swine. Resumen Tanto la creciente demanda de granos para la alimentación humana, como la reciente crisis generada por la producción de etanol a partir de maíz en el principal productor mundial del grano, están acorralando a los porcicultores en muchos países, incluido Colombia. Los altos precios del maíz obligan a los formuladores de alimento a buscar fuentes energéticas alternativas para alimentar los cerdos.


A pesar de que en Colombia se produce una gran variedad de cosechas durante todo el año, no hay muchas alternativas para reemplazar efectivamente al maíz. Las limitaciones presentadas por los potenciales ingredientes alternativos y sus derivados son, principalmente, sus altos contenidos de agua y/o fibra. Palabras clave: alimentos alternativos, alimento concentrado, cerdos, maíz, subproductos.


279 Agudelo JH. Alternative feedstuffs for swine Rev Colomb Cienc Pecu 2009; 22:278-286 Resumo A crescente demanda de grãos para a alimentação humana, bem como a recente crise gerada pela produção de etanol a partir do milho, estão encurralando suinocultores de muitos países, incluindo a Colômbia. Os altos preços do milho obrigam os fabricantes de alimentos a buscar fontes alternativas de energia para alimentar os suínos.


Apesar da Colombia produzir uma grande quantidade de colheitas durante todo o ano, não há muitas alternativas para substituir de forma efetiva o milho. As limitações apresentadas pelos potenciais ingredientes alternativos e seus derivados são, principalmente, seus altos teores de água e/ou fibra. Palavras chave: alimentos alternativos, alimentos balanceados, milho, subprodutos, suínos.


Introduction As human population grows, the demand for food continues to increase. This has been long known and is thus a somewhat predictable situation. So far, agriculture around the world has been able to cope with this demand by increasing productivity year after year.


Now, however, a new variable needs to be included in the supply and demand equation of grains: ethanol. Aside from the forever-increasing demand of grains for food, such as corn, this new demand for ethanol is strongly affecting the grain markets. Nowadays grain prices, including corn, have skyrocketed in the midst of an unprecedented bio-fuel fever.


In this scenario, swine nutritionists in many countries nd themselves desperately looking for corn alternatives to feed pigs. In a tropical country such as Colombia, which has the capability of growing a variety of crops year-round at different elevations, one would think there are plenty alternative feedstuffs to fully or partially replace an energy ingredient such as corn. Nevertheless, in the form they are generated by the industry, those crops and their derived materials or by-products present practical limitations, including high water and/or high ber contents.


Defining Alternative feedstuffs Alternative feedstuffs are the crop residues or food industry byproducts not consumed by humans but are suitable for feeding pigs, transforming pigs into pork - a human-edible product. Such alternative feedstuffs are edible waste products or co-products from agriculture or the food processing, food preparation or food service industries. Examples of such industries include grain milling, brewing and distillation; baking; fruit and vegetable processing; meat, milk and egg processing; seafood processing; prepared food manufacturing; and retail food outlets.


Alternative feedstuffs also include feeds not regularly fed to pigs, especially during times of low prices and/or surpluses, or during shortages of traditional feedstuffs. Alternative feedstuffs may include materials available locally that can be economical substitutes for expensive or not readily available traditional feedstuffs (Myer and Hall, 2004). Miller et al (1994) have proposed groupings of some potential byproducts for swine according to their primary product origin: animal (milk, meat and egg byproducts), grain (milling, baking, brewing, and distilling byproducts), sugar and starch production (cane, beet and corn molasses, and salvage candy), and vegetable materials (cull beans, roots and potato byproducts).


The suitability of an alternative feedstuff for a particular age or physiological stage of the pig depends, among many factors, on its legality of use, availability in the local market, cost (including transportation, storage, processing and labor), palatability, consistency, nutrient composition and availability, presence of potential health hazards (toxic or disease factors) or anti-nutritional factors, and potential effects on pork quality and perishability 3 including spoilage and rancidity (Miller et al. , 1994; Myer and Brendemuhl, 2001; Myer and Hall, 2004). Searching for Alternatives to Corn: a Crucial Task According to FAO (2004), global cereal production has been stagnating since 1996.


Global cereal utilization, on the other hand, has been continuing on an upward trend and has been Agudelo JH. Alternative feedstuffs for swine 280 Rev Colomb Cienc Pecu 2009; 22:278-286 exceeding production by signi cant amounts continuously since 2000. Several reports af rm that in the future swine production will compete directly with humans for cereal grains and high quality protein supplements (Close, 1993; Dierick et al, 1989; Pond, 1987).


