By Lesley WJ Nernberg, Lighthouse Agri-Solutions and Matthew Clark, FeedGuys Resources

Northern U.S. soybean growers and Southeast Asian feed mills are connected by a simple fact: Soybean meal (SBM) supplies approximately 60% of the digestible essential amino acids and roughly one quarter of the metabolizable energy in typical poultry diets. What happens to soybeans and meal between harvest in northern U.S. states and feed manufacturing directly affects feed cost, animal performance and ultimately the value of U.S. soybeans.  

At the recent Northern Soy Marketing (NSM) mission and seminar in Indonesia this past month, Dr. Bob Swick, Adjunct Professor at the University of New England in Australia, delivered a key message to both producers and feed millers illustrating that, “Quality of soybean meal starts with the bean, but it does not end at the crusher. Storage and handling can quietly degrade what growers and processors worked so hard to achieve.”  

Storage quietly eats amino acids 

Dr. Swick’s seminar topic, “Soybean Meal Quality as Affected by Storage of Beans and Meal,”highlighted how storage time, temperature and humidity can change the nutritional value of soybeans and SBM. In one of the key studies discussed, soybean meal samples from U.S. (dehulled), Brazilian (dehulled) and Brazilian (non-dehulled) origins were stored in a tropical warehouse at about 27oC and 60-85% relative humidity for up to five months. Over time, it was shown that: 

• Moisture content increased in all samples  

• Protein Dispersibility Index (PDI) and KOH solubility declined, indicating progressive protein damage 

• Total and digestible lysine and methionine decreased month by month, leading to poorer broiler chicken feed conversion ratio (FCR) even though feed intakes were similar.  

“Total and digestible lysine and methionine were decreased during storage of SBM under warm, humid conditions”, Dr. Swick summarized. “Storage has a detrimental effect on feed conversion, and there are real differences in storability among soybean meal origins.”  

What happens inside the meal: Protein 0xidation 

The biochemical changes behind these performance losses are mainly oxidation and structural damage to soy proteins.  

Dr. Swick highlighted other research where:  

• Protein carbonyls, a marker of protein oxidation, increased when SBM was stored at room temperature (about 22oC, 54% RH) for 45 days versus -20oC.  

• Free and total thiol groups (sulfhydryls) decreased, indicating formation of disulfide bonds and more cross-linked, less digestible proteins. 

• Total methionine content fell, and in vitro protein digestibility in pepsin dropped several percentage points.  

• Broiler weight gain and FCR were negatively affected by this relatively short room-temperature storage period, even though conditions were milder than typical tropical warehouses.  

“In practical terms, oxidation and cross-linking make those proteins hard for the bird to digest,” Dr. Swick noted. “You may still see 46% crude protein on paper, but you no longer have the same digestible amino acid value in the silo that you paid for at the SBM processing plant.” 

He also emphasized that amino acid losses during storage are not trivial and “amino acids may be lost to oxidation during storage at roughly 1% per month that can be easily worth around $10 USD per MT.” For high-volume feed mills, whichrepresents a significant hidden cost.   

Beans and meal in the tropics: Why origin and route matter 

For Southeast Asian feed manufacturers, the storage story begins long before the meal enters the feed mill. It starts with the climate where the beans were grown and stored, and continues across the entire logistics chain.  

Dr. Swick’s presentation compared typical or approximate ocean freight times to Jakarta from:  

• Brazil (Santos or Paranagua): 35-45 days 

• U.S. Pacific Northwest (PNW): 21-35 days

It was also noted that these sailing times did not include inland rail or barge time from crushing plant to port, port congestion at origin or destination, trans-shipment or stops through other major shipping hubs, or additional time in regional vessels before reaching the final destination.  Dr. Swick explained, “The longer and hotter the route, the bigger the window for access to moisture, oxidation, caking and loss of digestible amino acids. Shorter, cooler routes assist to keep more of the value that feed mills are buying.” 

In this, northern U.S. soybeans have an inherent advantage as they are produced and initially stored in a cooler climate, where ambient temperatures are on average lower and relative humidity is more manageable. This reduces the rate of deterioration in harvested beans and the risk of fungal damage or heat build-up before crushing. When these beans are processed into meal and shipped relatively quickly through the PNW, the total time “at risk” under high temperature and humidity is shorter than many South American routes.  

Why does this matter to feed mills?  

For Southeast Asian integrators and feed mills, these storage effects translate directly into formulation risk, performance variation, and cost. “Feed mills cannot afford surprises,” Dr. Swick stressed. “If you buy meal that looks fine from a label perspective but has lost amino acid value due to storage and transport, you either pay more to reformulate, or you may pay later through decreased animal performance.”  

From a feed mill perspective, hidden storage losses:  

• Increase safety margins on digestible amino acids, pushing diet cost higher 

• Contribute to unexpected variation in FCR or body weight uniformity across flocks or batches 

• Can trigger customer complaints or internal investigations when performance changes without any obvious cause 

This is where northern-grown U.S. soybeans and SBM can deliver differentiated value to Southeast Asian end users – providing more stable quality from farm to feeder, supported by objective quality metrics and logistical advantages. For U.S. soybean growers: The investment in agronomy, variety selection and careful post-harvest handling in a colder climate does provide value for importers of this key feedstock and ingredient.  

As Dr. Swick concluded to the Indonesian audience, “Storage conditions and time affect the nutritional quality of soybean meal. Shipping times and conditions from soybean field to broiler farm are important to consider, and amino acid losses during storage are real not theoretical.” 

Protecting value across the chain 

For NSM and its partners, there is opportunity to turn this science into practical collaboration by helping feed mills measure what matters, designing procurement strategies that favor more stable supply chains, and giving northern U.S. growers effective feedback that their quality efforts are recognized in the marketplace. When quality is protected from farm to feed mill, everyone wins!  

For more detailed data, analysis and technical support, contact the Northern Soy Marketing group or visit the NSM website for the latest research and resources.