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1.
Deborah V. Robertson-Andersson Michelle Potgieter Joakim Hansen John J. Bolton Max Troell Robert J. Anderson Christina Halling Trevor Probyn 《Journal of applied phycology》2008,20(5):579-595
Land-based abalone aquaculture in South Africa, based on the local species Haliotis midae, started in the early 1990s and has grown rapidly in the last decade, with 13 commercial farms now producing over 850 t per
annum. Over 6,000 t per annum of kelp Ecklonia maxima are now harvested for this purpose, and some kelp beds are reaching maximum sustainable limits. Research into seaweed aquaculture
as feed (Ulva and some Gracilaria) for abalone started in the late 1990s on the southeast coast (where there are no kelp beds) using abalone waste water. A
growing body of evidence suggests that a mixed diet of kelp plus other seaweeds can give growth rates at least as good as
compound feed, and can improve abalone quality and reduce parasite loads. A pilot scale Ulva lactuca and abalone integrated recirculation unit using 25% recirculation was designed and built on the south west coast of South
Africa using one 12,000-L abalone tank containing 13,200 15 ± 2.5 g abalone, connected to two 3,000-L seaweed tanks containing
an initial starting biomass of 10 kg of seaweed, replicated 3 times. In an 18-month period, there were no significant differences
in abalone health or growth rates, sediment build up and composition, mobile macro fauna densities and species between the
recirculation or the flow-through units. Transfer of oxygen generated by the seaweeds to the abalone tanks was poor, resulting
in the recirculated abalone tanks having lower (33%) dissolved oxygen concentrations than a comparable flow-through abalone
unit. Seaweed nutrient content and specific growth rates in the units were comparable to seaweeds cultivated in fertilized
effluent (SGR = 3.2 ± 3.4%.day−1; Yield = 0.2 ± 0.19 kg.m2.day−1). Indications were that at this low recirculation ratio the seaweeds in the units were nutrient limited and that there were
no negative effects to the abalone being cultivated in such a recirculation unit at this recirculation ratio. 相似文献
2.
Mesozooplankton assemblages in the shallow Arctic Laptev Sea in summer 1993 and autumn 1995 总被引:2,自引:0,他引:2
Mesozooplankton distribution and composition in the very shallow part of the Siberian Laptev Sea shelf were studied during
the German-Russian expeditions “Transdrift I” (August/September 1993) and “Transdrift III” (October 1995). Maximum abundances
were found close to the outflow of the Lena River (7,965 ind. m−3) and in the Yana river mouth (38,163 ind. m−3). Lowest abundances occurred in the northeast and west of the Laptev Sea (64–95 ind. m−3). Highest biomass values (104–146 mg DM m−3) were determined in the northern and northeastern part of the shallow Laptev Sea, as well as close to the river outflows,
with a record biomass maximum in the Yana river mouth (270 mg DM m−3). Biomass minima were situated north of the Lena Delta and in the western part of the shallow Laptev Sea (0.3–1.0 mg DM m−3). Copepods dominated in terms of abundance and biomass. Cluster analyses separated four mesozooplankton assemblages: the
assemblage “Lena/Yana” in the southern part, “Eastern-central” in the centre, “Kotelnyy” in the eastern part and “Taimyr”
in the western part of the shallow Laptev Sea. The small-sized neritic and brackish-water copepods Drepanopus bungei, Limnocalanus grimaldii and Pseudocalanus major occurred in enormous numbers and made up the bulk of zooplankton abundance and biomass in the very shallow part of the Laptev
Sea close to the rivers Lena and Yana. In the more northern and northeastern areas, Calanus glacialis, P. minutus and P. major were dominant copepod species, whereas Oithona similis and Acartia sp. became important in the western Laptev Sea. Appendicularians, as well as hydromedusae and the chaetognath Sagitta sp., contributed significantly to abundance and biomass, respectively, but not over the entire area studied. One can identify
taxon-specific distribution patterns (e.g. Sagitta predominated the biomass in a zone between the area heavily influenced by Lena/Yana and the offshore area to the north),
which differ from the patterns revealed by cluster analysis. Hydrographic features, especially the enormous freshwater inflow,
apparently determine the occurrence and formation of zooplankton aggregations. Extremely high numbers of small-sized neritic
and brackish-water copepods occurred locally, which were probably also supported by excellent feeding conditions. 相似文献
3.