This prediction is already a reality in most countries of the developing world (Oke, 1990), where human population obtains 58% of their total caloric intake from cereal grains as compared to 28% for the developed world (Ensminger et al, 1990). Among cereals, corn is an important food for the fast-growing human population. Currently in the western hemisphere, only four countries (U.S., Argentina, Paraguay and Bolivia) produce enough corn to ful ll their needs and export the excess, while nineteen other American countries show a permanent de cit in corn production (Ministerio de Agricultura y Desarrollo Rural de Colombia, 2005).


Colombia (a tropical country located in northern South America) is one of those countries where the demand for corn for both human and swine populations during the last decade chronically exceeded local production of this cereal. Colombian imports of corn started to climb in 1993 when the country opened its markets to free global trade. Since that year, the country has been steadily increasing its imports of yellow corn (Figure 1), which is used for animal production, particularly to feed poultry and swine.


0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 19911992199319941995199619971998199920002001200220032004200520062007 Year Colombian imports of yellow corn (thousand metric tons) Figure 1. Colombian imports of yellow corn (adapted from Martinez and Acevedo, 2004 and from Ministerio de Agricultura y Desarrollo Rural de Colombia, 2009). Corn imports by Colombia now account for 50.1% of the total corn consumed in the country .


Since 1996, and among all the commodities imported by this country, corn ranks rst in terms of total cost and volume. During 2004, Colombia imported 1,909,354 metric tons of corn (yellow and white) for a total cost of 332,085,000 USD, turning the country from a non- net importer twelve years before, into the 10 th largest world importer of this cereal (FAO, 2009). These ndings are interesting, taking into account that the country ranks 28 th in terms of human population (42 million), has a low consumption of animal protein, and is not a meat or egg exporter.


For Colombia, which is not particularly strong in animal production, the gure re ects a total dependency on foreign corn prices. The reason for the decline in local production and subsequent dependency on foreign corn is that local production is not competitive under the new global trade scheme. The magnitude of the corn de cit is similar for most Andean countries.


In most Central American countries this de cit is even greater, often exceeding 90% (FAO, 2004; Ministerio de Agricultura y Desarrollo Rural de Colombia, 2005). This situation forces swine nutritionists to consider partial replacement of corn with alternatives such as grain derivatives and other materials that are in low demand as direct food sources for the human population. Another reason for using locally-available alternative feedstuffs is the need for proper disposal of these materials.


In many countries alternative feedstuffs for pigs represent not only an economic 281 Agudelo JH. Alternative feedstuffs for swine Rev Colomb Cienc Pecu 2009; 22:278-286 option to lower production costs, but also an environmentally-friendly approach to the disposal of the enormous amounts of organic materials in times of increasing by-product generation and land ll shortages. According to Fadel (1999), the calculated total world dry matter tonnage for about twenty types of by-product feedstuffs was almost 1 billion metric tons in 1993, and about 65% of these feedstuffs were crop residues.


Over the next 20 years, this per capita tonnage will likely increase in developed countries and remain the same or slightly increase in developing countries, suggesting that byproducts will become an increasing waste problem. Thus, the role of pigs in recycling and cadding value d to many of these byproducts and wastes is becoming increasingly important as a viable waste management option. Alternative Energy-Feedstuffs In most swine diet formulations, ingredients that provide most of the energy (i.e., corn) usually represent the highest cost among all the dietary ingredients.


This is due to the high proportion of the diet that is accounted for the energy ingredients. In a typical corn-soybean meal (corn-SBM) diet provided to growing- nishing pigs, the total cost of corn is about 50% higher than the total cost of the soybean meal used. To illustrate this, a typical corn-SBM diet for growing- nishing pigs contains between 70 to 85% corn (avg.


77.5%) and 14 to 25% soybean meal (avg. 19.5%). Using the U.S.


prices reported on July 22, 2004 for both feedstuffs (Feedstuffs, 2004), i.e., $2.24/bushel of corn (1 bushel: 54 lb for U.S. No.2 grade corn, equivalent to $0.042/lb), and $239/ton of soybean meal ($0.12/lb), the corn component cost is 3.3 cents/lb of the corn-SBM mix, while the cost of SBM is 2.3 cents/lb of the total feed mix. Thus, for reasons of total cost, alternative energy feedstuffs should be considered rst when thinking about partially replacing swine diets.


