A series of experiments were conducted at the farm of CelAgrid in Kandal Province, Cambodia.
Experiment 1 consisted of two related cafeteria trials which were conducted to determine the feed preferences of local chickens when fed different feeds separately. The first trial was conducted for 4 weeks with 40 chickens allocated to 4 pens, with 10 birds per pen. They were given free access to three types of chopped green forages (taro leaf, duckweed and water spinach) and broken rice as source of energy. The daily dry matter (DM) intake of duckweed (3.9 g) was higher than that of water spinach (2.1 g), while the intake of taro leaf was relatively low (0.02 g). The daily crude protein (CP) intakes were 1.1 g, 0.5 g and 0.02 g for duckweed, water spinach and taro leaf, respectively. The second trial was conducted with the same duration and the same number of birds per pen. They were given free access to 3 types of fresh chopped carbohydrate feeds (cassava root, sweet potato tuber and banana fruit) and duckweed as the only source of protein The daily DM and CP intakes of sweet potato and cassava root were 16 g and 0.5 g, respectively, while the banana fruit intake was low.
Experiment 2 was carried out for 2 weeks with 240 local chickens at the age of 60 days (144 females and 96 males). The chicks were housed 10 per pen (4 males and 6 females). The experiment was a 4*2 factorial arrangement in a completely randomized design (CRD) with 3 replications. The chickens had free access to each of the carbohydrates (broken rice, cassava root, sweet potato tuber, and banana fruit) and each of two proteins feeds (soybean meal and duckweed). The total daily DM intake of the broken rice diets was 32.0 g, and was 26.6 g, 24.0 g and 22.5 g of fresh cassava root, sweet potato tuber and banana fruit, respectively. The CP intake of chickens on duckweed was 19.2 g, which was lower than of those fed on soybean meal (34 g). The CP intake of chickens fed different carbohydrates was similar (5-7 g) but the CP intake of the chickens fed on soybean meal was higher (10.4 g) than on duckweed (2 g). The chicks did not gain weight on duckweed, except on the broken rice diets, and had normal growth on soybean meal (4-6 g). Through linear regression analysis, the DM intake was shown to have high relationship with the average daily gain (R2=0.70).
Experiment 3 was carried out for 2 weeks with 210 local chickens (144 females and 96 males) at the age of 60 days. The chicks were housed 10 per pen (4 males and 6 females) and were allotted randomly to treatment. The experiment was 3*2 factorial arrangement in a completely randomized design (CRD) with 3 replications. Chickens had free access to each of three kinds of carbohydrate (cassava root, sweet potato tuber, and banana fruit) in the fresh form or as meal. The total daily DM intakes of the cassava root, sweet potato tuber and banana fruit diets were 21.0 g, 19.6 g and 29.0 g, respectively. The total intake of chickens fed the different forms of carbohydrate feed was not different and was around 20 g/day. The total daily CP intake was similar between the chickens fed on different types or forms of carbohydrate feed, and was around 1.5 g. Linear regression analysis showed that the weight change of chickens had a close relationship with the CP intake (p=0.011, r2=0.75).
Key word: Cafeteria, green forage, duckweed, water spinach, taro leaves, carbohydrate feeds, cassava root, sweet potato tuber, banana fruit