USE OF THE MOBILE NYLON BAG TECHNIQUE (MNBT) IN COMBINATION WITH THE ILEORECTAL ANASTOMOSIS TECHNIQUE (IRA) TO DETERMINE AMINO-ACID DIGESTIBILITY IN PIGS

Four Large White boars were surgically modified by means of the ileo-r ectal anastomosis technique (IRA) and also fitted with a simple duoden al cannula. A conventional ileal digestibility trial (randomised block design with four treatments and six periods used as replicates) colle cting total ileum digesta (TIG) was performed (n = 6). Treatments appl ied were: maize meal 75%; maize meal + 25% fish meal or sunflower meal (SM); and a standard diet (containing maize meal, fish meal and SM). The MNBT was applied after the digestibility trial, during which the p igs received the standard diet. Polyester bags containing the feed sam ples (standard diet, fish meal, SM or maize meal) were pre-digested wi th pepsin. No differences (P > 0.05) were found in apparent essential amino acid (AA) digestibilities between the two methods for maize meal , SM or the standard diet. MNBT determined apparent AA digestibility v alues for fish meal were lower(P less than or equal to 0.05) for leuci ne (5.5%), phenylalanine (6.4%), histidine (5.0%), arginine (5.3%) and cystine (5.5%) than that obtained with the TIG-method. Mixed (standar d) diet digestibility values calculated for the different AA were cons istently lower than actual values directly determined by the MNBT. The se results show that the MNBT combined with the IRA-technique can be s uccessfully used to determine the apparent AA digestibility of feedstu ffs. Apparent AA digestibility values individually determined with the MNBT can be used with some measure of accuracy to formulate practical pig diets. (C) 1997 Elsevier Science B.V.