Animal health problems caused by silicon and other mineral imbalances

Abstract

Plant growth depends upon C, H, 0, and at least 13 mineral elements. Six of these (N, K, Ca, Mg, P, and S) macro-elements normally occur in plants at concentrations greater than 1,000 mg kg-1 level. The remaining micro-elements (B, Cl, Cu, Fe, Mn, Mo, and Zn) normally occur in plants at concentrations less than 50 mg kg".

In Vitro Digestibility and Chemical Composition of Kikuyugrass as Influenced by Soil Silicon, Liming, and Genotype

“…The differences in common kikuyugrass Si between the Maile and Kohala soils were substantially smaller than the three-fold differences observed for these soils under field conditions (unpublished data from the study described by Mathews, Miyasaka, and Tritschler 1999). This observation agrees with the suggestions of Van Soest (1982) and Mayland and Shewmaker (2001) that removing the environmental effects different locations likely have on both passive (via the transpiration stream) and active Si uptake can reduce the magnitude of soil type effects on grass Si. Interestingly, common kikuyugrass IVDOM for the Kohala and Waialua soils was reduced at lower forage Si concentrations (17.9 to 18.9 g kg 21 ) than the 22 g kg 21 found to decrease Whittet digestibility at the same age of 2866 B. W. Mathews, J. R. Carpenter, and L. E. Sollenberger regrowth in the concurrent study discussed previously.…”

“…Soils at the higher-elevations sites studied in Hawaii are weathered Andisols (Acrudoxic Hydrudands) that are relatively low in soluble Si, whereas soils at the lower elevations are Inceptisols and Mollisols that have not been extensively leached of Si (Chadwick et al 2003). The mechanisms by which Si reduces forage organic-matter digestibility are not well understood but are thought to involve Si incorporation into (complexes) or onto (incrustation) the cell-wall structure and the suppression of digestive enzyme activity by soluble Si (Minson 1990;Van Soest 1982, 1994Mayland and Shewmaker 2001). It is also noteworthy that in some grass species Si may slightly enhance or have no effect on digestibility (Van Soest 1982, 1994.…”

“…Silicon has often been associated with reduced cellwall organic matter digestibility in grasses (Duble, Lancaster, and Holt 1971;Van Soest 1982, 1994Mayland and Shewmaker 2001). Soils at the higher-elevations sites studied in Hawaii are weathered Andisols (Acrudoxic Hydrudands) that are relatively low in soluble Si, whereas soils at the lower elevations are Inceptisols and Mollisols that have not been extensively leached of Si (Chadwick et al 2003).…”

Assessing the impact of supplements, food aversions, and silica on medusahead (Taeniatherum caput-medusae (L.) Nevski) use by sheep

“…Silica taken up by forage plants reduces microbial accessibility to cell walls (Smith and Nelson, 1975;Harbers et al, 1981), reducing apparent forage digestibility (Van Soest and Jones, 1968). It has been suggested that in vitro dry matter digestibility of forages decreases in 4 units for each unit of Si present in the forage (Mayland and Shewmaker, 2001). Collectively, the greater intake values of medusahead thatch (lower concentration of Si) -despite the low concentrations of CP and high concentrations of fiber in this stage -and positive effects of high-energy supplements on medusahead intake and preference suggest lambs were more constrained in their need for energy rather than protein while consuming the weed.…”

The Effect of Sward Management on the Mineral Content of Winter Grazed Herbage

“…Especially in low-input grazing systems, herbage is the major source of mineral nutrients for grazing ruminants (Phillips 2001), because an adequate supply of minerals by using concentrate diets is often difficult to ensure (Hartmans and Hemkes 1972, McDowell 1996, Underwood and Suttle 1999. Especially during winter grazing, diseases like grass tetany as a result of mineral imbalances or deficiencies in herbage mass are observed (Kemp and Ôt Hart 1957, Grunes et al 1970, Wallis deVries 1996, Mayland and Shewmaker 2001. Furthermore, especially F. arundinacea is described as a species with Ôhigh grass tetany potentialÕ because of its often comparatively low Mg concentrations (Wilkinson and Mays 1979, Sleper et al 1980, Crawford et al 1998.…”