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951.
I. Gabriel S. Mallet M. Leconte A. Travel J.P. Lalles 《Animal Feed Science and Technology》2008,142(1-2):144-162
The objective of the current study was to investigate the impact of including whole wheat in broiler diets on the development of the digestive tract. Chickens were fed a standard feed containing 400 g ground wheat/kg or the same diet with a part of the wheat given separately as whole grains that increased progressively from 200 g/kg at 8 d to 400 g/kg at 22 d. Every week, from 16 to 44 d, growth performance, modifications of the size of the digestive tract organs and intestinal enzyme activities were investigated. Morphology of villi and crypts in the small intestinal segments (duodenum, jejunum, ileum) were analyzed at 23 and 44 d. Microbacterial counts were performed in jejunal, ileal and caecal contents weekly from 16 to 44 d.During the adaptation period from 8 to 15 d, the birds fed the whole wheat diet had lower feed intake and lower weight gain. Thereafter, they showed improved growth performance so that by the end of the experiment, they had higher body weight compared to the standard-fed birds, 2430 ± 29 versus 2331 ± 36 g.Higher relative weights of gizzard (+26%) and pancreas (+12%) were observed from 16 to 44 d for whole wheat-fed birds compared to standard-fed birds. No differences in relative size of the different intestinal segments were observed, except that the jejunum was shorter. Increased villus to crypt length and surface ratios were observed at 23 d in the duodenum of whole wheat-fed birds, with no differences in morphometry between groups thereafter. Alkaline phosphatase activity was higher from 16 to 44 d in the duodenum and jejunum of whole wheat-fed birds. However, the activities of the digestive enzymes, leucine aminopeptidase and maltase, were similar between the two diets in the measured intestinal segments.A lower number of facultative anaerobic bacteria was found in the ileum of the whole wheat-fed birds, with no differences between treatments for Escherichia coli and for Lactobacillus counts. In the jejunum and the caeca, no differences in microflora counts were observed.The present results showed that feeding whole grains to broilers led mainly to modifications in the upper part of the digestive tract (gizzard, pancreas) and had little influence on the small and large intestine. 相似文献
952.
Responses of soluble amino acids and organic acids to either ambient (36 Pa) or elevated (100 Pa) CO2 treatments were determined using barley primary leaves (Hordeum vulgare L. cv. Brant). Total soluble amino acids were increased 33% by CO2 enrichment 9 days after sowing (DAS), but a decrease relative to the ambient CO2 treatment was observed with increasing leaf age. Marked declines of glutamine and asparagine were observed under CO2 enrichment, both diurnally and with advancing leaf age. Consequently, total soluble amino acids were 59% lower in the elevated compared to the ambient CO2 treatment 17 DAS. It was likely that chlorosis in response to CO2 enrichment negatively impacted soluble amino acid levels in older barley primary leaves. In contrast to the ambient CO2 treatment, glutamine and most other soluble amino acids decreased as much as 60% during the latter half of a 12 h photoperiod in primary leaves of 13-day-old seedlings grown under enhanced CO2. Malate was decreased about 9 percent by CO2 enrichment and citrate and succinate were increased by similar amounts when measured 9 and 13 DAS. Malate accumulation was also decreased about 20% by CO2 enrichment on a diurnal basis. The onset of CO2-dependent leaf yellowing had much less of an effect on organic acids than on soluble amino acids. This above results emphasized the sensitivity of N metabolism to CO2 enrichment in barley. Increased levels of citrate and succinate in response to CO2 enrichment suggested that the tricarboxylic acid cycle was upregulated in barley by CO2 enrichment. In summary, organic and amino acid levels in barley primary leaves were dynamic and were altered by age, diurnally and in response to CO2 enrichment. 相似文献
953.
