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Extension > Food > Small Farms > Alternative and small-scale livestock systems > Swine > Designing feeding programs for natural and organic pork production > Challenges in feeding organically raised pigs

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Designing feeding programs for natural and organic pork production

Challenges in feeding organically raised pigs

Jerry Shurson, Mark Whitney, Lee Johnston, Bob Koehler, Robert Hadad, Dean Koehler, Wayne Martin, Sarah Schieck

Managing pig health without antibiotics and animal-derived ingredients

Increase weaning age

Pigs in an organic system are often weaned no earlier than 28 days of age. After 28 days, the young pig's digestive system is mature enough to effectively digest cereal grain-based diets without adverse effects on health and performance. Some advisors recommend weaning at 35 days of age or more.

Implement high biosecurity procedures

Strict biosecurity is important for all swine operations. There are numerous publications describing effective biosecurity measures producers should implement on their farms to safeguard the health of their pigs. A brief summary of some important considerations in a biosecurity program are listed below. A more comprehensive description of biosecurity practices.

Closed herds

To minimize the risk of disease transmission, maintain closed herds (with limited or no addition of animals from other farms). If replacement animals are obtained from outside sources, they should be isolated and kept in separate facilities (preferably off-farm) for 60 days and blood tested for undesirable pathogens. In closed herds, the use of artificial insemination eliminates the need for the introduction of new boars to the breeding herd. If establishing a new herd for organic production, breeding stock with high health status will prevent the depressed pig performance typically caused by diseases and parasites.

Traffic control

Visitor access to animal facilities should be restricted. Post signs telling visitors where to report. Delivery trucks, particularly those that visit other farms or slaughter facilities, should be thoroughly cleaned before entering animal areas. Producers need to implement procedures that prevent rendering trucks from entering areas around pig facilities. On-farm methods for disposal of swine mortalities eliminate the risks associated with rendering trucks entering the farm. On-farm methods include composting, burial, and incineration. Limiting the contact of dogs, cats, birds, and wild animals with pigs will help eliminate the transfer of swine diseases.

Excellent sanitation

Keep facilities as clean as possible to minimize the concentration of pathogens in animal living areas. Dead animals should be disposed of using only approved disposal methods.

Provide the proper environment

Temperature, space, nutrition, and ventilation requirements of pigs must be met to minimize stress and the risk of disease.

Some practices to consider where appropriate and permitted are:

Use organically approved substances that may enhance health and performance such as diet acidifiers, oligosaccharides, enzymes, herbs, probiotics, and others approved by the certifying agency, guaranteeing no use of grain from genetically modified organisms (GMO) in swine diets.

Diet formulation is more difficult without the use of animal or grain by-products

Several feed ingredients can be grown organically and used in swine diets. The following is a summary of possible alternatives and a brief description of their contributions and limitations in swine diets. Approximate nutrient composition of these feed ingredients is provided in table 1. Nutrient composition will vary depending on area grown, processing technique utilized, year-to-year variation, maturity of the plant, and many other variables. The best method to determine nutrient composition is to obtain representative samples of each feed ingredient and send them to a commercial laboratory for nutrient analysis.

Table 1.
Nutritional comparison of potential ingredients to be used in an organic swine feeding system1, 2
Ingredient DE (kcal/kg) ME (kcal/kg) CP (%) Lys (%) Ca (%) P
Fat (%) Anti-nutritional factors3
Energy sources
Barley 3150 3073 11.3 0.4 0.06 0.35 2.11  
Barley, hulless 3266 3179 12.7 0.51 0.06 0.36 3.2  
Buckwheat4 2999 NA5 12.0 0.77 0.10 0.35 2.1 Fagopyrin, trypsin inhibitor, tannins
Corn 3451 3395 8.2 0.25 0.02 0.26 3.5  
Corn and cob meal6 3109 2779 7.8 0.17 0.06 0.24 3.2  
Oats 2627 2551 11.2 0.49 0.03 0.35 5.4  
Oats, naked 4126 4026 14.7 0.56 0.08 0.38 10.6  
Rye 3270 3191 11.7 0.43 0.08 0.30 2.0 Trypsin inhibitors, ergot, soluble pentosans
Sorghum, grain 3596 3532 9.4 0.22 0.02 0.27 3.4 Tannins
Triticale 3320 3228 13.6 0.46 0.04 0.33 1.8 Trypsin inhibitors, ergot, soluble pentosans
Wheat, hard red spring 3313 3215 14.5 0.39 0.06 0.39 1.8  
Protein sources
Alfalfa meal 1830 1720 16.2 0.74 1.14 0.30 1.7 Saponins, tannins
Canola, full fat 5234 5084 22.1 1.01 0.36 0.70 43.6 Glucosinolates, tannins, myrosinase
Fababeans4 3263 NA5 26.0 1.68 0.10 0.50 1.0 Trypsin inhibitor, hemagglutinin, tannins
Lentil, seeds 3540 3363 26.0 1.71 0.10 0.38 1.3 Trypsin and chymotrypsin inhibitor, tannins
Peas, field 3504 3353 22.2 1.63 0.09 0.42 1.2  
Soybeans, full-fat 4193 3938 37.6 2.23 0.31 0.53 20.2 Trypsin inhibitor, urease, hemagglutinin, lectins
Soybean meal, expelled 3876 3573 44.6 2.85 0.28 0.66 5.7  
Sunflower seeds, full fat 4517 4404 16.6 0.54 0.30 0.20 42.7  

