Increasing feed conversion efficiency in automatic milking systems: The impact of grain-based concentrate allocation and kikuyu (Pennisetum clandestinum) pasture state on kikuyu pasture digestibility

摘要

Automatic milking system (AMS) farms, rely upon voluntary cow traffic (the voluntary movement of cattle around a farm) for milk harvesting and feed consumption. Dairy cows on a pasture-based AMS farm typically move from depleted to fresh allocations of pasture in small groups, or individually, at differing times. The first cows moving to an allocation of fresh pasture get access to rapidly fermentable, ad libitum, high quality pasture in contrast to those cows accessing the same allocation towards the end of the access period. At the same time, grain-based concentrate (GBC) is allocated independent of the pasture state that cows access. Inclusion of a high level of GBC in the diet with high or low nutritive value forage, or variable states of forage, may create dramatic variations in rumen fluid pH, which may induce subacute ruminal acidosis (Bramlcy 2004), reduce feed conversion efficiency and negatively impact animal health. The aim of the current study was to determine the impact of pasture state and GBC allocation on the digestibility of kikuyu pasture.