Xyloglucans from seeds of Copaifera langsdorffii (XGC), Hymenaea courbaril (XGJ) and Mucuna sloanei (XGM) were obtained from milled and defatted cotyledons by aqueous extraction at 25 degrees C. The resulting fractions contained Glc, Xyl and Gal in molar ratios of 2.5: 1.5: 1.0 (XGC), 3.8: 2.6: 1.0 (XGJ) and 2.5: 1.6: 1.0 (XGM). HPSEC-MALLS/RI analysis showed that each polysaccharide fraction was homogeneous; M(w) values were 1.6 x 10(5), 2.0 x 10(5) and 1.5 x 10(5)g/mol, respectively. The effect of the xyloglucans on the production of O(2)*(-) and NO* and on the recruitment of macrophages to the mouse peritoneum was evaluated. All polysaccharides promoted an increase in the number of peritoneal macrophages in a dose-dependent manner. The largest increase, of 576% in comparison to the control group, was elicited by XGJ at 200 mg/kg. The effect of XGC, XGJ and XGM on O(2)*(-) production, in the presence or absence of phorbol 12-myristate 13-acetate (PMA), was not statistically significant. For NO(.) production, the lowest concentration of XGC (10 microg/ml) gave rise to an increase of 262% when compared to the control group; the effect was dose-dependent, reaching 307% at 50 microg/ml. On the other hand, XGJ at a concentration of 50 microg/ml enhanced NO* production by 92%. XGM did not affect NO* production significantly. The results indicate that xyloglucans from C. langsdorffii, H. courbaril and M. sloanei have immunomodulatory activity. 相似文献
954.
Leaf area estimation by simple measurements and evaluation of leaf area prediction models in Cabernet-Sauvignon grapevine leaves 总被引:2,自引:0,他引:2
For two growing seasons (2005 and 2006), leaves of grapevine cv. Cabernet-Sauvignon were collected at three growth stages
(bunch closure, veraison, and ripeness) from 10-year-old vines grafted on 1103 Paulsen and SO4 rootstocks and subjected to
three watering regimes in a commercial vineyard in central Greece. Leaf shape parameters (leaf area-LA, perimeter-Per, maximum
midvein length-L, maximum width-W, and average radial-AR) were determined using an image analysis system. Leaf morphology
was affected by sampling time but not by year, rootstock, or irrigation treatment. The rootstock×irrigation×sampling time
interaction was significant for all the leaf shape parameters (LA, Per, L, W, and AR) and the means of the interaction were
used to establish relationships between them. A highly significant linear function between L and LA could be used as a non-destructive
LA prediction model for Cabernet-Sauvignon. Eleven models proposed for the non-destructive LA estimation in various grapevine
cultivars were evaluated for their accuracy in predicting LA in this cultivar. For all the models, highly significant linear
functions were found between calculated and measured LA. Based on r
2 and the mean square deviation (MSD), the model proposed for LA estimation in cv. Cencibel [LA = 0.587(L×W)] was the most
appropriate. 相似文献
955.
Growth-ring variations of dwarf shrubs reflect regional climate signals in alpine environments rather than topoclimatic differences 总被引:1,自引:0,他引:1
Aim Our main aim is to determine if ring‐width variations in Empetrum hermaphroditum reflect regional or local topoclimate signals in an alpine environment. In the case that topoclimate provides the dominant signal, a secondary aim is to link these to spatial distribution patterns of different vegetation types. Location The study area is situated in the middle alpine belt in the Vågåmo region, Central Norwegian Scandes. Sampling sites cover different topoclimates: ridges, north‐facing slopes and south‐facing slopes. Methods We constructed ring‐width chronologies of E. hermaphroditum for each type of microsite for the common period 1951–2004. Climate data were prepared on an hourly, daily and growing‐season time scale. Climate–growth relationships were evaluated using bivariate correlations and regression tree methods for continuous time‐series analyses. In addition, extreme growth anomalies (pointer years) were compared with the climate conditions in those years. The impact of water supply on wood anatomy was determined by correlating the conductive area (percentage of vessel per growth ring) with a running mean (sum) of 10‐day intervals for temperature and precipitation. Results This study indicates that mean summer (June–August) temperatures determine the width of the growth rings of E. hermaphroditum irrespective of topoclimate. The length of the growing season, which is the most differentiating climatic factor between microsites, does not substantially alter the anatomical ring structure. Microsite differences in mean growth rates are attributed to the higher frequency of warm days. Extremely warm days limit ring‐width development at south‐facing slopes, while plants at ridges and north‐facing slopes still benefit from higher temperatures. As a consequence, pointer years are not developed synchronously at all microsites. Vessel formation is affected by available moisture, especially in the later part of the growing season. Main conclusions Topoclimate induces slight modifications of annual growth‐ring increments of E. hermaphroditum at different microsites. In contrast to the distribution patterns of vegetation types that are determined by snow cover, growth‐ring variations are related to summer temperature conditions, and the prominent regional climate signal is still reflected at all microsites. This offers the opportunity to reconstruct climatic change in alpine regions from dwarf shrub ring‐width chronologies. 相似文献
956.
