Integrating Fire Risk Considerations in Forest Management Planning in Spain – A Landscape Level Perspective

It is reasonable to assume that there is a relationship between the spatial distribution of forest fuels and fire hazards. Therefore, if fire risk is to be included into numerical forest planning, the spatial distribution of risky and non-risky forest stands should be taken into account. The present study combines a stand-level fire risk model and landscape level optimization to solve forest planning problems in which the fire risk plays an important role. The key point of the method was to calculate forest level fire resistance metrics from stand level indices and use these metrics as objective variables in numerical optimization. This study shows that maximizing different landscape metrics produces very different landscape configurations with respect to the spatial arrangement of resistant and risky stands. The landscapes obtained by maximizing different metrics were tested with a fire spread simulator. These tests suggested that the mean fire resistance of the landscape, which is a non-spatial metric, is the most important factor affecting the burned area. However, spatial landscape metrics that decrease the continuity of fire resistance in the landscape can significantly improve the fire resistance of the landscape when used as additional objective variables.     

Microsporidian xenomas in fish seen in wider perspective

The history of understanding xenoparasitic complexes or xenomas provoked in the host cell by various protists and especially by microsporidia is outlined. Microsporidia have been known to produce xenomas in oligochaetes (e.g., genera Bacillidium, Burkea, Hrabyeia, Jirovecia, species of the collective group Microsporidium), crustaceans (e.g., Abelspora, Mrazekia), insects (e.g., Polydispyrenia, Thelohania) and poikilothermic vertebrates, mostly fish (Alloglugea, Amazonspora, Glugea, Ichthyosporidium, Loma, Microfilum, Microgemma, Neonosemoides, Pseudoloma, Spraguea, Tetramicra). An overview of characters of xenomas caused by species of these genera is presented. The study of microsporidia causing xenomas in fish offers an insight into cell pathology and is of interest since many of these species are important agents of diseases in commercial fish. Xenomas produced from a few types of target cell display a complete change of organisation of the host cell and differ, according to the agent, in their structure. Recent data show that proliferation of the parasite may have already started in the cells transporting the parasites to the final site of xenoma formation. However, these are preliminary revelations and most of the facets of the life cycle are still to be clarified. Curiously, xenoma-forming microsporidia do not seem to be strictly host specific. The salient features of fish microsporidian xenomas are discussed, such as role of the xenoma, whether its features are host- or microsporidium-dependent, development and demise of the xenoma in the course of time, and host reaction phenomena. The need of further research is emphasised.     

Genetic analysis of carcass traits of steers adjusted to age, weight, or fat thickness slaughter endpoints

Carcass measurements from 1,664 steers from the Germ Plasm Utilization project at U.S. Meat Animal Research Center were used to estimate heritabilities (h(2)) of, and genetic correlations (r(g)) among, 14 carcass traits adjusted to different endpoints (age, carcass weight, and fat thickness): HCW (kg), dressing percent (DP), adjusted fat thickness (AFT, cm), LM area (LMA, cm(2)), KPH (%), marbling score (MS), yield grade (YG), predicted percentage of retail product (PRP), retail product weight (RPW, kg), fat weight (FW, kg), bone weight (BNW, kg), actual percentage retail product (RPP), fat percent (FP), and bone percent. Fixed effects in the model included breed group, feed energy level, dam age, birth year, significant (P < 0.05) interactions, covariate for days on feed, and the appropriate covariate for endpoint nested (except age) within breed group. Random effects in the model were additive genetic effect of animal and total maternal effect of dam. Parameters were estimated by REML. For some traits, estimates of h(2) and phenotypic variance changed with different endpoints. Estimates of h(2) for HCW, DP, RPW, and BNW at constant age, weight, or fat thickness were 0.27, -, and 0.41; 0.19, 0.26, and 0.18; 0.42, 0.32, and 0.50; and 0.43, 0.32, and 0.48, respectively. Magnitude and/or sign of r(g) also changed across endpoints for 54 of the 91 trait pairs. Estimates for HCW-LMA, AFT-RPW, LMA-YG, LMA-PRP, LMA-FW, LMA-RPP, and LMA-FP at constant age, weight, or fat thickness were 0.32, -, and 0.51; -0.26, -0.77, and -; -0.71, -0.89, and -0.66; 0.68, 0.85, and 0.63; -0.16, -0.51, and 0.22; 0.47, 0.57, and 0.27; and -0.44, -0.43, and -0.18, respectively. Fat thickness was highly correlated with YG (0.86 and 0.85 for common age and weight) and PRP (-0.85 and -0.82 for common age and weight), indicating that selection for decreased fat thickness would improve YG and PRP. Carcass quality, however, would be affected negatively because of moderate r(g) (0.34 and 0.35 for common age and weight) between MS and AFT. Estimates of h(2) and phenotypic variance indicate that enough genetic variation exists to change measures of carcass merit by direct selection. For some carcass traits, however, magnitude of change would depend on effect of endpoint on h(2) and phenotypic variance. Correlated responses to selection would differ depending on endpoint.     

