Rice husk is the hard protective covering of grains of rice, its obtained during the processing of paddy rice into head rice in rice milling industries.

2.4.1   Nutrient Composition of Rice Husk
            In the milling of rice, it has three fractions which are the bran, the hull, and brown rice. Rice bran has the highest energy and protein content followed by the brown rice while the rice hull has the lowest (Juliano, 1999b). Rice brown is the edible fraction.      Abrasive milling to remove the pericarp, seed coat, testa, aleurone layer and embryo to yield milled rice results in loss of fat, protein, crude fibre and neutral detergent fibre, riboflavin, ash, thiamine, niacin and  alpha      tocopherol (Barber 2008)

2.4.2      Starch Content of Rice Husk
            Starch remains the major constituent of milled rice at about 90 percent of the dry matter – starch is a polymer of D- glucose linked
  α (1-4) and usually consists of a linear fraction, amylase and a branched fraction amylopectin. Branched points are α (1-6) linkages.
Through innovative techniques it has been shown that rice amylose has two to four chains with a number of average degrees of polymerization (DPN) of 900 to glucose unit and a β-amylolysis limit of 73 to 87 percent (Hizukuri et al., 2010). It is a mixture of branched and linear molecules with DPN of 1100 to 1700 and 700 to 900, respectively. The branched fraction constitutes 25 to 50 percent by number and 30 to 60 percent by weight of amylase. The iodine affinity of rice amylase is 20 to 21 percent by weight.
            Rice amylopectins have β-amylolysis limits of 56 to 59 percent chain length of 19 to 22 glucose units, DPN of 500 to 1500 glucose units and 220 to 700 chains per molecule (Hizukuri et al., 1989).
            The iodine affinity of rice amylopectin is 0.4 to 0.9 percent in low and intermediate amylase rice but 2 to 3 percent in high amylase rice. Iso amylase disbranched amylopectins showed longest chain fractions (DPN >100) (9 to14 percent) in high amylose sample with higher iodine affinity than in low and intermediate amylose samples (2 to 5 percent) and waxy amylopectin (0 percent) (Hizukuri et al., 1989).
Juliano (1999), showed that the maximum true amylose content is 20 percent and also the additional iodine binding is due to the long linear chains in amylopectin (Takeda et al., 1987).

2.4.3   Protein Content of Rice Husk
            Endosperm (milled rice) protein consists of several fractions comprising of 15 percent albumin and the rest are alkaline soluble (Juliano, 1985b). Using sequential protein extraction, the mean ratio for 33 samples was found to be 9 percent prolamin, 7 percent albumin + globulin and 84 percent glutelin (Huebner et al., 1990).
            Ogawa et al., (1987) estimated that endosperm storage proteins were composed of 60 to 65 percent Pβ-11proteins 20 to 25 percentPβ-1proteins and 10 to 15 percent albumin and globulin in the cytoplasm.
            Rice starch granule amylose binds up to 0.7 percent protein that is mainly the waxy gene protein or granule- bound starchy synthase with a molecular mass of about 60 kilo daltons (kd) (villereal  and juliano, 1989b)
            The essential amino acid content of rice glutelin and prolamin sub-unit’s showed lysine as limiting in these polypeptides except in prolamin sub-unit which has 5.5 percent lysine and is limiting in methionine plus cystein.
            Thus, glutelin has a better amino acid score than prolamin except for the 16-kd prolamin sub-units. The 10-kd prolamin sub-units have high percent cystein content.

2.4.4   Lipid Content
            Lipid content of rice is mainly found in the bran fraction about 20 percent on dry matter basis, specifically as lipid bodies or spherosome in aleurone layer of the bran. About 1.5 to 1.7 percent is present in milled rice mainly non-starch lipids extracted by ether chloroform methanol and cold water saturated butanol (Juliano and Goddard, 1986). The major fatty acids of this lipid are linoleic acid, oleic and palmitic acids (Hemayathy and Prabhaker, 1987). The essential fatty acids in rice oil are about 29 to 42 percent linoleic acid and 0.8 to 1.0 percent linolenic acid (Jaiswal, 1983).
            The content of essential fatty acid may be increased with temperature during grain development but at the expense of reduction in total oil content (Taira and Fujii, 1979).

2.5       Multipurpose Trees
            Conventional feed stuff like the concentrates are usually expensive and not readily available in areas where goats are kept makes it difficult for small – scale farmers to adopt the suggested practice (Shoo, 1986).  Some multipurpose trees like Gmelina arborea have been documented as good alternatives feed supplement to animals (Majgaonka et al., 1987). In general, it has been seen as a fast – growing hard wood for plantation forestry and has a dual purpose agro forestry role.
            Carew et al., (1980) reported that sheep and goats have been traditionally sustained more on browse than on grasses in the rain forest areas of southern Nigeria, where there are hardly any pasture lands comparable to those in savannah regions of Northern Nigeria.
            Mecha and Adegbola (1980) studied the chemical composition of many browse plant and grasses eaten by goats, in Southern Nigeria. They reported that browse tree leaves tend to have lower crude fibre content than grasses harvested at same time. On the average, the browse species had more crude protein content even in the rain season (July-August).
            Most multipurpose plant provides green leaves for longer periods of the year than grasses. Otsyina and McKell (1985) stated that wide spread traditional use of browse as an available source of quality feed during the dry season is vitally important to maintain seasonal and yearly stability in livestock production and body conditions.
 Seria et al., (1995) described the effect of supplements on sheep grazing a dry season upland pasture which was part of an agro forestry system involving Gmelina arborea.
            Gmelina arborea has a high digestibility (Lowry, 1995) but showed that most of the rumen fermentation occurred very rapidly in the first 24 hours. Gmelina arborea is grown at wide spacing in pasture, in the wet – dry tropics. There would be a substantial dry – season leaf fall with digestibility so high that it could be regarded as an energy supplement (Wilson, 1990). Gmelina arborea is not nitrogen fixing, and the canopy is moderately dense, more so in the wet tropics than in Townville and there is every possibility that its shading would promote shade tolerant grasses (Lowry, 1995),
            Studies have shown that partial replacement of energy and protein sources from conventional feeding materials by browse plant leaves neither affect productivity in terms of growth performance and cost reduction (Amata and Bratte, 2008, Amata et al., 2009) nor haematological and serological characteristics (Amata, 2010).
Table: 1 Proximate composition of three browse plant
Dacroydes edulis
Gmelina arborea
Terminalis captappo
Moisture content (%DM)
Ash content (%DM)
Ether extract(%DM)
Energy (kcal. kg)
Cruds protein (%DM
Crude fibre (%DM)
           Source: Amata and Lebari, 2011.
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