957.
1996~ 1 999年 ,在云南省蒙自县草坝镇 (南亚热带北缘 )进行了亩产吨粮的种植模式研究。通过对春、夏、秋、冬播玉米 ,早、中、晚稻以及冬小麦的系统研究 ,以地上部分总干物重、籽粒产量、总入射辐照量、叶面积持续期 (灌浆期 )、氮肥的利用率和生产力、水生产力为指标 ,对早稻—晚稻、早稻—秋玉米、早稻—冬小麦、春玉米—晚稻、夏玉米—冬小麦、中稻—冬小麦和中稻—冬玉米 7种复种模式作了比较 ,选出中稻—冬玉米为一年两熟亩产吨粮的最佳种植模式。 相似文献
958.
959.
Forty-five samples from 1988–1995 of naturally contaminated grain, barley, wheat and oats, three samples of mixed feed, and
16 samples of grain artificially inoculated with Fusarium culmorum during the flowering stage were analysed for deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-acetyl-DON), culmorin and hydroxy-culmorins.
These compounds are secondary metabolites produced by the fungal species F. culmorum and F. graminearum. Acetonitrile-water extract of the samples was purified on a MycosepTM#225 column, derivetized using pentafluoropropionic anhydride (PFPA) and analysed by gas chromatography-mass spectrometry
(GC-MS). The amount of each of culmorin, 5-, 12-, 14 and 15-hydroxy-culmorin and one unknown hydroxy-culmorin were determined
relative to the amount of DON plus 3-acetyl DON for each sample. The ratio between the total amount of culmorin compounds
and the DON compounds ranged from 0.14 to 1.07 in the samples. This study shows that there is a strong correlation between
the amount of DON present in the grain and the amount of culmorin and hydroxy-culmorins present. The ratio of each of the
culmorin compounds relative to the amount of DON compounds were in the same range in the grain artificially inoculated by
F. culmorum as found in an earlier study for F. culmorum strains cultivated on rice, while the hydroxy-culmorin profile in the naturally contaminated grain was more similar to what
was found for the F. graminearum cultures in the same study [1]. These results indicate that F. graminearum may be a relatively important source for DON in grain also in relatively cold areas.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
960.
农药的生态安全特性指标Q方程的研究 总被引:6,自引:0,他引:6
以北京地区冬小麦麦田的麦长管蚜Macrosiphumavenae (Fabricius)与七星瓢虫Coccinellaseptem punctataLinnaeus幼虫为实验材料 ,选择抗蚜威、乐果、氰戊菊酯 3种常用农药 ,改传统的死亡几率值为存活几率值 ,得到 6条剂量对数—存活几率值回归直线和 6个方程。定义特定农药的不同剂量下害虫与天敌存活率比值叫生态安全系数Q。利用Origin 5.0软件上机对 3个Q(x)方程绘图 ,直观地显示了不同农药种类的差异。田间实验证明 ,防治前后的害虫益虫比值与Q方程计算值基本吻合。因此可能有较大的实用价值 相似文献