Comparison of voluntary feed intake, rumen passage and degradation kinetics between crossbred Brahmam cattle (Bos indicus) and swamp buffaloes (Bubalus bubalis) fed a fattening diet based on corn silage     

Toshiyoshi ICHINOHE  Edgar A. ORDEN  Arnel N. DEL BARRIO  Rosalina M. LAPITAN  Tsutomu FUJIHARA  Libertado C. CRUZ  Yukio KANAI 《Animal Science Journal》2004,75(6):533-540

Three crossbred tropical cattle and three crossbred buffaloes, fitted with rumen cannulas, were used to investigate the differences in feed intake, digestibility and parameters with rumen degradation kinetics between cattle and buffalo fed a fattening diet in the Philippines. The animals were fed a diet consisting of 50% corn silage (CS), 30% brewer's grain (BG) and 20% concentrate mixture (CM) on a dry matter (DM) basis, at a level of 3% bodyweight (BW) as DM. Total DM intake (DMI) and rumen fill were greater (P < 0.05) for buffaloes than for cattle, but significant differences were not detected between the animal species when those were expressed as percentage of BW. The DMI per metabolic body size for BG and CM were greater for buffaloes than for cattle (P < 0.05), whereas that of CS did not differ between the species (P > 0.05). The weight proportion of consumed feedstuffs differed between cattle and buffaloes (P < 0.05), although nutrient intake per total DMI did not differ significantly (P > 0.05) between the animal species. Nutrients digestibility was higher (P < 0.05) for buffaloes than for cattle. Ruminal passage rate constant of feed particles and rumen fluid did not differ (P > 0.05) between the animal species. Higher DM degradation rate constant and effective degradability with CS were prominent for buffaloes than for cattle (P < 0.05). Degradation parameters did not differ (P > 0.05) between cattle and buffaloes, neither with BG nor CM. The results indicate that the greater digestibility with DM and energy for buffaloes are ascribable to greater effective degradability of CS fed ad libitum level.  相似文献   

Phosphorus Fertilizer use in Pineapple Cultivation with in situ Residues Burning on Organic Soils     

《Communications in Soil Science and Plant Analysis》2012,43(9-10):1243-1254

Abstract

In Malaysia, pineapples are grown on peat soils, but most phosphorus (P) fertilizer recommendations are made without due quantification of P uptake; the distribution of P in roots, stem, leaves, peduncle, fruit, and crown; or loss through leaching even though P retention in peat soils is low. This study was conducted to determine applied P‐use efficiency under a conventionally recommended fertilization regime in pineapple cultivation with in situ residues burning before replanting. Results showed that most of the P uptake in pineapple can be found in the fruit, stem, leaves, and crown, but the general trend of P distribution was in the order of fruits>leaves>stem>crown>peduncle>roots. Phosphorus recovery in pineapple cultivation was about 40%, and this low recovery was attributed to leaching. Hence, fertilizer recommendations need to take into consideration P loss through leaching. This will help to increase P‐use efficiency because it is not possible to build up P content of peat soils. As a result, the need to assess the possibility of side‐dress applications of phosphatic fertilizers on peat soil is necessary.  相似文献   

中国热带能源作物产业发展策略研究     

张慧坚 《勤云标准版测试》2009,29(16)

概述了我国热带能源作物发展现状、存在问题，并依据国外热带能源作物发展过程中的经验，提出中国热带能源作物发展建议。  相似文献   

海南山地热带雨林生态旅游发展研究     

郑晓玲  薛杨 《热带林业》2010,38(4):35-37,12

实地调查海南山地热带雨林生态旅游资源,分析了海南山地热带雨林生态旅游对提高海南旅游竞争力、建设国际旅游岛方面的意义,以及海南山地热带雨林生态旅游发展现状及存在的问题,提出了演化经济学视角下的海南山地热带雨林生态旅游发展对策。  相似文献   

Fatty acid and lipid content of Oreochromis niloticus L. in Ethiopian lakes — dietary effects of phytoplankton     

T. Zenebe  G. Ahlgren  I. -B. Gustafsson  M. Boberg 《Ecology of Freshwater Fish》1998,7(3):146-158

Abstract— Herbivorous tilapia fish, Oreochrornis niloticus L. (Cichlidae), collected from five Ethiopian lakes were analyzed for lipid and fatty acid contents of the dorsal muscle using spectrophotometry and gas-liquid chromatography. The results showed remarkable variation between the lakes in both the lipid and total fatty acid content of the fish, 1.7–21 and 1.6–9.3% of dry weight (DW), respectively. Most fish from Lakes Haiq and Chamo contained higher levels of fat (≥ 10% DW) compared to fish from Lakes Ziway, Langeno and Awassa which contained ≤ 5% DW fat. A total of 28 fatty acids were identified. The saturated fatty acids ranged from 5.3–30 mg. gg⁻¹ DW, monounsaturated Fatty acids from 1.3–30 and polyunsaturated fatty acids from 6.8–29 mg. g⁻¹ DW. The most abundant fatty acids were palmitic acid, docosahexaenoic acid (DHA), oleic acid, stearic acid, palmitoleic acid, arachidonic acid and eicosapentaenoic acid (EPA). EPA and DHA alone amounted to 2.6–15 mg. g⁻¹ DW. The ω3/ω6 ratios ranged from 1.3–7.6 and L. Haiq fish showed the highest ratios, 5.1–7.6, indicating that the fat was of high nutritional quality. The reason for such variation is probably the varied diet available to the fish in the various lakes, This study, along with previous reports, confirms that the phytoplankton flora constituting the diet of O. niloticus varies greatly between the study lakes. The variation in phytoplankton is also reflected by the fatty acid pattern of net samples taken from the study lakes.  相似文献   

