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1.
Conventional feedstuffs in Brazil are expensive, which has led to the search for less conventional cheaper and locally available feedstuffs. Thus, this study was carried out to determine the dietary effect of dry sweet potato vines (SPV) on the performance and some carcass characteristics of rabbits. A total of twenty‐seven weaned White New Zealand rabbits (14 male and 13 female) 35 days old with an average initial weight of 755 g were allocated into three treatments. Nine rabbits were assigned to each treatment in a completely randomized design. Three diets were formulated to similar protein and energy levels: 0SPV – diet without inclusion of dry sweet potato vines; 10SPV – diet with 10% alfalfa hay replaced by dry sweet potato vines; and 15SPV – diet with 15% of alfalfa hay replaced by dry sweet potato vines. The experiment lasted for 49 days during which data for feed intake and body weight were recorded. The daily feed intake ranged from 73.17 to 78.02 g; daily weight gain from 22.32 to 23.17 g; feed conversion ratio (FCR) from 3.16 to 3.49 and final live weight ranged from 1839.44 to 1880.55 g. None of the evaluated performance parameters as well as carcass weight, heart weight and percentages of fat and protein in meat were significantly affected by any of the tested dietary treatments. However, the liver weight was statistically lower in animals fed the diets containing 10% of SPV, mainly due to lower glucose content. Glycogen within the tissue, did not differ significantly among treatments. It was therefore concluded that up to 15% of SPV can successfully be included in the diet of rabbits as a cheaper replacement for alfalfa hay without adversely affecting performance.  相似文献   
2.

Potassium has important physiological functions in eucalypt plantations, increasing their productivity when applied to soil via mineral fertilizers. There is interest in identifying alternative sources to KCl owing to its high cost and limited reserves. The aim of the study was to test the effect of replacing KCl with NaCl and phonolite rock powder. Two comparisons were made: (1) application of 283 kg ha?1 of KCl compared with that of 2125 kg ha?1 of phonolite rock powder (equivalent to 170 kg ha?1 of K2O in both treatments); (2) application of 139 kg ha?1 of NaCl compared with that of 183 kg ha?1 of KCl (equivalent to 2.33 kmol Na and K, respectively). Radial growth, soil water content, leaf water potential (Ψ), accumulated transpiration, stem volume and biomass increment, as well as water use efficiency (WUE) were evaluated. In the first comparison, both fertilizations presented equal values for all characteristics evaluated. In the second, the accumulated transpiration in trees fertilized with KCl was 17% higher than that in plants fertilized with NaCl. In contrast, the WUE was 20% higher in the trees fertilized with NaCl than in those fertilized with KCl, reflecting the lower water consumption for the same increment in stem volume and biomass. We conclude that phonolite rock powder and NaCl are possible substitutes for conventional K fertilization performed with KCl.

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3.
Black snook, Centropomus nigrescens, have been identified as a promising candidate for aquaculture although, like many of the Centropomid species, high mortality associated with early larval stages presents a significant bottleneck to their commercialization. The digestive capacity of black snook larvae throughout the first 37 d after hatch (d.a.h.) was evaluated by quantifying digestive enzyme activities using biochemical techniques. Results showed that black snook larvae have alkaline proteases at hatching, which are known to be important during the first days of feeding for digestion. Toward the end of the study, acid proteases concentration increased (37 d.a.h.). Enzymes for lipid digestion, pancreatic lipase and bile salt‐activated lipase, were already present in the larvae before exogenous feeding commenced, and their activity increased with age and growth (length). Intracellular digestion, measured as the activity of leucine‐alanine peptidase, was high early on (5 d.a.h.) and decreased as development progressed (next 32 d). In contrast, alkaline phosphatase activity was lowest at first feeding and subsequently increased with age. Overall patterns in enzyme activity suggest the possibility of live feed weaning before 32 d.a.h. if artificial diets can be properly balanced.  相似文献   
4.