Nevertheless, most of the potential alternative feedstuffs available also have their own inconveniences. Table 1 presents the nutrient composition of corn, compared to several alternative feedstuffs commonly available in tropical countries. According to Myer and Brendemuhl (2001), the main disadvantages of the byproducts listed in Table 1 are: Table 1 .


Nutrient composition of corn and some alternative feedstuffs (adapted from Myer and Brendemuhl, 2001). FeedstuffDescription Nutritional value for pigs (as fed basis) RFV 1 vs. DMME 2 ProteinLysineFatFiberCaP Corn (%)(kcal/kg)(%)(%)(%)(%)(%)(%) (%) Corn Grain8934008.30.263.92.20.030.25100 Rice Bran, full fat90300012.50.6012.0110.051.7070-100 Bran, fat ex- tracted 91260014.00.651.5130.101.4060-80 Polishings90330013.00.5013.020.101.2095-100 Broken8933008.00.300.60.60.040.1895-100 Paddy8928009.00.302.0100.050.2570-80 Bananas Ripe, whole257501.0<0.100.10.50.010.0320-25 Green, whole267001.0<0.100.10.50.010.0315-20 Cassava Meal8933003.00.100.550.120.1595-100 Fresh3512001.0<0.100.21.50.040.0530-40 Sugar cane Molasses8022003.0<0.100.100.700.0860-70 Juice18700<1.0<0.10<0.120.200.0515-25 Stalks255001.0<0.100.580.100.0510-20 Potatoes Chips or fries9044006.00.2030.010.100.20120-150 Cooked flakes9235008.00.400.520.100.20100 Pulp, dried8822006.00.200.390.100.2060-70 Boiled227002.40.100.10.50.020.0515-25 Raw205002.00.100.10.50.020.0510-15 Resturant food waste Non-dried208005.00.205.010.100.1015-25 1 RFV (relative feed value): nutritional value relative to corn.


2 Metabolizable energy. Agudelo JH. Alternative feedstuffs for swine 282 Rev Colomb Cienc Pecu 2009; 22:278-286 1.


Rice ( Oryza sativa ) byproducts: rice bran is a bulky, brous material with high potential for rancidity depending on the fat level. Rice polishings are not as bulky and brous as rice bran, but they also have the problem of potential rancidity. Broken rice has a high energy content, but is low in lysine.


Paddy rice is highly brous and has a higher risk of a atoxin contamination. 2. Bananas have a high moisture content.


Whole, green bananas have a large concentration of tannins, which lowers its palatability for pigs. 3. Fresh cassava also has a high moisture content, while some varieties of the root may contain large residual concentrations of toxic cyanhydric acid in the meal.


4. Sugar cane juice has high moisture content. The stalks have the same problem and are also a bulky material.


5. Raw potatoes are high in moisture. In general, cooking improves byproduct utilization of potatoes.


6. Food waste from restaurants is not only high in moisture, but also highly variable in nutritional value; besides, using food waste to feed swine has been banned in Colombia since 2007. As shown in Table 1, the main limitations presented by these materials in the forms they are generated by the industry- are their high water content, high ber content, or both.


In general, most of the common energy-feedstuffs available in tropical countries make no signi cant protein contribution to the diet. Those feedstuffs require further processing to increase their dry matter content, thus increasing, in turn, their cost. Many non-processed feedstuffs are inexpensive because they are basically waste byproducts.


It is usually the cost of transport and drying which limits their potential as economical alternatives. Drying is sometimes recommended to facilitate handling and incorporation into dry diets. Drying also concentrates the nutrients, which is necessary when feeding animals that combine a limited gastrointestinal capacity with a high growth potential.


As mentioned, digestibility of the dietary nutrients present in feedstuffs varies according to different factors, including the amount and type of ber present in the diet (Noblet and Le-Goff, 2001; Wisemann and Cole, 1985). Crude ber is comprised of three major fractions: cellulose, hemicellulose and lignin. These components are measured by detergent ber analysis, which determines neutral detergent ber (NDF) and acid detergent ber (ADF).


The NDF is the insoluble residue in a neutral detergent solution after eliminating the plant cell contents. It represents the cell wall constituents or cellulose, hemicellulose and lignin. The ADF is the residue comprised of cellulose and lignin.