T.K. Dutta M.K. Agnihotri P.K. Sahoo V. Rajkumar Arun K. Das 《Small Ruminant Research》2009,85(1):34-41
Thirty two Barbari kids (5-month old of 10.62 ± 0.09 kg BW, 16 males and 16 females) were equally divided into four groups to monitor growth, nutrient utilization, rumen fermentation, blood metabolites, carcass traits, meat and sausage quality on diet based on Cajanus cajan straw (60) and concentrate mixture (40) to have different protein–energy ratio in the diets (Diet 1—CP 12%, TDN 55%, Diet 2—CP 12%, TDN 60%, Diet 3—CP 14%, TDN 55% and Diet 4—CP 14%, TDN 60%). The experimental kids in each group were fed the respective diets at 4% of their body weight and limited quantity (300–400 g/kid/day) of oat fodder. The average DM intake/kg W0.75 during growth period was significantly (P < 0.05) higher in Diet 1 (low protein–low energy) than Diet 4 (high protein–high energy). Kids under Diet 2 (low protein–high energy) and Diet 4 (high protein–high energy) gained 7.2% and 14.5% more weight respectively per day compared to those on Diet 1 (low protein–low energy), however, values of final body weight, average daily gain and feed conversion efficiency (%) were not significantly different (P > 0.05). The pH and total VFA concentration in the rumen liquor were similar (P > 0.05) among the four treatment groups. TCA precipitable-N was insignificantly (P > 0.05) higher in Diet 4 than other diets. Glucose, urea–nitrogen, total protein, albumin and globulin concentration in plasma were unaffected by treatments. TDN intake, DCP and TDN percentages were also similar (P > 0.05) among the four groups. Nitrogen balance (g/day/kid) values also showed no significant variation. Dietary effect was also not significant (P > 0.05) in the values of hot carcass weight, dressing percentage, carcass physical composition, variety meat yield and fat deposition but not breast fat thickness and kidney fat accumulation, which were significantly (P < 0.05) higher in Diet 2. Chemical composition values of Longissimus thoracis muscle were similar (P > 0.05) in percentage moisture, fat and ash, while CP was significantly (P < 0.05) higher in Diets 2 and 3 than Diets 1 and 4. There were no significant differences (P > 0.05) in the chemical composition of sausages prepared using meat from the kids of different treatments. Therefore, it may be concluded that pelleted feed of Diet 2 responded with better growth rate, quality of carcass traits and meat quality. 相似文献
4.
Margareth da Silva Copertino Thiago Tormena Ulrich Seeliger 《Journal of applied phycology》2009,21(1):31-45
The growth, biofiltering efficiency and uptake rates of Ulva clathrata were studied in a series of outdoor tanks, receiving waste water directly from a shrimp (Litopenaeus vannamei) aquaculture pond, under constant aeration and two different water regimes: (1) continuous flow, with 1 volume exchange a
day (VE day-1) and (2) static regime, with 1 VE after 4 days. Water temperature, salinity, pH, dissolved inorganic nitrogen (DIN), phosphate
(PO4), chlorophyll-a (chl-a), total suspended solids (TSS), macroalgal biomass (fresh weight) and tissue nutrient assimilation were monitored over 12 days.
Ulva clathrata was highly efficient in removing the main inorganic nutrients from effluent water, stripping 70–82% of the total ammonium
nitrogen (TAN) and 50% PO4 within 15 h. Reductions in control tanks were much lower (Tukey HSD, P < 0.05). After 3 days, the mean uptake rates by the seaweed biomass under continuous flow were 3.09 mg DIN g DW day−1 (383 mg DIN m−2 day−1) and 0.13 mg PO4 g DW day−1 (99 mg PO4 m−2 day−1), being significantly higher than in the static regime (Tukey HSD, P < 0.05). The chl-a decreased in seaweed tanks, suggesting that U. clathrata inhibited phytoplankton growth. Correlations between the cumulative values of DIN removed from the water and total nitrogen
assimilated into the seaweed biomass (r = 0.7 and 0.8, P < 0.05), suggest that nutrient removal by U. clathrata dominated over other processes such as phytoplankton and bacterial assimilation, ammonia volatilization and nutrient precipitation. 相似文献
5.
