The effect of dietary level of soybean oil and palm oil on apparent ileal amino acid digestibility and postprandial flow patterns of chromic oxide and amino acids in pigs

Abstract

A study was conducted to evaluate the apparent ileal digestibilities of amino acids in pigs (initial weight 78 kg) fed diets supplemented with either soybean or palm oil, at either 100 or 200 g kg–1 diet. A control diet with no added fat was also evaluated. All diets contained 5 g chromic oxide kg–1. The pigs were surgically fitted with a simple T cannula at the distal ileum, and were allowed to adapt to each experimental diet for 5 d. This was followed by 1 d of continuous collection of ileal digesta between feedings, and a second day of continuous collection separated into six 2-h postprandial time blocks to determine postprandial flow patterns of chromic oxide and amino acids. The apparent ileal leucine and arginine digestibilities were improved (P < 0.05) by 3.8 and 3.6%, respectively, with 200 g soybean oil kg–1 diet. Linear improvements (P < 0.05) were found in the apparent ileal digestibilities of serine, histidine, arginine, tyrosine, and leucine when 100 and 200 g soybean oil kg–1 diet were supplemented to the control diet, and for serine, histidine, arginine, and phenylalanine with the addition of 100 and 200 g palm oil kg–1 diet. Quadratic responses (P < 0.05) were found in the apparent ileal digestibilities of isoleucine and leucine with the addition of 100 and 200 g palm oil kg–1 diet. The postprandial flow patterns of chromic oxide and amino acids were very stable despite the different dietary treatments. Also, amino acid digestibility coefficients determined at different postprandial sampling times had low variability. In conclusion, the addition of high levels of soybean and palm oil to a semipurified swine diet increased the apparent ileal digestibilities of some amino acids. Also, the two fat sources affected some apparent ileal amino acid digestibility coefficients differently. Key words: Pigs, ileal, amino acid digestibility, fat, postprandial flow patterns