Systemic Immunosuppression by Methylprednisolone and Pregnancy Rates in Goats Undergoing the Transfer of Cloned Embryos

The presence of the zona pellucida has been perceived as a requirement for the oviductal transfer of cloned embryos at early stages of development while protecting the embryo from an immune system response. We hypothesized that steroid hormone therapy could reduce a potential cellular immune response after the transfer of zona‐free cloned embryos into the oviduct of recipient female goats. In Experiment 1, seven does were used to study the systemic immunosuppressant effect of the methylprednisolone administration (for 3 days) on blood cell counts. Whole blood was collected prior to treatment with methyprednisolone and then on Days 1, 2, 3, 4, 7, 14, 21 and 28 after the first dose of methylprednisolone for the analysis of haematological parameters. Methylprednisolone treatment significantly reduced circulating white blood cells and neutrophils in comparison with pre‐treatment levels, demonstrating a systemic immunosuppressant effect. In Experiment 2, a group of 58 does were used as recipient females to study the effect of administration of methylprednisolone for 3 days on the establishment of pregnancies after the transfer of zona‐free cloned embryos into the oviducts. No effects on pregnancy rates on Day 30 were observed regarding the distinct treatment groups (control vs. methylprednisolone), the source of oocytes (in vivo‐ vs in vitro‐matured) or the presence or absence of the zona pellucida in embryos. In summary, methylprednisolone was effective at inducing a systemic immunosuppressed state in goats, but the treatment prior to embryo transfer did not affect pregnancy rates. Moreover, pregnancy rates were similar between zona‐free and zona‐intact goat cloned embryos.     

Economic and financial model to the mass-rearing of Macrolophus pygmaeus (Rambur) (Heteroptera: Miridae), a biological control agent against the tomato moth Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in protected culture

BACKGROUND

Tuta absoluta (Meyrick) is a major pest of tomato produced in glasshouses and open field, causing severe damages to crops, reducing the quality of tomato fruits. The current maintenance of the pest populations below the economic threshold is not achieved by natural and classical control, thus requiring the continuous application of biological control agents (BCAs), under an augmentative or inoculative approach. The present study aims to develop an economic and financial model to evaluate the commercial viability of a continuous mass production of Macrolophus pygmaeus (Rambur), a BCA commonly used against the tomato moth, Tuta absoluta, in protected culture. The estimations for our model were based on two approaches: the farm-level impact analysis and the benefit–cost analysis.

RESULTS

The results of the farm-level analysis show that the adoption of a more sustainable biological control approach is profitable for farmers and the benefit–cost analysis provides evidence that the investment on a new factory dedicated to the mass rearing of M. pygmaeus to control tomato moth populations generates a positive net present value (NPV) of 7.2 million euros, corresponding to an internal rate of return (IRR) of 28.4% per year.

CONCLUSION

Our results are in line with (i) the more recent European Commission proposals for a new Regulation on sustainable use of plant protection products, which includes the reduction of 50% the use and risk of chemical pesticides by 2030 and (ii) most of the existing literature which conclude that new projects on BCA production are worth investments. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Fenvalerate residues on cattle hair coat from impregnated ear tags

A simple small-scale method for the determination of fenvalerate residues on cattle hair by gas–liquid chromatography with electron capture detection was developed and applied to the determination of fenvalerate residues from Bovaid^R ear tags. Recoveries were found to be 96–104% at 10–100 μg g^?1 levels of fenvalerate. The minimum detection limit of this method was 1 pg g^?1. With one ear tag, fenvalerate was adequately distributed over the entire body and persisted for at least 80 days on the hair of cattle.     

Anatomy of the patent ductus venosus in the cat

The biplanar mesenteric vein portovenograms of 10 cats with left divisional intrahepatic portosystemic shunts consistent with a patent ductus venosus (PDV) were reviewed. A corrosion cast of the hepatic portal vasculature was made post mortem from one individual that died post operatively following surgical attenuation of the shunting vessel. On the basis of the combined surgical, post mortem and imaging data, these left divisional shunts were found to have consistent anatomy, each having a straight vessel which drained into a venous ampulla before draining into the caudal vena cava at the level of the diaphragm. The left phrenic vein and left hepatic vein both entered the ampulla independently of the shunting vessel. The anatomical similarity between these findings in the cat and the PDV in the dog suggest that it is appropriate to describe this particular portosystemic shunt as a PDV.     

Vector-borne parasitic zoonoses: emerging scenarios and new perspectives

Changing climate is not the only driver for alterations in the dynamic interaction between arthropod vectors of zoonotic parasites and their hosts, including humans. A suite of other factors ranging from urbanization and deforestation to changing demographics in both developing and developed countries, the impact of the recent economic crisis, increased global movement of people and animals and follow-on effects of major catastrophes. This article reviews the most important vector-borne parasites of zoonotic concern that are changing/expanding their distribution patterns in both endemic and/or previously non-endemic areas. We include the discussion of the changing aspects of malaria, leishmaniasis, babesiosis, Chagas disease as well as of some spirurid and filarioid nematodes.     

Staging of Pacific flyway brant in relation to eelgrass abundance and site isolation, with special consideration of Humboldt Bay, California

Spring distributions of black brant (Branta bernicla nigricans) are closely related to that of their primary food plant, eelgrass (Zostera marina). Using historical (1931-2001) brant data from Humboldt Bay, California, we show that proportional use of two main feeding areas in the bay strongly reflects food abundance. We used multiple regression to investigate whether the spatial relationship between brant and eelgrass holds at the flyway level. We related peak brant numbers at 11 staging areas in the Pacific flyway to the sites' Z. marina abundance and isolation from other important staging areas. We explained 90% of the variation in peak brant numbers across sites with these variables; isolated bays with high eelgrass abundance supported the most brant. Our results emphasize the importance of protecting large eelgrass habitats along the Pacific Coast, particularly in bays that are geographically isolated from other large staging areas.