Soybeans – an excellent protein source, but...

Soybean meal (SBM) is universally recognized as one of the few sources of plant-based protein that contains all the essential amino acids necessary to animal growth and development. Yet, when standard SBM is used in starter feed, young animals have a hard time digesting and absorbing many of these vital nutrients. Soy’s natural content of anti-nutritional factors (ANFs) is the reason.

In soybeans, ANFs cover a range of substances that provide important protection against mold, bacteria and over-consumption by wild animals. In piglet feed, they represent a health risk. Many scientific studies have documented their harmful effect on the development and functionality of the gut, reducing the utilization of nutrients and compromising growth.

Removing the problem

The obvious way to overcome this challenge is to minimize the ANF content of the soy in young animal feed. Heat treatment by toasting, extrusion or steaming is widely used. But there are drawbacks when excessive heat is applied. Protein denaturation results in loss of nutritional value, and the Maillard reaction – when reducing sugars and amino acids form irreversible complex bindings – leads to a further reduction in amino acid utilization.

Although it is possible to avoid such problems by applying a moderate heat treatment of maximum 110°C for 30 minutes, this is not sufficient to inactivate all ANFs. Additional advanced enzymatic treatment is necessary to reduce ANFs to a tolerable level so young animals can digest the soy proteins in their feed and gain full nutritional benefit, avoiding potential health issues.

Hamlet Protein has identified the ANFs that are least tolerated by piglets and, as such, are most critical to their health and development. The patented process at Hamlet Protein is designed to inactivate these ANFs gently and effectively to optimize the availability of the essential amino acids in their specialty soy proteins, e.g. HP 300.

Anti-nutritional factors critical to piglet health

The formulation of piglet feed has come into sharper focus as authorities around the world have imposed more restrictions on the use of antibiotics and zinc oxide. This has brought an even greater need to minimize diet-related health risks and ensure full utilization of the nutrient content.

The challenge is that, up to the age of seven to eight weeks, piglet guts lack a fully developed enzymatic system and have limited digestive capacity. For this reason, piglets are dependent on easily digestible and high quality protein in their feed to support organ and muscle development. Diets that fail to meet these nutritional requirements will compromise this development and cause a slowdown in growth that is never recovered.

Oligosaccharides, trypsin inhibitors and antigens are the critical ANFs to avoid in a soy-based piglet starter feed. They are all reduced to a minimum in HP 300.

Oligosaccharides

Oligosaccharides in soy protein are fermented by bacteria in the small intestine as the necessary enzymes are not available to break them down. Gas produced by the fermentation process causes flatulence. Those oligosaccharides that are not fermented have an osmotic effect that draws water from the gut lining, speeding up gut transit time and leading to scouring.

Trypsin inhibitors

Trypsin inhibitors restrict the digestibility of protein, which then passes unabsorbed into the colon without contributing to animal growth. In the colon, undigested protein is fermented by bacteria, including potential pathogens, which produce toxic end-products that impair the integrity and functions of the intestinal membrane. Toxins absorbed from the gut activate the immune system, which requires energy to combat the toxins. In this way, there is less energy available for piglet growth, resulting in lower performance.

Antigens

Antigens have a negative impact on the gut membrane, causing inflammatory lesions and compromising the gut’s ability to absorb nutrients. Negative effects include increased mucus production, intestinal villi atrophy and cellular apoptosis. Another consequence of a compromised, more permeable gut is that large and potentially harmful molecules can pass the gut lining and cause an allergic reaction. The subsequent activation of the immune system draws on energy and nutrients, reducing the resources available to support piglet growth. Recent research indicates that the greater the exposure to antigens, the greater the impact on piglet health.