Phosphorus and Dairy/Beef Nutrition

Phosphorus (P), a required nutrient for all livestock, has numerous essential physiological functions in the body that include energy transfer (ATP), structure of bone, teeth, and membranes, and buffering pH changes in the rumen (salivary phosphate). Ruminants use a larger proportion of dietary P than nonruminants because rumen microbes produce phytase, the enzyme that hydrolyzes P from phytate. The majority of P in most grains is in phytate form, a P form largely unavailable to swine and poultry

Phosphorus and Dairy/Beef Nutrition

Phosphorus (P), a required nutrient for all livestock, has numerous essential physiological functions in the body that include energy transfer (ATP), structure of bone, teeth, and membranes, and buffering pH changes in the rumen (salivary phosphate). Ruminants use a larger proportion of dietary P than nonruminants because rumen microbes produce phytase, the enzyme that hydrolyzes P from phytate. The majority of P in most grains is in phytate form, a P form largely unavailable to swine and poultry

Association of the 17-kDa extrinsic protein with photosystem II in higher plants

The structural association of the spinach 17-kDa extrinsic protein of photosystem II with other extrinsic and membrane-bound components of the photosystem was investigated by labeling the 17-kDa extrinsic protein with the amino-group-specific reagent N-hydroxysuccinimidobiotin both on intact photosystem II membranes or as a free protein in solution. After isolation of the biotinylated molecules, the modified 17-kDa proteins were allowed to rebind to photosystem II membranes which were depleted of the 17-kDa component. Differential binding of the protein biotinylated in solution compared to unmodified 17-kDa protein or 17-kDa protein modified on PSII membranes was observed. This indicated possible steric or ionic interference because of biotinylated lysyl residues present on the protein modified in solution. Biotinylated sites on the different modified 17-kDa proteins were identified by trypsin and Staphylococcus V8 protease digestion, followed by affinity chromatography enrichment of the biotinylated peptides and analysis of the peptide fragment mixture by nanospray liquid chromatography-tandem mass spectrometry. Four lysyl residues that were modified when the protein was biotinylated in solution were not biotinylated when the protein was modified on the PS II membrane (90K, 96K, 101K, and 102K). These residues appear to identify a protein domain involved in the interaction of the 17-kDa protein with the other components of the photosystem. © 2005 American Chemical Society

Research and demonstration updates: ISU Rhodes Research Farm and PFI on-farm cooperator data

A recently completed study compared the economic return of hooped buildings versus conventional facilities. Factors considered included pig growth rate, feed efficiency, developing growth function, distrib-qtion of growth, production costs and returns, and rate of return on investment

Arctic system on trajectory to new state

The Arctic system is moving toward a new state that falls outside the envelope of glacial-interglacial fluctuations that prevailed during recent Earth history. This future Arctic is likely to have dramatically less permanent ice than exists at present. At the present rate of change, a summer ice-free Arctic Ocean within a century is a real possibility, a state not witnessed for at least a million years. The change appears to be driven largely by feedback-enhanced global climate warming, and there seem to be few, if any processes or feedbacks within the Arctic system that are capable of altering the trajectory toward this “super interglacial” state

Recycled water causes no salinity or toxicity issues in Napa vineyards

In response to Napa Sanitation District's interest in expanding its delivery of recycled water to vineyards for irrigation, we conducted a feasibility study to assess the suitability of the water for this use. We adopted two approaches: comparing the water quality characteristics of the recycled water with those of other local sources of irrigation water, and evaluating soil samples from a vineyard that was irrigated for 8 years with the recycled water. Results indicate that the quality of the recycled water is suitable for irrigation, and also that long-term accumulation of salts and toxic ions have not occurred in the vineyards studied and are unlikely to occur. Nutrients in the recycled water may be beneficial to vineyards, though the levels of nitrogen may need to be reduced by planting cover crops in some vineyards