Kristina Liesener Valeriu Curtui Richard Dietrich Erwin Märtlbauer Ewald Usleber 《Mycotoxin Research》2010,26(1):23-30
A total of 62 samples of commercial horse feed preparations (complementary feeds) containing cereal mixtures (“muesli” or
mash, n = 39; pelleted feeds, n = 12), and plain horse feed grains (maize, n = 5; oats, n = 4; barley, n = 2) were purchased from 21 different producers/distributors from the German market. All samples were analysed by competitive
enzyme immunoassays (EIA) for six different mycotoxins (mycotoxin groups). Analytes (detection limit, mean recovery) were:
deoxynivalenol (DON, 10 μg/kg, 84%), zearalenone (ZEA, 5 μg/kg, 93%), fumonisin B1 (FB1, 2 μg/kg, 113%), T-2 toxin (T-2, 0.1 μg/kg, 71%), sum of T-2 + HT-2 toxin (T-2/HT2, 0.2 μg/kg, 97%), ochratoxin A (OTA, 0.2 μg/kg,
67%), and total ergot alkaloids (Generic Ergot Alkaloids “GEA”, 30 μg/kg, 132%). All samples contained DON (16–4,900 μg/kg,
median 220 μg/kg), T-2/HT-2 (0.8–230 μg/kg, median 24 μg/kg), and T-2 (0.3–91 μg/kg, median 7 μg/kg). ZEA was detected in
98% of the samples (7–310 μg/kg, median 61 μg/kg). Most samples (94%) were positive for FB1 (2–2,200 μg/kg, median 27 μg/kg). Ergot alkaloids were detected in 61% of samples (28–1,200 μg/kg, median 97 μg/kg), OTA
was found in 42% of samples (0.2–4 μg/kg, median 0.35 μg/kg). The results demonstrate that a co-contamination with several
mycotoxins is very common in commercial horse feed from the German market. The toxin concentrations were in most cases well
below the levels which are usually considered as critical or even toxic. The highest mycotoxin concentrations were mostly
found in single-grain cereal feed: the maximum values for DON and FB1 were found in maize, the highest T-2/HT-2 toxin concentrations were found in oats, and the highest concentration of ergot
alkaloids was found in barley. In composed feeds, no correlation between cereal composition and mycotoxin levels could be
found. 相似文献
6.
Role of secondary metabolites as defense chemicals against ice-ice disease bacteria in biofouler at carrageenophyte farms 总被引:1,自引:0,他引:1
Charles S. Vairappan Sangeetha P. Anangdan Kai Lee Tan Shigeki Matsunaga 《Journal of applied phycology》2010,22(3):305-311
Carrageenophyte farming is an expanding economical activity in North Borneo Island, Malaysia. During routine monitoring of
“ice-ice” disease and epiphyte outbreak at commercial farms, it was apparent that culture lines were heavily (60–80%) infested
with biofoulers, particularly Acanthophora spp. and Laurencia majuscula. However, only L. majuscula showed dominance and flourished even during “ice-ice” disease outbreak. Presence of chemical defense against seaweed pathogens
was investigated in two populations of L. majuscula collected from three major carrageenophyte farms in two districts; (A) Lohok Butun, Selakan Island, and Bum-Bum Island, in
Semporna district, and (B) Telutuh, Carrington Reef, and Balambangan Island, in Kudat district. The first population contained
elatol (1), and iso-obtusol (2), and, second population contained (Z)-10,15-dibromo-9-hydroxy-chamigra-1,3(15),7(14)-triene (3) and (E)-10-15-dibromo-9-hydroxy-chamigra-1,3(15),7(14)-triene (4), as their antibacterial metabolites. All four metabolites showed highly selective inhibition against “ice-ice” disease bacteria
compared to human pathogens at 30 μg disk−1. In addition, seasonal variation of these compounds at two representative farms (Selakan Island [P-1] and Balambangan Island
[P-2]) revealed a 120–170% increase in concentration during “ice-ice” disease outbreak. Microscopy of fresh specimens showed
the presence of corps en cerise, which is the synthesis and storage site of halogenated metabolites at superficial cortical cells, branch tips, and trichoblasts.
This suggests the importance of these metabolites as defense chemicals against “ice-ice” disease bacteria in L. majuscula that grows on seaweed culture lines. 相似文献
7.
Charles S. Vairappan Chong Sim Chung A. Q. Hurtado Flower E. Soya Genevieve Bleicher Lhonneur Alan Critchley 《Journal of applied phycology》2008,20(5):477-483
High density commercial farming of carrageenophyte Kappaphycus alvarezii is often plagued with “ice-ice” disease and epiphyte infection, which eventually leads to reduced production and in some
cases collapse of crop. Epiphyte outbreak has been occurring regularly in major carrageenophyte farms in the Philippines,
Indonesia, Malaysia and Tanzania. Infected materials from these countries were studied to establish baseline information on
the epiphyte’s identity, density, symptoms and secondary infection on the host seaweed. The causative organism was identified
as Neosiphonia apiculata (Hollenberg) Masuda et Kogame, based on its morphological features. Epiphyte density on host seaweed materials decreased in the following order:
the Philippines (88.5 epi cm−2), Tanzania (69.0 epi cm−2), Indonesia (56.5 epi cm−2) and Malaysia (42.0 epi cm−2). Initial symptoms were the presence of tiny black spots, indicating the embedded tetrasporeling in seaweed cortex layer.
