Partial substitution of concentrates by maize silage in rations for organic dairy cows and its influence on performance and utilization efficiency

Summary in the original language of the document

The aim of the present study was to investigate the influence of partial substitution of purchased concentrates with maize silage on feed intake, energy and nutrient supply, milk production and feed utilization efficiency in organic dairy cows.
In the experiment, two winter rations were compared. In the experimental group (E) 2/3 of average herd concentrate intake were replaced by maize silage. In group E total dry matter, protein und energy intake was significantly lower than in the control group (C) (16.3 and 17.8 kg, 99 and 110 MJ NEL, 2170 and 2460 g crude protein, respectively). Milk yield decreased in group E by 1.7 kg, which was not statistically significant. Ruminal nitrogen balance and dietary protein to energy ratio was significantly lower in group E as compared to group C (-8 and 22 g, 21 and 24 g/MJ NEL, respectively). The diet for group E had no effect on milk composition, except milk urea content, which was in tendency lower in group E (15 and 17 mg 100ml-1). Estimated milk yield from forage was considerably higher in group E (15.9 vs 13.5 kg). Efficiency of nitrogen (N) utilization was tendencially higher in group E.