Nguyen Thi Hong Nhan et al., 1999. Livest. Res. Rural Dev., 11 (3)

The growing and utilization of Trichanthera gigantea by farmers in the Mekong delta has increased rapidly since the introduction of the tree in 1991.  From the three stem cuttings imported in 1991 it is estimated that the trees are now grown and used by more than 1,000 farmers in South Vietnam. Experiments were carried out with lactating sows, growing-fattening pigs and fattening ducks to evaluate the use of the fresh leaves of Trichanthera gigantea  as a supplement to traditional diets based on rice bran and broken rice. The experiments with pigs were done in the homesteads of collaborating farmers who already were growing and using Trichanthera gigantea as feed. The experiment with ducks was done on a private farm close to Cantho University. Average intakes of fresh leaves were:  4.2 and  3.6 kg for lactating sows (Large White *  Baxuyen [local]) and fattening pigs (same type of crossbred) equivalent to 130 and  112 g/crude protein/head/day, respectively.  Performance (litter size and weights for the sows and growth rate of fattening pigs) was the same on diets with and Trichanthera gigantea. Pigs offered Trichanthera gigantea leaves ate less concentrates than the controls and feed costs were significantly lower. For the experiment with Muscovy ducks (age range 30 to 90 days) , fish meal or soya bean were omitted from the concentrate (the control diet contained 10% of each)  when T gigantea . leaves were fed.  Average intakes of leaves were 61 g/day  for ducks fed the diet without fish meal  and 66 g/day when the soya bean meal was omitted. Concentrate intakes were similar on all diets as was growth rate.  Feed costs were lower for both diets containing Trichanthera gigantea. The skin and fat of the carcasses of ducks fed Trichanthera gigantea leaves were more pigmented (yellow rather than white) a characteristic appreciated by local consumers. Comparing results with reports from the Cauca Valley in Colombia, from where the Trichanthera gigantea originated, it appears that nutritive value was higher for the Trichanthera gigantea grown in the Mekong delta.  It is suggested that the ecosystem in the delta (1,200 to 2,000mm rainfall and high humidity) was more favourable for rapid growth of the Trichanthera gigantea (resulting in higher nutritive value) than the ecosystem in Colombia (less than 1,000 mm rainfall and lower humidity).