  • 1. Prochilodus lineatus (Prochilodontidae, Characiformes) is a migratory species of great economic importance both in fisheries and aquaculture that is found throughout the Jacuí, Paraíba do Sul, Paraná, Paraguay and Uruguay river basins in South America. Earlier population studies of P. lineatus in the rio Grande basin (Paraná basin) indicated the existence of a single population; however, the range of this species has been fragmented by the construction of several dams. Such dams modified the environmental conditions and could have constrained the reproductive migration of P. lineatus, possibly leading to changes in the population genetic structure.
  • 2. In order to evaluate how genetic diversity is allocated in the rio Grande basin, 141 specimens of P. lineatus from eight collection sites were analysed using polymerase chain reaction–restriction fragment length polymorphism (PCR‐RFLP) with 15 restriction enzymes.
  • 3. Forty‐six haplotypes were detected, and 70% of them are restricted. The mean genetic variability indexes (h = 0.7721 and π = 1.6%) were similar to those found in natural populations with a large effective size. Fst and Exact Test values indicated a lack of structuring among the samples, and the model of isolation by distance was tested and rejected.
  • 4. The haplotype network indicated that this population of P. lineatus has been maintained as a single variable stock with some differences in the genetic composition (haplotypes) between samples. Indications of population expansion were detected, and this finding was supported by neutrality tests and mismatch distribution analyses.
  • 5. The present study focused on regions between dams to serve as a parameter for further evaluations of genetic variability and the putative impact of dams and repopulation programmes in natural populations of P. lineatus. Copyright © 2011 John Wiley & Sons, Ltd.
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5.
In the common bean crop in Brazil, the requirement of the value for cultivation and use trials is that these experiments must be conducted over two years in three locations per region. Information in regard to the necessary number of years to ensure precision in cultivar recommendation and the influence of evaluated years in the estimation of the GE interaction are still scarce. Using grain yield of five check varieties assessed over 11 years in three sowing seasons per year, the aims of this study are as follows: to measure the relative contribution of the GE interaction, evaluating the implication of the number of years in the estimates of the GE interaction, and infer how many years are needed to ensure precision in cultivar recommendation. For instances, analysis of variance was carried out involving all environments and also combinations of years. The results showed that the GE interaction was greater than all other cross‐effects involving lines. The use of at least two years allows good coincidence in cultivar recommendation compared to the whole period. Increasing the evaluation time is a good strategy, especially when it is difficult to grow three different sowing seasons.  相似文献   
6.
Tree mortality in Amazonia has been related to regional variation in soil, topography and climatic disturbances, but the magnitude of the effect of these factors on tree mortality at local and mesoscales remains poorly determined. We investigated tree mortality in 72 1-ha permanent plots spanning 64 km2 of tropical moist forest in Reserva Ducke, Manaus, Brazil. Plots were censused three times (2000-2003, 2003-2005, and 2005-2008), resulting in two census intervals. The relationships of soil and topography to tree mortality were dependent on tree size. Small- and medium-sized trees (1 ? dbh < 30 cm) had similar relationships of mortality with soil and topography, while large trees (dbh ? 30 cm) showed different (or no) relationships. The effects of soil and topography on tree mortality also varied temporally. In the second census interval after storms, soil and topography explained about one-fourth of the spatial variation in mortality of small- and medium-sized trees (<30 cm dbh), whereas no effects were detected in the first census interval. In particular, soil fertility was the most important predictor of tree mortality in the study area. Topography alone (altitude and slope) was associated with only 12% of the spatial variation in tree mortality and the magnitude of the effect of soil and topography on tree mortality also increased after storms. In general, plots on more fertile soils, on steep slopes and sandy soils in valleys showed greater tree mortality than those on plateau with well-drained clayey soils. Therefore, disturbance history and tree size should be included when scaling up tree mortality from local to regional scales. As much variation remains unexplained, other landscape features, such as watershed morphology and wind exposure, may be necessary to make more precise predictions on patterns of tree mortality in Central Amazonia.  相似文献   
7.
