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171.
Context
Natural disturbances can have a considerable negative impact on the productivity of forest landscapes. Yet, disturbances are also important drivers of diversity, with diversity generally contributing positively to forest productivity. While the direct effects of disturbance have been investigated extensively it remains unclear how disturbance-mediated changes in diversity influence landscape productivity. Considering that disturbances are increasing in many ecosystems a better understanding of disturbance impacts is of growing importance for ecosystem management.Objectives
Here, our objectives were to study the effect of disturbance on tree species diversity at different spatial scales (α and β diversity), and to analyze how a disturbance-mediated variation in tree species diversity affects forest productivity.Methods
To account for long-term interactions between disturbance, diversity, and productivity and test a range of disturbance scenarios we used simulation modeling, focusing on a temperate forest landscape in Central Europe.Results
We found an overall positive effect of disturbance on tree species diversity both with regard to α and β diversity, persisting under elevated disturbance frequencies. Productivity was enhanced by within- and between-stand diversity, with the effect of α diversity decreasing and that of β diversity increasing through the successional development. Positive diversity effects were found to be strongly contingent on the available species pool, with landscapes containing species with different life-history strategies responding most strongly to disturbance-mediated diversity.Conclusions
We conclude that, rather than homogenizing disturbed areas, forest managers should incorporate the diversity created by disturbances into stand development to capitalize on a positive diversity effect on productivity.172.
Lucía M. Campero Javier Moreno-Gonzalo María C. Venturini Gastón Moré Andrea Dellarupe Magdalena Rambeaud Ignacio E. Echaide Beatriz Valentini Carlos M. Campero Dadín P. Moore Dora B. Cano Marcelo Fort Rinaldo A. Mota Marcos E. Serrano-Martínez Carlos Cruz-Vázquez Luis M. Ortega-Mora Gema Álvarez-García 《Tropical animal health and production》2018,50(1):75-84
We carried out an inter-laboratory trial to compare the serological tests commonly used for the detection of specific Neospora caninum antibodies in cattle in Ibero-American countries. A total of eight laboratories participated from the following countries: Argentina (n = 4), Brazil (n = 1), Peru (n = 1), Mexico (n = 1), and Spain (n = 1). A blind panel of well-characterized cattle sera (n = 143) and sera representative of the target population (n = 351) was tested by seven in-house indirect fluorescent antibody tests (IFATs 1–7) and three enzyme-linked immunosorbent assays (ELISAs 1–3; two in-house and one commercial). Diagnostic performance of the serological tests was calculated and compared according to the following criteria: (1) the “Pre-test information,” which uses previous epidemiological and serological data; (2) the “Majority of tests,” which classifies a serum as positive or negative according to the results obtained by most tests evaluated. Unexpectedly, six tests showed either sensitivity (Se) or specificity (Sp) values lower than 90%. In contrast, the best tests in terms of Se, Sp, and area under the ROC curve (AUC) values were IFAT 1 and optimized ELISA 1 and ELISA 2. We evaluated a high number of IFATs, which are the most widely used tests in Ibero-America. The significant discordances observed among the tests regardless of the criteria employed hinder control programs and urge the use of a common test or with similar performances to either the optimized IFAT 1 and ELISAs 1 and 2. 相似文献
173.
Ana Lúcia Almeida Santana Paulo Levi de Oliveira Carvalho Eliseu Carlos Cristofori Poliana Caroline da Silva Chambo Mariana Barbizan Ricardo Vianna Nunes Cristine Regina Gregory Jansller Luiz Genova 《Tropical animal health and production》2018,50(3):477-484
The aim of this study was to evaluate the effect of supplementation of pig diets in the growth and termination phases with different calcium sources. In experiment I, 36 whole males were distributed in randomized blocks in six groups, with six replications. A basal diet was formulated to meet the animals’ nutritional requirements except for calcium (0.09%), and the sources evaluated (calcitic limestone, monodicalcium phosphate, calcinated bone flour, and oyster flour) replaced the basal diet to provide 0.59% of total calcium. To determine the endogenous calcium, a diet containing low calcium (0.019%) was given simultaneously to another group of animals. Feces and urine were collected for determination the coefficients of apparent and true digestibility. In experiment II, 160 piglets were distributed in randomized blocks in four treatments, with five replications and four animals per experimental unit. Carcass and performance parameters, calcium concentration in bone and serum, and bone parameters were evaluated. The data were submitted to analysis of variance and factorial. The calcium source did not influence the digestibility coefficients determined by total collection (P > 0.05). The digestibility of Ca from oyster flour estimated by collection with an indicator was higher than that from the other sources (P < 0.05). Calcium sources did not interfere in the evaluated parameters (P > 0.05). The sources studied in this work can be used to supplement growing pigs’ diets. 相似文献
174.
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176.
