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21.
A. Lara G.D. Mendoza L. Landois R. Barcena M.T. Snchez-Torres R. Rojo J. Ayala S. Vega 《Livestock Science》2006,105(1-3):105-108
Forty multiparous cows (599 kg ± 18 kg BW) were fed with a basal diet (19.6% CP, 35% RUP, and 1.7 Mcal kg− 1 NEl) with alfalfa, corn silage and concentrate (49% forage: 52% concentrate). After calving, cows were randomly assigned to the treatments, which consisted in four levels of ruminally protected methionine (RPM): 0, 8, 16 and 24 g d− 1 of Mepron®M85 (Degussa Co.). Experiment was conducted for 120 days with measurements of milk production, composition, body weight, body condition score and DM intake every 15 days (3 consecutive days) starting on day 5 postpartum. Data were analyzed with the repeated measures model (four treatments in 8 periods through lactation). No treatment effects were detected on DM intake (20.38 ± 2.51 kg d− 1), body weight (599.78 ± 19.78 kg), body condition score (2.51 ± 0.19 units) and milk fat. However, milk production and protein yield were increased with addition of RPM (P < 0.01). Milk production responded quadratically to methionine level. Holstein cows with a mean production of 35 kg d− 1 milk require addition of ruminally protected methionine (16 g d−1) to improve milk production. 相似文献
22.
Francisco J. Martín‐Peinado Francisco Bruno Navarro Maria Noelia Jimnez Manuel Sierra Francisco J. Martínez Ana Romero‐Freire Leopoldo Rojo Emilia Fernndez‐Ondoo 《Land Degradation \u0026amp; Development》2016,27(7):1709-1720
This work evaluated how pine plantations established on old fields and degraded lands influence soil properties in comparison with adjacent unplanted areas that undergo into secondary succession, and native forests, analysing the effects of abiotic variables and stand characteristics in the afforestation process. Thirty‐two paired sites (pine plantations versus unplanted areas) and 10 native forests were selected in the SE Spain. In total, 74 soil profiles were studied, and 222 composite soil samples were collected at three different depths. Soil organic carbon, cation exchange capacity, and C : N ratio showed significantly greater values in pine plantations in relation to the unplanted areas (0–5 cm), and the mean values of soil organic carbon, nitrogen (N), C : N ratio, and cation exchange capacity in these pine plantations were similar to those found under native forests. Only K+ concentrations were clearly higher in the native forests than in the other land uses for all depths analysed. Pine plantations in the drier and warmer areas showed lower soil quality in relation to the paired unplanted areas, as well as the younger and denser ones; it may be because under these situations, more time is needed to produce an improvement. In fact, the paired net variations increased with the stand age and/or tree size. In conclusion, pine plantations were in general more efficient in improving parameters related to soil quality, especially in locations with high soil water retention capacity, which in our study area were found at higher and cooler elevations. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
23.
E. Fernández-Ondo?o L. Rojo Serrano M. N. Jiménez F. B. Navarro M. Díez F. Martín J. Fernández F. J. Martínez A. Roca J. Aguilar 《European Journal of Forest Research》2010,129(4):707-717
In the 20th century, in the Mediterranean area, many extensive afforestation efforts were made with the primary objective
of protecting soils from erosion and improving their fertility. This study evaluates the effects of the afforestation undertaken
in the Guadalentín basin (SE Spain) with respect to the organic and inorganic soil constituents and physico-chemical soil
properties. Given the phytoclimatic environments in the basin (sclerophyllous and hyperxerophyllous), paired samples were
taken beneath the tree canopy of the pine plantations and in nearby open zones. With the same methodology, samples were taken
from areas considered to be native forest. The data were submitted to different multivariate analyses of variance (two-way
MANOVAs) in order to compare the effects and interactions of the factors CANOPY (with and without trees), PHYTOCLIMATE (sclerophyllous
and hyperxerophyllous), and TYPE OF FOREST (afforested or native) on the dependent variables measured (soil variables). Significant
differences were found at 0–10 cm in soil depth under pine afforestations in relation to adjacent open areas. Below this depth,
differences were found only between phytoclimatic environments. No significant interactions were found between the variables
analysed at any of the depths, indicating that the effects of the afforestations on the soil characteristics were independent
of the phytoclimatic environment. The afforestation in the Guadalentín basin, in the two phytoclimatic environments considered
increased the soil fertility. Nevertheless, the native forests presented the highest soil organic-carbon contents, mainly
in the sclerophyllous phytoclimate type (Quercus ilex subsp. ballota forests). Therefore, although the afforestations improved the soil fertility in relation to the open areas, the maximum potential
has probably not been reached in relation to that observed in the native forests. The effects that forest development (age,
basal area) over time exerts on soil properties remain to be verified by further research. 相似文献
24.