The Mexican silverside, Menidia estor, is a species with great regional importance and with very high prices in local markets. Unfortunately, due to high fisheries pressure, environmental degradation and pollution, the species has become endangered. Recently, there has been much progress in the biotechnology of this species, aimed at its culture, and the present paper describes the advances in feeding and nutrition of those important fish. M. estor is a stomachless, zooplantophagous fish, which also occasionally feeds on small fish and crustaceans in the adult stage. Studies on the digestive enzymatic activities show high proteolytic capacity and a late or different model of digestive maturation from that described for marine stomach fish. Nutritional studies on M. estor have shown that juveniles have dietary requirements of about 400 g kg?1 protein and 80 mg kg?1 vitamin C. The upper level of dietary carbohydrate for good growth and survival for juveniles is about 150 g kg?1. Based on the high docosahexaenoic acid (DHA) content in flesh when fed on diets low in DHA, it is believed that the species has the capacity to biosynthetize >20‐carbon fatty acids from 18‐carbon fatty acids. The high levels of DHA in flesh makes this fish a very significant potential component of human nutrition. Using these findings the first practical diets for commercial culture of the species have been developed.  相似文献   
8.
Osteosarcoma is the most commonly reported bone tumor in dogs, typically affecting the axial and appendicular skeleton. Involvement of the paranasal sinuses and the nasal cavity is extremely rare. This report describes a 6-year-old, female, cross-breed dog presented with signs of 90 days duration and diagnosed with a mass located in the right nasal cavity. Radiography, rhinoscopy, and computed tomography findings suggested the presence of an intranasal tumor. Osteosarcoma in the nasal cavity was diagnosed based on histopathological examination and clinical and imaging findings. Survival time was 12 months from diagnosis.  相似文献   
9.
OBJECTIVE: To determine pharmacokinetic variables and pharmacologic effects of the S(-) isomer of bupivacaine (S[-]-BPV) in dogs. ANIMALS: 6 adult male Beagles. PROCEDURE: Dogs received S(-)-BPV (1 mg/kg of body weight) i.v., and 15 days later, the same dogs received 1.8 mg/kg epidurally. Pharmacokinetic variables and pharmacologic effects were determined for each route of administration. RESULTS: After i.v. administration, plasma concentration versus time curves were adjusted, using biexponential equations that indicated a rapid distribution phase followed by a slower elimination phase, with a mean +/- SD half-life of 33.5 +/- 17.0 minutes. Mean plasma clearance was 21.0 +/- 10.7 ml/min/kg, and mean volume of distribution at steady state was 0.8 +/- 0.2 L/kg. After i.v. administration, mean peak plasma concentration was 2.6 +/- 0.7 micrograms/ml; after epidural administration, it was 0.9 +/- 0.5 microgram/ml at approximately 3 minutes. Half-life after epidural administration was 5 times longer than that observed after i.v. administration. Motor block began immediately after the end of epidural administration and lasted for 3 to 4 hours. Changes in systolic blood pressure and heart rate after epidural administration were slight but occurred at the same time that plasma concentration peaked. After i.v. administration, motor block or variations in physiologic variables studied were not observed. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, the pharmacologic behavior of S(-)-BPV was similar to that of the bupivacaine racemate, but motor block attributable to S(-)-BPV lasted longer than that attributable to the racemate, with lower plasma concentrations observed at equivalent sample collection times.  相似文献   
10.
The early development of the digestive biochemistry of three cultured Atherinopsids (two Odontesthes species and Chirostoma estor) was investigated. Relatively high lipolytic and high alkaline proteolytic activities were found in all species. In addition, gene expression of lipase and trypsin during the early development of C. estor not only indicates an early onset of the lipase activity but also demonstrates a major importance of protein digestion in this species. However, despite all of them share similar habitats, differences in their digestive activities were evident. The rise in the activities of brush border membrane enzymes correlated with the decrease in cytosolic activities, used as indicator of maturation of the digestive tract, was detected in both species of Odontesthes at 9 weeks after hatching. In contrast, no similar signs were measured in C. estor, this being in agreement to the long weaning period (nearly 5 months) reported for this species.  相似文献   
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