Development of Protocol for Lyophilization of Goat Rumen Fluid

Background: Rumen fluid has been used as microbial inoculum to treat indigestion in ruminant animals and to conduct in vitro rumen fermentation experiments. Lyophilization of the goat rumen fluid will provide continuous supply of rumen inoculums either for laboratory studies or for transfaunation in treating digestive disorders sequelae to high grain rations. However, no standard protocol is available for lyophilizing goat rumen fluid. Hence, this study was designed to develop a protocol to lyophilize goat rumen fluid as an alternate source for fresh goat rumen fluid. Methods: The study was conducted using 5 × 3 × 3 factorial design with four different cryoprotectants viz., 10% skim milk powder, 10% skim milk powder + 5% sodium glutamate, 5% glycerol, 5% DMSO and no cryoprotectant, at three pre freezing (2, 24 and 48 hours) and three freeze drying (8, 24 and 32 hours) time intervals to standardize protocol for lyophilizing goat rumen fluid. The viability of rumen microbes in the “lyophilized goat ruminal inoculum”, was determined via in vitro gas production study. Result: Pre freezing (-80°C deep freezer) duration of 48 hours with 32 hours of time duration in lyophilizer (-45°C) was ideal for lyophilizing goat rumen fluid with or without the addition of various cryoprotectants. Glycerol used at 5% as cryoprotectant resulted in significantly (P less than 0.05) highest gas production at all (12, 24 and 48) incubation hours studied indicating better viability of rumen microbes.