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排序方式: 共有329条查询结果,搜索用时 31 毫秒
61.
Robles Jimenez Lizbeth E. Ruiz Perez Jose A. Nicolas Di Lorenzo Chay Canul Alfonso J. Ramirez-Rivera Julio Cesar Villegas-Estrada Daniela Vargas-Bello-Pérez Einar Gonzalez-Ronquillo Manuel 《Tropical animal health and production》2020,52(3):1257-1267
Tropical Animal Health and Production - Currently for the reduction of methane (CH4) emissions are using fodder rich in condensed tannins, however, not yet known exactly how they act in the rumen... 相似文献
62.
Nícolas Z. dos Santos Stephen A. Prior Juarez Gabardo Julio C. Valaski Antonio C. V. Motta Antonio Ferreira Neto 《Journal of plant nutrition》2013,36(5):750-769
The amount and composition of crop residues added to soil in agroecosystems can influence decomposition processes and soil organic matter levels. This study aimed to evaluate residues (quantity and quality) of different corn cultivars commonly used in Brazilian cropping systems. The experiment was conducted for two seasons (2005/2006 and 2006/2007) in Rolândia, Paraná State, Brazil. Ten corn cultivars that represent five degrees of breeding development (i.e., landrace, commercial variety, double cross, triple cross, and single cross hybrids) were evaluated. At harvest, carbon (C) and nitrogen (N) of non-yield residue and grain were determined. Except for grain C, other measures (grain N concentration, residue C and N concentration, and C:N ratio) varied among cultivars. In general, the hybrids had higher residue C and lower residue N concentrations than the landraces and commercial varieties. Findings suggest that breeding selection may have altered residue production and composition, which may influence soil C dynamics. 相似文献
63.
Charles D. Foy Julio C. de Paula Jose A. Centeno Emilia Ivanova Jücker 《Journal of plant nutrition》2013,36(4-5):769-782
Plant genotypes within species differ widely in tolerance to excess manganese (Mn) that may occur in acid soils, or in neutral or alkaline soils having poor aeration caused by imperfect drainage or compaction. However, Mn tolerance mechanisms in plants are largely unknown. Silicon (Si) is reported to detoxify Mn within plants, presumably by preventing localized accumulations of Mn associated with lesions on leaves. Because Mn is paramagnetic, electron paramagnetic resonance (EPR) spectroscopy, shows promise as a tool for characterizing toxic and non‐toxic forms of Mn in tolerant and sensitive plants. The objective of our study was to use EPR to: i) determine the chemical/ physical state of Mn in Mn‐tolerant and ‐sensitive snapbean cultivars; and ii) characterize the protective effects of Si against Mn toxicity. Manganese‐sensitive Wonder Crop 2 (WC) and Mn‐tolerant Green Lord (GL) cultivars of snapbean were grown at pH 5.0, in a greenhouse, in a modified Steinberg solution containing: Mn=0.05mg.L‐1 (optimal); Mn=1.0mgL‐1 (toxic); Mn=1.0 mg L‐1 plus Si=4 mg L‐1; and Mn=0.05 mg L‐1 plus 4 mg Si L‐1. All trifoliate leaf samples exhibited a 6‐line EPR signal that is characteristic of hexaaquo Mn2+. In both cultivars, a higher EPR Mn2+ signal‐intensity generally correlated with lower total leaf mass, higher total Mn concentrations and more pronounced symptoms of toxicity. Tolerance to excess Mn coincided with lower Mn2+ signal intensity. Silicon treatments ameliorated Mn toxicity symptoms in both genotypes, decreased total leaf Mn concentrations, and decreased EPR Mn2+ signal intensity. Results suggest that Mn toxicity is associated with reduced electron transport and accumulation of oxidation products in leaves. Amelioration of Mn toxicity by Si is regarded as connected with a reduction in this Mn‐induced process. Results indicated that EPR spectroscopy can be useful in investigating the biochemical basis for differential Mn tolerance in plants. The EPR observations might also help plant breeders in developing Mn‐tolerant cultivars. 相似文献
64.
