Micronutrient, magnesium and phosphorus effects on biomass and leaf tissue nutrient concentrations of field grown Leucaena leucocephala     

S. H. Khan  R. L. Bingham  P. Felker 《Agroforestry Systems》1997,37(2):157-173

To optimize biomass and crude protein (CP) production for leucaena (Leucaena leucocephala) in southern Texas, field trials were conducted with treatment combinations of three levels of phosphorus (P) , two levels of Mg and two levels of soluble trace element mixture (STEM). The P was banded in the soil while the Mg and micronutrient blend were applied to the foliage. A combination of P (22 kg ha^-1), Mg and STEM fertilizers significantly increased biomass from 2555 kg ha^-1 to 3028 kg ha^-1. This treatment was associated with an increase in leaf CP from 27.9% to 31.0%. P fertilizer had no significant effect on leaf P, but significantly increased leaf nitrogen (N) and leaf copper (Cu). A foliar spray of Mg significantly increased leaf N, P, and Cu. A foliar spray of a complete micronutrient blend increased leaf Cu. Biomass production was correlated positively (decreasing order) with leaf Cu, N, and Mg and negatively with Zn. Leaf N was positively correlated with leaf P and calcium. The critical tissue concentrations (CTC) (where 90% of predicted maximum leaf protein was obtained) were 0.18% and 4.49 mg kg^-1 for leaf P and Cu, respectively. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Avoiding the loss of shade coffee plantations: how to derive conservation payments for risk-averse land-users     

Luz Maria Castro  Baltazar Calvas  Patrick Hildebrandt  Thomas Knoke 《Agroforestry Systems》2013,87(2):331-347

We usually have only limited knowledge about the economic consequences of land-use decisions, thus they are uncertain. We analyze the implications of this uncertainty on conservation payments (CP) to preserve wildlife-friendly shade coffee production in southwest Ecuador, when conversion to maize is the most profitable alternative. Our objective is twofold: First, we analyze the consequences of applying Stochastic Dominance (SD) to derive CP, an approach making only minimal assumptions about the preferences of farmers. Second, we investigate the effects of land-use diversification to reduce CP by allowing for shade coffee on part of a landholding, and maize production on what remains. CP derived by SD turned out to be at least twice the amount calculated by an alternative method which maximizes a concave utility function—US$ 166 to US$ 294 ha^?1 year^?1 instead of US$ 86 ha^?1 year^?1. Given this result, we doubt that the assumptions underlying SD are reasonable for farmers, who are known to be risk-averse. Allowing for land-use diversification has a significant impact on CP. The optimal portfolio share of shade coffee is 27 % and for maize 73 % for moderately risk-averse farmers—without any CP. A larger share of shade coffee is preferable for strongly risk-averse farmers—51 and 49 % maize. The amount of CP necessary to encourage the expansion of shade coffee to 75 % is US$ 40 ha^?1 year^?1 (for moderately risk-averse) and US$ 19 ha^?1 year^?1 (for strongly risk-averse farmers). Stimulating diversification may thus help to significantly reduce CP necessary to preserve less profitable agroforestry options.  相似文献   

Nutritive quality and morphological development under partial shade of some forage species with agroforestry potential     

C. H. Lin  M. L. McGraw  M. F. George  H. E. Garrett 《Agroforestry Systems》2001,53(3):269-281

The shade environment produced in agroforestry practices affects the morphology, anatomy and chemical composition of intercropped forages and, therefore, may affect forage quality. During the summer-fall growing season of 1994 and 1995, 30 forage cultivars were grown in 7.6 L (two gallon) pots in full sun, 50%, and 80% shade created by placing shade cloth over a greenhouse frame. Fifteen legumes and grasses that were similar in yield under full sun and shade treatments were selected for quality analysis. With the exception of 'Kobe' lespedeza, D. paniculatum and D. canescens, acid detergent fiber (ADF) was either not affected or was slightly increased by shade. Except for Kobe lespedeza and 'Martin' tall fescue, shade either did not affect or slightly increased the neutral detergent fiber (NDF) of the shade-tolerant forages. Crude protein (CP) percentage increased in most shade-grown forages; however, shade had less effect on CP of legumes than of grasses. Other than Kobe lespedeza, total mass of CP per pot (TCP) was unaffected or increased under 50% shade for all species. Total crude protein of hog peanut, D. esmodium paniculatum and D. canescens was greater under both 50% shade and 80% shade than in full sun. The decrease in ADF of Kobe lespedeza, D. paniculatum and D. canescens under the shade treatments might be associated with maintenance of a higher leaf:stem weight ratio under shade. However, the leaf:stem ratios of the same cultivars grown at different light intensities did not strongly correlate with NDF, CP, and TCP values. In general, on selected species, internodal length and leaf area increased while specific leaf dry weight decreased for plants grown in shade compared to those grown in full sun. The data indicated that forage quality of some species could be enhanced by shade. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Ecological functions of persistent Japanese cedar litter in structuring stream macroinvertebrate assemblages     

