Effects of Rumen Fill on Intake and Milk Production in Dairy Cows Fed Perennial Ryegrass

Physical limitation often limits dry matter intake (DMI) of high producing cows or cows fed high forage diets. The extent to which DMI is regulated by distention in the rumen depends upon the cow’s energy requirement and filling effects of the diet offered (Allen, 2000). The objective here was to challenge middle lactation dairy cows with rumen fill (rumen inert bulk – RIB) feeding ryegrass fresh cut (indoors) or grazed to determine whether RIB affects intake and milk production

Rationalité, relativisme, évolution sociale: une analyse critique du modèle cognitiviste de Boudon-Weber

This essay mainly concerns the foundation of a method of inquiry appropriate to the study of social reality. It starts from a criticism of Boudon-Weber's cognitivist method, the lacks of which seem particularly qualified for underlining the methodologic difficulties afflicting social thought. These lacks helps us to point out the reason and potentialities of our proposal on method that may be denominated 'social objectivism'. This proposal suggests additional objections both to Weber's cultural relativism and Boudon's anti-relativism, as well as to the notion of rationality and the theory of social evolution developed by those authors. A different notion of rationality is proposed and an alternative explanation of social process, referable both to the evolution and organization of human societies, is sketched out that may also be extended to the interpretation of historical processes

High-resolution stimulated Raman spectroscopy and analysis of v2 and v3 bands of 13C2H4 using the D2h top data system

HRMS 2015, Dijon, France, August 24-28, 2015Peer Reviewe

Does the Feeding Behaviour of Dairy Cows Differ When Fed Ryegrass Indoors vs. Grazing?

Dairy cows eating ryegrass ingest smaller boli when grazing than when fed indoors (93 vs. 142 g; Boudon et al., 2004). To investigate whether this difference in bolus affects feeding behaviour of the cows, an automated system (chewing halters) was used to monitor feeding behaviour of cows given ad libitum access to perennial ryegrass in individual feed troughs (indoor feeding, IF) or at pasture (grazing, GR)

Acquisition efficiency of Flavescence dorée phytoplasma by Scaphoideus titanus Ball from infected tolerant or susceptible grapevine cultivars or experimental host plants

The rate of Flavescence dorée phytoplasma (FDP) acquisition by the leafhopper vector Scaphoideus titanus Ball was tested under field and glass house conditions confining healthy reared nymphs on canes of FDP-infected grapevines or on FDP-infected cuttings collected in the field during the dormant season. Acquisition tests were performed using FD-tolerant (Merlot) or highly susceptible (Pinot blanc) grapevine cultivars, or alternatively using experimentally infected broadbean plants. Frequency of FDP acquisition by leafhoppers was evaluated using a polymerase chain reaction (PCR) assay. Different batches of insects were confined on the same infected source plants in the vineyard for acquisition access periods (AAP) of 7 d at a time at intervals of 15-20 d during spring and summer. When diseased Pinot blanc grapevines were used as source plants, acquisition by leafhoppers and transmission to healthy grapevines increased over summer, while almost no acquisition or transmission was observed when diseased Merlot grapevines were used as source plants. Tests conducted under controlled conditions confirmed that Merlot is a poorer source of FDP than Pinot blanc; the optimum FDP source for S. titanus was broadbean although this plant is not a natural host of the leafhopper. It is assumed that grapevine cultivars play an important role in influencing the proportion of FDP-infected leafhoppers in the vineyards and therefore influencing the rate of disease progress.

Flavescence doree in France and Italy - Occurrence of closely related phytoplasma isolates and their near relationships to Palatinate grapevine yellows and an alder yellows phytoplasma

Grapevine yellows (GY) are diseases of Vitis vinifera caused by phytoplasmas. On the basis of DNA analysis, it is possible to distinguish different groups and subgroups among grapevine phytoplasmas. Flavescence doree (FD), the most serious problem in European vineyards, is caused by a phytoplasma which belongs to the elm yellows group (EY or 16SrV), Differences between 7 phytoplasma isolates in this group, found until now in French, Italian and German grapevines, and 4 phytoplasmas in the same group, isolated mainly from elm and alder in Europe and America, were investigated. These 11 EY-group isolates plus 3 non-EY phytoplasmas, were compared by PCR-RFLP analyses of two different DNA fragments using 8 restriction enzymes. Two French and two Italian grapevine isolates, classified as FD, appeared to be closely related and were also closer to an Italian alder phytoplasma. One French and one Italian FD isolate always showed the same restriction pattern. On the opposite, the three German grapevine isolates related to alder phytoplasmas in Germany appeared to be closer to the two elm phytoplasmas from America and Europe.

Detection of flavescence dorée phytoplasma in grapevine in northern Spain

Research NoteGrapevine yellows diseased stocks were observed in vineyards of the Alt Emporda area, northern Spain. Phytoplasma was detected and characterized by PCR-RFLP in the region of the 16S rDNA of phytoplasmas or by ELISA. For the first time a FD phytoplasma was detected in Spain

Diversity among mycoplasma-like organisms inducing grapevine yellows in France

As antibodies and molecular probes which were previously obtained for diagnosis of grapevine flavescence doree (FD; a yellows disease induced by a MLO), showed to be highly specific, a survey of grapevine samples collected in different viticultural areas in France was undertaken, using a PCR method with primers allowing amplification of a part of the 16S rRNA gene of most MLOs, and restriction analyses of the amplified products (AHRENS and SEEMÜLLER 1992). The presence of MLO was established in all the different grapevine samples, and their diversity was demonstrated. The typcial pattern yielded by FD sensu stricto-MLO was found in samples from southern vineyards, including a symptomless rootstock. Two different patterns were found in samples affected by bois noir disease of northern French vineyards, one of these patterns being previously undescribed. The present survey was non exhaustive and should be followed in the frame of a large collaboration between viticultural countries. It showed the diversity in causal agents of diseases which converge in symptomatology, and emphasizes on the need of specific diagnosis tools, for identification of each of the vector species, for epidemiological studies, and availability of planting material