Enhanced soybean meal in poultry feeds economic implications
On September 19-20, 2000 at the 61st Minnesota Nutrition
Conference in Bloomington, MN., the Minnesota Soybean Research and Promotion
Council sponsored a Technical Symposium on Soybean Meal.
Six papers highlighted some of the most recent research underway with
soybean meal. This newsletter will review some of the information presented
to the nearly 250 persons attending the Conference. Copies of the Minnesota
Nutrition Conference Proceeding can be obtained from the University
of Minnesota Extension Service, Professional Education & Conference
Planning-2303, P.O. Box 64780, St Paul, MN 55164-0780.
Keith Smith reported that soybean meal is the premier supplemental protein
source in U.S. livestock and poultry rations due to its nutrient composition,
availability and price. Researchers have over seventy years of research
experience that supports use of soybean meal in livestock and poultry
rations. Soybean meal accounts for about two-thirds of the total oilseed
meal use in the world with the balance divided between rapeseed, cottonseed,
sunflower, peanut, palm kernel and copra meals. According to USDA, soybean
meal makes up 93% of the total oilseed meal available to the U.S. feed
manufacturer. Alternative oilseed meals are used in some feed formulations
when available and competitively priced with soybean meal. Smith reported
that poultry and swine account for nearly three-quarters of soybean
meal use; poultry (50.4%), swine (23.7%), beef (12.2%), dairy (5.7%),
petfoods (2.6%), other feed uses (2.9%) and non-feed uses (2.5%). He
summarized the presentation by stating that soybean meal’s composition,
availability and price combine to make it the protein source of choice
in livestock and poultry rations.
Smith, Keith. 2000. Overview of soybean meal use. 61st
Minnesota Nutrition Conference Proceeding. p1-4.
Drs. Lawrence Johnson and Tang Wang (Center for Crops Utilization, Iowa
State University) indicated that there has been more changes in soybean
processing in the past decade than there were over the past three decades.
These processing changes have been driven by more concerns over process
efficiency, cost reduction, solvent emissions, and energy reduction
than concerns for meal quality. Dr. Johnson discussed the increased
use of hot dehulling to facilitate more complete hull removal to meet
higher protein and lower fiber specifications in the meal; the use of
expanders to speed oil extraction, aid solvent drainage and reduce energy
requirements of solvent evaporation; and improved methods of meal desolventizing,
toasting and drying to produce meals of more consistent quality.
Most of the presentation was spent discussing a survey that compared
the composition and quality characteristics of meal processed in thirteen
dry extruding-expanding processing units; 9 solvent extraction plants
and one screw-press operation. Representative meal samples were obtained
in July, October and February from soybeans grown in the 1998 crop year.
Comparative analyses are found in the table:
Composition of soybean meal produced by:
| Solvent-extracting | Expelling-Extruding | Screwpressing | ||
| Protein | (%) | 48.8a | 42.5b | 43.2b |
| Oil | (%) | 1.2a | 7.2b | 6.3b |
| Fiber | (%) | 3.7a | 5.4b | 5.9b |
| Urease | (+pH) | 0.04a | 0.07a | 0.03a |
| KOH solubility | (%) | 89.1a | 88.1a | 61.6b |
| PDI | (%) | 44.5a | 18.1b | 10.6c |
| Rumen bypass | (%) | 36.0a | 37.6a | 48.1b |
| Trypsin inhibitor | (mg/g) | 5.46+/-0.41 | 5.52+/-0.28 | 0.30 |
The main effects with different letters are significantly different at p=0.05, and values are adjusted to a 12% meal moisture content.
These data show significant differences in composition between soybean meals that are available to the feed formulator. The author’s conclusion was that despite changes in meal processing, good quality meal continued to be produced. There are significant differences in the composition characteristics of meals depending on the extraction process employed. The feed formulator needs to be aware of these differences in assuring the ration specifications are met.
Johnson, L.A. and T. Wang. 2000. Effects of processing on soybean meal quality. 61st Minnesota Nutrition Conference Proceeding. p5-17.
Marshall Stern and co-workers (Department of Animal Science, University of Minnesota) reviewed protein supplementation of ruminants. Amino acids are supplied to the duodenum of ruminants by microbial protein synthesized in the rumen, undegraded dietary protein and endogenous protein. Because the microbial protein is highly digestible in the small intestine, it is important to maximize microbial protein synthesis in the cow’s rumen. Ruminal degradation of dietary protein is an important factor influencing the intestinal amino acid supply to ruminants.
Dr. Stern stated that when formulating diets for ruminants, several criteria can be used to select the protein supplement including palatability, ruminal protein degradability, protein quality, intestinal absorption of amino acids, cost per unit of the protein, availability and consistency of product and the impact on animal performance. Solvent-extracted soybean meal is highly palatable, has a well-balanced amino acid profile and meets several of the criteria needed in a protein supplement. While soybean meal is extensively degraded in the rumen and provides an excellent source of nitrogen for the rumen microbes, it may not provide enough undegraded intake protein to meet the demands of the high producing dairy cow in early lactation. Research has focused on improving the rumen bypass properties of soybean meal, while not damaging digestibility of the high quality protein in the small intestine. Dr. Stern reviewed the various techniques used to increase rumen bypass of soy protein including heat processing; and treatment with formaldehyde, tannins, bentonite, acids or alkalis; encapsulation with blood, zein or fat; and formulation with zinc salts. Dr. Stern reported several studies that used various laboratory techniques to evaluate the effect of treating soybean meal on ruminal protein degradability and intestinal protein digestion. In general, soybean meal can provide an excellent source of ruminal degradable protein that provides ammonia nitrogen, amino acids and peptides allowing microbes to produce maximum levels of high quality microbial protein. The undegraded soy protein is also of high quality and readily digested in the small intestine. Therefore, untreated soybean meal can provide a source of readily degradable protein for microbial growth and treated soybean meal can provide an excellent source of ruminal undegraded protein if treated properly. The nutritionist has the challenge to formulate dairy rations using available feed ingredients to balance the need for both rumen degradable and bypass protein in the diet of a high-producing dairy cow.