基于功能群分类法的海口市红城湖浮游植物群落特征分析          下载免费PDF全文

朱为菊  肖明珠  常开心  丁兆建  冯志国 《水生态学杂志》2022,43(6):78-84

分别于2016年11月、2017年3月、2017年7月对海口市红城湖浮游植物群落进行了调查，采用CCA方法对浮游植物FG、MFG、MBFG功能群和水体环境因子进行分析。结果表明：FG、MFG、MBFG功能群具有季节演替特征，其主要影响因子为水温(WT)、pH值、电导率(Cond)、总可溶性氮(TSN)。3种功能群对环境均具有较好的解释度和相关性，其中FG和MFG功能群对环境的解释度优于MBFG功能群。功能群划分法对总磷识别的灵敏度低于以传统分类法鉴定的优势种。以上结果表明，在水域生态学研究中，需要将功能群划分法与传统分类法相结合。  相似文献   

Quantifying the extent of river fragmentation by hydropower dams in the Sarapiquí River Basin,Costa Rica     

Elizabeth P. Anderson  Catherine M. Pringle  Mary C. Freeman 《水产资源保护:海洋与淡水生态系统》2008,18(4):408-417

• 1. Costa Rica has recently experienced a rapid proliferation of dams for hydropower on rivers draining its northern Caribbean slope. In the Sarapiquí River Basin, eight hydropower plants were built between 1990 and 1999 and more projects are either under construction or proposed. The majority of these dams are small (<15 m tall) and operate as water diversion projects.
• 2. While the potential environmental effects of individual projects are evaluated prior to dam construction, there is a need for consideration of the basin‐scale ecological consequences of hydropower development. This study was a first attempt to quantify the extent of river fragmentation by dams in the Sarapiquí River Basin.
• 3. Using simple spatial analyses, the length of river upstream from dams and the length of de‐watered reaches downstream from dams was measured. Results indicated that there are currently 306.8 km of river (9.4% of the network) upstream from eight existing dams in the Sarapiquí River Basin and 30.6 km of rivers (0.9% of the network) with significantly reduced flow downstream from dams. Rivers upstream from dams primarily drain two life zones: Premontane Rain Forest (107.9 km) and Lower Montane Rain Forest (168.2 km).
• 4. Simple spatial analyses can be used as a predictive or planning tool for considering the effects of future dams in a basin‐scale context. In the Sarapiquí River Basin, we recommend that future dam projects be constructed on already dammed rivers to minimize additional river fragmentation and to protect remaining riverine connectivity.

Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Influence of the pore structure of wood on moisture desorption at high relative humidities     

《Wood material science & engineering》2007,2(1):33-44

The influence of the porous structure on moisture desorption of two temperate and five tropical hardwoods was studied. Two experimental techniques were used to perform moisture desorption tests from full saturation at 25°C. The first one was the saturated salt solutions [between 33% and 90% relative humidity (RH)] and the second one was the pressure membrane method (above 96% RH). More emphasis was given to results obtained at high RH, given that sorption in that case is mainly governed by the capillary forces. The porous structure of these hardwoods was characterized by mercury intrusion porosimetry (MIP) and by quantitative anatomical analysis. The results showed that desorption of liquid water was very different among the hardwood species. The MIP technique appeared as an important tool to evaluate the fluid paths within wood, which permitted the prediction of water behavior in wood during drainage from full saturation at high RH. Quantitative anatomical results were very useful for explaining the first steps of drainage and mercury penetration in wood.  相似文献   

Environmental preferences of longlining for yellowfin tuna (Thunnus albacares) in the tropical high seas of the Indian Ocean   总被引：3，自引：0，他引：3  

LI MING SONG  YU ZHANG  LIU XIONG XU  WEN XIN JIANG  JIA QIAO WANG 《Fisheries Oceanography》2008,17(4):239-253

A survey of yellowfin tuna, Thunnus albacares , fishing ground was carried out on board of the Chinese longliners from September 15 to December 12, 2005 in the tropical high seas of the Indian Ocean. The depth at which each yellowfin tuna was hooked was estimated using a stepwise regression analysis of theoretical hook depth and observed average hook depth measured using a temperature depth recorder. Water temperature, salinity, chlorophyll  a , dissolved oxygen and thermocline, which are important variables influencing yellowfin tuna habitats, were measured in the survey. Catch rates of yellowfin tuna were then analyzed with respect to depth, temperature, salinity, chlorophyll  a , dissolved oxygen and thermocline. We suggest that the optimum ranges of swimming depth, water temperature, chlorophyll  a and dissolved oxygen concentration for yellowfin tuna are 100.0–179.9 m, 15.0–17.9°C, 0.090–0.099  μ g L⁻¹, 2.50–2.99 mg L⁻¹, respectively; that salinity has less influence on the vertical distribution of adult yellowfin tuna; and that yellowfin tuna are mainly distributed within the thermocline in the high seas of the Indian Ocean. Our results match the yellowfin tuna's vulnerability to deep longline fishing gear well.  相似文献   

Unanticipated effect of climate change on an aquatic top predator of the Atlantic rainforest          下载免费PDF全文

Justo Herrera  Agustín Solari  Luis O. Lucifora 《水产资源保护:海洋与淡水生态系统》2015,25(6):817-828