Abstract

Taro (Alocasia odora L.) petioles are widely used as a component of pig diets in Central Viet Nam because they contain a range of important nutrients such as protein and carbohydrates. However, the petioles are known to contain high levels of oxalates which can substantially reduce the absorption of calcium from the digestive tract. Six young crossbred (Large White x Mong Cai) pigs (mean weight 56 ± 1.6 kg were fitted with PVC T-piece cannulas at the terminal ileum and then housed in individual metabolism cages. The pigs were fed either 50% fresh or 50% ensiled taro petioles along with rice bran and rice wine by-products. The experiment was designed to determine the flow of oxalates and calcium past the terminal ileum over a 24-hour period. Ensiling the taro petioles significantly reduced the total intake of oxalates in the test diets resulting in significantly (p<0.05) lower flows of total and soluble oxalate past the terminal ileum. Ensiling the taro petioles led to a significant reduction in the % soluble oxalates absorbed prior to the ileum compared to the fresh diet (30.6 vs 34.5%). The total calcium intake of the pigs fed the two diets were similar but the flow of calcium past the ileum was significantly reduced in the pigs fed the ensiled petiole diet. The total amount of calcium bound to insoluble oxalate passing the terminal ileum were similar for the fresh or ensiled diets (23.8 vs 28.0%) when compared to the total intake of calcium.