Vegetative form emerged after 2 weeks measuring less than 0.5 mm in length with a density of less than 25.0 epi cm−2. Upon maturation, infected seaweed takes on a “hairy” appearance with “goose-bumps” like cortical swellings. The epiphyte
appears as a solitary plant with multiple secondary rhizoids or as multiple epiphytes appearing from a single cortical opening.
At the end of infection, the epiphytes left dark pits on the cortical swelling, and the carrageenophytes are infected by opportunistic
bacteria. Bacterial enumeration of healthy and infected seaweed materials showed an increase of more than 300% in total bacterial
count on infected materials dominated by Alteromonas sp., Flavobacterium sp. and Vibrio sp. 相似文献
8.
Potential of the seaweed Gracilaria lemaneiformis for integrated multi-trophic aquaculture with scallop Chlamys farreri in North China 总被引:2,自引:0,他引:2
Yuze Mao Hongsheng Yang Yi Zhou Naihao Ye Jianguang Fang 《Journal of applied phycology》2009,21(6):649-656
In this study the red alga, Gracilaria lemaneiformis, was cultivated with the scallop Chlamys farreri in an integrated multi-trophic aquaculture (IMTA) system for 3 weeks at the Marine Aquaculture Laboratory of the Institute
of Oceanology, Chinese Academy of Sciences (IOCAS) in Qingdao, Shandong Province, North China. The nutrient uptake rate and
nutrient reduction efficiency of ammonium and phosphorus from scallop excretion were determined. The experiment included four
treatments each with three replicates, and three scallop monoculture systems served as the control. Scallop density (407.9 ± 2.84 g
m−3) remained the same in all treatments while seaweed density differed. The seaweed density was set at four levels (treatments
1, 2, 3, 4) with thallus wet weight of 69.3 ± 3.21, 139.1 ± 3.80, 263.5 ± 6.83, and 347.6 ± 6.30 g m−3, respectively. There were no significant differences in the initial nitrogen and phosphorus concentration between each treatment
and the control group (ANOVA, p > 0.05). The results showed that at the end of the experiment, the nitrogen concentration in the control group and treatment
1 was significantly higher than in the other treatments. There was also a significant difference in phosphorus concentration
between the control group and the IMTA treatments (ANOVA, p < 0.05). Growth rate, C and N content of the thallus, and mortality of scallop was different between the IMTA treatments.
The nutrient uptake rate and nutrient reduction efficiency of ammonium and phosphorus changed with different cultivation density
and time. The maximum reduction efficiency of ammonium and phosphorus was 83.7% and 70.4%, respectively. The maximum uptake
rate of ammonium and phosphorus was 6.3 and 3.3 μmol g−1 DW h−1. A bivalve/seaweed biomass ratio from 1:0.33 to 1:0.80 (treatments 2, 3, and 4) was preferable for efficient nutrient uptake
and for maintaining lower nutrient levels. Results indicate that G. lemaneiformis can efficiently absorb the ammonium and phosphorus from scallop excretion and is a suitable candidate for IMTA. 相似文献
9.