65.
The objective was to determine the effect forage-to-concentrate (F:C) ratio and stage of lactation on methane emissions, digestibility, nutrient balance, lactation performance, and metabolic responses in lactating goats. Twenty Murciano-Granadina dairy goats were used in an experiment divided into 3 periods: early (30 d), mid (100 d), and late (170 d) lactation. All goats were fed a diet with 35:65 F:C (FCL) during early-lactation. Then, 1 group (n = 10 goats) remained on FCL through mid- and late-lactation while the other group (n = 10 goats) was fed a diet with 50:50 F:C at mid-lactation (FCM) and 65:35 (FCH) at late lactation. A greater proportion of concentrate in the diet was associated with greater overall intake and digestibility (P < 0.05). Energy balance was negative in early-lactation (−77 kJ/kg of BW0.75, on average) and positive for FCL at mid- and late-lactation (13 and 35 kJ/kg of BW0.75, respectively). Goats fed FCM and FCH maintained negative energy balance throughout lactation. Plasma concentrations of non-esterified fatty acids at mid-lactation were greater for FCM than FCL (680 mEq/L), and at late-lactation concentrations were greater for FCH and FCL (856 mEq/L). A similar response was detected for plasma β-hydroxybutyrate. Methane emission was greater (P < 0.05) for FCM than FCH (1.7 g CH4/d). This study demonstrated that differences in F:C across stages of lactation lead to distinct metabolic responses at the level of the rumen and tissues. 相似文献
66.
Julio C. Barbosa Sarah S. Barreto Alice K. Inoue-Nagata Marcelo S. Reis Ana Carolina Firmino Armando Bergamin Filho Jorge Alberto Marques Rezende 《Journal of General Plant Pathology》2009,75(6):440-443
Nicandra physaloides, a common weed in South America, was found to be infected by an isolate of Tomato severe rugose virus (ToSRV), a bipartite begomovirus. The plants developed severe yellow rugose mosaic and were collected in São Paulo State, Brazil. This isolate of ToSRV was transmitted by Bemisia tabaci B biotype from infected plants of N. physaloides to healthy plants of N. physaloides and tomato in a glasshouse. This is the first report of natural infection of N. physaloides by ToSRV in Brazil. 相似文献
67.
Juan Manuel Serrano-Rodríguez Carles Mengual Setefilla Quirós-Carmona Julio Fernández Juan Manuel Domínguez Juan Manuel Serrano-Caballero Juan Morgaz Rocio Navarrete-Calvo Rafael J. Gómez-Villamandos Maria del Mar Granados 《Veterinary anaesthesia and analgesia》2019,46(2):226-235
Objective
To assess the pharmacokinetics (PK) and conduct a clinical laboratory evaluation of acetaminophen in Beagle and Galgo Español (GE) dogs.Study design
Prospective randomized experimental trial.Animals
A total of 20 healthy dogs – 10 Beagles and 10 GE (six males and four females in both groups).Methods
Acetaminophen (10 and 20 mg kg–1) was administered intravenously (IV) to the dogs on two different occasions. Plasma concentrations were analysed by high-performance liquid chromatography. PK analysis was undertaken using compartmental modelling with ADAPT 5 software. Simulations after multiple IV doses were investigated. Clinical laboratory values such as red blood cell (RBC) count, haemoglobin (Hb), haematocrit (Ht), white blood cell (WBC) count, platelet count, total proteins, alanine aminotransferase (ALT), aspartate aminotransferase, urea and creatinine were measured before and 24 hours after acetaminophen administration in combination with clinical examination to assess side effects resulting from the drug.Results
A two-compartmental model best described time–concentration profiles of acetaminophen. PK parameters were different as a result of a breed effect. For doses of 10 and 20 mg kg–1, respectively, clearance values were 1.70 (1.15–2.27) and 1.62 (1.06–2.86) L kg–1 hour–1 for Beagles and 1.18 (0.70–1.39) and 1.08 (0.67–1.35) L kg–1 hour–1 for GE; elimination half-life values were 2.64 (0.52–4.46) and 2.86 (0.87–4.63) hours for Beagles and 3.49 (1.89–7.80) and 4.57 (2.08–8.90) hours for GE. Significant differences were also found between GE and Beagles in the RBC count, Ht, Hb, WBC count and serum ALT before drug administration, and these differences were maintained 24 hours later, independent of the dosage used. For each breed, no side effects resulting from IV acetaminophen administration were observed at doses of either 10 or 20 mg kg–1.Conclusions and clinical relevance
IV PK of acetaminophen was different between Beagles and GE dogs. Side effects were not detected. Further studies are necessary to evaluate the PK in a clinical context. 相似文献68.
