Factors affecting the occurrence, duration of hospitalization and final outcome in canine parvovirus infection

The objectives of this matched case-control study in a veterinary teaching hospital were to investigate the influence of signalment and historical data on the odds of occurrence of canine parvovirus (CPV) enteritis and the potential usefulness of the clinical signs and clinicopathologic abnormalities recorded on admission as prognostic indicators of mean duration of hospitalization (DOH) and outcome of the disease. Ninety-four puppies with natural CPV enteritis and 188 age-matched controls were studied. The odds to develop CPV enteritis were higher in purebreds compared to mixed-breed puppies. Vomiting and depression at the time of admission were associated with a prolongation of DOH by 2 and 1.75 days, respectively. The lymphopenic and hypoalbuminemic dogs were hospitalized for 1.9 and 2.5 more days, respectively, compared to those without these abnormalities. The odds of non-survival were higher in those puppies with evidence of systemic inflammatory response syndrome (SIRS) at the time of admission.     

Genetic evaluation of breeding strategies for improvement of dairy cattle in Kenya

Cost-benefit analysis using net present value (NPV) as the economic evaluation criterion was used to investigate the economic merits of four breeding strategies used for genetic improvement of dairy cattle in Kenya. The breeding strategies were evaluated over a 25-year period. The costs involved in setting up and running each strategy were obtained from large-scale dairy cattle farms, and government and private institutions involved in genetic improvement of dairy cattle. Only benefits from genetic improvement were considered. The impact on NPV due to changes in genetic and economic parameters was investigated. The ranking of the breeding strategies greatly differed with genetic ranking. Among the local selection programs, a strategy utilizing young bulls, sons of local bulls, was more profitable than one utilizing old progeny tested bulls. Continuous semen importation was not an economically viable alternative. The strategy utilizing young bulls progeny of imported bulls (PIB) was only viable if imports were from countries which are >2.00 SD in genetic merit above the local dairy cattle population. The ranking of strategies was not sensitive to changes in genetic parameters but to economic parameters. The use of local semen from young bulls progeny of local proven bulls is recommended. Alternatively, PIB can be utilized but the semen will have to be imported from countries which are >2.00 SD above the local dairy cattle population or the cost of imported semen should be ≤ US$40 per straw.     

Enhancing management effectiveness of invasive lionfish using distance sampling and detection probability

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A note on sea lice abundance on farmed Atlantic salmon in Scotland 2011–2013: significant regional and seasonal variation

Sea lice are the most economically damaging parasite affecting marine Atlantic salmon production the dominant sector of UK aquaculture. The Scottish Salmon Producers' Organisation has published mean adult female lice abundance for four regions for 2011–2013 and for 30 areas in 2013. An analysis of these data shows that sea lice abundance is highly seasonal with values lowest in the first half of the year. Abundance also varies by region, the regional patterns vary from year‐to‐year but overall the highest abundance was found in the northern part of mainland Scotland. While most areas had low lice abundance, in a few areas the abundance was persistently above average; these areas were clustered together. There was no significant year‐on‐year trend in lice abundance, and trends appear to vary between regions. Although previous Scottish analyses have been carried out using data from a large company, this analysis cover 95% of production in all salmon farming regions of Scotland and it can be extended as more data become available.     

Long‐term changes in unionid assemblages in the Rio Grande,one of the World's top 10 rivers at risk

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Alterations in serum electrolytes, antioxidative enzymes and haematological parameters of Labeo rohita on short-term exposure to sublethal dose of nitrite

An experiment was conducted to study the effects of short-term exposure to sublethal levels of nitrite on electrolyte regulation, antioxidative enzymes and haematological parameters in Labeo rohita juveniles. The fishes were exposed to graded levels of nitrite (0-15?mg?l(-1)) for different duration (0, 12, 24, 48 and 96?h). The 96-h LC(50) value for L. rohita (avg. wt, 66.5?±?0.5?g) was found to be 11.28?mg?l(-1). Activities of antioxidative enzymes (catalase and superoxide dismutase), acetylcholine esterase (AChE) and methaemoglobin reductase, serum electrolytes (sodium, potassium and chloride), haematological parameters and blood glucose level significantly varied (P?相似文献   

Dietary L‐tryptophan modulates growth and immuno‐metabolic status of Labeo rohita juveniles exposed to nitrite

Effect of nitrite exposure on growth and immuno‐metabolic responses of Labeo rohita fed L‐tryptophan (TRP) was studied. Fish previously fed normal and elevated levels of tryptophan for 60 days were exposed to nitrite (2.0 mg L^?1) for another 45 days with same feeding regime. There were four treatment groups, viz., TRP₀‐N (control), TRP₀+N, TRP_0.75+N (0.75% supplemental tryptophan in the diet) and TRP_1.5+N (1.5% supplemental tryptophan in the diet). Highest weight gain% and SGR were observed in control and lowest in TRP₀+N. Dietary supplementation of elevated levels of tryptophan augmented weight gain% and SGR. Nitrite exposed groups recorded higher catalase, SOD, LDH, AST and ALT activities compared with control. However, activities reduced with additional levels of tryptophan supplementation. Nitrite exposure reduced WBC count, total protein, albumin, globulin and lysozyme activity compared with unexposed group but groups which were fed additional amounts of tryptophan restored total protein, albumin and globulin similar to TRP₀‐N. In conclusion, nitrite exposure had adversely affected growth, increased activities of LDH, AST, ALT, catalase, but decreased WBC, serum protein, lysozyme and acetylcholine esterase activity of L. rohita. Normal requirement of tryptophan was unable to combat nitrite stress. However, dietary fortification with tryptophan (minimum 0.75% of diet + normal requirement) found effective in combating nitrite induced stress.     

Continuous cultures of phytoplankton

The development of cultures of phytoplankton adapting throughout several days in an axenic, continuous-flow chemostat to yield a steady kinetic state of competing species is described mathematically. The adaptation of the growth rate to the chemostat environment inhibits integration of the equation of conservation of phytoplankton populations, though eventually when a steady state is reached the growth rate becomes equal to the rate of flow through the chemostat. Representation of species growth rates by a Verhuls formulation utilising experimentally determinable intra- and interspecies interaction constants permits the rapid prediction of the adaptation and alteration in the populations of competing phytoplankton species with changes in the chemostat environment. Illustrations of the behaviour of two and three competing species are extended to consideration of the stabilities of cultures of many competing species. Stable steady states of phytoplankton in a continuous-flow chemostat comprise a classic thermodynamic system and consequently the utilisation of light energy by the cells varies inversely with their growth rate. It is probable that when growth is nutrient limited, intra-and interspecies interaction parameters diminish as the demands of consumption are more nearly matched by the ratios of the limiting nutrients.