Masaru Sakai  Yosihiro Natuhara  Keitaro Fukushima  Ayumi Imanishi  Kensuke Imai  Makoto Kato 《Journal of Forest Research》2013,18(2):190-199

Stream macroinvertebrate assemblages are expected to be affected by the abundance and constitution of litter from surrounding forests. We compared forest floor cover, overland flow, stream environment, and stream macroinvertebrate assemblages between the catchments of a Japanese cedar plantation (CP) and a primary deciduous forest (DF). Both systems experience excessive deer browsing. Understory vegetation cover was higher in the DF than in the CP in summer, although cover was low (<20 %), possibly because of excessive deer browsing. Litter cover was much higher in the CP than in the DF in summer as a result of the long abscission period, slow breakdown, and low rate of dispersal of Japanese cedar litter compared to deciduous litter. Monthly overland flow was always lower in the CP than in the DF, and substrate size was smaller in the DF stream. In the CP, cedar litter accumulated in the stream, probably because of its low breakdown rate and morphology, and abundant shredder taxa characterized the macroinvertebrate assemblage. In contrast, abundant burrower taxa characterized the macroinvertebrate assemblage in the DF stream. These results imply that Japanese cedar litter functions in structuring the macroinvertebrate assemblage by supplying persistent food resources for detritivores, and by buffering fine sedimentation via overland flow under excessive deer browsing.  相似文献   

Hopper (Homoptera: Auchenorrhyncha) diversity in shaded coffee systems of Turrialba, Costa Rica     

L. Rojas  C. Godoy  P. Hanson  C. Kleinn  L. Hilje 《Agroforestry Systems》2001,53(2):171-177

Diversity of hopper species (suborder Auchenorryncha) in coffee (Coffea arabica) plantations with no shade (C) was compared with the diversity in plantations with shade of either poró (Erythrina poeppigiana) (CP) or poró plus laurel (Cordia alliodora) (CPL) in Turrialba, Costa Rica. Species-abundance and rarefaction curves were plotted for each system, and indices of diversity (Shannon-Wiener), dominance (Simpson), species evenness, and similarity (Jaccard) were calculated. The majority of hopper species and individuals belonged to the Cicadellidae family. A particular species dominated in each system: Graphocephala sp. (C), Fusigonalia lativittata (CP) and Hebralebra nicaraguensis (CPL). The richness and diversity of hopper species were highest in the CP system, followed by the CPL and C systems. Species similarity was closest between the CP and CPL systems, but varied considerably according to plant component and geographic location of each plot. Even though hoppers have not been reported as coffee pests in Mesoamerica, some of them cause serious problems elsewhere. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Tree canopy effect on grass and grass/legume mixtures in eastern Nebraska     

Michael E. L. Perry  Walter H. Schacht  Gregory A. Ruark  James R. Brandle 《Agroforestry Systems》2009,77(1):23-35

