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Matching Livestock Systems with Available Resources |
MEKARN Regional Conference 2007 |
A series of trials were conducted in 2006 and 2007 on a smallholding farm in OMon district of Cantho City in the Mekong Delta of Vietnam to evaluate use of animal wastes for the production of earth worms (Perionyx excavatus) and the effect of using these as protein supplements in diets of growing crossbred ducks and fresh turtle (Trionyx sinensis), and vermicompost for planting water spinach (Impoea aquatica).
The experiment on producing earth worms included four treatments with four replicates. The worms were supplied with different wastes: (1) fresh cattle manure (FCM); (2) a mixture of cattle manure and composted cattle manure (MCM), (3) composted cattle manure (CCM), and (4) a mixture of fresh water hyacinth and pig manure after kept together in one week (HPM). These wastes offered to the worms once every five days. The biomass gains of the fresh worms after 60 days were: 962, 12, 476 and 1772 g per square meter, and the waste conversion ratios (kg DM/kg fresh worm) were: 14, 2630, 58 and 8 for FCM, MCM, CCM and HPM, respectively.
The experiment on ducks fed the worms as part or complete replacements for protein supplement in the diets lasted from 14 to 60 days of age. There were three treatments with four replicates and four ducklings per group: (1) ducklings confined and fed a commercial mash control diet (Ctr), (2) ducklings confined and fed a diet based on 50% protein of soyabean replaced by that from the fresh worms (50R) and (3) ducklings confined and fed a diet that replaced 100% protein of soyabean by the fresh worms (100R). Daily live weight gains were 45.8, 47.8 and 47.5 g and feed conversion ratios 3.3, 3.1 and 3.2 for the Ctr, 50R and 100R, respectively.
The trial on fresh turtles that were fed the worms from 30 to 90 days old included three treatments with three replicates and two young turtles per group. The treatments were: turtles confined in buckets with swimming water and fed (1) commercial pellet control (CPC), (2) confined as (1) and fed fresh small fishes minced (FFM), and (3) confined as (1) and fed whole the living worms (WEW). The live weights were 10.2, 11.5 and 13.1 g, and the gains were 3.2, 5.0 and 7.3 g for CPC, FFM and WEW, respectively.
Vermicompost that remained after harvesting the worms was used to plant water spinach (WS) with three treatments and three replicates. The treatments were: (1) the WS fertilized with 35 g/m2 of urea (CtrU), (2) the WS with 25 kg/m2 of vermicompost (VCP), and (3) the WS with (2) plus 20% urea of (1) (UCP). After 25 days, growth rates of the biomass of the vegetables were 0.33, 0.29 and 0.42 kg/m2, and after a 15 day growth of the second cut, the biomass was: 0.92, 0.86 and 1.10 kg/m2 for the CtrU, VCP and UCP, respectively.
Use of animal wastes to produce earth worms and vermicompost to raise ducks, turtles and vegetables is a way to increase outputs of farm products and decrease using inorganic chemicals in agriculture.