Heathland creation on improved grassland using sulphur: is there a conflict between optimal application rates for plant and animal communities?

We examined the effectiveness of using elemental sulphur (a soil acidifier) as a method for creating heathland on improved pasture. We determined i) optimal rate of sulphur application to control mesotrophic grasses ii) if invertebrates avoid areas of sulphur application. Results indicated that optimal sulphur application attracted invertebrates

Correlation between in vitro cytotoxicity and in vivo lethal activity in mice of epsilon toxin mutants from Clostridium perfringens

Epsilon toxin (Etx) from Clostridium perfringens is a pore-forming protein with a lethal effect on livestock, producing severe enterotoxemia characterized by general edema and neurological alterations. Site-specific mutations of the toxin are valuable tools to study the cellular and molecular mechanism of the toxin activity. In particular, mutants with paired cysteine substitutions that affect the membrane insertion domain behaved as dominant-negative inhibitors of toxin activity in MDCK cells. We produced similar mutants, together with a well-known non-toxic mutant (Etx-H106P), as green fluorescent protein (GFP) fusion proteins to perform in vivo studies in an acutely intoxicated mouse model. The mutant (GFP-Etx-I51C/A114C) had a lethal effect with generalized edema, and accumulated in the brain parenchyma due to its ability to cross the blood-brain barrier (BBB). In the renal system, this mutant had a cytotoxic effect on distal tubule epithelial cells. The other mutants studied (GFP-Etx-V56C/F118C and GFP-Etx-H106P) did not have a lethal effect or cross the BBB, and failed to induce a cytotoxic effect on renal epithelial cells. These data suggest a direct correlation between the lethal effect of the toxin, with its cytotoxic effect on the kidney distal tubule cells, and the ability to cross the BBB

The Protective Effect of L-carnitine on Ionizing Radiation-induced Free Oxygen Radicals

Ionizing radiation is known to generate reactive oxygen species (ROS) that can be removed by antioxidants.  L-carnitine, a natural component of mammalian tissue, is a necessary factor in the utilization of long-chain  fatty acids to produce energy. Furthermore it has been shown that L-carnitine is an antioxidant which has  a scavenger effect on ROS and a stabilizing effect on damaged cell membranes. The aim of the study was  to evaluate the potential protective effect of L-carnitine on radiation-induced free radicals in hamsters. Lcarnitine  was given by gavage at a dose of 50 mg/kg for 15 consecutive days before irradiation with a single  dose of 8 Gy. 24 h after radiation exposure, the hamsters were sacrificed and samples were taken from  blood and tissues, and the biochemical and histopatological determinations were carried out. In the irradiated  group, there were significant increases in plasma and liver malondialdehyde (MDA) with marked  reduction in glutathione (GSH) levels in the liver, compared with controls. In red blood cells, superoxide  dismutase (SOD) and catalase activities were also reduced. All these effects were reversed by L-carnitine.  In conclusion, L-carnitine with its antioxidant and free radical scavenging properties could play a modulatory  role against the cellular damage produced by free radicals induced by ionizing radiation.

Effects of outdoor plant varieties on performance, egg quality, behavior, and economic analysis of Turkey local chicken from 20 to 36 weeks of age

   This study was carried out to examine the effects of three plant combinations (white clover-perennial ryegrass, bird’s-foot trefoil-perennial ryegrass, and alfalfa-perennial ryegrass) planted in the outdoor area of ​​the free-range system on the performance, egg quality, and behavioral characteristics of Turkey local chicken. Performance characteristics of chickens (egg production, feed consumption, feed efficiency, broken egg rate, dirty egg rate, ground laying rate) were evaluated at 4-week intervals from 20 weeks to 36 weeks of age. In the study, the local layer genotype ATAK-S was used. Each group in the study consisted of 3 different plant varieties, formed from 4 replications. The mean values of hen-day egg production, and hen-day cumulative egg yield of layers in experimental groups were found to be between 91.16% and 94.76%, and between 87.89 and 91.67 %, respectively, and there was no statistical difference between the experimental groups. Similarly, there were no statistical differences between the experimental groups in terms of feed consumption, feed efficiency, egg weight, egg mass, broken-cracked egg ratio, or internal and external egg quality characteristics. There were no differences between the experimental groups in terms of time budgets allocated to various behavioral characteristics. In this study, outdoor area use was found to be quite high (41.04-41.56%) in all experimental groups. As a result, it was determined that the use of white clover-perennial ryegrass, bird’s-foot trefoil-perennial ryegrass, and alfalfa-perennial ryegrass vegetation combinations in the free-range system encourages layers to go to the outdoor. In addition, it has been found that these practices have positive effects on birds in terms of both their performance and their well-being. &nbsp