A study to determine the feasibility of producing forage for grazing livestock under trees was conducted as a step toward evaluating the potential for silvopasture systems in the northern and central Great Plains. The effects of overstory leaf area index (LAI), percentage understory light transmittance (LT), and soil moisture (SM) on yield and crude protein (CP) of big bluestem [Andropogon gerardii Vitman; (BB)], smooth bromegrass [Bromus inermis Leyss.; (SB)], and mixtures with birdsfoot trefoil [Lotus corniculatus L.; (BFT)] were examined. The study was conducted in both Scotch pine (Pinus sylvestris L.) and green ash (Fraxinus pennsylvancia Marsh.) tree plantations, at the University of Nebraska Agriculture Research and Development Center near Mead, Nebraska. Thirty-six plots representing a wide range of canopy cover were selected at each location and seeded in April 2000 to BB, SB, or mixtures with BFT. Measurements of LAI, LT, and SM were taken throughout the 2001-growing season and plots were harvested in June and September 2001. Soil moisture generally did not explain much of the variability in yield or CP for BB, SB, or BFT. Cumulative LAI or LT averaged over the growing season was the best predictor of yield or CP, particularly under the pine. Yields of BB and SB increased as LAI decreased or LT increased. Conversely, the CP of BB and SB increased as LT decreased for both the June and September harvests. Both BB and SB maintain relatively high productivity under partial shading; however, BFT yields were low at LT levels below 75%. At the time of the research, the senior author was research assistant, Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68853-0915.  相似文献   

Chemical characteristics of saponins from Paris fargesii var. brevipetala and cytotoxic activity of its main ingredient, paris saponin H     

Wen F  Yin H  Chen C  Liu X  Xue D  Chen T  He J  Zhang H 《Fitoterapia》2012,83(4):627-635

More attention was paid to the anti-tumor activity of Rhizoma Paridis (RP) recently, of which the wild resource was decreased significantly. This study was aimed to elucidate the chemical characteristics of Paris fargesii var. brevipetala (PFB) that may be administrated as alternate resource of legal RP. A HPLC-ELSD method was established to characterize the steroid saponins in rhizomes of PFB and two legal Paris species [Paris polyphylla var. chinensis (PPC) and P. polyphylla var. yunnanensis (PPY)] in Chinese Pharmacopoeia (CP). Ten saponins (paris saponins I, II, V, VI, VII, H, gracillin and other three paris saponins) were involved as standards. The results indicated that PFB contained pennogenyl saponins as the main components with small amounts of diosgenin saponins. The total contents of the detected saponins in PFB ranged from 9.12mg/g to 85.33mg/g. Nine of the twelve PFB samples own a total content of paris saponins I, II, VI, and VII more than 6.0mg/g (meeting the standard of CP 2010 edition). Principal Component Analysis (PCA) and Partial Least Squares-Discriminate Analysis (PLS-DA) both confirmed the fact that saponin profiles of PFB, PPC and PPY were different from each other. In addition, paris saponin H (Ps H), the predominant saponin of PFB (>50%), was tested in vitro to evaluate its cytotoxic activities on HepG2, A549, RPE and L929 cells with a positive control of Cisplatin. Ps H showed a remarkable cytotoxic activity on A549 cells with an IC(50) value of 1.53±0.08μg/mL.  相似文献   

Intake, rumen digestion, digestibility and microbial nitrogen supply in sheep fed Cynodon nlemfuensis supplemented with Gliricidia sepium     

L. Ramirez-Aviles  J. A. Alayon  J. C. Ku-Vera 《Agroforestry Systems》1998,41(2):115-126

Four Pelibuey sheep fitted with flexible rumen cannula were fed increasing levels of Gliricidia sepium foliage (gliricidia) in a 4 × 4 Latin square design. Treatments were: control, 10, 20 and 30% (dry basis) of gliricidia mixed in a basal diet of Cynodon nlemfuensis (stargrass) hay. Dry matter (DM), organic matter (OM) and crude protein (CP) intakes were linearly increased (P < 0.05) from 45.2, 40.4, 2.0 to 71.5, 63.3 and 6.8 g/kg W^0.75/d, for the control and the 30% gliricidia diet, respectively. Similarly, increments of gliricidia in the diet resulted in a linear increase in DM, OM and CP apparent disgestibilities from 43.7, 48.4 and 27.0 to 50.7, 54.7 and 57.3%, for the control and 30% gliricidia diet, respectively. There was no effect (P > 0.05) of supplementation with gliricidia on rumen dry matter digestion of stargrass. Microbial nitrogen (N) supply to the small intestine had a trend towards an increase from 4.9, for the control, to 9.6 g N/d, for the 30% diet, though it was not significant (P > 0.05). It is concluded that, gliricidia might be incorporated into low quality diets since it increases total DM intake, supplies highly degradable N to the rumen and appears to increase the microbial N supply to the small intestine of sheep. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