The difference obtained when subtracting NDF and ADF is the hemicellulose fraction of ber. The NDF is partially fermented in the large intestine into volatile fatty acids (VFA) such as acetic, propionic and butyric acids, also producing CO 2 , H 2 , CH 4 , urea and heat. It is known that regardless of its source, an increase in NDF decreases energy availability and may increase fecal loss of nitrogen (Sauber and Owens, 2001).


Both the old crude ber analysis, as well as the newer detergent methods of analysis, underestimate the amount of total ber due to their inability to recover soluble ber components such as pectin, mucilage, gums and B-glucans (Grieshop et al , 2001). In growing pigs, digestibility coef cients for dietary ber are lower than coef cients for other nutrients. According to Noblet and Le Goff (2001), average ber digestibility is 40 to 50%, ranging from around zero in high lignin sources (e.g., wheat straw) to between 80 and 90% in high pectin sources (e.g., sugar beet pulp and soybean hulls).


Thus, the ber digestibility depends on the ratios of lignin to pectin in feedstuffs, with lignin being indigestible, while pectin is almost completely digestible. In addition, hemicellulose is more digestible than cellulose, but both are just partially digested. It is also known that digestibility increases with body weight, so adult sows can utilize ber better, but this utilization of ber also depends on the botanical origin of the ber (Noblet and Le Goff, 2001).


Thus, for a better understanding of the nutritional value of feedstuffs, the information 283 Agudelo JH. Alternative feedstuffs for swine Rev Colomb Cienc Pecu 2009; 22:278-286 obtained by the proximate analysis should be complemented with digestion and balance trials to assess how well those nutrients are utilized by the pig. In Table 2, digestible and metabolizable energy, as well as digestible protein results, are shown for several of the feedstuffs in Table 1.


Table 2. Digestible energy and protein for pigs in selected feedstuffs (as fed basis) (adapted from Ensminger et al., 1990). Feedstuff Description DigestibleMetabolizableCrudeDigestible energyenergyproteinprotein (kcal/kg)(kcal/kg)(%)(%) CornGrain, yellow333832469.97.3 Rice Bran, with germs32502971139.5 Polishings371334281210.1 Paddy, ground329031077.55.1 BananasFruit, dehydrated353533553.51.6 Peelings, dehydrated342532408.66 CassavaMeal, dehydrated292327482.21.6 Fresh112710631.20.5 SugarcaneMolasses, dehydrated266324859.77 Potatoes Tubers, fresh8788302.20.7 Tubers, boiled9188692.21.5 Tubers, dehydrated345032618.15.6 Peelings, fresh8828352.11.5 RestaurantBoiled, wet110510533.62.8 food waste 1 Boiled, dehydrated, ground4293409016.112.8 1 The use of food waste to feed pigs has been declared illegal in Colombia since 2007.


Availability of alternative feedstuffs Despite the overall shortage in corn, it is interesting to note that Colombia is an important producer and net exporter of several potential alternative feedstuffs or derivatives. In 2003, Colombia was ranked 1 st worldwide as an exporter of plantains and sugar cane, and 4 th as an exporter of bananas. It was also among the top 10 exporters of fresh fruits, roots and tubers and among the top 20 exporters of paddy rice (FAO, 2004).


These gures mean not only that the country produces more of these staples than are required to ful ll its internal demand, but also that there is a competitive production infrastructure that is generating important amounts of materials that are potentially interesting for feeding swine. Table 3 illustrates Colombian production and world rankings among the top 20 producers of several feedstuffs. Table 3.


Colombian production of several potential alternative feedstuffs during 2005 (adapted from FAO, 2009). Product Colombian production (metric ton/year) World rank Coffee, green682.580 4 Plantains3.400.000 2 Avocados185.811 4 Tropical fruits1.150.000 5 Sugar cane39.849.240 7 Bananas1.600.00010 Pineapples419.64712 Cassava2.125.16318 Potatoes2.623.19421 Cow milk, whole, fresh 6.770.00021 Rice paddy2.602.30021 From the feedstuffs listed in Table 3, all but coffee are generally considered energy sources. Agudelo JH.


