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1.
Blood samples were collected every 2 h during a 24 h period from 6 cows of one herd and 10 cows of another herd. In a third herd 9 cows were sampled every 2 h from 6 a.m. to 8 p.m. Concentrations of total bile acids, acetoacetate, glucose and free fatty acids were determined in blood plasma. A marked difference in individual bile acid concentrations and patterns of diurnal variation was found. For most cows the highest bile acid values were observed between 2 and 6 a.m. (overall mean (+/- SD) at 6 a.m.: 104 +/- 84 mumol/l, range: 20-307 mumol/l). Fourteen cows with a bile acid value greater than 90 mumol/l at 6 a.m. ("high BA") were characterized as a group by showing a pronounced decrease in the mean bile acid concentration after morning feeding. In the group of 11 cows with a 6 a.m. bile acid value less than 90 mumol/l ("low BA") the time of day did not contribute significantly to the bile acid variation. For the "high BA" group a nearly synchronous variation between the mean values of the 3 feeding dependent parameters (acetoacetate, glucose and free fatty acids) and the mean values of bile acids was found. The within animal coefficients of correlation between bile acids and the feeding dependent parameters were significantly higher in the "high BA" group than in the "low BA" group. No direct connection was found between bile acid levels and the quantity of concentrates fed or the individual milk yield. 相似文献
2.
Ismaïl Boujenane Abdelkader Chikhi Oumaïma Lakcher Mustapha Ibnelbachyr 《Tropical animal health and production》2013,45(6):1391-1397
This study examined the viability of 4,554 D’man lambs born alive at Errachidia research station in south-eastern Morocco between 1988 and 2009. Lamb survival to 1, 10, 30 and 90 days old was 0.95, 0.93, 0.93 and 0.92, respectively. The majority of deaths (85.7 %) occurred before 10 days of age. Type and period of birth both had a significant effect on lamb survival traits, whereas age of dam and sex of lamb did not. The study revealed a curvilinear relationship between lamb’s birth weight and survival traits from birth to 90 days, with optimal birth weights for maximal perinatal and preweaning survival varying according to type of birth from 2.6 to 3.5 kg. Estimation of variance components, using an animal model including direct and maternal genetic effects, the permanent maternal environment as well as fixed effects, showed that direct and maternal heritability estimates for survival traits between birth and 90 days were mostly low and varied from 0.01 to 0.10; however, direct heritability for survival at 1 day from birth was estimated at 0.63. Genetic correlations between survival traits and birth weight were positive and low to moderate. It was concluded that survival traits of D’man lambs between birth and 90 days could be improved through selection, but genetic progress would be low. However, the high proportion of the residual variance to total variance reinforces the need to improve management and lambing conditions. 相似文献
3.
Harizia Abdelkader Benguerai Abdelkader Elouissi Abdelkader Mahi Tayeb Bonal Raul 《植物病害和植物保护杂志》2021,128(6):1547-1556
Journal of Plant Diseases and Protection - This study investigated chemical composition, repellent and biocidal activities of Salvia officinalis essential oil against Aphis fabae. In total, 19... 相似文献
4.
P. Mazliak A. Ben Abdelkader 《Plant foods for human nutrition (Dordrecht, Netherlands)》1968,16(1-4):176-196
Résumé Les principes de la séparation des lipides polaires des autres catégories lipidiques, puis de la séparation des différents lipides polaires entre eux sont rapidement passés en revue. Les principaux systèmes, récemment décrits, permettant de réaliser ces séparations sur couche mince, sur papier silicé ou en couplant un fractionnement préalable sur colonne avec une chromatographie ultérieure sur couche mince, sont présentés. Plusieurs exemples sont fournis de l'application de ces méthodes d'analyse aux lipides polaires de divers fruits, tubercules ou feuilles vertes.
Abréviations utilisées PA acide phosphatidique - PI phosphatidylinositol - PS phosphatidylsérine - PE phosphatidyléthanolamine - PG phosphatidylglycérol - PGP diphosphatidylglycérol (cardiolipine) - MGDG monogalactosyldiglycéride - DGDG digalactosyldiglycéride - LN lipides neutres 相似文献
Summary The principles of the separation of polar lipids from the other lipid categories, then the principles of the separation of the various polar lipids between them, are rapidly reviewed. The main systems, recently described, thanks to which it is possible to achieve these separations on a thin-layer, on silica paper, or by coupling a preliminary column fractionation with an ulterior thin-layer chromatography are presented. Several examples of the application of these methods of analysis to the polar lipids of various fruits, tubers, or green leaves, are given.
