Feed efficiency in piglets

Feed efficiency is always a crucial issue in animal production. Like most animals, piglets need to grow quickly and efficiently. Therefore, high-energy diets containing a high proportion of fats are commonly used. These fats can only add value if they are digested. However, fat digestibility is limited in weaned piglets, which restricts efficient growth.

Improved fat digestion

At weaning, young piglets encounter digestive difficulties. While their digestive tract is not yet fully developed, they are switched from easily digestible mother's milk to solid feed with a high fat content. Young piglets do not produce enough bile acids and have low enzymatic activity, resulting in suboptimal conditions for proper fat emulsification and digestion. These factors combine to put the animals' gut health and performance under stress. 

To address the above challenges, the industry needs a comprehensive solution that leads to optimal feed digestion, faster piglet growth, improved piglet health and lower feed costs. Feed additives based on hydrolysed lecithins, better known as lysolecithins, are rapidly gaining popularity in this context.

Lecithins versus lysolecithins

Lecithins occur naturally in plants and are commonly used in animal feed as a cheap source of energy. Besides energy, lecithins provide the animals with phosphorus and choline. Furthermore, the molecule is amphiphilic, which means that it has both hydrophilic and hydrophobic properties.

Since lecithins have a low hydrophilic-lipophilic balance, water-in-oil emulsification is promoted. In contrast, hydrolysed lecithins (lysolecithins), which contain only one fatty acid instead of two, are more hydrophilic and promote oil-in-water emulsification. Lysolecithins have the ability to emulsify fats into smaller fat droplets, resulting in an increased surface area that allows easier enzymatic hydrolysis of fat by pancreatic lipase. In addition, lysolecithins have high levels of lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE). Both LPC and LPE have the ability to interact with the phospholipid bilayer of epithelial call membranes, increasing their fluidity and permeability and facilitating nutrient uptake.

Proof in the field trial

In a recent trial on a practical farm with research facilities in Germany, the effect of FRA LeciMax Dry on the performance of weaned piglets during 35 days after weaning was tested. The product is based on hydrolysed lecithins and was used at 500g per tonne of feed. The performance of these piglets (experimental group) was compared with piglets in the control group that received the same formulation without the addition of lysolecithins to the feed.

The beneficial effects of adding 500g FRA LeciMax Dry were evident throughout the trial period. The negative influence of the decrease in the production not only of bile acids but also of digestive enzymes, especially lipase, normally observed after weaning, was significantly alleviated, as reflected in the improved growth and feed conversion, as shown in Table 1.

The significant increase in body weight 35 days after weaning is of great economic interest, as heavier piglets make better fattening pigs. Adding 500 grams of FRA LeciMax Dry to a normal feed resulted in a 1.19 kg higher final weight after 35 days. As a rule of thumb, a one kilogram increase in body weight at the beginning of the fattening phase shortens the fattening period by one week, resulting in lower feeding costs.

In addition, the significantly lower feed input led to lower feed costs per kilogram of piglet gain, and lower mortality resulted in more piglets being sold for fattening. An economic calculation therefore showed a return on investment (ROI) of 63. These results show that feed is better utilized when lysolecithins are used. This is explained by improved fat emulsification, followed by better enzymatic hydrolysis and absorption of fat as well as other nutrients.

The added value of lysolecithins for piglet diets is increasingly recognized by industry experts. André Meeusen, a Belgian feed consultant and animal nutritionist, comments: "Adding lysolecithins to the feed always leads to more piglet growth and better piglet health. The piglet's ability to digest solid feed and feed fats is relatively low, especially during the weaning period. This may be due to a lack of emulsifying substances. Weaned piglets do not produce enough bile acids and phospholipids to properly emulsify fat from the feed. For this reason, piglet digestive enzymes have difficulty hydrolyzing proteins and fats in the aqueous environment of the digestive tract, resulting in reduced fat and protein utilization. Lysolecithins support the animal's digestive system. Nutrients, especially fats and proteins, are used more efficiently and piglets grow better. In addition, fewer diarrhea problems occur because the amount of available nutrients for pathogenic microflora is reduced. These benefits are seen not only when lysolecithins are added to dry feed, but also to liquid feed."

This article shows that feeds are better utilized when lysolecithins are added and also confirms the results in the literature that better fat absorption leads to better protein utilization by weaned piglets. In conclusion, the addition of lysolecithins to piglet diets improves feed conversion, growth rate and sales weight of piglets and, above all, has great economic potential.