Griselda Margarita Rodríguez-Figueroa Evgueni Shumilin Ignacio Sánchez-Rodríguez 《Journal of applied phycology》2009,21(1):19-26
The coastal marine sediments near Santa Rosalía on the eastern coast of the Baja California Peninsula (Mexico) are heavily
polluted by metals due to copper mining and smelting over the past century (up to 1984). The present study compares the accumulation
of metals in the brown seaweed Padina durvillaei from the central segment of the coast of Santa Rosalía (polluted by Co, Cu, Mn and Zn) and from two segments north and south
of the known “hot spot”. The seaweed samples were collected in May and August 2004 and June 2005 at 13 stations located along
the Santa Rosalía mining region. Heavy metal concentrations were measured by instrumental neutron activation analysis (Co
and Fe) directly in dried homogenized subsamples or by flame atomic absorption spectrophotometry (Cd, Cu, Mn, Ni, Pb and Zn)
after complete strong acid digestion of sub-samples. The means and standard deviations of the concentrations in dry tissues
of Padina durvillaei specimens for all the studied metals and stations lie in the following sequence: Cd (3.6 ± 1.6 mg kg−1) < Co (6.5 ± 6.1 mg kg−1) < Pb (7.8 ± 6.2) < Ni (9.96 ± 5.28 mg kg−1) < Cu (53 ± 38 mg kg−1) < Zn (63 ± 43 mg kg−1) < Mn (295 ± 269 mg kg−1) < Fe (2243 ± 2325 mg kg−1). This increase of the average concentrations was statistically significant. Principal Component Analysis showed that Factor
1 (36.46%) displays high positive loadings for Co, Cu, Mn and Zn, reflecting the influence of local anthropogenic pollution
on the seaweed composition, while Factor 2 (26.91%) is important for Co, Fe and Ni and probably corresponds to the adsorption
or accumulation of terrigenous elements of the regional origin, while Factor 3, with a high positive loading for Pb and a
high negative loading for Cd, is probably controlled by local and regional anthropogenic input of Pb and episodic supply of
Cd by local upwellings. The results of ANOVA for each element do not show any significant differences between the average
concentrations for Cd, Fe, Ni and Pb in the seaweed of the three segments, or between the central and southern segments for
Cu, Mn and Zn. Cobalt contents in the seaweed from the northern and central segments are, however, significantly different
from the southern segment. This indicates that element concentrations in Padina durvillaei generally do not follow the drastic increases and gradients of Cu, Co, Mn and Zn contents detected in surface sediments.
The apparent contradiction could be explained by a low geochemical mobility of these metals in the polluted sediments, composed
mainly of stable residues of smelter wastes, with very low content of organic matter usually driving diagenetic mobilization
of some metals into interstitial waters and then to the overlying water. 相似文献
10.
A seaweed with the local name “endong” is a rare eucheumoid variety that has recently been farmed in Tawi-Tawi, southern Philippines.
Local farmers describe it as “eel-like” because of its long, slender and smooth thalli. Being somewhat similar in appearance
to the dominantly farmed seaweed “tambalang” (Kappaphycus alvarezii var. tambalangii), farmers mix their harvests of “endong” with those of “tambalang”. We analyzed the hydrocolloid extract from “endong” using
spectroscopic and chemical techniques. The extract’s infrared and nuclear magnetic resonance (1H and 13C) spectra, and sulfate and 3,6-anhydrogalactose contents revealed carrageenan of the iota-type, similar to extracts from
another farmed species, Eucheuma denticulatum. This result implies that “endong” carrageenan exhibits physico-chemical properties different from those of kappa-carrageenan
of “tambalang”. The findings of this study are of significance to the seaweed industry, as carrageenan quality problems could
potentially arise from a mixed harvest. Seaweed farmers are advised to separate their harvests of “endong” and “tambalang”.
Presented at the 19th International Seaweed Symposium, Kobe, Japan 相似文献
11.
C. Wirth E.-D. Schulze W. Schulze D. von Stünzner-Karbe W. Ziegler I. M. Miljukova A. Sogatchev A. B. Varlagin M. Panvyorov S. Grigoriev W. Kusnetzova M. Siry G. Hardes R. Zimmermann N. N. Vygodskaya 《Oecologia》1999,121(1):66-80
The study presents a data set of above-ground biomass (AGB), structure, spacing and fire regime, for 24 stands of pristine
Siberian Scots pine (Pinus sylvestris) forests with lichens (n = 20) or Vaccinium/mosses (n = 4) as ground cover, along four chronosequences. The stands of the “lichen” site type (LT) were stratified into three chronosequences
according to stand density and fire history. Allometric equations were established from 90 sample trees for stem, coarse branch,
fine branch, twig and needle biomass. The LT stands exhibited a low but sustained biomass accumulation until a stand age of
383 years. AGB reached only 6–10 kgdw m−2 after 200 years depending on stand density and fire history compared to 20 kgdw m−2 in the “Vaccinium” type (VT) stands. Leaf area index (LAI) in the LT stands remained at 0.5–1.5 and crown cover was 30–60%, whereas LAI reached
2.5 and crown cover was >100% in the VT stands. Although nearest-neighbour analyses suggested the existence of density-dependent
mortality, fire impact turned out to have a much stronger effect on density dynamics. Fire scar dating and calculation of
mean and initial fire return intervals revealed that within the LT stands differences in structure and biomass were related
to the severity of fire regimes, which in turn was related to the degree of landscape fragmentation by wetlands. Self-thinning
analysis was used to define the local carrying capacity for biomass. A series of undisturbed LT stands was used to characterise
the upper self-thinning boundary. Stands that had experienced a moderate fire regime were positioned well below the self-thinning
boundary in a distinct fire-thinning band of reduced major axis regression slope −0.26. We discuss how this downward shift
resulted from alternating phases of density reduction by fire and subsequent regrowth. We conclude that biomass in Siberian
Scots pine forests is strongly influenced by fire and that climate change will affect ecosystem functions predominantly via
changes in fire regimes.