In vivo anthelmintic activity of Butea monosperma against Trichostrongylid nematodes in sheep     

Iqbal Z  Lateef M  Jabbar A  Ghayur MN  Gilani AH 《Fitoterapia》2006,77(2):137-140

Seeds of Butea monosperma administered as crude powder (CP) at doses of 1, 2 and 3 g/kg to sheep naturally infected with mixed species of gastrointestinal nematodes exhibited a dose and a time-dependent anthelmintic effect. The maximum reduction of 78.4% in eggs per gram of feces (EPG) was recorded on day 10 after treatment with 3 g/kg. Levamisole (7.5 mg/kg), a standard anthelmintic agent, exhibited 99.1% reduction in EPG.  相似文献   

Dactylis glomerata Growing Along a Light Gradient in the Central Appalachian Region of the Eastern USA: III. Nonstructural Carbohydrates and Nutritive Value     

D. P. Belesky  N. J. Chatterton  J. P. S. Neel 《Agroforestry Systems》2006,67(1):51-61

Microsite conditions influence plant development and resource allocation of Dactylis glomerata L. (orchardgrass), a traditional pasture species with potential as an understory crop in woodlots. A field experiment was conducted to determine how open (O), shaded woodland (W) and open-to-shaded woodland transition zone (E_O, E_W) microsites influenced the quantity and distribution of nonstructural carbohydrate (TNC) and crude protein (CP) among plant parts of defoliated orchardgrass. Plants established in spring (SP) or late summer (LS) were clipped each time mean sward height reached 20 cm. Microsite conditions influenced nutritive value of herbage. Nutritive value was acceptable when not more than 45–50% light attenuation (as a function of shading by nearby trees) occurred relative to open pasture. Twice as much TNC accumulated in stembases of LS compared to SP plants. Concentrations of TNC were least in plants growing at W, regardless of planting time. Stembase TNC depletion occurred in SP plants, regardless of microsite, and LS plants growing at W. CP concentrations were greater in herbage from W compared to O sites, suggesting the N needs of the plant were met with minimal fertilizer N inputs. The ratio of C:N and thus herbage energy expressed as total digestible nutrients (TDN), relative to CP declined as shade increased. Increased protein content is offset by lower fiber, lower nonstructural carbohydrate and the possibility of reduced preference by grazers. Nutritive value is improved by modest amounts of shade relative to plants growing in full sunlight, and allowing cool temperate origin grasses to vernalize is beneficial in terms of productivity, nutritive value, and persistence. Ths US Government’s right ot retain a non-exclusive, royaltyfree license in and to any copyright is acknowledged.  相似文献   

Protection and fastness of green color of moso bamboo (Phyllostachys pubescens Mazel) treated with chromium-based reagents     

Shang -Tzen Chang  Ting-Feng Yeh 《Journal of Wood Science》2001,47(3):228-232

The attractive green color of moso bamboo (Phyllostachys pubescens Mazel) culms fades without chemical treatment. Chromated copper arsenate (CCA) has been used to protect the green color of bamboo, but CCA is harmful to factory workers and the environment. To overcome the toxicity of arsenic in CCA, two chromium-based formulas developed by the authors, chromated copper phosphate (CCP) and chromated phosphate (CP), were evaluated for their protection of the green color of moso bamboo. The results revealed that bamboo treated with CP had a greener color than those treated with CCA or CCP. The concentration, treatment time, and CrO₃/H₃PO₄ ratio in CP solution greatly affected the color of moso bamboo culms. The attractive green color, which resembles the color of fresh-cut moso bamboo, was obtained by treating bamboo with 2% CP solution at 60°C for 3h, using a 11 CrO₃/H₃PO₄ ratio in aqueous solution. In addition, the CP-treated moso bamboo exhibited excellent green color fastness in both accelerated ultraviolet lightfastness testing and outdoor weathering exposure.  相似文献   

Trees and windbreaks in the Sahel: establishment,growth, nutritive,and calorific values     

