The use of forages such as water spinach and sweet potato vines in pig feeding can have socio-economic benefits for small scale farmers in Cambodia as these feeds can be easily cultivated and harvested on the farm. Incorporating these two crops in the farming system will also be of benefit to the environment as they can utilize efficiently the waste manure from pigs to produce high biomass yield of superior nutritive content.
An experiment to evaluate these forages as protein sources for pigs was done in the ecological farm of the Center for Livestock and Agriculture Development (CelAgrid) located in Rolous Village, Rolous Commune, Kandal Stoeung district, Kandal Province, about 25 Km from Phnom Penh City, Cambodia.
Crossbred (Local * Yorkshire [or *Landrace]) pigs (16 castrated males and 16 females) of 10-11 kg live weight were used in a 2*4 factorial arrangement to study the effect of different protein levels derived from mixtures (50:50 DM basis) of water spinach and fresh sweet potato vines in basal diets of broken rice or cassava root meal and rice bran.
Both broken rice and a mixture of cassava root meal and rice bran were suitable sources of energy to complement the mixture of sweet potato and water spinach foliages in diets of growing pigs. Growth rates were the same on both energy sources but feed conversion was better with broken rice.
Growth rate and feed conversion were improved as the level of protein provided by the combined sweet potato and water spinach foliages was raised, but the relationships were curvilinear, indicating there was no further improvements in growth rate and feed conversion when the crude protein exceeded 14% in the diet DM
Key words: crossbred pigs, protein requirement, sweet potato vines, water spinach, intake, growth, FCR