Supplementation of dietary lipids in the concentration of conjugated linoleic acid in milk fat

Abstract

In the food of animal origin it is possible to find natural substances, conjugated linoleic acid (CLA), mainly in the fat milk, meat and foods naturally enriched in this acid and their isomers. CLA has different bioativas properties and is original of the incomplete biohidrogenation of the linoleic and linolenic acids carried by the rumen bacteria or by the desaturation of the trans-11 in the mammary gland and small intestine. The fat addition to diets of the lactating cows has been common practice as a form of increasing the energy density of the diet without to cause the disturbances metabolic provoked by the increase of the carbohydrates inclusion quickly fermented, mainly in cows of high production, because in the first weeks of milking the lactating cows are in a negative balance energy in the face of the food intake is not maximized still. Diets supplemented with fat and roughage:concentrate relationship, as well as, the effectiveness of the fiber of the roughage can increase the milk production, decreasing the fatty acids production and altering his profile in the milk. Fat milk is formed by a great amount of saturated fatty acids of short chain and the use of diets with added fat, alter his pattern, reducing the amount of saturated fatty acids by the increase of the unsaturated. Like this, several works have been carried to study the amount and fat type to be added the diet, his acceptability and digestibility with the purpose of increase the contents of CLA and acids trans-11 in fat milk. Keywords: Acids trans, CLA, milk, constituents of milk.