J. P. A. Lamers  K. Michels  R. J. Vandenbeldt 《Agroforestry Systems》1994,26(3):171-184

Tree and windbreak species considered for the Southern Sahelian Zone (SSZ) of West Africa have to be evaluated following multiple criteria such as fast establishment, shelter efficiency, production of feed for livestock, and firewood. An on-station experiment was conducted on a sandy soil in southwest Niger between 1988 and 1993 to assess the establishment, growth, nutritive, and calorific values of seven species considered for windbreaks:Andropogon gayanus, Bauhinia rufescens, Acacia holosericea, Acacia nilotica, Acacia senegal, Faidherbia albida, andAzadirachta indica. Mortality and stem diameter were monitored twice a year. From 20 months after planting (MAP) onwards, species were annually trimmed to 2 m height and to 1 m sidewards of the main stem. Fresh and dry weight of leaves, twigs, wood, and fruits were recorded. Leaves were analyzed for crude protein (CP) and metabolizable energy (ME) content. Wood was analyzed for its gross calorific value and its ash content. At 56 MAP, all species had less than 5% morality, except forA. holosericea, which had a mortality rate of 15.9%.A. indica andA. holosericea showed the highest stem diameter among species with 12.2 and 11.8 cm, respectively, at 56 MAP.A. senegal had the highest dry matter production with 22.3 t ha^–1 at 56 MAP, followed byA. indica (12.0 t ha^–1),A. holosericea (11.7 t ha^–1) andB. rufescens (11.2 t ha^–1), butA. holosericea was most productive at earlier harvests. OnlyA. senegal (6.4 t ha^–1) andA. indica (5.1 t ha^–1) had a significant wood production, whereasA. holosericea (5.7 t ha^–1) had the highest phyllodes production. Leaves ofA. senegal andA. indica had highest CP contents of 258 and 214 g kg^–1, respectively. The leaves of all species exceptA. gayanus had a higher CP:ME ratio than natural pasture in the region. The calorific values of firewood did not differ significantly among the species.A. nilotica, the species with one of the lowest firewood production, had the highest Fuelwood Value Index of 6.6. The choice of species for planting trees and windbreaks in the SSZ must be oriented along these criteria. Further research should be directed towards cost-benefit analyses, land tenure and property rights in combination with surveys on local knowledge of rural people.  相似文献   

Effect of Spirulina fusiformis on cyclophosphamide and mitomycin-C induced genotoxicity and oxidative stress in mice     

K. Premkumar  A. Pachiappan  Suresh K. Abraham  S. T. Santhiya  P. M. Gopinath  A. Ramesh   《Fitoterapia》2001,72(8):398-911

Spirulina fusiformis was tested for its possible in vivo protective effects against cyclophosphamide (CP) and mitomycin-C (MMC) induced genotoxicity and oxidative stress in mice. Pre-treatment with S. fusiformis (250, 500 and 1000 mg kg(-1), p.o., daily for 5 days) significantly reduced the chromosomal damage and lipid peroxidation with concomitant changes in antioxidants and detoxification systems. All the three tested doses were effective in exerting a protective effect against CP and MMC.  相似文献   

