (NRD), Skretting Feed Products Gemma starter feed (Gemma), and Salt Creek Progression fish starter diet (Progression). While all diets supported good growth, after 6 weeks scup fed the NRD diet were of significantly greater length and weight (P?<?0.05) than fish fed the other diets. The effects of each diet on fish growth were significantly different from each other (P?<?0.05), with final live weight (g), total length (mm), relative growth rate (RGR), and daily weight gain (DWG) measurements higher for fish fed the NRD diet. Scup fed the Gemma diet were of significantly greater length and weight than fish fed the Progression diet. The specific growth rate (SGR) of scup fed either the NRD or Gemma diets were not significantly different; however, both of these diets produced fish with significantly higher SGR than those fed the Progression diet. Feed conversion ratios (FCR) of scup fed either the NRD or the Gemma diets were significantly lower than the FCR of fish fed the Progression diet. SGR values were 6.6%, 6.3%?and 5.6%/day, and FCR values were 1.03, 1.11, and 1.31 for fish fed the NRD, Gemma, and Progression diets, respectively. RGR values were 1,439%, 1,212%, and 895%, and DWG values were 0.33 g, 0.27 g, and 0.20 g/day for scup fed the NRD, Gemma, and Progression diets, respectively.     

Rapid pneumococcal evolution in response to clinical interventions

Epidemiological studies of the naturally transformable bacterial pathogen Streptococcus pneumoniae have previously been confounded by high rates of recombination. Sequencing 240 isolates of the PMEN1 (Spain(23F)-1) multidrug-resistant lineage enabled base substitutions to be distinguished from polymorphisms arising through horizontal sequence transfer. More than 700 recombinations were detected, with genes encoding major antigens frequently affected. Among these were 10 capsule-switching events, one of which accompanied a population shift as vaccine-escape serotype 19A isolates emerged in the USA after the introduction of the conjugate polysaccharide vaccine. The evolution of resistance to fluoroquinolones, rifampicin, and macrolides was observed to occur on multiple occasions. This study details how genomic plasticity within lineages of recombinogenic bacteria can permit adaptation to clinical interventions over remarkably short time scales.     

Silvicultural and economic aspects of pure and mixed native tree species plantations on degraded pasturelands in humid Costa Rica

Reforestation of degraded land in tropical regions provides one means of restoring ecosystems and improving rural livelihoods. Most plantations in humid tropical regions are established in pure plots, including few species of high commercial value, generally exotics. The present study compares growth and economic viability of 15–16 year-old trees of native species in pure and mixed plantations on degraded pasturelands at La Selva Biological Station, Costa Rica. The species with the best growth were Vochysia guatemalensis, Virola koschnyi, Jacaranda copaia, Terminalia amazonia, and Hieronyma alchorneoides. The mixed plantations performed better than pure plantations for all growth variables considered, including height, diameter at breast height, volume, and aboveground biomass. Mixed plantations outperformed pure plantations economically, with Net Present Value (NPV) of 1,124 to1,124 to 8,155/ha and Internal Rate of Return (IRR) of 7.7–15.6% depending on the species mixture. The most profitable pure plantations were those of Vochysia guatemalensis, with NPV and IRR of $6,035/ha and 14.3%, respectively; Hieronyma alchorneoides ($6,035/ha and 14.3%, respectively; Hieronyma alchorneoides (2,654 and 10.8%); and Virola koschnyi ($1,906/ha and 9.22%). These are the estimated benefits that would be accrued at harvest. These projections are realistic since the decision to harvest is generally mandated not just by profit maximization but by economic necessity, thus many small- to medium-scale farmers in Costa Rica harvest plantations prior to the completion of the rotation length. Mixed plantation may be the preferred system for reforestation with native species designed for timber production or carbon sequestration because this system is more economically viable and productive than pure plantations.     

Foliage re-establishment of <Emphasis Type="Italic">Pinus palustris</Emphasis> Mill. saplings after spring or fall prescribed fire

Repeated fire is key to the viability of longleaf pine (Pinus palustris Mill.) ecosystems, but its acceptance as a management tool may depend on satisfactory longleaf pine growth. This is because longleaf pine establishment often has the dual-purpose of ecosystem restoration and stemwood production. Timely recovery of scorched foliage among longleaf pine seedlings and saplings supports maximum juvenile growth. We identified two means of foliage re-establishment in the growing season after prescribed fire regardless of the season of fire application. New foliage growth after spring or fall fire was correlated with un-scorched foliage biomass and the presence of lateral branches. After prescribed fire in spring, foliage biomass recovery also appeared to benefit from the mobilization of starch. The high carbon demand of foliage recovery after fall prescribed fire was associated with interruption of seasonal starch accumulation in the stem and taproot. The implication of low starch accumulation in stem and taproot tissues during the growing season after fall prescribed fire is unknown and warrants further investigation. Our results demonstrate a positive influence of residual foliage, lateral branches, and stored starch on timely foliage recovery of young longleaf pines after fire. Together with knowledge of longleaf pine development and fuel and climate conditions at the time of prescribed fire, this information will aid prescribed fire practitioners charged with maintaining longleaf pine stands of high vigor.     

Efficacy and safety of mitomycin C as an agent to treat corneal scarring in horses using an in vitro model

Objective Mitomycin C (MMC) is used clinically to treat corneal scarring in human patients. We investigated the safety and efficacy of MMC to treat corneal scarring in horses by examining its effects at the early and late stages of disease using an in vitro model. Procedure An in vitro model of equine corneal fibroblast (ECF) developed was used. The ECF or myofibroblast cultures were produced by growing primary ECF in the presence or absence of transforming growth factor beta‐1 (TGFβ1) under serum‐free conditions. The MMC dose for the equine cornea was defined with dose‐dependent trypan blue exclusion and (3‐4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assays after applying MMC to the cultures once for 2 min. The efficacy of MMC to control corneal scarring in horses was determined by measuring mRNA and protein expression of corneal scarring markers (alpha‐smooth muscle actin and F‐actin) with western blotting, immunocytochemistry and/or quantitative real‐time polymerase chain reactions. Results A single 2‐min treatment of 0.02% or less MMC did not alter ECF phenotype, viability, or cellular proliferation whereas 0.05% or higher MMC doses showed mild‐to‐moderate cellular toxicity. The TGFβ1 at 1 ng/mL showed significant myofibroblast formation in ECF under serum‐free conditions. A single 2‐min, 0.02% MMC treatment 24 h (early) after TGFβ1 stimulation significantly reduced conversion of ECF to myofibroblasts, however, a single 0.02% MMC treatment 11 days after TGFβ1 stimulation showed moderate myofibroblast inhibition. Conclusions That MMC safely and effectively reduced scarring in ECF by reducing the degree of transdifferentiation of corneal fibroblasts to myofibroblasts in vitro. Further clinical in vivo investigations are warranted using MMC in horses.