Cinética dos anticorpos de origem colostral contra a toxina épsilon de Clostridium perfringens tipo D em cordeiros

Enterotoxemia, uma das mais importantes enfermidades que acomete os pequenos ruminantes domésticos, é causada principalmente pela toxina épsilon de Clostridium perfringens tipo D. O presente estudo avaliou a cinética de anticorpos colostrais antitoxina épsilon em cordeiros nascidos de ovelhas submetidas a dois diferentes tipos de manejo sanitário. Um grupo de ovelhas prenhes (n=6) foi vacinado com uma dose única de vacina comercial polivalente contra clostridioses contendo toxóide épsilon na sua formulação cerca de 30 dias antes da data prevista para a parição. Outro grupo de ovelhas (n=6) de mesma idade gestacional não foi vacinado. Imediatamente após o parto, antes da ingestão do colostro, foram colhidas amostras sanguíneas dos respectivos cordeiros, bem como aos 30 e 60 dias de idade e submetidas à avaliação sorológica pelo teste de ELISA indireto. Os resultados encontrados permitem concluir que a vacinação de ovelhas prenhes 30 dias antes do parto contra a enterotoxemia causada pela toxina épsilon, com dose única de produto comercial, induz imunidade passiva em níveis considerados protetores (>0,5UI/ml) aos cordeiros por, no mínimo, 60 dias de idade

Kinetics of epsilon antitoxin antibodies in different strategies for active immunization of lambs against enterotoxaemia

Enterotoxaemia, a common disease that affects domestic small ruminants, is mainly caused by the epsilon toxin of Clostridium perfringens type D. The present study tested four distinct immunization protocols to evaluate humoral response in lambs, a progeny of non-vaccinated sheep during gestation. Twenty-four lambs were randomly allocated into four groups according to age (7, 15, 30 and 45 days), receiving the first dose of epsilon toxoid commercial vaccine against clostridiosis with booster after 30 days post vaccination. Indirect ELISA was performed after the first vaccine dose and booster to evaluate the immune response of the lambs. Results showed that for the four protocols tested all lambs presented serum title considered protective (≥0.2UI/ml epsilon antitoxin antibodies) and also showed that the anticipation of primovaccination of lambs against enterotoxaemia conferred serum title considered protective allowing the optimization of mass vaccination of lambs

Increasing density leads to generalization in both coarse-grained habitat selection and fine-grained resource selection in a large mammal

Summary 1. Density is a fundamental driver of many ecological processes including habitat selection. Theory on density-dependent habitat selection predicts that animals should be distributed relative to profitability of habitat, resulting in reduced specialization in selection (i.e. generalization) as density increases and competition intensifies. 2. Despite mounting empirical support for density-dependent habitat selection using isodars to describe coarse-grained (interhabitat) animal movements, we know little of how density affects fine-grained resource selection of animals within habitats [e.g. using resource selection functions (RSFs)]. 3. Using isodars and RSFs, we tested whether density simultaneously modified habitat selection and within-habitat resource selection in a rapidly growing population of feral horses (Equus ferus caballus Linnaeus; Sable Island, Nova Scotia, Canada; 42% increase in population size from 2008 to 2012). 4. Among three heterogeneous habitat zones on Sable Island describing population clusters distributed along a west-east resource gradient (west-central-east), isodars revealed that horses used available habitat in a density-dependent manner. Intercepts and slopes of isodars demonstrated a pattern of habitat selection that first favoured the west, which generalized to include central and east habitats with increasing population size consistent with our understanding of habitat quality on Sable Island. 5. Resource selection functions revealed that horses selected for vegetation associations similarly at two scales of extent (total island and within-habitat zone). When densities were locally low, horses were able to select for sites of the most productive forage (grasslands) relative to those of poorer quality. However, as local carrying capacity was approached, selection for the best of available forage types weakened while selection for lower-quality vegetation increased (and eventually exceeded that of grasslands). 6. Isodars can effectively describe coarse-grained habitat selection in large mammals. Our study also shows that the main predictions of density-dependent habitat selection are highly relevant to our interpretation of RSFs in space and time. At low but not necessarily high population size, density will be a leading indicator of habitat quality. Fitness maximization from specialist vs. generalist strategies of habitat and resource selection may well be apparent at multiple spatial extents and grains of resolution