对印度亚热带潮湿气候中的多种用途树叶作为草料的质量评价(英文)   总被引：1，自引：0，他引：1  

Chander Datt  M. Datta  N. P. Singh 《林业研究》2008,19(3):209-214

多种用途树种和灌木在农业系统中有重要的作用,在减少饲料供求矛盾和补充世界各地饲料赤字,提高动物生产力方面有很大的潜力。同时,评价草料各种营养特性,利于生产定量平衡的饲料。评价12种多种用途树种(Acacia auri-culiformis,Albizzia procera,Dalbergia sissoo,Gliricidia macu-lata,Leucaena leucocephala,Samanea saman,Azadirachta in-dica,Eucalyptus hybrida,Gmelina arborea,Michelia champaca,Morus alba,和Tectona grandis)的树叶的营养特性,其中分别包括6种豆科和非豆科树种,指标包括:常规成分,细胞壁成分,总鞣质含量,大量(Ca和P)与微量元素(Fe,Cu,Zn,Mn和Co)含量,干物质体外消化率与有机物消化率以及代谢能量值。结果表明上述各参数都有明显的差异。有机物,粗蛋白质含量,石油醚提取物总量,粗纤维含量,无氮浸出物,总灰分的平均值分别为:(92.02±0.30)%,(16.00±0.74)%,(3.05±0.13)%,(18.97±1.07)%,(54.00±1.12)%和(7.98±0.30)%。豆科树种较非豆科树种有更高的粗蛋白质含量(18.30%和13.70%)。细胞壁成分中的中性洗涤纤维素,酸性洗涤纤维,半纤维,纤维素,酸性木质素含量平均值分别为:(52.48±1.05)%,(31.72±0.97)%,(20.76±0.88)%,(16.97±0.70)%和(9.57±0.62)%。总鞣质含量为(4.22±0.32)%。Ca与P之比合理,多种树种叶中Fe和Mn含量丰富,P,Cu,Zn和Co水平低于标准水平含量。干物质体外消化率与有机物消化率平均值分别为(48.96±1.30)%和(50.69±1.36)%。代谢能量值为(6.95±0.11)MJ·kg-1。粗蛋白质含量与干物质体外消化率与有机物消化率和代谢能量值成正相关;而这三个参数与中性洗涤纤维素,酸性洗涤纤维,和酸性木质素含量成负相关。结果表明:银合欢可作为优良饲料的树种,因为它具有最高的干物质体外消化率与有机物消化率以及代谢能量值(65.20%,67.66%和7.95MJ·kg-1),而Gliricidia maculata,Morus alba,Azadirachta indica,Dalbergia sissoo和Samanea saman可做较好类型饲料的树种,其它树种做饲料质量差。  相似文献   

The quantity and quality of feed available to indigenous chickens under the scavenging system in semi-arid Eastern Kenya     

S. M. Nzioka  E. O. Mungube  M. D. Mwangi  L. Muhammed 《East African Agricultural and Forestry Journal》2017,82(1):57-69

Free range indigenous chickens suffer from low productivity due to inadequate quantity and quality of feed, high predation and high mortality rates. The aim of the study was to establish the nutritional gaps in the free range chickens’ diets. A total of 40 farmers from two locations participated in the study. The study used 548 chickens aged 7–8 months purchased from farmers. The experimental chickens were slaughtered before weighing the carcass and crop content. The weight of the gastro-intestinal tract, heart and liver was also recorded. The crop contents were analysed after drying in the oven for 48 hours at 60 °C to determine what was consumed. The mean live weight of the experimental chickens was 1443 ± 296?g. The chickens mainly fed on maize, which accounted for over 80% of their diet. The estimated metabolizable energy (ME) of the crop contents for the study chickens was 2887.8 Kcal/kg. Although the chickens from Kionyweni had significantly (P<0.05) higher ME than those from Kilome, it was lower than the 3044 Kcal/kg recommended for scavenging chickens. The crude protein (CP) was 10.6 ± 2.8%, which was lower than the 16–18% CP requirement for layers. The essential amino acids available to the chickens in the two study areas included lysine, tryptophan and methionine-cysteine. Their availability was higher during the rainy season compared to the dry season.  相似文献   

Utilization of browse supplements with varying tannin levels by Ethiopian Menz sheep: 2. Nitrogen metabolism     