Alternative feedstuffs for swine 284 Rev Colomb Cienc Pecu 2009; 22:278-286 Nutritional information is available for most of the feedstuffs listed. 8Coffee grounds 9 is a material for which limited information is available. According to Ensminger et al (1990), and on ´as-fed´ basis, ´coffee grounds´ has 10.2% CP, equivalent to 6.1% digestible protein for pigs.


It also has 74% DM, 9.3% EE, 1.2% ash, 0.09% Ca, 0.06% P, and 21.5% CF. Rice bran: an interesting partial substitute Rice bran is an alternative feedstuff that could be used to partially substitute for corn in temperate as well as tropical zones. It is abundant and inexpensive in many countries.


According to the NRC (1998), rice bran contains 13.0% EE, 13.3% CP, 1.61% total P, and 2,040 kcal/kg of net energy, which is not too different from corn (2.395 kcal/kg). Although richer in fat (13%) in comparison to corn (3.9%), rice bran is also richer in ber (23.7% NDF and 13.9% ADF for rice bran versus 9.6% NDF and 2.8% ADF for corn), which makes it poorly digestible by the young pig. Because of the high fat content, it often turns rancid during storage.


According to Cunha (1977), it has about 90 to 95% the feeding value of corn if used at a level not more than 20 to 30% of the diet. When used at higher levels, its relative feeding value decreases and it tends to produce 8soft pork 9 (soft carcass fat due to high concentrations of unsaturated fats), which can negatively affect the market value of pigs. Cunha (1977) also indicates that the material should be used fresh in order to prevent rancidity because this rancidity decreases palatability.


As a substitute, he proposes the use of de-fatted or solvent 3extracted rice bran, which has about the same feeding value as corn when fed at levels no higher than 30% of the diet, and does not produce soft pork. Besides of its low cost, rice bran is also interesting because of its high concentration of total P. Total P in rice bran is about ve times higher than in corn, and three times higher than in soybean meal, but most of it is present in the form of phytic P.


About 75% of the P in rice bran is bound as phytic acid (Cromwell and Coffey, 1991). That form of P is not available and is almost completely excreted by the pig, creating an environmental concern. The low availability of P in rice bran is due to its low digestibility.


In a series of trials, Jongbloed et al (1999) reported 14% of P digestibility for rice bran (range: 9 to 20%), 19% for corn (range: 12 to 26%), and 39% for soybean meal (range: 33 to 46%). Table 4 shows rice bran and several traditional energy feedstuffs and byproducts ranked by phytate P concentration. Among these feedstuffs, rice bran has the highest content of unavailable P, and thus it has the greatest pollution potential unless exogenous phytase is added to the diet.


Table 4. Energy feed sources and their unavailable phosphorus contents (Adapted from NRC, 1998). Feedstuff Phosphorus, % TotalBioavailableNon availableTotal unavailable Rice bran1.6125751.21 Wheat bran1.2029710.85 Wheat middlings, < 9.5%fiber0.9341590.55 Corn grits (hominy Feed)0.4314860.37 Oat groats0.4113870.36 Barley, six row0.3630700.25 Oats 0.3122780.24 Corn 0.2814860.24 Sorghum0.2920800.23 Wheat, soft red winter0.3950500.20 Wheat, hard red winter0.3750500.19 Whey, dried0.7297 300.02 285 Agudelo JH.


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Accessed: Feb. 10, 2009. Conclusion There is not ca magic bullet d to replace corn in terms of a single alternative energy-feedstuff that ful lls all of the nutritional advantages of corn at a proper price.


If we consider only the feed value (e.g. nutrient composition), there are few potential feeds and byproducts, locally produced, that could be included in swine diets. When reviewing the current literature, it is apparent that a 100% corn- based feed is ideal for optimal swine production.


However, supplementing a high corn-based feed with alternative byproducts might be a solution to still achieve acceptable results. Examples include the supplementation of a corn-based diet with de- fatted or solvent-extracted rice bran, in combination with lysine-rich byproducts derived from industrial preparations of foods, or with byproducts derived from industrial ethanol production. However, more research is needed to explore alternatives to 100% corn-based animal feed, and especially combinations of corn products and nutrient dense industrial byproducts.


Furthermore, when designing alternative feedstuffs for swine in Colombia, other important considerations, such as cost of dehydrating, transport, and practicability of mixing in a commercial feed at the industrial level should be taken into account. Nevertheless, if cost and market values permit it, optimal dietary compositions of feed for maximal swine production should always include the highest percentage of corn possible. Feedstuffs.


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