Agnote 273 No. J22 April 1998 Agdex No: 121/10 ISSN No: 0157-8243 Rice as a Livestock Feed D. Ffoulkes, Animal Production Officer, Darwin HISTORICAL In Asia rice has been cultivated for many centuries as the staple feed for human consumption and farmers value the by products of the rice mill as livestock feed. Furthermore, they often keep a proportion of the grain harvest to supplement their buffaloes and cattle during pregnancy and lactation or prior to the ploughing season. Rice straw is also fed as a basal diet to these animals. It is only relatively recently in Australia that rice millings have been incorporated into commercial stockfeeds, particularly for horses. In the NT there is interest in retaining part of the crop as supplementary feed for livestock on the farm as well as grazing the stubble during the dry season. COMPOSITION The proportions of byproducts arising from processing the grain for human consumption are shown below. As there are no commercial processing plants in the NT we will only deal with the nutritive value of rough rice and brown rice for livestock. The chemical composition of rice grain (with and without the husk) and rice straw are presented as approximate values in Table 1. The crude protein levels are not high but the quality of the protein components is good. On removal of the husk the fibre content of the grain is reduced. A large proportion of the carbohydrate is in the form of starch and there are significant amounts of fat (present as oil) in the grain. Rice straw retains reasonable levels of protein and digestible dry matter should reach 40-50% for cattle. There may however be high oxalate levels in the straw 2 which binds calcium making it unavailable to the ruminant animal. Sulphur is also a critical nutrient for cattle and the levels in straw will depend on soil characteristics and fertiliser application. The comparison in Table 2 of rice with other cereal grains grown in the NT shows there is little difference between chemical composition except for higher levels of the protein components (amino acids). RICE FOR PIGS AND POULTRY Rice is high in energy and rich in vitamin B complex especially niacin (required for cell metabolism) and vitamin E (antioxidant). It is also a good source of linoleic acid which is an essential fatty acid required to maximise egg production. The oils in rice are unsaturated (ie. have a lower melting point) and tend to form a softer fat tissue in animals if large amounts of grain are fed. This may be overcome by reducing the level in the diet during the final weeks of fattening. Rice hulls are of little nutritive value to livestock but are sometimes used to dilute high energy diets. Rations for growing and fattening pigs contain 50-70% grain as maize or sorghum or a mixture of both, and any proportion of these cereals may be replaced by rice. However if more than 50% of these cereals in pig and poultry rations is replaced by rough rice then feed efficiency is likely to fall although growth rates may not be affected. In preparing rations, uncracked grains may be fed to chickens but both the rough and dehusked grains should be finely ground for pigs. RICE FOR HORSES The energy fraction of rice is easily digested by horses and can be fed according to the animal’s exercise load. Animals which tend to exhibit a hot temperament on high energy rations appear to be more manageable when fed rice. The high quality of the rice proteins means that they are used efficiently for muscle growth, and the vitamins and oils give animals a characteristic lustre and bloom that is associated with rice feeding. Although rough rice is similar in energy content to oats, it is less palatable due to the presence of the husk and should not be fed at more than 20% of the ration. Brown rice however can be used to replace the traditional cereals in rations for feeding pregnant and lactating mares and as a supplement for working horses. Both rough and brown rice should be cracked before feeding. RICE FOR RUMINANT ANIMALS (CATTLE, BUFFALO, SHEEP AND GOATS) Farmers in Asia and Latin America traditional feed 1-2 kg per day of rice to their pregnant or lactating cattle, and in India it is used as a grain source in home- made molasses lick blocks for dairy buffaloes. In the NT it is envisaged that a major use of cereals as a livestock feed in the future will be for finishing cattle or buffalo under semi- confined or feedlot conditions. The results of a feeding experiment done at Berrimah 3 Research Farm showed no differences in performance of animals fed 84% of the fattening ration as either crushed sorghum, crushed rough rice or unprocessed brown rice whereas growth rates and feed efficiency were distinctly poorer with uncrushed rough rice presumably due to the indigestibility of the husk. Feeding strategies based on the forage of the rice crop appear to be promising for finishing cattle during the dry season. Table 1. Approximate chemical composition (% as fed) of rice straw, rough rice grain and dehusked grain Straw Grain Rough Grain Brown Husk Protein 5 7 8 3 Fibre 33 10 1 40 Carbohydrate 48 78 82 Low Fat 1 2 1 0.4 Ca 0.4 0.06 0.04 0.04 P 0.15 0.28 0.38 0.06 Na 0.14 0.05 0 - S 0.04 0.04 0.13 - Table 2. Comparison of Chemical composition (% as fed) of rice grain with sorghum and maize Rice Rough Rice Brown Sorghum Maize Protein 7-9 8-9 9-11 9-11 Methionine * 0.12 0.21 0.13 0.18 Lysine * 0.25 0.31 0.21 0.25 Fibre 8-11 1-4 1-3 3-4 Carbohydrate 78 82 68-74 80 Fat 2 1 3 3-4 Ca 0.06 0.04 0.04 0.02 P 0.28 0.38 0.30 0.20 Na 0.05 - 0.04 0.03 S 0.04 - - 0.10 * Amino acids of high nutritive value Please visit us on our website at www.primaryindustry.nt.gov.au While all care has been taken to ensure that information contained in this Agnote is true and correct at the time of publication, the Northern Territory of Australia gives no warranty or assurance, and makes no representation as to the accuracy of any information or advice contained in this publication, or that it is suitable for your intended use. No serious, business or investment decisions should be made in reliance on this information without obtaining independent/or professional advice in relation to your particular situation.