R. J. Kaitho  N. N. Umunna  I. V. Nsahlai  S. Tamminga  J. van Bruchem 《Agroforestry Systems》1997,39(2):161-173

The effect of different condensed tannins concentrations on protein metabolism from browse supplements was investigated in a 90-day trial using sixty-six male Ethiopian Menz sheep. Teff straw (Eragrostis tef) was fed ad libitum (control diet), or supplemented with 190 g dried leaves of six Sesbania sesban accessions with increasing levels of condensed tannin (S1, S2, S3, S4, S5 and S6), lablab (Dolichos lablab), tagasaste (Chamaecytisus palmensis), leucaena (Leucaena leucocephala) and goetzei (Sesbania goetzei) in a completely randomized block design. The condensed tannins were highest in goetzei; S6, S5 and leucaena, intermediate in S4, S3, S2 and S1, and lowest in tagasaste and lablab. The supplemented animals had significantly (P < 0.05) higher total dry matter and nitrogen (N) intake than the ones fed teff straw alone. The digestibility of N was lower for the control diet than for any other treatment (P < 0.05). S1 and S2 supplemented diets had significantly higher (P < 0.05) N digestibilities than all other diets. Faecal N, urinary N and urinary N per kg N excreted were significantly different (P < 0.0001) between diets. With increasing tannin levels (among Sesbania accessions) there was a significant decrease (P < 0.05) in urinary N (S1 > S2 > S3 > S4 > S5), and an increase (P < 0.05) in faecal N (S1 < S2 < S3 < S4 < S5). Supplementation increased faecal N output significantly (P < 0.0001) as well as the N retention. Among the forage supplements, N retention was significantly (P < 0.0001) lower in lablab-, tagasaste-, leucaena-, S4- and goetzei-supplemented diets, than for S1, S2, S5 and S6. Apparent nitrogen digestibility was positively correlated (P < 0.001) with the supplement dry matter and crude protein (CP) degradation after 24 h (r = 0.93 and r = 0.85, respectively), the CP content (r = 0.87), and was negatively correlated with acid detergent fibre and neutral detergent fibre (r = –0.87 and –0.87, respectively). The CP degradability characteristics of the forages differed (P < 0.001) in water solubility (93–470 g kg^-1 CP), rate of degradation (2.58–9.73 %/h), lag phase (–1.36–13.37 h), and estimated escape protein (262–619 g kg^-1 CP). With increasing tannin levels (among Sesbania accessions), there was a significant decrease (P < 0.0001) in the rate of degradation (S1 > S2 > S3 > S4 > S5), and an increase in the estimated escape protein. The estimated rumen degradable protein (supplements) varied from 482 to 744 g kg^-1 CP, while intestine digestible protein and the undegradable protein varied from 140 to 314 g kg^-1 CP, hence the browses can supply adequate levels of rumen degradable and bypass protein. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Potential contribution of <Emphasis Type="Italic">Quercus durata</Emphasis> and <Emphasis Type="Italic">Adenostoma fasciculatum</Emphasis> supplemented with <Emphasis Type="Italic">Medicago sativa</Emphasis> on intake and digestibility in sheep and goats     

Nelmy Narvaez  Arieh Brosh  Miguel Mellado  Wolfgang Pittroff 《Agroforestry Systems》2011,83(3):279-286

A digestion trial was conducted to estimate the potential contribution of the chaparral browse Quercus durata (leather oak) and Adenostoma fasciculatum (chamise) on intake and nutrient digestion in goats and sheep. Four wether Kiko goats (avg. wt. 22.9 kg) and four wether Targhee sheep (avg. wt. 39.6 kg) were housed in metabolism cages. Alfalfa pellets were used as a dietary supplement. Digestibility of the shrubs was measured by difference and metabolizable energy (ME) and ME intake (MEI) were calculated from digestibility and plants intake values. Oak and chamise had low crude protein (CP) content (6.5 and 4.3% DM) and high content of extractable condensed tannins (17.8 and 9.8% DM). In vitro organic matter digestibility (OMD) and ME for oak and chamise were 35.6 and 33.1% and 5.0 and 4.7 MJ/kg DM, respectively. In vivo OMD (calculated by difference with alfalfa) and MEI, for browse were greater (P < 0.01) for goats fed chamise compared to sheep. In oak, OMD was similar for both animal species but MEI was greater (P < 0.01) for goats. Greater (P < 0.05) DM and CP intakes (per kg BW^0.75) were observed for goats fed either oak or chamise compared with sheep. When an energy source was given as supplement, the potential contribution of chamise and oak to total ME requirements for maintenance was about 58.3 and 60.4% in goats and about 17.1 and 32.9% in sheep, respectively. In consequence, metabolizable energy supplied by these shrubs may not be adequate for maintenance when, during grazing, they are consumed in high proportions with other chaparral plants that may have lower nutritional value than the alfalfa supplemented in this study. Under an appropriate supplementation program, goats could be more effective than sheep to control fuel load in California chaparral, as they consume more chamise and leather oak and obtain more nutrients from them.  相似文献   

13C CP/MAS nuclear magnetic resonance study of the peroxide bleaching of ultra high yield chemimechanical pulp produced from sound and spruce budworm killed balsam fir     

