Cross protection studies on Bordetella bronchiseptica in mice using an intracerebral challenge model.

Protective activities of heat-inactivated (60 degrees C for 30 min) merthiolate preserved Bordetella bronchiseptica and B. pertussis bacterins were compared in intraperitoneally immunized mice challenged intracerebrally (i.p./i.c.) or intraperitoneally (i.p./i.p.). In the i.p./i.c. assay (Kendrick test), a B. pertussis bacterin protected mice against challenge with B. pertussis 18-323, as well as against phase I cytotoxic and non-cytotoxic strains of B. bronchiseptica. A B. bronchiseptica bacterin, prepared from a phase I cytotoxic strain, gave protection against two phase I B. bronchiseptica strains, irrespective of their cytotoxin-production. A non-cytotoxic phase I strain of B. bronchiseptica elicited protection against the homologous strain only. Neither cytotoxic nor non-cytotoxic B. bronchiseptica strains protected mice challenged with B. pertussis 18-323. Vaccines prepared from phase III strains of B. bronchiseptica were not protective at all against any of the challenge strains. No such differences in the protective activities of the bacterins could be detected by the i.p./i.p. method. They seem to cross-protect equally well. The results indicate that the Kendrick test may be useful in testing potency of different B. bronchiseptica bacterins.     

Analysis of Growth and Productivity of Indian Mustard (Brassica juncea) in Relation to FYM, Nitrogen and Source of Fertilizer

A field experiment was conducted during the winter seasons of 1992–93 and 1993–94 at Anand to study the effect of FYM, nitrogen and source of fertilizer on growth and yield of mustard [ Brassica juncea (L.) Czernj & Cosson]. The results showed significant variation in leaf area index (LAI), crop growth rate (CGR), dry matter production and seed yield. The direct effect of farmyard manure (FYM) was conspicuous in improving the growth of mustard. FYM application at 10 tonnes ha⁻¹ significantly increased the LAI, CGR and dry matter accumulation per plant at almost all the stages during first year study (1992–93) and in pooled analysis. Similarly, nitrogen application registered maximum LAI, CGR at 75 kg level and RGR and NAR at 50 kg level at almost all the during both years. Sulphur carrying source (Ammonium sulphate plus single super phosphate) increased all stages growth characters. Maximum dry matter accumulation per plant and seed yield were recorded with highest levels of FYM (20 tonnes ha⁻¹), N (75 kg ha⁻¹) and source having S. Seed yield was strongly associated with LAI and dry matter accumulation per plant at all the stages.     

The effects of stubble burning and tillage on soil carbon sequestration and crop productivity in southeastern Australia

Abstract. In Australia, stubble burning and tillage are two of the major processes responsible for the decline of soil organic carbon concentration in cropped soils, and the resulting soil degradation. However, the relative importance of these two practices in influencing the soil organic carbon concentration and the long-term impact on soil quality and productivity are not clear. The effects of stubble burning as practised by farmers in southeastern Australia were evaluated in two field trials, one of 19 years duration, the other of 5 years. Conventional tillage (three tillage passes) led to greater loss of soil organic carbon than stubble burning. Loss of total soil organic carbon attributed to stubble burning in the 0–10 cm layer was estimated to be 1.75 t C ha⁻¹ over the period of the 19-year trial, equivalent to 29% of that lost due to tillage. In the 5-year trial, no change in soil organic carbon due to stubble burning was detectable. Changes in soil quality associated with stubble burning detected in the longer trial included a reduction in macro-aggregate stability, and increases in pH and exchangeable K⁺. Only the latter two were detected in the shorter trial. A higher mean wheat yield (average 0.15 t ha⁻¹) following stubble burning was observed in the 19-year trial but not in the 5-year trial. Research to monitor the longer term effects of stubble burning is needed, and to identify conditions where loss of soil organic carbon is minimized.     

Enzootic abortion in a goat herd, caused by mixed infection with Coxiella burnetii and Chlamydia psittaci. Case report]

We report on an outbreak of enzootic abortion in a herd of goats with high losses caused by mixed infection with Coxiella burnetii and Chlamydia psittaci. Both agents could be detected by microscopic investigation of smears from afterbirths by Giménez staining and by a capture enzyme-linked immunofluorescence assay (Capture ELIFA). Additionally, Coxiella burnetii was isolated from the same tissues in BGM cell cultures. Serological investigations with CF, indirect ELIFA, and IF tests revealed high antibody titers against both agents in most animals. Coxiella antigen was still detected 91 days later in milk samples of two infected goats by Capture ELIFA.     