1Nutrient values presented on an as-fed basis derived from NRC (2012). DE = Digestible energy, ME = Metabolizable energy, CP = Crude protein, Lys = Total lysine, Ca = Total calcium, P = Total phosphorus.
2For limits on dietary concentration of individual ingredients see discussions of individual grains on pages 11-14.
3All cereal grains contain varying levels of phytate and may contain mycotoxins.
4Values obtained from Nontraditional Feed Sources for Use in Swine Production, P.A. Thacker and R.N. Kirkwood (eds.), 1990, Butterworth Publishers, Stoneham, MA.
5NA = Not available.
6Values obtained from NRC (1982) U.S. – Canadian Tables of Feed Composition, 3rd Ed.

Energy sources

Cereal grains serve as the major energy source in swine diets. They are high in carbohydrates (starch), palatable, and highly digestible. However, they are low in lysine (and other amino acids), vitamins, and minerals compared to the pig's requirement. Therefore, cereal grain-based diets must be supplemented with other ingredients to meet amino acid, vitamin, and mineral requirements for optimal health and performance.

Corn has the highest energy value of all cereal grains and is generally the most economical grain source in swine diets in Minnesota. Because genetically modified corn varieties are now grown widely under commercial conditions, unintended cross-pollination could occur with corn produced in compliance with organic standards. This cross pollinated corn is currently considered as organic since it was produced in a certified organic production system.

Corn and cob meal is a feedstuff that can be produced on the farm and incorporated into swine diets. It is low in energy compared to most other energy sources, and fits well in late finishing and gestation diets.

Wheat is equal to corn in feeding value and is very palatable if not ground too finely. However, it is usually a more expensive energy source than corn and as a result has not been used commonly in Minnesota.

Barley is higher in fiber and protein than corn. Because of its higher fiber content, the energy value ranges from 90% to 100% of corn. High quality barley can be an excellent grain source for swine diets.

Hulless barley contains more protein and less fiber than normal barley. Despite its higher nutritional value in relation to barley, performance of pigs is generally similar when fed either barley or hulless barley.

Oats, like barley, are higher in fiber and protein than corn, resulting in an energy value of approximately 80% of corn.

Naked oats (hulless oats) are much lower in fiber and higher in oil and protein content than oats. As a result, their digestible energy content is 30% to 35% higher than conventional oats. Hulless oats have a good balance of amino acids, with only lysine and methionine present in amounts insufficient to meet the pig's requirement. Hulless oats can support satisfactory growth performance when used as the sole grain source for grow-finish pigs, with almost no supplemental protein required. Although naked oats have been grown successfully in Canada and the northern regions of the U. S., disappointing yields are sometimes reported.

Grain sorghum is similar to corn in nutritional value and can completely replace corn in swine diets. However, specially developed bird-resistant varieties that are high in tannins have only 80% to 90% of the feeding value of corn. Grinding is essential for efficient utilization because this grain is small and very hard.

Buckwheat is most commonly grown as a grain for human consumption. The protein quality of buckwheat is considered to be among the best in the plant kingdom. However, buckwheat is relatively low in digestible energy compared to other grains due to its high fiber and low oil content. The other significant factor limiting the use of buckwheat in swine diets is the presence of the anti-nutritional factor, fagopyrin. Fagopyrin causes skin lesions and intense itching when pigs are exposed to sunlight. No more than 50% inclusion in grow-finish diets and 80% in gestation diets should be allowed. Avoid using buckwheat in starter and sow lactation diets.

Rye has an energy value intermediate to wheat and barley, and the protein content is similar to barley and oats. Although amino acid balance is similar to barley and wheat, its amino acid digestibility is 5% to 10% lower. Furthermore, rye is very susceptible to ergot, a fungus that reduces pig health and performance. Rye also contains several toxic anti-nutritional factors that reduce its nutritional value for swine. There is no limit on the amount of rye that can be fed to gestating sows, although an upper limit of 50% in grow-finish and 40% in lactation diets is suggested.

Triticale is a grain produced by crossing Durum wheat with rye. Very little triticale has been grown in the northern U.S. and Canada. Even though it has a digestible energy value similar to wheat, it is similar to rye in regard to the presence of several anti-nutritional factors and susceptibility to ergot.

