Degradability of Forages in Sacco

Rumen degradability of freeze dried silages of grasses and red clover was observed by incubation in sacco in dairy cows. Later cutting lowered the degradability of organic matter (OM) and protein (N) with some differences between grass species, and with clover rather less affected than grasses. Non linear regression constants confirmed that clover silages lost less OM and N initially, but further losses occurred at a faster rate than for grass silages. Losses of OM and N equalled more in clover than grasses. Formic acid treatment lowered initial losses of N but increased further losses of N as well as OM. Effective protein degradability (EPD) was lowered by later cutting. Stipulated outflow rate from the rumen affected EPD slightly differently for grass and clover silages. EPD differed neglibly between silages according to treatment.