Stern, Marshall, Lisa Aga and Alex Bach. 2000. Improving soybean meal use by ruminants. 61st Minnesota Nutrition Conference Proceeding. p. 18-32.
Dr. Robert Easter (Department of Animal Science, University of Illinois) discussed a major collaborative research project designed to maintain soybean meal’s premier role as protein of choice in swine rations both domestically and internationally. Researchers at the University of Illinois organized a major collaborative research effort to investigate several areas that impact soybean meal use in swine rations. Research teams were organized to investigate processing factors that influence protein digestibility; to characterize the carbohydrate fraction of soybean meal; to investigate bioactive compounds in soybean meal on reproduction and carcass composition; to determine the effects of soybean meal on pork quality; and to study the economic importance of potential changes in soybean meal use in domestic and international markets. Results are showing major advantages for research that is carefully designed, conducted at several institutions, using common sources of carefully-characterized soybean meal, and using accepted laboratory techniques. The study to determine amino acid availability was conducted at five institutions using similar techniques and meal sources. Results indicated differences between laboratories; variation in digestibility by region and/or by processor; values that were not below “book–values”; and confirmed the opportunity for further increasing soy protein’s amino acid digestibilities. Research on the isoflavone effects on reproduction, growth and muscle development with studies in both pigs and rats have produced no major surprises; there were some small positive changes, but nothing of great significance. Studies to compare meat quality and sensory scores of pork from pigs fed various protein sources produced few differences in tenderness or juiciness. They found the pigs fed extruded full-fat soybean had pork loin samples with a more desirable pork flavor. The project has been successful in showing how a team of 29 nutritionists can design and implement a major research project that targets soybean meal use in swine rations. Results reported to date confirm the preferred status of soybean meal in swine diets.
Easter, Robert A, Steven T. Sonka and Marilyn L. Nash. 2000. New collaborative research on the use of soybean meal in swine diets. 61st Minnesota Nutrition Conference Proceedings. p33-43.
Dr. Tom Sauber (DuPont Specialty Grains) reported that traditional plant breeding and biotechnology is being used to enhance the value of soybeans and soybean meal. Researchers have targeted several soybean traits in efforts to develop soybeans with improved nutritional attributes. Dr. Sauber reviewed research efforts that have produced commercial soybean varieties with altered fatty acid profiles; efforts to increase protein and levels of critical amino acids; studies to genetically improve phytic acid utilization; and research to reduce protease inhibitors, lectins, antigenic proteins and oligosaccharides that have negative effects on nutrient utilization. Sauber indicated that companies like DuPont are investing significant resources to determine the genetic control of these traits and to integrate these traits into high yielding germplasm. Companies are working to develop marketing strategies that involve producers, elevators, processors and end-users to assure these value-added agricultural products are made available to the nutritionist. Dr. Sauber concluded by stating that soybean traits have been developed that improve the quality of oil, nutritional value of meal and agronomic performance of new value-added soybean varieties. Animal studies have confirmed the nutritional value of some of the value-added traits that DuPont Specialty Grains have added to genetically enhanced corn and soybean varieties.
Sauber, Tom. 2000. Performance in pigs of soybean meals produced from genetically enhanced soybeans. 61st Minnesota Soybean Nutrition Conference Proceedings. p44-51.
Dr. Craig Coon (Poultry Nutrition Department, University of Arkansas) indicated that several genetically enhanced cereal grains and oilseeds with added quality traits for the feed industry are currently being developed for commercial release within the next five years. He highlighted research that is underway to develop high-yielding soybean lines with low oligosaccharides, high lysine levels, low lectins and low Kunitz trypsin levels, and higher methionine and protein levels. Each of these traits would provide the poultry nutritionist opportunities to formulate rations that support more efficient poultry production.
Dr. Coon spent a major portion of this presentation discussing the cost of these genetically enhanced improvements. He discussed the need to provide grower premiums/incentives to producing the new value-added variety; costs involved in the segregating and preserving the identity of the valued-added variety; and for costs associated with the end-user incorporating the new variety into existing feed formulations. These costs must be taken into consideration in determining the value of these new value-added cereal grains and oilseed protein ingredients. The bottom line is that the new value-added ingredients must compete with traditional ingredients on the basis of composition and price. Dr. Coon provided one chart that showed the feed ingredient saving per ton of various poultry feeds when diets were formulated with high-protein, high-lysine, or high-methionine soybean meals. The value of the genetically improved soybean meal depends on the specie, the age of the animal and ration specifications. Additional research is needed to confirm the economic benefits of value-added ingredients in order to replace traditional feed ingredients like soybean meal.
Coon, Craig. 2000. Enhanced soybean meal in poultry feeds economic implications. 61st Minnesota Nutrition Conference Proceedings. p52-63.
