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21.
The responses of the plasma concentrations of catecholamines and cortisol in horses to varied relative intensities of exertion were examined. The plasma concentrations of cortisol, epinephrine and norepinephrine increased significantly (p<0.05) with exertion. The plasma cortisol concentrations at relative work intensities of 48.3%±1.4%, 82.3%±2.0% and 99.6%±0.4% of VO2max were 114%, 124%, and 126%, respectively, of those at rest, whereas the plasma epinephrine concentrations were 239%, 772% and 3483%, and the norepinephrine concentrations were 138%, 255%, and 1121% of the values at rest. There was a significant (p<0.0001) relationship between the plasma epinephrine and norepinephrine concentrations. The blood lactate concentration and the plasma epinephrine and norepinephrine concentrations were significantly (p<0.0001) related, as were the relative work intensity (%VO2max) and the plasma epinephrine and norepinephrine concentrations. The relationships between the plasma cortisol concentration and work intensity or blood lactate concentration were not significant (p>0.05). This study demonstrates a relationship between relative work intensity and indicators of adrenal medullary and sympathetic activity during brief exertion in horses.  相似文献   
22.
Objective Canine leishmaniosis is a disease characterized by the wide distribution of the parasite throughout the tissues of the host. The purpose of this study was to describe the presence of Leishmania spp. and associated inflammation in ocular‐associated muscles of dogs with patent leishmaniosis. Procedures Smooth muscles (iris dilator muscle, iris sphincter muscle, ciliary muscle, Müller muscle, smooth muscle of the periorbita and smooth muscle of the nictitating membrane) and striated muscles (orbicularis oculi muscle, obliquus dorsalis muscle and dorsal rectus muscle) were evaluated. Routine staining with hematoxylin and eosin and immunohistochemistry to detect Leishmania spp. were performed on tissue sections. Results Granulomatous inflammation was seen surrounding muscular fibers and was composed mainly of macrophages with scattered lymphocytes and plasma cells. This infiltrate could be seen in 52/473 (10.99%) samples of smooth muscle and 36/142 (25.35%) samples of striated muscle. Parasites were detected in 43/473 (9.09%) samples of smooth muscle and in 28/142 (19.71%) samples of striated muscle. Conclusions To the authors’ knowledge, this is the first report assessing the presence of Leishmania spp. and associated infiltrate in intraocular, extraocular and adnexal smooth and striated muscles. The inflammation present in those muscles could contribute to clinical signs already described, such as blepharitis, uveitis, and orbital cellulitis.  相似文献   
23.
We investigated 2 outbreaks of osteomalacia as a result of phosphorus (P) deficiency in herds of lactating beef cows grazing subtropical native pastures in Uruguay. Cows exhibited pica, difficulty to stand and walk, rib fractures, and body weight loss even with adequate forage availability. Osteopenia and severe osteomalacia were observed on gross and histologic examination. The concentrations of bicarbonate-extractable P in soil (4.0, 4.1 mg P/kg), total P in pasture (0.9, 1.1 g P/kg), inorganic P in serum (1.0, 0.71 mmol P/L), and P in bone (73 mg P/mL) were all low. Although injectable and mineral salt supplements provided additional P in both outbreaks, these supplementary amounts were insufficient to prevent P deficiency. The P ingested by the cows from the pasture and supplements would have provided 20–55% of their daily P requirements of ~21 g P/d. Osteomalacia occurred in cattle at the 2 ranches as a result of severe P deficiency in the soil and forage, and inadequate P supplementation. Following diagnosis, control of P deficiency in beef cattle requires estimation of the amount of pasture P ingested and provision of sufficient additional supplementary P to meet the animals’ requirements.  相似文献   
24.
Journal of Pest Science - Increasing either inter- or intraspecific plant diversity has shown the potential to engender bottom-up and top-down effects upon herbivorous pests. Nonetheless, because...  相似文献   
25.
European Journal of Forest Research - The resistance of different genotypes to abiotic stress may be due to genetic effects and/or to phenotypic plasticity allowing them to acclimate to variable...  相似文献   
26.
