Response of pigs fed a basal diet of water spinach (Ipomoea aquatica) to supplementation with oil or carbohydrate

Prak Kea

Royal University of Agriculture,
Faculty of Animal Science and Veterinary Medicine
Chamcar Daung, Cambodia
prakkea@yahoo.com / prakkea@hotmail.com

Introduction

Cambodia is one of the poorest developing countries in the world. The country covers 181, 035 km² and has a population of over 11 million. The economy is based mainly on agriculture, of which rice production is ranked in the first place. Nearly 90% of the population live in rural areas and earn their living in the agricultural sector in a crop-livestock production system dominated by smallholder farmers. Almost all farmers keep livestock; usually pigs, chickens, fish, cows and buffaloes, of which pig production is dominant, with 12 118 273 head (APH 2001). The goals for the agriculture sector are improve the food security, reducing poverty and preserving the natural resources on a long term and sustainable basis (Cambodian government planning program 1995). To contribute to improvements of animal production, especially pig production, one of the most important factors that needs attention is feed, because feed accounts for about 80% of the cost of pig production (Peter et al 1984). The policy of the government is to simultaneously develop the quantity and quality of commercial feed, and make use of the locally available feed resources in the different ecological and economic regions. Crop residues account for about 80% of the total animal feed in the North (Lich and Tuyen 2001). For that reason there have been many studies on the preservation and processing of agro-industrial by-products as feed resources, with the aim to use them more effectively in sustainable agricultural systems.

African palm oil (Elaeis guineensis), which is a product of extracting oil from oil palm seeds, has great potential for use as an energy source in diets of pigs. The oil from the fleshy outer skin of the fruit is customarily included (at about a 5% level) in pig and poultry rations as a source of vitamins A and D and to reduce dustiness in the feed.

On the other hand, the by-products derived from the agricultural sector are abundant in Cambodia such as rice bran and broken rice. There are good  opportunities for the farmers to use these by-products as animal feed and to supplement them with vegetables in the traditional system used for pig raising in the region. The large water surfaces areas have also brought potential advantages to farmers by facilitating the cultivation of water plants such as water spinach (Ipomoea aquatica) all year round for human consumption and animal  feeding.  

According to Le Thi Men (1999) the annual fresh matter yield from water spinach in Vietnam can be as high as 455 tonnes or 40 tonnes dry matter per ha from 17 three week vegetative cycles. In Cambodia, yields of up to 24 tonnes of fresh biomass/ha were achieved in a growth period of only 30 days from the time of sowing the seed on the soil by using the effluent from a biodigester (Kean Sophea and Preston 2001). On an annual basis this represents of the order of 20 to 25 tonnes of dry matter/ha with 4 to 6 tonnes/ha of protein. This high yield potential enables many farmers to get a regular high income from harvesting water spinach and selling it to local markets.

Objectives

The aims of this study were to determine ways of improving the utilization water spinach (Ipomoea aquatica) as the major protein source for growing pigs. 

Two experiments were carried out with fresh water spinach as the major source of protein.

• The first aimed to evaluate the effect of increasing the energy density of the diet, on feed intake, digestibility and N retention, by adding graded levels of palm oil.
• The second was a study of supplementing the diet with small quantities of fish meal on growth performance and feed conversion.

References