The Economic Benefit of Increased Yield and Digestibility in a Perennial C\u3csub\u3e4\u3c/sub\u3e Grass

Big bluestem (Andropogon gerardii Vitman) is a perennial C4 grass native to the North American tallgrass prairie (Weaver, 1954). It provides productive, high quality forage during late spring and summer in the Great Plains, USA (Mitchell et al., 1994). Increasing forage yield and digestibility can increase livestock performance and grassland profitability (Casler & Vogel, 1999). This study aimed to compare the economic value of 2 big bluestem strains developed by 3 generations of breeding for increased forage yield and digestibility with the base populations from which they were derived

Divergent Breeding for Tiller Digestibility Modified Leaf, Sheath, and Stem Composition of Switchgrass (\u3cem\u3ePanicum Virgatum\u3c/em\u3e L.)

Switchgrass (Panicum virgatum. L.) is a cross-pollinated, C4 species that is native to the prairies of temperate North America. Breeding to improve its forage quality has been conducted using post-heading, whole-tiller in vitro dry matter digestibility (IVDMD) as the selection criterion. One breeding cycle (C-1) for low IVDMD and three cycles for high IVDMD (C1, C2, C3) were completed in a switchgrass population adapted to the USA mid-latitudes. Sward trials demonstrated that whole plant IVDMD had been improved (Hopkins et al., 1993). The objective of this study was to determine the effect of breeding for tiller IVDMD on leaf, sheath, and stem digestibility and composition of plants of the derived populations

Development of small and medium enterprises through clusters and networking : a comparative study of India, Pakistan and Sri Lanka

Clusters have several advantages. These include a high degree of networking which stimulates productivity, ability to diversify and to acquire the capacity to new products when the demand for existing products falls. The policy makers are searching ways to create new clusters. With an even more globalized world and increased competition the appeal of clusters has become stronger and more urgent. Yet, the formation and the sustenance of the clusters has somehow remained a mystery. There has been a limited research carried out in this direction. No doubt it is a complex area and no figurative results can be highlighted to show as to how the development of industrial clusters has taken place. The authors go about seeking answers to these questions by examining the experience of some of the prominent and successful clusters, their formation and sustenance in the three countries. The study further investigates various initiatives, the role and the results thereof in development of clusters.peer-reviewe

Micromesh Fabric Pollination Bags for Switchgrass

Pollination bags for making controlled crosses between switchgrass (Panicum virgatum L.) plants were made from a polyester micromesh fabric with a mesh size of 41 μm, which is smaller than the mean reported 43 μm diameter of switchgrass pollen. When used in paired-plant crosses between switchgrass plants, the mean amount of seed produced per plant was about 1 g, or approximately 800 seeds, which was significantly greater than the 10 to 250 seeds produced previously in paired-plant crosses of switchgrass using paper pollination bags. The four- to tenfold increase in seed produced per cross enables the progeny of the crosses to be evaluated in larger numbers in genetic studies and in replicated space-transplanted or seeded sward evaluation trials. The micromesh pollination bags cost about $15 each because of fabric costs but could be reused for 10 or more pollination seasons at an annual cost per cross of about$1.50 or less

Empirical model for quasi direct current interruption with a convoluted arc

This contribution considers various aspects of a quasi direct current, convoluted arc produced by a magnetic field (B-field) connected in parallel with an RLC circuit that have not been considered in combination. These aspects are the arc current limitation due to the arc convolution, changes in arc resistance due to the B-field and material ablation, and the relative significance of the RLC circuit in producing an artificial current zero. As a result, it has been possible to produce an empirical equation for predicting the current interruption capability in terms of the B-field magnitude and RLC components

Differential Roles for Octanoylated and Decanoylated Ghrelins in Regulating Appetite and Metabolism

Since its identification in 1999, ghrelin has been identified in all vertebrate groups. The “active core” of ghrelin is highly conserved among vertebrates, suggesting its biological activity to be also conserved. In fish, both acylated forms of ghrelin have been identified; however, the ratio of the ghrelin-C8 to ghrelin-C10 is not as great as observed in mammals. In the tilapia (Oreochromis mossambicus), ghrelin-C10 is the major form of ghrelin. Since fish are known to inhabit every ecological niche on earth, studies on fish have provided valuable insight into vertebrate physiology in general; it is likely that understanding the role of both acylated forms of ghrelin, in more detail, in fish will result into novel insights in the biology of ghrelin within vertebrates. In this paper we discuss ghrelin's role in regulating appetite and metabolism in fish, in general, and provide evidence that the two tilapia ghrelins exhibit different biological roles

Modifying crops to increase cell wall digestibility

Improving digestibility of roughage cell walls will improve ruminant animal performance and reduce loss of nutrients to the environment. The main digestibility impediment for dicotyledonous plants is highly lignified secondary cell walls, notably in stem secondary xylem, which become almost non-digestible. Digestibility of grasses is slowed severely by lignification of most tissues, but these cell walls remain largely digestible. Cell wall lignification creates an access barrier to potentially digestible wall material by rumen bacteria if cells have not been physically ruptured. Traditional breeding has focused on increasing total dry matter digestibility rather than cell wall digestibility, which has resulted in minimal reductions in cell wall lignification. Brown midrib mutants in some annual grasses exhibit small reductions in lignin concentration and improved cell wall digestibility. Similarly, transgenic approaches down-regulating genes in monolignol synthesis have produced plants with reduced lignin content and improved cell wall digestibility. While major reductions in lignin concentration have been associated with poor plant fitness, smaller reductions in lignin provided measurable improvements in digestibility without significantly impacting agronomic fitness. Additional targets for genetic modification to enhance digestibility and improve roughages for use as biofuel feedstocks are discussed; including manipulating cell wall polysaccharide composition, novel lignin structures, reduced lignin/polysaccharide cross-linking, smaller lignin polymers, enhanced development of non-lignified tissues, and targeting specific cell types. Greater tissue specificity of transgene expression will be needed to maximize benefits while avoiding negative impacts on plant fitness.cauliflower mosiac virus (CaMV) 35S promote