Zusammenfassung Die Grundsätze der Trennung der polaren Lipide von den anderen Lipiden, und der verschiedenen polaren Lipide untereinander werden kurz besprochen. Die kürzlich beschriebenen Verfahren, welche diese Trennungen auf Dünnschichten möglich machen, auf Kieselgel oder durch Kupplung mit einer vorherigen Säulen-Fraktionierung und anschließender DC werden dargestellt. Mehrere Beispiele werden bezüglich der Anwendung dieser analytischen Verfahren für polare Lipide in verschiedenen Früchten, Knollen oder grünen Blättern gegeben.
Abréviations utilisées PA acide phosphatidique - PI phosphatidylinositol - PS phosphatidylsérine - PE phosphatidyléthanolamine - PG phosphatidylglycérol - PGP diphosphatidylglycérol (cardiolipine) - MGDG monogalactosyldiglycéride - DGDG digalactosyldiglycéride - LN lipides neutres 相似文献
5.
Glutamate dehydrogenase (GLDH), sorbitol dehydrogenase (SDH), 5''-nucIeotidase (5''-ND) and cholin esterase (CHE) were determined in the sera of 37 dogs with various liver diseases. The values for these parameters were compared with the values for aspartate and alanin aminotransferase (ASAT, ALAT), alkaline phosphatase (ALP), γ-glutamyl transferase (γ-GT) and albumin (ALB). GLDH was found to be the most sensitive enzyme parameter (sensitivity 92 %), its values also reflecting the degree of liver cell necrosis well. Next in sensitivity followed ASAT and ALP. SDH values were correlated to ALAT values but had a low sensitivity (43 %). 5''-ND discriminated markedly better between biliary tract disturbance and other lesions than ALP and somewhat better than γ-GT. CHE had a wide reference range, low sensitivity, and was not correlated to ALB. Single determinations of CHE may thus not be of diagnostic value in dogs. 相似文献
6.
Sébastien Migneault Ahmed Koubaa Fouad Erchiqui Abdelkader Chaala Karl Englund Michael P. Wolcott 《Wood Science and Technology》2011,45(3):521-532
Wood–plastic composites (WPC) were produced with white birch pulp fibers of different aspect ratios (length-to-diameter),
high-density polyethylene, and using two common processes: extrusion or injection molding. Three additive levels were also
used: no additive, compatibility agent, and process lubricant. Fiber size was measured with an optical fiber quality analyzer.
Tensile properties of WPC were measured and modeled as a function of fiber aspect ratio. Models were fitted to experimental
values using the minimum sum of squared error method. A shift from the oriented fiber case (injection molding) to the randomly
oriented fiber case (extrusion) was achieved using a fiber orientation factor. Fiber/matrix stress transfer increased with
increasing fiber aspect ratio. Stress transfer was reduced with the use of process lubricant. Unexpectedly, the compatibility
agent had the same effect. Fiber strength and stiffness contributions to the composite were lower than those of intrinsic
fiber properties. 相似文献
7.
Summary To check if the oxygen concentration in the cell medium-higher at low temperatures-is a factor regulating the synthesis of
polyunsaturated fatty acids, the effects of temperature and oxygen concentration were studied in vitro on the activity of
the microsomal oleyl-coenzyme A desaturase of potato tubers. The highest activity of this enzyme was observed at 30° C, and
not at low temperatures, and at an oxygen concentration of about 20%. These results suggest that the above hypothesis is not
valid for the potato tuber cell.
Zusammenfassung Um zu prüfen. ob die Sauerstoffkonzentration in der Zelle-bei niedriger Temperatur h?herein regulierender Faktor bei der Synthese der mehrfach unges?ttigten Fetts?uren ist, wurde der Einfluss der Temperatur und der Sauerstoffkonzentration auf die Aktivit?t der mikrosomalen Oleyl-coenzym A Desaturase der Kartoffelknollen in vitro untersucht. Die h?chste Aktivit?t des Enzyms wurde bei einer Temperatur von 30°C gefunden und nicht bei tieferen Temperaturen (Abb. 1) und bei einer Konzentration von ca. 20% Sauerstoff (Abb. 2). Diese Ergebnisse zeigen, dass die angeführte Hypothese im Falle der Kartoffelknollen nicht zutrifft.
Résumé Pour vérifier si l'hypothèse selon laquelle la concentration en oxygène du milieu cellulaire-plus élevée à basse température-est un facteur régulant la synthèse des acides gras polyinsaturés, les effets de la température et de la concentration en oxygène sur l'activité de l'oléyl-coenzyme A désaturase microsomale du tubercule de pomme de terre ont été étudiés in vitro. L'activité la plus élevée de l'enzyme est observée pour la température de 30°C et non à basse température (Fig. 1) et pour une concentration en oxygène d'environ 20% (Fig. 2). Ces résultats suggèrent que l'hypothèse exposée plus haut n'est pas valable dans le cas du tubercule de pomme de terre.相似文献
8.