J. M. Willis  F. G. Herring 《Wood Science and Technology》1987,21(4):373-380

Summary The chemimechanical pulping (CMP) of sound balsam fir and the subsequent peroxide bleaching of the CMP pulp were investigated using solid state ¹³C CP/MAS NMR. A parallel study was made of a CMP pulp produced from spruce budworm killed balsam fir. Changes in the lignin and hemicellulose components were readily evident. The residual lignin and carbohydrate macromolecules in dead balsam fir CMP appeared to be the same as those in the sound wood CMP, before and after bleaching.We are indebted to Mr. S. S. Johal and Dr. J. V. Hatton of PAPRICAN, Vancouver, B.C., for generously supplying the wood and pulp samples. We also appreciate the assistance of Dr. N. R. Jagannathan with the ¹³C CP/MAS NMR measurements. Financial support from NSERC, in the form of a Postdoctoral Fellowship (JMW) and operating grants (FGH), is gratefully acknowledged  相似文献   

Mitigation of effects of extreme drought during stage III of peach fruit development by summer pruning and fruit thinning     

Lopez G  Mata M  Arbones A  Solans JR  Girona J  Marsal J 《Tree physiology》2006,26(4):469-477

A water deficit during stage III of fruit growth was established with the aim of determining if it is possible to achieve an improvement in tree water status by summer pruning and fruit thinning. The experiment was set up as a randomized block split-plot design across trials (irrigation) where pruning was assigned to the main plot and fruit thinning to the sub-plots. The irrigation treatments were (1) standard full irrigation (FI), and (2) suppression of irrigation during stage III of fruit growth until leaves visibly withered (LWI); the pruning treatments were (1) experimental summer pruning (EP), and (2) standard summer pruning (CP); and three fruit thinning intensities were applied to facilitate analysis of the effects of the treatments in relation to fruit load. Changes in amount of light intercepted and in tree stem water potential (Psi stem) were evaluated. The EP treatment reduced the amount of light intercepted by the tree. In the FI treatment, there was a significant reduction in fruit growth measured as both water accumulation and dry mass accumulation. Under FI conditions, reductions in fruit load as a result of EP were not accompanied by a significant improvement in Psi stem. In the LWI treatment, EP produced a significant improvement of 0.17 MPa in Psi stem, but there was no improvement in fruit growth compared with CP trees. A reduction in fruit load from 350 (commercial load) to 150 per tree significantly improved Psi stem by 0.3 MPa at the end of stage III of fruit growth. These results indicate that improvements in water status in response to pruning may be insufficient to promote fruit growth if the pruned trees are unable to provide an adequate supply of assimilates to the developing fruits.  相似文献   

Intake and relative palatability indices of acacia species fed to sheep and goats   总被引：1，自引：0，他引：1  

H. K. Mokoboki  L. R. Ndlovu  M. M. Malatje 《Agroforestry Systems》2011,81(1):31-35

An experiment was conducted to determine preference intake and relative palatability indices of Acacia karroo, Acacia nilotica, Acacia tortilis, Acacia sieberiana and Acacia rhemniana in sheep and goats using a completely randomized design. The size of Experimental Farm from which the browses were harvested was 1842.75 ha. The leaf samples were randomly collected from various young trees. The samples were analysed for proximate composition, measured for intake and relative palatability indices of sheep and goats. Dry matter (DM) content ranged from 917.4 to 936.8 g/kg DM and organic matter from 822.9 to 892.2 g/kg DM. All acacia species contained crude protein content (CP) of more than 7–17% required for grazing animals. The content of neutral detergent fibre (ADF) and acid detergent fibre ranged from 372.8 to 658.1 and 150.0 to 464.6 g/kg DM, respectively and were significantly (P < 0.05) different among the species. All of the acacia species had low levels (0–5.57 g/kg DM) of condensed tannins. The intakes of all feeds except A. karroo and A. rhemniana were high in both sheep and goats. The leaves from A. sieberiana had the highest palatability indice (Pi) while those of A. rhemniana had the lowest Pi in both sheep and goats. It was concluded that there was an effect of acacia species on intake and relative palatability indices. Species A. sieberiana, A. nilotica and A. tortilis have potential as livestock fodder, based on moderate to high CP value, low ADF, low tannins, high intake and relative palatability indices.  相似文献