Protein sources

Full-fat soybeans contain approximately 18% oil and are of the most value in diets for weaned pigs and lactating sows. Although research conducted at the University of Nebraska has shown that feeding diets containing raw (unheated) soybeans to gestating sows will produce satisfactory performance, soybeans must be heat-treated to be used successfully in all other production phases. Properly heat-treated soybeans are an excellent protein source for swine. Soybeans contain anti-nutritional factors including trypsin inhibitors, urease, and hemagglutinin. Trypsin inhibitors and urease can be destroyed by proper roasting or extruding processes. However, overheating reduces amino acid digestibility and must be avoided. For optimal quality, soybeans should be roasted for 3 to 5 minutes with an exit temperature of 240 to 260 degrees F. The exit temperature for extruded soybeans should be 280 degrees F. Because soybeans contain 13% to 15% more energy than soybean meal, concentrations of other dietary nutrients must be increased to compensate for the lower feed consumption that naturally occurs when feeding high energy diets.

Mechanically-extruded soybean meal (non-solvent) can be produced as an organic substitute for conventionally manufactured (solvent extracted) soybean meal. Organically-produced soybeans can be mechanically extruded to produce a high-quality meal containing high protein and energy levels. Fat level of the meal may vary from 5% to10% depending on moisture content of the beans and efficiency of oil extraction during processing.

Field peas are grown primarily for human consumption, but they can effectively replace a portion of the grain and protein supplement in swine diets. The digestible energy content of peas is high and they are a good source of lysine. However, peas are low in methionine and tryptophan, which limits their use in most swine diets. Peas can be included in swine diets at up to 15% for starter pigs, 15% for sows, and can completely replace soybean meal in grow-finish diets. Peas also contain anti-nutritional factors including trypsin inhibitors and hemagglutinin, however, the level of these factors is generally not considered to be high enough to reduce performance. Many producers may choose to raise field peas in conjunction with barley as these two ingredients can be successfully incorporated into a swine feeding program.

Alfalfa's nutritional quality varies with stage of maturity, soil fertility, and methods of harvesting, handling, and storage. The more mature alfalfa is at the time of harvest (or time of consumption, if grazed) the lower its nutritional value for swine. Mature alfalfa is higher in fiber and lower in protein as compared to less mature alfalfa. The major factor that limits the nutritional value of alfalfa in swine diets is its low digestible energy content. Compared to cereal grains, alfalfa contains only half as much digestible energy. Alfalfa is a good source of most vitamins, and is an excellent source of vitamins A, E, and K. Alfalfa is high in calcium but has only moderate amounts of phosphorus. Therefore, diets containing alfalfa must be supplemented with phosphorus to maintain the desired 1:1 to 1.5:1 calcium:phosphorus ratio.

Alfalfa also contains saponins and tannins which are anti-nutritional factors that reduce growth rate of pigs. The use of alfalfa in weanling and young growing pig diets is not recommended due to its low energy digestibility, poor palatability, and the presence of anti-nutritional factors. Alfalfa fits better in diets for sows than for growing pigs. Sows have a greater capacity for fermentation in the hindgut that allows for greater fiber digestion and improved energy utilization. Furthermore, studies conducted at the University of Minnesota have shown increased litter size and lactation feed intake when sows were fed alfalfa haylage during gestation.

Canola is the primary oil seed crop produced in Canada. It contains 40% oil and 20% protein, making it a high energy, moderately high protein source. Canola can be effectively used at up to 15% in diets for all phases except for gestating and lactating sows, which should be limited to 10%.

Fababeans contain 24% to 30% protein and a digestible energy level intermediate between soybean meal and barley. Fababeans are low in oil content (1.5%) and the oil is high in unsaturated fatty acids. This makes it very susceptible to rancidity if the beans are stored for more than one week after grinding. Fababeans contain several anti-nutritional factors including trypsin inhibitors, hemagglutinin, and tannins. For optimal nutritional value, fababeans should be roasted or extruded before feeding. Fababeans can be effectively added at up to 15% of starter diets, 20% of grower diets, and 15% of sow diets without adversely affecting performance.

Lentils are a poorer source of lysine, methionine, and threonine than peas. However, lentils can be included at up to 30% of the diets for swine as long as diets are carefully formulated to ensure adequate amino acid levels.

Sunflower seeds are high in oil (40%) and fiber (29%) and moderately high in protein (20%). Unheated sunflower seeds are more digestible than heated seeds. Upper limits of inclusion for sunflower seeds are up to 10% of the diet for weaned and grow-finish pigs, and up to 30% of the diet for gestating and 20% of the diet for lactating sows. As is the case with canola and corn, a large amount of GMO-derived sunflower seeds is used in commercial production, and therefore precautionary measures should be taken to ensure organic status.

Read next: Suggested diets



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