Ritter MJ Ellis M Bowman R Brinkmann J Curtis SE DeDecker JM Mendoza O Murphy CM Orellana DG Peterson BA Rojo A Schlipf JM Wolter BF 《Journal of animal science》2008,86(11):3137-3145
This study evaluated effects of trailer design and season on physical indicators of stress during loading and unloading and transport losses (dead and nonambulatory pigs) in market-weight pigs (BW = 129.6 +/- 0.40 kg). A total of 109 trailer loads of pigs (n = 17,256 pigs) from 1 farm were used in a randomized complete block design with a 2 x 4 factorial arrangement of treatments: 1) trailer design (potbelly vs. straight-deck) and 2) season (spring vs. summer vs. fall vs. winter). A subset of loads (n = 42) was used to examine effect of distance pigs were moved during loading [short (<24 m) vs. long (47 to 67 m)] on physical indicators of stress and transport losses. This study was conducted on 7 d per season at 1 farm with 4 loads (2 on potbelly and 2 on straight-deck trailers) being transported each day to 1 commercial packing plant. Pigs from different farm groups were mixed on the trailer and provided with 0.45 m(2)/pig floor space during an approximately 4-h journey to the plant. The percentage of pigs exhibiting open-mouth breathing, skin discoloration, and muscle tremors was recorded during loading and unloading. Additionally, dead pigs on arrival at the plant and nonambulatory pigs at the farm and at the plant were recorded. Effects of trailer design on open-mouth breathing and skin discoloration during unloading were dependent on season (trailer design x season interaction; P < 0.05). Pigs unloaded from potbelly trailers had a greater (P < or = 0.05) incidence of open-mouth breathing in the spring and summer and a greater (P < 0.05) incidence of skin discoloration in the spring, summer, and winter than pigs unloaded from straight-deck trailers. The incidence of total nonambulatory pigs at the plant was greater (P < 0.05) in the winter than in the spring and summer. The long compared with short distance moved treatment resulted in a greater (P = 0.001) incidence of open-mouth breathing and skin discoloration during loading and tended (P = 0.06) to increase the incidence of nonambulatory pigs at the farm. However, there was no effect of trailer design, season, or loading distance on total losses at the plant. In summary, physical indicators of stress (open-mouth breathing and skin discoloration) were increased with the long distance moved during loading treatment and were greater during unloading for potbelly than straight-deck trailers; however, trailer design, season, and loading distance had minimal effects on total transport losses. 相似文献
25.
