The economic benefits of forage improvement in the United States

The United States is a large country with a diversity of forage ecosystems and forage species to fill the varied management options within each ecosystem. For example, the American Seed Trade estimates seed of 5,500 varieties representing 1,500 grass and 4,000 legume species are produced annually. The economic benefits of forage improvement are both direct (seed and hay sales) and indirect (saleable animal products, nitrogen fixation and conservation uses). The benefits of improving forages through breeding are likewise important due to the current use of improved varieties to underpin these systems and their direct and indirect products. Because of the diversity of species and management systems, only a few case studies were examined in this paper to estimate these benefits. These were the alfalfa (Medicago sativa L.) industry (economic value of US$8.1 billion per year), the forage and livestock systems of the southeastern USA (economic value estimated overall at US$11.4 billion per year), and switchgrass (Panicum virgatum L.) and its potential use as bio-energy feedstock (economic value of needing an additional 28 million acres of production to supply the estimated future feedstock needs). The overall conclusion is that the economic benefits from forage improvement in the USA have been, and continue to be, immense. However, future resources are going to fewer crops, and these crops are the ones that have greater economic value and where biotechnology can be applied. This will favor alfalfa and penalize forage grasses. Even for crops with an identifiable path to market, this concentration of resources in fewer hands requires development of consortia where organizations can leverage their resources with others who possess complementary resources. The Consortium for Alfalfa Improvement is a good example of how this could work.     

ATP-driven exchange of histone H2AZ variant catalyzed by SWR1 chromatin remodeling complex

The conserved histone variant H2AZ has an important role in the regulation of gene expression and the establishment of a buffer to the spread of silent heterochromatin. How histone variants such as H2AZ are incorporated into nucleosomes has been obscure. We have found that Swr1, a Swi2/Snf2-related adenosine triphosphatase, is the catalytic core of a multisubunit, histone-variant exchanger that efficiently replaces conventional histone H2A with histone H2AZ in nucleosome arrays. Swr1 is required for the deposition of histone H2AZ at specific chromosome locations in vivo, and Swr1 and H2AZ commonly regulate a subset of yeast genes. These findings define a previously unknown role for the adenosine triphosphate-dependent chromatin remodeling machinery.     

Whales before whaling in the North Atlantic

It is well known that hunting dramatically reduced all baleen whale populations, yet reliable estimates of former whale abundances are elusive. Based on coalescent models for mitochondrial DNA sequence variation, the genetic diversity of North Atlantic whales suggests population sizes of approximately 240,000 humpback, 360,000 fin, and 265,000 minke whales. Estimates for fin and humpback whales are far greater than those previously calculated for prewhaling populations and 6 to 20 times higher than present-day population estimates. Such discrepancies suggest the need for a quantitative reevaluation of historical whale populations and a fundamental revision in our conception of the natural state of the oceans.     

Feeding cotton products to cattle.

Despite the potential for gossypol toxicosis (particularly in pre-ruminants) and risk factors associated with impaired fertility in bulls, cottonseed products offer a safe alternative feed for cattle producers when fed at recommended levels. Beef producers seeking to lower production costs should consider using cotton byproducts in their feeding programs. If carefully incorporated, cotton byproduct feeds can reduce feed costs while maintaining or increasing the level of cattle performance. Cottonseed meal will remain a standard protein supplement for beef cattle throughout the country. Whole cottonseed has much potential for Southern producers near cotton gins if it is purchased in a timely fashion and fed according to recommendations. Cotton gin trash, cottonseed hulls, and cotton textile mill waste also have potential economic benefits, especially to producers located near cotton and cottonseed processing facilities.