Laboratory-scale ensiling of Golden Apple Snails (GAS) (Pomacea spp)

A laboratory-scale study on ensiling Golden Apple Snails (GAS) (Pomacea spp) was conducted in order to compare different additive to snail ratios for the preservation of GAS for several months for later use as a protein feed for fattening pigs. Mature snails were purchased, the shells and covers removed and then the flesh washed with clean water and drained before being chopped into small pieces 0.5–1 cm in size. The prepared GAS was then mixed with the additive mixture of molasses and rice bran (1:9, fresh basis) in three different proportions of additive to fresh snails: 1:1, 1:2 and 1:3 on a fresh basis, and designated MRS1, MRS2 and MRS3, respectively. Each mixture had a total weight of 6 kg after mixing, and was then divided into 6 equal parts (each of 1 kg) per treatment that were placed in plastic bags that were then sealed to avoid air contamination. Each bag was put into a 3 L plastic container, and each container included a replicate of each treatment, according to a Completely Randomized Design. Samples of GAS silage were analyzed at 0, 7, 14, 21, 28, 56, 84 and 168 days. Initially the MRS1 silage had a brown color that was somewhat darker for MRS2 and MRS3. After 7 days the color for all treatments changed to yellow-brown and each had a good smell. The color did not change further, but treatments MRS2 and MRS3 had a dark surface. Dry matter (DM) and organic matter (OM) contents decreased with ensiling time in all treatments (P<0.05). Crude protein (CP) remained constant in MRS1, except for a higher value at 21 days, and increased with ensiling time in MRS2 and MRS3 (P<0.05). The concentration of ammonia-N increased with time of ensiling on all treatments, and the highest value of 1.62 % of DM was for the MRS3 silage at 168 days. pH values fell to below 5.0 in the first 7 days of ensiling (P<0.05) on all treatments and then remained constant, except for treatment MRS3, in which pH increased to 5.34 at 14 days (P<0.05) and then remained constant up to 168 days. DM and CP contents were different among treatments at all sampling times during ensiling, due to the different ratios of FGAS to the additive mixture. pH values were not different among treatments at 0 and 7 days, but thereafter were higher in MRS3 (P<0.05) than in the other two silages. It was concluded that Golden Apple Snail can be successfully preserved for at least 24 Back to contents Lampheuy