Mariana P. Berton Rosiane P. Silva Felipe E. Carvalho Hermenegildo Lucas Justino Chiaia Priscila S. Oliveira Joanir P. Eler Georgget Banchero Jos B. S. Ferraz Fernando Baldi 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2019,136(6):495-504
Infection with Haemonchus contortus is the most economically important gastrointestinal nematode parasitosis and the most important cause of mortality in sheep production. The aim of this study was to estimate variance components of gastrointestinal parasite resistance traits, maternal efficiency (ME) and ewe adult weight (AW) in Santa Inês breed in tropical conditions. The phenotypic records were collected from 700 animals, belonging to four flocks located south‐east and north‐east in Brazil. The evaluated traits were as follows: degree of anaemia assessed using the FAMACHA chart (FMC), haematocrit (HCT), white blood cell (WBC), red blood cell (RBC), haemoglobin (HGB), platelets (PLT), faecal egg count (EPGlog), ME, metabolic maternal efficiency (MME), AW and metabolic ewe adult weight (MAW). From the 700 animals, 576 (82% of the evaluated population) were genotyped with the Ovine SNP12k BeadChip (Illumina, Inc.). Markers with unknown genomic position, located on sex chromosomes, monomorphic, with minor allele frequency <0.05, call rate <90% and with excess heterozygosity were excluded. The variance components were estimated using a single‐trait animal model with ssGBLUP procedure. The correlation between the parasite's resistance indicators and the ME suggested that selecting animals with both higher adult weight and ME will also favour the selection of animals with better resistance to gastrointestinal nematodes parasites, specially H. contortus. Therefore, since there are few or no studies with Santa Inês breed in this area, it is important to study those traits to better manage selection programs. 相似文献
177.
Rosiane P. Silva Mariana P. Berton Laís Grigoletto Felipe E. Carvalho Rafael M. O. Silva Elisa Peripolli Letícia M. Castro Jos Bento S. Ferraz Joanir P. Eler Raysildo B. Lbo Fernando Baldi 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2019,136(2):118-133
The aim of this study was to estimate genetic parameters and identify genomic regions associated with carcass traits obtained by ultrasound and visual scores in Nellore cattle. Data from ~66,000 animals from the National Association of Breeders and Researchers (ANCP) were used. The variance components for backfat thickness, rump fat thickness and Longissimus muscle area (LMA) were estimated considering a linear model whereas a threshold model for body structure (BS), finishing precocity (FP) and musculature (MS) traits. The SNP solutions were estimated using the ssGBLUP approach by considering windows of 10 consecutive SNPs. Regions that accounted for more than 1.0% of the additive genetic variance were used. Genes identified within the significant windows, such as FOXA3, AP2S1, FKRP, NPASI and ATP6V1G1, were found to be related with MS, while OMA1 and FFGY with BS and FP traits. The PLTP, TNNC2 and GPAT2 genes were found in the regions associated with LMA, as well as TKT, FNDC5 and CHRND can strongly be related with fat deposition. Gene enrichment analysis revealed processes that might be directly influenced the organism growth and development. These results should help to better understand the genetic and physiological mechanisms regulating growth and body composition, muscle tissue development and subcutaneous fat expression, and this information might be useful for future genomic studies in Nellore cattle. 相似文献
178.
Albendazole treatment in laying hens: Egg residues and its effects on fertility and hatchability
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Laura Moreno Mariana Bistoletti Hector Fernández Lucila Cantón Laura Ceballos Candela Cantón Carlos Lanusse Luis I. Álvarez 《Journal of veterinary pharmacology and therapeutics》2018,41(5):726-733
This work characterized the egg residual concentrations of albendazole (ABZ ) and its sulphoxide (ABZSO ) and sulphone (ABZSO 2) metabolites and evaluated their effect on egg fertility and hatchability after ABZ treatments to laying hens. Seventy hens were allocated in groups: Group‐1 was the control without treatment; Group‐2 received a single ABZ oral dose (10 mg/kg); Group‐3, ‐4 and ‐5 were treated with ABZ in medicated feed over 7 days at 10, 40, or 80 mg kg?1 day?1, respectively. Eggs were analyzed to determine the ABZ /metabolite level by HPLC or subjected to incubation to evaluate the fertility and hatchability. Only ABZSO and ABZSO 2 metabolites were quantified in egg after ABZ single oral administration with maximum concentrations of 0.47 ± 0.08 and 0.30 ± 0.07 μg/ml, respectively. ABZ and its metabolites were found in eggs after 7‐day ABZ treatments. The egg residue exposure estimated as AUC s (areas under the concentration vs . time curve) were 100.5 (ABZ ), 56.3 (ABZSO ) and 141.3 μg hr g?1 (ABZSO 2). ABZ administration did not affect the egg fertility at any dosages. Egg hatchability was not affected by ABZ treatment at 10 mg/kg in medicated feed, but it decreased when the dose was 4–8 times higher. These results should be considered when ABZ is used for deworming laying hens. 相似文献
179.
180.
Marilene de Farias Brito Alessandra dos Santos Belo-Reis José Diomedes Barbosa Daniel Guimarães Ubiali Ana Paula de Castro Pires Elizabeth Sampaio de Medeiros Renata Pimentel Bandeira de Melo Pedro Paulo Feitosa de Albuquerque Elise Yamasaki Rinaldo Aparecido Mota 《Tropical animal health and production》2016,48(7):1497-1501