Effect of Inclusion of Emulsifier Digestfast on Monogastric Species Diets

Current demand for improvements in production performance (feed conversion rate, average daily gain, speed of growth, etc.) in animal production implies very high needs for metabolizable energy. These needs can only be met with the contribution of fat in the diet.

Fats are necessary for maintenance of body temperature, synthesis of hormones, proper functioning of the central nervous system and muscle metabolism (Bjorntorp,1991). Vitamins, A, D, E and K are fat soluble, which means they are digested, transported and absorbed in the presence of fats (Leeson, 1993). Fat in animal diets increases palatability of feed and improves the efficiency of energy use. In addition, reduces the speed of feeds transit along the gastrointestinal tract, allowing a better absorption of nutrients (Baiao and Lara, 2005).

Fat in the diet also affects the digestibility, absorption, ingestion and metabolism of other ingredients such as carbohydrates, proteins and minerals (Leeson, 1993 and March, 1980). Excess of fat reduce digestibility, feed intake, less weight causing economical loses in livestock production.

Fat digestion occurs in a few stages. Initially, large drops of fat are emulsified in aqueous medium of the digestive system, to which the peristaltic movements contribute. Water and oil are not miscible, so bile salts help in the mixing process, as a natural emulsifier.

Smaller fat drops offer a greater contact surface to the action of the lipases, secreted by the pancreas, responsible for hydrolysing or fragmenting the fat. The next step is formation of micelles. When they meet the membrane of the intestinal microvilli they are disintegrated so that the free fatty acids can be absorbed by the lipophilic part of the mentioned membrane.

The long-chain unsaturated fatty acids and monoglycerides form micelles quickly, while the saturated ones have a lower capacity to form micelles due to their lower polarity.

The addition of synthetic emulsifiers is a relatively recent possibility when compared to other feed additives commonly used. Emulsifiers act by increasing the active surface of fats, allowing a higher action of the lipases and favoring formation of micelles. Its positive effect is more pronounced the lower digestibility of fat, and the higher the level fat added to the diet.

It is important to take care of a good health of the organs directly related to the metabolism of fats - the liver and the pancreas. Diseases that impair bile secretion, and liver disorders, lead to serious deficiencies in the absorption of fats, as also happens with diseases that affect the pancreatic secretion of enzymes with lipase activity. Several medicinal plants such as milk thistle and artichoke, which are very useful in favouring its proper functioning. Milk thistle owes its properties to silymarin, a complex composed of silybin, silcristine and silidianin.

Its mechanism of action allows to activate the production and secretion of bile, improving the function of the liver and gall bladder, and facilitates digestion of fatty substances. Another plant recommended to improve the process of digestion of fats is the artichoke. The basal artichoke leaves are depurative and favor hepatobiliary function; for its active ingredients, improve drainage, have a slight diuretic effect and detoxify the body. The artichoke has a stimulating effect on pancreatic activity, which enhances the secretion of the aforementioned enzymes.

The addition of plant extracts to the emulsifier helps these organs, increasing the effectiveness of said emulsifier and guaranteeing a wide margin of safety in a feed formula.

To certify the activity and quality of plants used, it is necessary to know and standardize their content in active principles, as well as to protect them in a such way, that they support feed manufacturing processes.

Several scientific studies carried out in different livestock species, have shown that the use of a nutritional emulsifier combined with extracts of medicinal plants (DIGEST FaST®, Lipidos Toledo SA) has a positive effect on the fat digestion efficiency and allows to reduce the cost of the diet.

In pigs, the test was carried out on an experimental farm (Catalonia, Spain). 132 animals (60 entire males and 72 females) were used, hybrid line crossbreed with Pietrain, which were divided into 2 treatments. The CONTROL BATCH diets corresponded to diets used conventionally on the farm, while to make the diets of the EXPERIMENTAL LOT the substitutions indicated in the following table 1 were made:

Table 1. Diets used in the study.

The test was carried out in the second semester of 2016 and last approximately 14 weeks. The results evaluated zootechnical performance on the farm and performance at the slaughterhouse. The results are presented in table 2.

Table 2. Effect of treatment on zootechnical performance and carcass quality in pigs.

This study showed that the emulsifier DIGEST FAsT® allows to replace efficiently fat (lard) in the diet, maintaining and even improving some of productive and quality indicators of the carcass.

In poultry sector, quickly growing broilers are very efficient animals in transformation of feed they eat into meat for human consumption. This high growth rate also implies very high needs for metabolizable energy, needs that can only be met with the contribution of fat in the diet, because there is no other raw material that contains the energy required by the broiler for its growth (Acevedo, 2012).

Tests carried out with emulsifier combined with plant extracts confirm, the great usefulness of the additive in broiler nutrition. The experiment carried out in Spain using 1kg of the additive to replace 10kg of lard in the diet throughout the productive cycle, concluded with favorable results, collected in the table 3.

Table 3. Effect of the treatment on the zootechnical performance in broiler.

Additionally, in a trial conducted at the High Institute of Agronomy in Tunisia, a positive effect of the additive was observed on the reduction of oxidation and lower growth of microorganisms in the broiler meat stored at a temperature of 4ºC for 6 days - a factor of big importance in the meat industry and distribution chains.

Due to supply constraints, environmental conditions of high heat stress, “oily chicken” problems and others, proportionally high protein and low-fat formulas are still being made, compared to the standards of different genetics companies in many countries of the world. The use of emulsifiers allows to optimize the energy balance and the profile of fatty acids used.

Among the advantages of the use of DIGEST FAsT® emulsifier are:

- The possibility to reduce the cost of the diet: can replace up to 10 kg of fat. - Use "On-top" in prestarter diets to improve the digestion of fats. - Improve the digestion of saturated fats (lard, tallow) - Possibility of formulation hypercaloric diets (for example for lactating sows) - Use less concentrated raw materials. - Optimize the profile of fatty acids, for example, linoleic acid in diets rich in corn and soybeans.

Bibliography available at: authors of the article.