Perioperative medical care for equine abdominal surgery

Rational perioperative management improves the success rate of abdominal surgery. Important aspects of management are discussed, including principles of fluid therapy, nutrition, intravenous catheterization, antimicrobial prophylaxis, and the use of nonsteroidal anti-inflammatory medication. Current advances in the area of immunotherapy are mentioned.     

Resident Dendritic Cells in the Epidermis: Langerhans Cells, Merkel Cells and Melanocytes

Résumé— En plus des kératinocytes, l'épiderme contient des cellules résidentes de morphologie dendritique. Ce sont principalement la cellule de Langerhans, la cellule de Merkel et le mélanocyte. Ces cellules ont des fonctions diverses dans le tégument. Le mélanocyte assure la pigmentation cutanée et la protection contre les radiations U.V., et pourrait intervenir également dans la modulation de l'inflammation cutanée. La cellule de Langerhans intervient dans la surveillance immunologique des surfaces corporelles ecternes. La cellule de Merkel a des fonctions neuroendocrines. Cet article donne un aperçu de la structure et de la fonction de ces trois importantes populations cellulaires dans la peau. [Resident dentritic cells in the epidermis: Langerhans cells, Merkel cells and melanocytes (Cellules dentritiques résidentes de l'épiderme: cellules de Langerhans, cellules de Merkel et mélanocytes). Resumen— La epidermis contiene, además de los queratinocitos, células résidentes de morfologia dendria dendritica. Estas son principalmente las células de Langerhans, las células de Merkel y los melanocitos. Estas células tienen varias funciones en el integumento. Los melanocitos se encargan de la pigmentación y protección de la piel contra la radiación ultravioleta y tarrtbién participan en la regulación de la inflamación cutánea. Las células de Langerhans ayudan en la regulación inmunológica en la superficie externa. Las células de Merkel tienen funciones neuroendocrinas. Esta revisión da un repaso general a la estructura y función de tres importantes células de la piel. [Resident dendsuitic cells in the epidermis: Langerhans cells, Merkel cells and Melanocytes (Células résidentes en la epidermis: células de Langerhans, células de Merkel y melanocitos). Abstract— In addition to the keratinocytes, the epidermis contains resident cells of dendritic morphology. These are principally the Langerhans cell, Merkel cell and melanocyte. These cells have a number of different functions in the integument. The melanocyte is responsible for skin pigmentation and protection against UV radiation, and may also play a role in the modulation of cutaneous inflammation. The Langerhans cell aids in the immunological monitoring of the body's external surfaces. The Merkel cell has neuroendocrine functions. This review gives an overview of the structure and function of these three important cells of the skin.     

Serological responses of specific pathogen-free foals to equine herpesvirus-1: primary and secondary infection, and reactivation.

Serum antibody (virus neutralisation, complement fixation, IgM and IgG) responses to equine herpesvirus-1 (EHV-1) infection were measured in six foals which were initially free from EHV-1 and EHV-4 infection and maternally-derived antibodies. Following primary infection, high titres of virus neutralisation and complement fixation antibodies were detectable against EHV-1, however, corresponding antibody levels against EHV-4 were low or inapparent, although the two viruses share a number of cross-reactive epitopes. In addition, following the primary infection with EHV-1, IgM levels increased before those of IgG, virus neutralisation and complement fixation antibodies, peaked sooner and thereafter declined. Stimulation of IgM levels was observed on secondary infection with EHV-1 given 61 days later. In contrast, IgG, virus neutralisation and complement fixation antibodies following primary infection were more sustained and no increase in their levels was observed on secondary infection. No consistent changes in IgM or IgG levels were seen after administration of dexamethasone to reactivate latent virus.     

Managing the lactating sow for optimal weaning and rebreeding performance.

Management of the lactating sow influences milk production and subsequent reproduction through changes in nutrient intake. The management goal during lactation is to maximize feed intake. Decreasing the effective environmental temperature, increasing the nutrient density of the lactation diet, maintaining fresh adequate supplies of feed and water, and preventing excess weight gain during the prior gestation period will increase nutrient intake during lactation. Effective environmental temperature of the lactating sow can be maintained in the thermoneutral zone by using drip cooling, increased ventilation rates and flooring materials with superior conductive properties. Sow parity, genetics, litter size, and disease level will also influence feed intake. Management practices must account for these factors and, thus, should be tailored to individual farm situations to ensure adequate nutrient intake and prevent aberrations in subsequent reproductive performance.