Golden apple snails and Tra fish by-products as protein supplements in diets of fattening ducks                            

Bui Xuan Men and Nguyen Thanh Cong* 

Colledge of Agriculture and Applied Biology, Cantho University, Vietnam,
bxmen@ctu.edu.vn
^*Agricultural Extension Center, Dongthap province, Vietnam

Abstract

Two on-farm experiments were conducted in Dongthap province and Cantho City of the Mekong Delta in the rainy seasons of 2008 and 2009 to evaluate the use of golden apple snails (Pomacea) and Tra fish (Pangasius) by-products as protein supplements to replace the soybean meal in diets of ducklings. In experiment 1, 72 commercial meat ducks (Cherry Valley breed) were used in a completely randomized design, with 3 dietary treatments and 4 replicates. The ducks were fed 0, 50 and 100% protein of the snails replacing protein from soybean meal in the diets of 16% protein for the ducklings from 28-60 days of age. Each plot of the experiment consisted of 6 ducks balanced for sex. In experiment 2, in total 480 crossbred meat ducks (crosses of Cherry Valley drakes and Nong Nghiep ducks) were used, with 4 treatments, 3 replicates and 40 ducks balanced for sex per replicate (pen). The dietary treatments were 100% soya bean meal (SBM) as protein supplement, 50% of SBM replaced by Tra fish by-products (TF50), 100% of SBM replaced by Tra fish by-product (TF100), and 50% of SBM replaced by golden apple snails (GS50). The diets were offered ad-libitum to the ducks from 21 to 60 days old.

In experiment 1, daily live weight gains of the ducks supplemented with the snails (54.8-57.4g/day) were higher than those fed the 100% SBM diet (44.2g/day).  Feed conversion ratios of the ducks fed the snail diets were lower than those fed the SBM diets. In experiment 2, the daily live weight gains were 45.7, 45.4, 40.9 and 46.2 g for the SBM, TF50, TF100 and GS50 diets, respectively. Corresponding DM feed conversion ratios were 3.24, 2.91, 2.55 and 3.19, respectively.

The use of golden apple snails and Tra fish by-products as protein supplements in the diets of meat ducks had several benefits including decreased feed costs, increased employment opportunities (gathering snails in the rice fields and working in the Tra fish processing plants) and decreased pollution (toxic chemicals are otherwise used to kill the snail pests).

Key words: Benefits, feed conversion, growth, pollution, soybean meal

Experiment. 1: Daily weight gains of the CV. ducks offered diets with or without GS	Experiment 2. Daily weight gains of the crossbred ducks supplemented TF or GS in diets