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Effect of inclusion of emulsifier digestfast on monogastric species diets
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by Sujka1, E., Téllez1, S., López1, I., Callejo2*, A 1 Lípidos Toledo, S.A.; 2Universidad Politécnica de Madrid, Dpto. de Producción Agraria
urrent demand for improvements in production performance (feed conversion rate, average daily gain, speed of growth, etc.) in animal production implies very high needs for metabolisable 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
62 | January 2018 - Milling and Grain