Intoxication by Astragalus garbancillo var. garbancillo in llamas

Lysosomal storage diseases are inherited and acquired disorders characterized by dysfunctional lysosomes. Intracytoplasmic accumulation of undegraded substrates leads to impaired cellular function and death. Several plant species are toxic to livestock because of the presence of indolizidine alkaloids, including swainsonine, which cause a storage disease. Swainsonine-induced nervous disease (i.e., locoism) of sheep and cattle is well recognized in several parts of the world, particularly in the western United States and in parts of Australia. Spontaneous intoxication by Astragalus garbancillo var. garbancillo was suspected in a group of 70 llamas (Lama glama) in Jujuy Province, northwestern Argentina. The animals grazed an area dominated by stands of A. garbancillo var. garbancillo. Clinical signs were staggering, ataxia, hypermetria, and progressive weight loss. The clinical course in individual animals was ~50 d. The main microscopic changes were Purkinje cell degeneration, necrosis, and loss, associated with intracytoplasmic vacuolation, meganeurite formation, and Wallerian degeneration. Specific positive labeling for ubiquitin was observed in axonal spheroids. Composite leaf and stem samples of A. garbancillo var. garbancillo analyzed by high-performance liquid chromatography contained 0.03% swainsonine. Based on the microscopic lesions, clinical history, and plant analysis, a diagnosis was made of storage disease caused by consumption of swainsonine-containing A. garbancillo var. garbancillo.EEA SaltaFil: Marín, Raúl E. Universidad Nacional de Jujuy. Facultad de Ciencia Agrarias; Argentina.Fil: Micheloud, Juan Francisco. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta. Área de Sanidad Animal; Argentina.Fil: Vignale, Nilda D. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias; Argentina.Fil: Gimeno, Eduardo Juan. Universidad Nacional de la Plata. Facultad de Ciencias Veterinarias. Cátedra de Patología General;Argentina.Fil: O'Toole, Donal. Wyoming State Veterinary Laboratory ; Estados UnidosFil: Gardner, Dale R. USDA-ARS Poisonous Plant Research Laboratory; Estados UnidosFil: Woods, Leslies. University of California–Davis. California Animal Health and Food Safety Laboratory System; Estados UnidosFil: Uzal, Francisco A. University of California–Davis. California Animal Health and Food Safety Laboratory System, San Bernardino; Estados Unido

Testing the influence of habitat experienced during the natal phase on habitat selection later in life in Scandinavian wolves

Natal habitat preference induction (NHPI) occurs when characteristics of the natal habitat influence the future habitat selection of an animal. However, the influence of NHPI after the dispersal phase has received remarkably little attention. We tested whether exposure to humans in the natal habitat helps understand why some adult wolves Canis lupus may approach human settlements more than other conspecifics, a question of both ecological and management interest. We quantified habitat selection patterns within home ranges using resource selection functions and GPS data from 21 wolf pairs in Scandinavia. We identified the natal territory of each wolf with genetic parental assignment, and we used human-related characteristics within the natal territory to estimate the degree of anthropogenic influence in the early life of each wolf. When the female of the adult wolf pair was born in an area with a high degree of anthropogenic influence, the wolf pair tended to select areas further away from humans, compared to wolf pairs from natal territories with a low degree of anthropogenic influence. Yet the pattern was statistically weak, we suggest that our methodological approach can be useful in other systems to better understand NHPI and to inform management about human-wildlife interactions