Inclusion levels of tree and herbaceous legumes on nutritive quality of grass silage : results from on-farm trials

Samenvatting

The escalating prices of protein concentrate supplements and increasing demand for dairy products in Ethiopia call for preservation of surplus forage during the growing season, to be fed to dairy cows at time of feed shortage. The objective of this on-farm study was to evaluate the nutritive quality of Napier and Desho grass silages with tree legume (sesbania) and herbaceous legumes (alfalfa, lablab, and faba bean) as legume components. Napier or Desho grasses were ensiled in bags with each legume at 0, 20, 30 and 40% inclusion levels (fresh weight). Replicates included nine and six farms in Mecha and Ad’aa districts, respectively. Silage bags were opened after 60 days, samples were taken for chemical analyses and evaluated for physical features. Data were analyzed using a completely randomized design in SPSS and differences among means separated using Duncan’s. Silages were firm at Mecha and fairly firm at Ada’a. No mold appeared. pH values varied from 3.94 to 4.5 and increased (p < 0.001) with increasing levels of legume inclusion. The crude protein values followed a similar pattern to that of the pH. The fiber contents, NDF (p < 0.001) and ADF (p < 0.05/p < 0.01) declined while that of ADL increased (p < 0.001) with increasing legume inclusion levels. The different legume-based silages were assessed as highly palatable and revealed that the use of tree and herbaceous legumes can improve the nutritive quality of grasses.