Received: 2 July 1998 / Accepted: 10 June 1999 相似文献
12.
Distribution of abundance, biomass, production and productivity of macrozoobenthos in the sub-Antarctic Magellan Province (South America) 总被引:3,自引:3,他引:0
Distribution of abundance, biomass, productivity and production of macrozoobenthos was investigated in four study areas in
the Magellan region (South Patagonian Ice-Field, Strait of Magellan, Beagle Channel, Continental Shelf). Using a Reineck box
corer and a multibox corer, a total of 277 quantitative benthos samples were taken at 78 stations in water depths between
8 and 1139 m during the Joint Chilean-German-Italian Magellan “Victor-Hensen Campaign” in 1994, the “Polarstern” expedition
ANT XIII/4 in 1996 and the Chilean expeditions “Cimar Fiordo II + III” in 1996 and 1997, respectively, on board RV “Vidal
Gormaz”. Mean abundance in the South Patagonian Ice-Field was significantly lower than in the Strait of Magellan and the Beagle
Channel. Biomass and abundance decreased clearly with depth (20–300 m to 700–1500 m: 3.9 gC m−2 to 0.6 gC m−2; 2832 ind. m−2 to 569 ind. m−2). Average abundance, biomass and production of the whole Magellan region are lower (2318 ind. m−2, 3.2 gC m−2, 0.62 gC m−2 year−1) than in the high Antarctic Weddell Sea. In the Magellan region, macrozoobenthos composition of abundance is mainly dominated
by polychaetes (56%), followed by arthropods (16%), echinoderms (10%) and molluscs (11%). Comparisons of our present results
with those of high Antarctic areas make it clear that the Magellan region has a transitional character.
Accepted: 21 December 1998 相似文献
13.
Abbas Ali Gheisari Abbas Sanei Abdolhossein Samie Mohamad Mehdi Gheisari Majid Toghyani 《Biological trace element research》2011,142(3):557-571
This experiment was conducted to evaluate the effect of zinc, manganese, and copper sources (inorganic vs. organic) in the
diet on laying performance and eggshell quality characteristics. One hundred and eighty Hy-Line W-36 layers at 38 weeks of
age were allocated to 36-layer cages of five hens each. Each six cages were randomly assigned to one of the six experimental
diets fed from 38 to 53 week of age. In three experimental treatments, the basal diet was supplemented with 65–75–7 or 65–75–7
or 40–40–7 mg/kg of Zn, Mn, and Cu, respectively, from their oxide or sulfate sources. Three other groups were fed diets supplemented
with 20–20–3.5 or 40–40–7.5 or 60–60–10.5 mg/kg of organic forms of Zn, Mn, and Cu, respectively. Dietary treatments significantly
did affect feed intake (P < 0.001), feed conversion ratio (P < 0.001) and percentage of broken eggs (P < 0.05). Substitution of Zn and Mn oxides (65 and 75 mg kg−1, respectively) with equal amounts of their sulfate forms significantly improved feed intake, feed conversion ratio, percentage
of broken eggs, and Haugh Unit (P < 0.05). In addition, laying hens maintained their performance when substitution of Zn and Mn oxides and Cu sulfate (65,
75, and 7 mg kg−1, respectively) reduced up to 20, 20, and 3.5 mg kg−1 by amino acid complexes of the microelements. The results showed that a corn–soybean diet supplemented with the organic forms
of Zn, Mn, and Cu at a dosage 50% to 75% lower than NRC recommendation is sufficient to maintain laying performance and can
improve eggshell and albumen qualities of the egg in laying hens. 相似文献
14.