In this study, lipid classes and fatty acid composition were determinedin eggs of P. vannamei as a function of survival to zoeaIII stage. Spawns were reared individually to zoea III and grouped, accordingtotheir final survival to this larval stage, into spawns of high and lowsurvival.Eggs of individual spawns were analyzed for lipid and fatty acid composition ofneutral and polar lipids and the results were then grouped according tosurvivalto zoea III. The lipids within each group (high and low survival to zoea III)were pooled for the separation of phospholipids and the analysis of their fattyacid composition.Higher levels of triglycerides, carotenoids, and linoleic (18:2n-6) acid ineggs were associated with improved survival to zoea III. Linoleic acid washigher in spawns from the high survival group in both neutral and polarfractions and in most of the phospholipid classes analyzed. Docosahexanoic acid(DHA) was not related to survival to zoea, probably because its content washighenough (> 15% of total fatty acids) to satisfy embryo and early larvaldevelopment needs. A high content of eicosapentaenoic acid (EPA) was found inphosphatidylethanolamine, lysophosphatidylethanolamine, phosphatidylserine, andphosphatidylinositol compared to other phospholipid classes, suggesting aspecific role of EPA in these lipids. These results describe the specificphospholipid composition of penaeid eggs and could (potentially) be used aspredictive indicators of larval quality for research and production purposes.  相似文献   
27.
28.
The reproductive potential of males plays an important role in the productivity of captive penaeids. Males present a large variability in their reproductive potential, and thus the selection of appropriate males for reproduction is highly desirable. The present study compares sperm quality at the beginning of the experiment (baseline values) with variations in sperm quality as a result of consecutive spermatophore regenerations. This was done to evaluate possible predictive criteria for optimal sperm quality based on morphological and biochemical criteria in pond-reared Pacific white shrimp Litopenaeus vannamei males. Sperm quality was similar between left and right spermatophore. Sperm count and proportion of normal sperm increased by 86 and 65% (P < 0.05) respectively, from baseline values to third spermatophore regeneration. Proportion of dead sperm progressively decreased with consecutive regenerations, attaining values 33% lower by the third regeneration, compared to baseline values. This indicates that no decrease in sperm quality occurs in L. vannamei during consecutive regenerations and that the existing spermatophores at stocking of males should be expelled to have higher sperm quality in regenerated spermatophores. Furthermore, this procedure allows selecting individuals with high baseline sperm quality based on significant correlations between baseline and regenerated sperm quality observed in the present work. Baseline values of glucose concentration in the hemolymph were positively correlated to baseline values of sperm count (r = 03, P < 0.05). In contrast, baseline values of several lipids in the hemolymph were negatively correlated to several traits of sperm quality at first sampling (baseline values) or at first regeneration. These results are discussed in terms of nutritional requirements of males and of possible predictive criteria of sperm quality.  相似文献   
29.
Design information for the use of sand beds to remove suspended solids from wastewater discharged from recirculating aquaculture systems (RAS) was developed. Wastewater from a commercial RAS tilapia farm with 2% total solids and 1.6% total suspended solids (TSS) was applied to sand columns to determine infiltration rates and phosphorus capture. Various hydraulic loading rates and drying periods between application events were evaluated. Infiltration rates stabilized after five application events to 3.5 cm/day (S.D.=1.7). Practically, all suspended solids were captured at the top of the columns, creating the primary resistance to infiltration. Concrete sand removed approximately 93% of the soluble phosphorous in the wastewater and wollastonite, an economical aggregate alternative to sand, removed at least 98%. A modified Darcy equation is presented to predict infiltration based upon TSS and the number of sequential applications.  相似文献   
30.
The extrusion process allows the production of nixtamalized corn flour rich in arabinoxylans, which help to prevent cardiovascular and intestinal diseases. During extrusion, physiochemical properties of nixtamalized corn flour are negatively modified. The use of enzymes such as xylanase in order to obtain nixtamalized corn flour using extrusion has been studied as an alternative to reduce these changes in corn flour tortilla. The aim of this research was to evaluate changes in protein solubility of extruded nixtamalized corn flour with and without different concentrations of xylanase enzyme (0.05, 0.075, and 0.1 %, w/w). Soluble proteins of each corn flour were extracted and analyzed by SE-HPLC, while insoluble proteins were determined by the combustion method. In addition, each corn flour was analyzed by scanning electron microscopy (SEM). Results showed that the extruded nixtamalized corn flour, with and without xylanase, increased the protein solubility, and this effect was lower in extruded nixtamalized corn flour with xylanase. Insoluble protein diminished in corn flours either with or without xylanase enzyme. The addition of xylanase reduces the effect that the extrusion process has on the solubility proteins of extruded nixtamalized corn flour.  相似文献   
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