A PCR technique for the detection of Jaagsiekte sheep retrovirus in the blood suitable for the screening of ovine pulmonary adenocarcinoma in field conditions

Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring contagious lung neoplasia caused by jaagsiekte sheep retrovirus (JSRV). Although no specific circulating antibodies against the virus can be detected in infected sheep, JSRV proviral DNA sequences can be found in peripheral blood leukocytes (PBLs) in clinically affected and in a proportion of in contact animals. In this study, existing hemi-nested PCR procedure is compared with a new one-step PCR technique that was developed to minimise potential DNA contamination and reduce sample and reagent handling. Different blood preparations were assessed and the best results were achieved on DNA prepared from buffy coat. The sensitivity of this PCR was lower in JSRV infected sheep without lesions of OPA than in clinically affected sheep, which indicate that this PCR may not be not fully appropriate for screening of individual sheep, but rather to provide results at flock level. This PCR is the only currently available blood test for detection of JSRV infected sheep and may be useful in epidemiological studies and in control programmes of OPA.     

Effects of hemolysis, lipemia, hyperbilirrubinemia, and anticoagulants in canine C-reactive protein, serum amyloid A, and ceruloplasmin assays

The objective of the present study was to determine the effects that hemolysis, lipemia, bilirubinemia, and anticoagulants might have on the most commonly used assays for C-reactive protein and serum amyloid A, and determination of ceruloplasmin values in dogs. Solutions of hemoglobin, lipid, and bilirubin were added to serum aliquots. Additionally, serum and plasma samples with different anticoagulants (heparin, EDTA, and citrate) were obtained from healthy dogs. Hemolysis, lipemia, and hyperbilirubinemia interfered significantly with the C-reactive protein and ceruloplasmin results, but not with those for the serum amyloid A assay. The use of anticoagulants produced significant changes in the results for the assays tested. However, the magnitude of the differences caused by the interfering substances does not appear to have an important impact on the clinical interpretation of the tests.     

Use of ear tags and injectable transponders for the identification and traceability of pigs from birth to the end of the slaughter line

A total of 557 newborn piglets were used to compare eight identification devices, including one plastic ear tag as a control (C, n = 348) and two types of electronic ear tags (E1, n = 106; and E2, n = 103), and five types of injectable transponders (n = 557): small 12-mm (D12, n = 116; and S12, n = 110), medium 23-mm (T23, n = 108), and large (32-mm, T32, n = 115; and 34-mm, S34, n = 108). Injections were made s.c. in the auricle base (n = 248) and intraperitoneally (n = 309) using a new technique. All piglets were identified with two devices, but using electronic ear tags in conjunction with injection in the auricle was avoided on the same pig. Readability of devices was checked during fattening (until 110 kg BW) and slaughtering. On-farm losses were lower for control than for electronic ear tags (C = 1.1%; E1 = 8.8%; and E2 = 44.9%; P < 0.01); the latter also suffered electronic failures (E1 = 5.5%; and E2 = 55.1%; P < 0.001). On-farm losses of transponders injected in the auricle base were greater in large (S34 = 72.5%; and T32 = 46.3%; P < 0.05) than in small transponders (S12 = 19.4%; and D12 = 17.1%), but T23 (29.8%) only differed from S34. Transponder size did not affect on-farm losses for intraperitoneal injections in which only one loss was recorded (0.4%). All ear tags had similar losses during transportation to the slaughterhouse (1.2%), but no losses were observed in injectables. Slaughtering losses did not differ between ear tags (C = 11.2%; and E1 = 6.4%), but apart from losses, 12.8% of E1 failed electronically. Injection site affected losses and breakages during slaughtering (auricle base = 6.4%; and intraperitoneal = 0%), but recovery time did not significantly differ (auricle base = 28.6 s; and intraperitoneal = 18.9 s). Transponders in the auricle base were recovered by sight (30.2%), palpation (27.4%), or by cutting (42.5%). Intraperitoneal transponders were mainly recovered loose in the abdominal cavity (81.4%), whereas 18.6% fell on the floor. As a result, traceability varied significantly (P < 0.05) between control (86.7%) and electronic ear tags (0 to 68.1%) and injectable transponders, with the auricle base (17.8 to 75.0%) having lower values than intraperitoneal (98 to 100%). Intraperitoneal injection was a very effective tool for piglet identification and traceability, ensuring the transfer of information from farm to slaughterhouse. To warrant the use of this technique in practice, transponder recovery requires further investigation.     

