An In Vitro Technique for Evaluation of Bloat Potential of Alfalfa

An in vitrofermentation technique for predicting bloat-producing potential of forage was developed. Gas evolution and foam volume were measured at 20-min. intervals during a 3-hr, incubation of a mixture of fresh ground alfalfa, artificial saliva and rumen fluid at 39° C. From these a gas evolution index (GEI) and foam stability index (FSI) were calculated. The correlation between these indices and average maximum bloat scores of assay groups of steers was determined. The simple correlation coefficients for 1965 and 1966, respectively, were as follows: GEI 0.71 (P<.01) and 0.61 (P<.10), FSI 0.72 (P<.01) and 0.92 (P<.01). The multiple correlation coefficients for 1965 and 1966 were 0.90 (P<.01) and 0.92 (P<.01), respectively.