Lamia Lahouar Fatma Ghrairi Mouldi El Felah Hichem Ben Salem Abdel Hedi Miled Mohamed Hammami Lotfi Achour 《Journal of physiology and biochemistry》2011,67(1):27-34
The aim of the present study is to evaluate the effects of diet enriched with dietary fiber of barley variety “Rihane” and
azoxymethane on serum and liver lipid variables in male rats. Forty male rats were divided into four groups and fed on control
diet or experimental diet that contained control enriched with dietary fiber of barley variety “Rihane”. Animals were injected
with saline (controls) or azoxymethane (20 mg/kg body weight s.c.) at 7 and 8 weeks of age. The experimental diet significantly
decreased cholesterol level compared with the control diet. Rats fed with BR diet significantly increased the serum high-density
lipoprotein (HDL) cholesterol and significantly decreased low-density lipoprotein (LDL) cholesterol concentrations. The experimental
diet decreased the atherogenic index (p < 0.05) compared with the control diet. Whereas the azoxymethane induced a significant increase of liver lipid, serum LDL
and triglyceride concentrations, but it caused a significant reduction of HDL. Consequently, the ratio of HDL/TC decreased
significantly compared with the control (p < 0.05). Accordingly, these results indicated that the diet enriched with dietary fiber of barley variety “Rihane” could
be effective in decreasing the atherogenic risk factors in rats whereas the use of the azoxymethane as colon-specific carcinogen
substance altered the lipid metabolism. 相似文献
15.
F. J. Gallego C. Benito 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(3):393-399
Aluminium (Al) tolerance in roots of two cultivars (“Ailés” and “JNK”) and two inbred lines (“Riodeva” and “Pool”) of rye
was studied using intact roots immersed in a nutrient solution at a controlled pH and temperature. Both the cultivars and
the inbred lines analysed showed high Al tolerance, this character being under multigenic control. The inbred line “Riodeva”
was sensitive (non-telerant) at a concentration of 150 μM, whereas the “Ailes” cultivar showed the highest level of Al tolerance
at this concentration. The segregation of aluminium-tolerance genes and several isozyme loci in different F1s, F2s and backcrosses between plants of “Ailés” and “Riodeva” were also studied. The segregation ratios obtained for aluminium
tolerance in the F2s analysed were 3 : 1 and 15 : 1 (tolerant : non-tolerant) while in backcrosses they were 1 : 1 and 3 : 1. These results indicated
that Al tolerance is controlled by, at least, two major dominant and independent loci in rye (Alt1 and Alt3). Linkage analyses carried out between Al-tolerance genes and several isozyme loci revealed that the Alt1 locus was linked to the aconitase-1 (Aco1), nicotinamide adenine dinucleotide dehydrogenase-2 (Ndh2), esterase-6 (Est6) and esterase-8 (Est8) loci, located on chromosome arm 6RL. The order obtained was Alt1-Aco1-Ndh2-Est6-Est8. The Alt3 locus was not linked to the Lap1, Aco1 and Ndh2 loci, located on chromosome arms, 6RS, 6RL and 6RL respectively. Therefore, the Alt3 locus is probably on a different chromosome.
Received: 18 March 1997 / Accepted: 21 March 1997 相似文献
16.
Unsurprisingly, survey results indicate that Texas biology and biological anthropology faculty with expertise in an evolutionary
area strongly support teaching “just evolution” (100%; N = 54) and not creationism/intelligent design. Importantly, they do not think that religious faith is incompatible with acceptance
of evolutionary biology (91%; N = 55), even though 50% (N = 52) describe themselves as “not at all religious.” As school boards nationwide debate science standards, it is important
that faculty with relevant expertise have a voice. Biological anthropologists should not be overlooked as a public resource
in these debates. 相似文献
17.
Beob G. Kim Merlin D. Lindemann Gary L. Cromwell 《Biological trace element research》2010,133(2):181-196
We investigated the effects of supplemental chromium (Cr) as Cr (III) picolinate on pigs fed high-fat diets (HFD) in a 56-day
experiment. Thirty-two crossbred pigs (9.6 kg) were allotted to four treatments with four blocks and two pigs/pen. Treatments
included: (1) low-fat diet (fat < 3.5%; LFD) with no Cr, (2) HFD (fat > 30%) with no Cr, (3) HFD with 1,000 ppb Cr, and (4)
HFD with 2,000 ppb Cr. Pigs fed HFD gained weight faster, consumed less, and had lower feed:gain (p < 0.05). Pigs fed HFD had higher respiration rates than pigs fed LFD on d 41 (p < 0.05). Plasma insulin on d 14 linearly decreased with Cr (p = 0.05). Plasma cholesterol concentrations were higher in the pigs fed HFD than those fed LFD, but were largely unaffected
by supplemental Cr. Consumption of HFD resulted in greater carcass weight, perirenal fat, and backfat measures (p < 0.01) compared with the LFD group. Cr resulted in linear reductions of hot carcass weight (p = 0.08) and average backfat (p < 0.05). The effects of Cr on carcass fat measures were more pronounced in castrated males than in females. These results
indicate that Cr attenuates some effects of a HFD, mainly body fat accretion of pigs, and especially in castrated pigs. 相似文献
18.