Molecular characterization and phylogenetic analysis of Newcastle disease virus isolates from healthy wild birds

Wild waterfowl is considered a natural reservoir of potentially infectious agents and a source of pathogenic viruses like avian paramyxoviruses type 1 (APMV 1). In 1997, commercial poultry in Argentina had reached the status of being free from virulent Newcastle disease virus (NDV) infections. Vaccination and biosecurity measures are actively performed to maintain this preferential sanitary condition. However, the risk of reintroduction of pathogenic viruses is always present. In this context, we conducted a study to describe the status of wild healthy birds in a geographic region relevant for the poultry industry. The presence of anti-NDV antibodies was determined in different species in all areas sampled suggesting previous contact with NDV. Seven ND viruses were isolated and characterized as apathogenic strains by biological and molecular methods. The phylogenetic analysis revealed that the majority of the Argentinian isolates form a subgroup related to viruses of genotype II. The results presented here highlight the importance of maintaining strict biosecurity measures and vaccination programs in poultry industries in order to preserve the virulent NDV-free status for commercial flocks in the country.     

Effects of dietary conjugated linoleic acid and high-oleic sunflower oil on performance and egg quality in laying hens

(1) Laying hen performance, yolk fatty acid (FA) concentrations, sensory quality and firmness of eggs were evaluated with respect to the inclusion in the diet of conjugated linoleic acid (CLA) and high-oleic acid sunflower oil (HOSO). (2) Nine diets were arranged factorially, with three concentrations of CIA (0, 1 and 2 g/kg) and HOSO (10, 20 and 30 g/kg). (3) Type of diet did not affect egg production traits. (4) Dietary addition of CLA decreased yolk lipid content and yolk lipid concentrations of monounsaturated FA, C(20:4 n-6) and C(22:6 n-3), but increased those of CLA and saturated FA. (5) Dietary addition of HOSO increased monounsaturated FA concentrations in the yolk lipid but decreased those of CLA and saturated FA. (6) CLA supplementation increased yolk moisture and firmness and impaired the sensory quality of eggs. (7) An interaction between CLA and HOSO addition was found as effects of CLA addition on yolk lipid CLA concentrations and egg quality traits were smaller when the amount of HOSO in the diet increased. (8) Regression equations have been calculated in order to predict yolk CLA and C(18:1), concentration from dietary composition, and yolk firmness from yolk FA composition.     

Use of ELISPOT and ELISA to evaluate IFN-gamma, IL-10 and IL-4 responses in conventional pigs

ELISPOT and ELISA were standardised for pig interferon-gamma (IFN-gamma), interleukin-10 (IL-10) and interleukin-4 (IL-4) with the aim to study the evolution of the immune response in conventional pigs from birth to 6 months of age and also to compare results of both techniques. Five pigs were bled at 1, 6, 9, 12 and 22 weeks of age and peripheral blood mononuclear cells (PBMC) were stimulated with phytohemagglutinin. The frequencies of cytokine secreting cells (CSC) and the levels of secreted cytokines were compared. For IFN-gamma the mean of CSC increased with age (p<0.05) from an average of 486/10(6) PBMC at first week of age to 1256/10(6) PBMC at 22 weeks of age. No correlation was found between the number of IFN-gamma CSC and the cytokine levels obtained by ELISA. For IL-10, frequencies of CSC did not increase with age of pigs, having a low of 315/10(6) PBMC at first week of age and a high of 1485/10(6) PBMC at six weeks. Comparison of ELISA and ELISPOT results for IL-10 showed a certain degree of correlation (r=0.74; p<0.05). Spontaneous secretion was observed in unstimulated cultures. For IL-4, frequencies of CSC were low (50-70/10(6) PBMC). In this case, comparison of ELISA and ELISPOT could not be done because cytokine levels in culture supernatants were often below the detection limit of the IL-4 ELISA. All these values can serve as a reference for future studies and also, our observations suggest that ELISPOT and ELISA should be carefully interpreted and do not necessarily correlate.