25 June 2025

3 minute read

By: Lee Williamson

Dr. Maria Mendoza, Global Consulting Expert with Evonik, recently spoke to The Pig Site’s Sarah Mikesell at the World Pork Expo in Des Moines, Iowa, USA, about trypsin inhibitors in soy products and how that effects the digestion of amino acids. 

Tell me about trypsin inhibitors in soy products.

Trypsin inhibitors are a protein in the soy products that is an anti-nutritional factor because it can bind to digestive enzymes in the pig. This will prevent the digestion of amino acids. Today, it is a parameter of quality of soy products, but unfortunately it is not routinely monitored. This is relevant because we see variability of this parameter depending on if you're using soybean meal or soy expeller. There will be a difference in the amount and in the variability.

Why is it important to monitor the quality of soy products?

Today, this topic has become more relevant because there is a higher supply of soy products in the market due to the expansion of crushing plant capacity in the US. There is more interest from producers to understand how much soybean meal they could use in the pigs’ diet without harming the performance of the animals. Additionally, we see that some plants have more variability on this parameter than others.

Also, the price of soybean meal is coming down, making it a more attractive ingredient to incorporate in the feed. This is why it's more relevant today to monitor because of the opportunity of using the ingredient in greater amounts.

What is the impact of trypsin inhibitors in nursery pigs?

All animals will be affected; however, nursery pigs are more sensitive to these types of issues because they really need highly digestible ingredients to be able to perform. Based on the data that we have developed and worked on over the years, we see that when the trypsin inhibitor activity reaches a point of 1.5 milligrams per gram in the feed in the complete diet, animals start reducing their performance mainly related to losing digestibility of amino acids.

Interestingly, we found that it didn't affect digestibility of energy. The main impact is really related to amino acid availability.

What solutions are available to solve this issue?

It's an issue more related to monitoring. When customers and producers feel comfortable with the risk and knowing where that risk is, they have the tools to change their diet. This means that if they can categorize their suppliers to determine which ones have higher levels and which ones have more variability, then they can purchase the ingredients and know how to use them in the feed.

At Evonik, we have AMINORED, which offers NIR calibrations to monitor the quality of soybean meal. We monitor trypsin inhibitors and reactive lysine, which is another parameter that we are not covering today. However, both are very important and related to the quality of soy products. We offer calibrations to our customers and support them by obtaining samples from their suppliers and sharing the variability of these parameters. This is one of the ways that we at Evonik support our customers.