Effect of inclusion rate and chop length of lucerne (medicago sativa) silage in a total mixed ration with maize (zea mays) on milk yield and composition in dairy cattle

摘要

Utilising legume silages in dairy systems reduces the need for inorganic fertiliser use for forage production, which has both economic and environmental benefits. Combining lucerne, which is high in rumen degradable protein, with maize as a source offermentable energy in the ration can enhance microbial protein synthesis. Furthermore, lucerne chop length can alter the rate of particle breakdown in the rumen. Longer chop lengths increase physically effective neutral detergent fibre (peNDF) and stimulate chewing and saliva production, which benefits rumen pH (Zebeli et al., 2006). However, shorter chop lengths increase dry matter intake (DMI), which can increase milk yield and energy balance (Kononoff and Heinrichs, 2003). The hypothesis of this study was that lower lucerne inclusion and shorter chop length would increase DMI and milk yield.