Twenty multiparous Holstein cows in midlactation grazed pastures of 4 forage mixtures in a 12-wk study repeated during 2 grazing seasons to determine if forage mixture complexity affected intake and productivity of lactating dairy cows. The forage mixtures were 1) orchardgrass plus white clover [2 species (SP)]; 2) orchardgrass, white clover, and chicory (3SP); 3) orchardgrass, tall fescue, per...

In dryland farming areas of Montana, annual precipitation is not sufficient for annual planting of cereal grains. Instead, a crop-summer fallow farming system is used to conserve soil moisture and increase available nitrogen for subsequent crop growth. Managing this summer fallow, either by mechanical means or with herbicides, is the highest variable cost associated with dryland grain productio...

Endophytic fungi are plant symbionts living asymptomatically within plant tissues. Neotyphodium spp., which are asexual vertically transmitted systemic fungal endophytes of cool-season grasses, are predicted to be plant mutualists. These endophytes increase host plant resistance to environmental stresses and/or increase the production of alkaloid-based herbivore deterrents. The ubiquity of this...

Two experiments were carried out during summer and winter conditions to determine if Dictyocaulus vivipams infective larvae could survive on pasture during these seasons in Louisiana. Pairs of tracer calves were grazed in August and September on a pasture that was heavily contaminated in May and then left free of cattle during June-July. These tracers were not infected with D. vivipams, indicat...

We present preliminary evidence for the existence of a genetic landscape-level structuring that might be a consequence of depressed pollen flow across heavily grazed populations of Cypella herbertii.

The small acmaeid limpet Patelloida lat istr~gata Angas and clumps of macroalgae are found in midshore intertidal regions dominated by barnacles. Interactions between limpet and algae were investigated experimentally to determine the effect of the herbivore on microalgae (this term includes propagules of macroalgae) as well as on macroalgal plants, and also the influence of both forms of algae ...

Tall alpine herb field is largely absent from the Tasmanian alpine zone. This absence has been attributed to marsupial grazing. Small islands in the upper Ouse River valley are partly dominated by Craspedia paludicola, a showy tall alpine herb. The herbs dominate on the upstream ends of the islands. The surrounding vegetation on the banks is mainly grassland. The tall herbs are a very minor ele...

This study describes the development of periphytic communities established on artificial Ž . substrates in tilapia Oreochromis niloticus cages during a 10-week experiment conducted in the Meghna River, Bangladesh. Qualitative and quantitative characteristics of the periphyton were recorded, including diatom community composition and primary productivity. Fish grazed actively on the periphyton a...

Managing uncertainty and risk is an increasing challenge for running profitable grazing systems. There is continual pressure to increase efficiency and productivity, while at the same time there is mounting scrutiny of the impact of grazing systems on the environment. Of particular interest is the impact of nitrogen and phosphorus losses from grazed pasture systems to water and the atmosphere. ...