Passage of Legume and Grass Seeds Through the Digestive Tract of Cattle and Their Survival in Faeces

Seeds of 10 legumes and eight grasses found in tropical and subtropical pastures were placed directly into the rumens of cattle. Their survival and rate of passage through the digestive tract was studied over a 160-h period. After excretion, the survival of seed was followed in dung pats. Overall, more legume seeds than grass seeds survived passage through the digestive tract but there was marked variation between species in both grasses (0-64%) and legumes (0-78%). Survival of the legume seeds, both in the animal and in the dung, was largely dependent on the fraction of hard or impermeable seed in the sample. Soft seed swelled on imbibition, the seed-coat ruptured, and seeds became fragmented especially after 70 h in the digestive tract (...)