Two experiments were conducted to determine the effect of fibrous diets, with or without enzyme supplementation, on ileal and total tract digestibility and performance of local (Mong Cai, MC) and exotic (Landrace x Yorkshire, LY) weaned piglets.
In the first experiment, ileal and total tract digestibility of low and high fibre diets (100 and 200 g/kg neutral detergent fibre (NDF)), with or without enzyme supplementation (a-amylase, b-glucanase, cellulase and protease) was determined in two breeds of piglet at an initial age of 30 days. The breeds were local (Mong Cai, MC) and exotic (Landrace x Yorkshire, LY). The experiment was done according to a 2 x 2 x 2 factorial completely randomized design with 4 replications.
The ileal and total tract apparent digestibility of organic matter (OM), crude protein (CP), crude fibre (CF), neutral detergent fibre (NDF), acid detergent fibre (ADF) and amino acids (AA) in the high fibre diet was lower than in the low fibre diet (P<0.01). The ileal apparent digestibility of nutrients and amino acids was similar (P>0.05) between MC and LY, while the total tract apparent digestibility of nutrients was higher for the MC than for LY (P<0.05). Enzyme supplementation of the high-fibre diet improved the digestibility of all dietary components (P<0.05) at ileum and total tract, but there was no effect of enzyme supplementation of the low fibre diet (P>0.05).
In the second experiment 24 weaned piglets from two breeds (4.2 ± 0.4 kg for Mong Cai and 7.5 ± 0.4 kg for Landrace x Yorkshire), with an equal number of males and females, were used to study the effect of supplementing a high fibre diet with an enzyme mixture (a-amylase, b-glucanase, cellulase and protease) on the performance of the piglets. The experiment was done according to a 2 x 2 factorial completely randomized designed, with six replicates.
The results show that in the post-weaning period the enzyme supplement increased average daily gain (ADG) by 11.6% (P<0.01) and decreased feed conversion ratio (FCR) by 12.5% (P<0.05) compared with the diet without enzyme supplementation, whereas enzyme supplementation had no effect in growing pigs (P>0.05). Average daily feed intake was not influenced by enzyme supplementation. The Mong Cai had higher feed and nutrient intake per kg live weight (P<0.01) than Landrace x Yorkshire, but lower ADG and FCR (P<0.001).
It can be concluded that enzyme supplementation of the fibrous diets improved both the digestibility of all dietary components at ileum and total tract and the growth performance in weaned piglets