Bruno C. Perez Julio C. C. Balieiro Roberto Carvalheiro Fabio Tirelo Gerson A. Oliveira Junior Juliana M. Dementshuk Joanir P. Eler Jos B. S. Ferraz Ricardo V. Ventura 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2019,136(1):23-39
The objective of the present study was to investigate the impact of considering population structure in cow genotyping strategies over the accuracy and bias of genomic predictions. A small dairy cattle population was simulated to address these objectives. Based on four main traditional designs (random, top‐yield, extreme‐yield and top‐accuracy cows), different numbers (1,000; 2,000 and 5,000) of cows were sampled and included in the reference population. Traditional designs were replicated considering or not population structure and compared among and with a reference population containing only bulls. The inclusion of cows increased accuracy in all scenarios compared with using only bulls. Scenarios accounting for population structure when choosing cows to the reference population slightly outperformed their traditional versions by yielding higher accuracy and lower bias in genomic predictions. Building a cow‐based reference population from groups of related individuals considering the frequency of individuals from those same groups in the validation population yielded promising results with applications on selection for expensive‐ or difficult‐to‐measure traits. Methods here presented may be easily implemented in both new or already established breeding programs, as they improved prediction and reduced bias in genomic evaluations while demanding no additional costs. 相似文献
69.
Abstract The Hach CEL/700 Organic Matter Laboratory provided estimates of organic carbon concentrations in pond soil samples comparable to those obtained by the commonly-used Walkley-Black method. Dry ashing at 350–400 C tended to overestimate soil organic matter concentrations, and this procedure requires too much equipment and laboratory expertise for use on most aquaculture farms. The Hach kit can provide practical aquaculturists a simple and reliable method for measuring organic matter in pond soils. Samples from brackishwater ponds should be treated with mercuric sulfate to prevent chloride interference and overestimation of organic matter. 相似文献
70.
Affinity purification of copper-chelating peptides from sunflower protein hydrolysates 总被引:1,自引:0,他引:1
Megías C Pedroche J Yust MM Girón-Calle J Alaiz M Millan F Vioque J 《Journal of agricultural and food chemistry》2007,55(16):6509-6514
Copper-chelating peptides were purified from sunflower protein hydrolysates by affinity chromatography using immobilized copper. A variety of protein hydrolysates were obtained by incubation with the proteases Alcalase and Flavourzyme for different periods of time. Chelating activity was indirectly determined by measuring the inhibitory effect of hydrolysates on the oxidation of beta-carotene by copper. Copper-binding peptides purified from the two hydrolysates that inhibited oxidation by copper the most contained 25.4 and 42.0% histidine and inhibited beta-carotene oxidation 8 and 3 times more than the original hydrolysates, which had 2.4 and 2.6% histidine, respectively. Thus, histidine content is not the only factor involved in antioxidant activity, and probably other factors such as peptide size and amino acid sequence are also important. This work shows that affinity chromatography can be used for the purification of copper-chelating peptides and probably other metals of nutritional interest such as calcium, iron, and zinc. In addition to their antioxidant potential, chelating peptides are of nutritional interest because they increase bioavailability of minerals. 相似文献