IMPORTANCE OF THE USE OF DIFFERENT DIGESTIBILITY TECHNIQUES IN PIG NUTRITION AND FOOD FORMULATION

The nutritional value of a meal for pigs could be expressed using a digestibility coefficient whereas the type of digestibility may be assessed by the point of origin of the sample: 1) ileal Digestibility (IDI), attempts to increase the accuracy in the assessment of a nutrient contribution by using surgically modified animals. 2) fecal Digestibility (FD), is a simple technique, marred by the fact that the digestible proportion of a nutrient is modified by bacteria in the large intestine, showing a change in the amino acid profile of the ileum content compared to the one in feces. Regardless of the place and the technique used to obtain the sample, different types of digestibility can be observed: 1) apparent digestibility (AD), this method does not allow to know the proportion of protein and/or amino acids (AA) associated with the diet nor the proportion of endogen nitrogen secretion (EN), furthermore, the amount of food assimilated by the animal can only be assumed. 2) True Digestibility (TD), includes the value of EN excretion in its determination, therefore, it offers a more accurate digestion values of a given food item. 3) Real Digestibility is determined by correcting the AA DA by the quantity of endogen AA using an isotopic dilution technique. 4) Standard Digestibility is determined by correcting the AD by the minimum AA endogen loss using an average flux of endogen AA.