Zoran Pavlović Ivanka Miletić Živan Jokić Zlatica Pavlovski Zdenka Škrbić Slađana Šobajić 《Biological trace element research》2010,133(2):197-202
A 16-week-long experiment was performed to compare the effect of sodium selenite (SS) and selenium-enriched yeast (SY) supplementation
on eggshell quality and also to evaluate breaking force correlation with other parameters of shell quality originating from
hens fed with selenium supplementation. One hundred Shaver 579 hens (27 weeks old) with similar body size were randomly divided
for five dietary treatments: basal diet without selenium supplementation and basal diets with two levels of selenium supplementation
(0.4 or 0.8 mg/kg) via SS or SY. No adverse effect of Se inclusion in hen's feed, regardless of its source, on shell breaking
force, shell deformation, shape index, shell thickness and shell percentage, were observed throughout the current study (P > 0.05). Moderate correlations were found between breaking force and nondestructive shell deformation for all diets (P < 0.05). There was no significant overall correlation between egg breaking force and shell thickness or/and percentage shell
in the presence of selenium supplemention (P > 0.05). Shape index in all four selenium-supplemented groups was not related to the breaking force (P > 0.05). Selenium supplementation of up to 0.8 mg/kg, regardless of its source, in the diet of laying hens in their first
phase of laying does not adversely affect eggshell quality. 相似文献
19.
Joseph J. Hendricks John D. Aber Knute J. Nadelhoffer Richard D. Hallett 《Ecosystems》2000,3(1):57-69
Nitrogen controls on fine root substrate quality (that is, nitrogen and carbon-fraction concentrations) were assessed using
nitrogen availability gradients in the Harvard Forest chronic nitrogen addition plots, University of Wisconsin Arboretum,
Blackhawk Island, Wisconsin, and New England spruce-fir transect. The 27 study sites encompassed within these four areas collectively
represented a wide range of nitrogen availability (both quantity and form), soil types, species composition, aboveground net
primary production, and climatic regimes. Changes in fine root substrate quality among sites were most frequently and strongly
correlated with nitrate availability. For the combined data set, fine root nitrogen concentration increased (adjusted R
2 = 0.46, P < 0.0001) with increasing site nitrate availability. Fine root “extractive” carbon-fraction concentrations decreased (adjusted
R
2 = 0.32, P < 0.0002), “acid-soluble” compounds increased (adjusted R
2 = 0.35, P < 0.0001), and the “acid-insoluble” carbon fraction remained relatively high and stable (combined mean of 48.7 ± 3.1% for
all sites) with increasing nitrate availability. Consequently, the ratio of acid-insoluble C–total N decreased (adjusted R
2 = 0.40, P < 0.0001) along gradients of increasing nitrate availability. The coefficients of determination for significant linear regressions
between site nitrate availability and fine root nitrogen and carbon-fraction concentrations were generally higher for sites
within each of the four study areas. Within individual study sites, tissue substrate quality varied between roots in different
soil horizons and between roots of different size classes. However, the temporal variation of fine root substrate quality
indices within specific horizons was relatively low. The results of this study indicate that fine root substrate quality increases
with increasing nitrogen availability and thus supports the substrate quality component of a hypothesized conceptual model
of nitrogen controls on fine root dynamics that maintains that fine root production, mortality, substrate quality, and decomposition
increase with nitrogen availability in forest ecosystems in a manner that is analogous to foliage. 相似文献
20.
Rafael Rodrigues Loureiro Renata Perpetuo Reis Alan T. Critchley 《Journal of applied phycology》2010,22(1):101-104
Diseases such as “ice-ice” and “goose bumps” are responsible for loss of almost 70% of infected Kappaphycus production. To improve the growth of K. alvarezii and reduce the impact of diseases, the effect of the commercial Ascophyllum nodosum extract was tested. Five grams of apical branches of each K. alvarezii variant (n = 6) were bathed at different extract concentrations (e.g., 5, 10, 15, 20, 25, and 30 g L−1) for 1 hour. To test the effect of the extract on epiphytes apical tips were not cleaned. After 2 weeks, the epiphytes such
as Cladophora sp. and Ulva sp. disappeared. Polysiphonia subtilissima survived but its appearance was weak. The highest K. alvarezii growth rates were observed at extract concentrations of 15 and 20 g L−1 (p < 0.001), almost double the expected for a 45-day production cycle used at Sepetiba Bay, Brazil. These results show that
the extract was efficient at improving the growth of K. alvarezii and reducing the presence of some epiphytes. 相似文献