The response of three durum wheat cultivars (C: Chen’s, V: Vitron, W: Waha) to irrigation was studied during 4 years in semi-arid
Algeria (Chlef). The four treatments were NI (unirrigated), EI (early irrigation, up to heading), LI (late irrigation, from
heading) and FI (full irrigation, over the entire season). FI increased rainfed grain yield (1,300 kg ha−1) by 270%, EI by 107%, and LI by 67%. The variety × irrigation interaction was significant each year. Under irrigation, cv.
Vitron was generally the most productive cultivar while in rainfed conditions cv. Waha always resulted in the highest grain
yield. Grain yield increased exponentially with seasonal evapotranspiration (r
2 = 0.741) and harvest index (r
2 = 0.873). Water use efficiency for grain ranged from 4.6–5.3 kg ha−1 mm−1 (NI) to 9.6–10.8 kg ha−1 mm−1 (FI) as a function of cultivar and irrigation, cv. Vitron and cv. Waha (full irrigation) and cv. Waha (rainfed) being the
most efficient cultivars. According to the evaporation pan method, the seasonal crop coefficient (K
c) values for the three cultivars were 0.64 (V), 0.62 (W) and 0.54 (C). The corresponding peak K
c values were 1.0, 0.97 and 0.89, respectively. K
c was closely related to leaf area index (LAI) and specific logarithmic relationships were calculated for each cultivar. Irrigation
scheduling should be adapted to the type of cultivar in relation to its potential yield and LAI development pattern. 相似文献
9.
Mathias Craul Lounes Chikhi Vitor Sousa Andriatahiana Rabesandratana Elke Zimmermann 《Biological conservation》2009,142(12):2862-2871
Madagascar’s diverse and mostly endemic fauna and flora suffer from recent landscape changes that are primarily caused by high levels of human activities. The loss and fragmentation of forest habitats are well known consequences of human activities. In this study, we investigate the effects of forest fragmentation on presence, abundance and genetic diversity in a larger-bodied lemur species, Lepilemur edwardsi, in northwestern Madagascar. In addition, we characterized the genetic differentiation among populations and demographic changes. We found L. edwardsi at only 13 (76.5%) of 17 visited sites, 11 of which were situated in the Ankarafantsika National Park (ANP). We captured between two and 17 individuals per site. We sequenced the mtDNA d-loop of all samples and genotyped 14 microsatellite loci in two exemplary populations for demographic analyses. A negative influence on forest fragmentation could be detected, since the fragments had a lower genetic diversity than sites in the ANP. Genetic differentiation between populations ranged from low to high but was almost always significant. A typical pattern of isolation-by-distance could not be detected and the data could rather be interpreted as results of random genetic drift. The data furthermore revealed signals of a demographic collapse of about two orders of magnitude in the two exemplary sites. This decline probably started during the last few hundred years of intensified human disturbances and population growth. Given the results of this study, urgent conservation actions are needed and should concentrate on an effective protection of the few remaining populations in order to ensure the long-term survival of L. edwardsi. 相似文献
10.
The exceptional biodiversity of Madagascar is threatened by anthropogenic landscape changes that took place during the 2000 years of human colonization. This study focuses on the influence of geographic distance and forest fragmentation on genetic diversity and population differentiation of three rare, nocturnal, arboreal lemur species in northwestern Madagascar. Historic declines in population sizes as a consequence of forest fragmentation are quantified and dated. Eighteen sites were visited, and a total of 205 Microcebus ravelobensis, 45 M. bongolavensis and 78 M. danfossi were genotyped with eight microsatellite loci. Genetic differentiation among the sites, as measured by FST, ranged from 0.01 to 0.19. These values were significant in almost all cases and indicated genetic structure in the samples. Isolation-by-distance was detected in one species and a STRUCTURE analysis indicated that fragmentation further promoted genetic differentiation. Bayesian methods revealed that populations from all three species underwent a major demographic collapse of around two orders of magnitude. This decrease probably began after the arrival of humans, most likely within the last 500 years. This result suggests that anthropogenic changes may have been limited during the first 1500 years of human colonization in all three ranges. Two of the study species (M. danfossi, M. bongolavensis) lack effectively protected areas in their ranges. Consequently, quick conservation actions are now needed in order to secure the remaining genetic diversity of these species. 相似文献