Rojo Alberto; Dieguez-Aranda Ulises; Rodriguez-Soalleiro Roque; Von Gadow Klaus 《Forestry》2005,78(4):385-401
Two silvicultural alternatives for Scots pine (Pinus sylvestrisL.) plantations in north-western Spain were simulated and compared.One corresponded to the current management practice appliedin the region and the other was an intensive silvicultural regime.Both alternatives were described by a specific combination ofplantation density, precommercial treatments, thinning patternand rotation age. Stand development of each silvicultural alternativewas generated using a regional growth and yield model implementedin a simulator called GesMO, for three site qualities that representedpoorest, intermediate and best sites found in the region. Differenttimber grades associated with each alternative were predicted,and estimates of costs and selling prices were used to predicta cash flow pattern for each of the simulated alternatives.The alternatives were ranked using the criterion of net presentvalue of an infinite series of rotations. Sensitivity analysis,in terms of basic prices, discount rate and rotation length,was also carried out. In addition, the effects of risk of fireon net revenues were evaluated. For the present regional marketconditions the results showed that the currently applied alternativeis not the best one if the main aim is profit maximization.For very poor quality sites the proposed schedules are uneconomicalfor all silvicultural alternatives. 相似文献
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Marcus Vinicius Vieira Borges Janielle de Oliveira Garcia Tays Silva Batista Alexsandra Nogueira Martins Silva Fabio Henrique Rojo Baio Carlos Ant?nio da Silva Junior Gileno Brito de Azevedo Glauce Taís de Oliveira Sousa Azevedo Larissa Pereira Ribeiro Teodoro Paulo Eduardo Teodoro 《林业研究》2022,(2):591-599
In forest modeling to estimate the volume of wood, artificial intelligence has been shown to be quite effi-cient, especially using artificial neural networks (A... 相似文献
28.
J. Illanes M. J. Blanquez M. E. Gonzalez C. Rojo 《Anatomia, histologia, embryologia》1995,24(4):217-221
The teratogenic effect of alcohol on chick embryos has been confirmed by many investigators. However, how this occurs is unknown. The aim of this study was to establish a teratogenic pattern of alcohol effects, on the first stages of development in avians. Fertilized eggs were infused through the air space of the shell on day 0, with ethanol in concentrations of 20%, 40% and 60%. The control group was infused with 0.1 ml of NaCl at 0.9%. At a second stage, the eggs were treated on the 4th day of incubation, using the same method. In both groups the eggs were removed on the 11th day of incubation. The teratological manifestations that appeared more frequently were evisceration, haemorrhagic embryos, oedema, cranial deformities, lack of eyes, and umbilical hernia, showing every embryo a clear reduction in size and body weight. 相似文献
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Irene Rojo Alejo J. Irigoyen Amalia Cuadros Antonio Calò José M. Pereñíguez Ramón Hernández-Andreu Fabiana C. Félix-Hackradt Francisca Carreño Carlos W. Hackradt José A. García-Charton 《水产资源保护:海洋与淡水生态系统》2021,31(7):1670-1685
- Marine protected areas (MPAs) are used as fisheries management and conservation tools. Well-enforced no-take zones allow the rebuilding of natural populations of exploited species; however, there is still controversy on the role of buffer zones.
- The effectiveness of MPAs could be underestimated, as fish population assessments depend largely on traditional methodologies that have difficulties in detecting predatory fish because of their low abundances, their patchy distribution, and their reaction to the presence of divers.
- The performance of different census methods was compared in assessing the protection benefits for large predatory fishes under different protection levels (i.e. no-take and buffer zones) in five Mediterranean MPAs. Specifically, conventional strip transects (CSTs, 50 × 5 m2) and tracked roaming transects combined with distance sampling (TRT + DS, variable lengths) were compared, including a series of TRT-derived estimators with variable transect lengths and fixed widths of 20, 10, and 6 m (TRT20, TRT10, and TRT6, respectively). Additionally, the effectiveness of the MPAs studied and protection levels for conserving large predatory species was evaluated.
- Transects covering larger areas (i.e. TRT + DS and TRT20) allowed the detection of a greater number of species and yielded more accurate estimates of density and biomass than transects of narrower fixed widths, particularly the CSTs, which were associated with the lowest richness detection capability, accuracy, and precision. On average, both no-take zones and buffer zones appeared effective for the conservation of predatory fishes, indicating that multiple protection areas were ecologically effective. Differences between MPAs were also observed, however, probably arising from both local environmental and management factors.
- We suggest the implementation of methodologies with larger transects for the study of large predatory fish, combined with CSTs for the rest of the fish community, in order to avoid biases in predatory population assessments, which are key indicators of MPA effectiveness.