Die Bodenkultur - Journal for Land Management, Food and Environment
L. GRUBER and R. STEINWENDER:
Nutrient and mineral supply of dairy cows by forage
Results of an investigation in practical dairy farms of Austria
From 1978 to 1990 the feed intake of cows was investigated in 40 practical dairy farms of Austria (Lower Austria, Styria, Carinthia), combined with chemical analysis of the feed stuff. Because of repeated measurements in some farms the whole number of the data set was N= 71. The farms were investigated by the work of the farming extension service because of infertility and metabolism problems as well as to view the forage situation. The farms (the mean annual yield per cow was 5390 ± 850 kg milk) were controlled by the official performance recording. The milk yield was recorded during the feed intake measurements or at least near this time. The feed intake was recorded - as a mean of the herd by the farmer assisted by an advisor or a milk recorder during one to seven days. The mean forage intake was 15.5 kg DM in summer and 11.8 kg DM in winter.
Most of this difference was due to the different energy concentration of the forage (5.65 and 5.08 MJ NEL) and the different amount of concentrates (2.1 and 3.3 kg DM) in these both saisons. The theoretical milk yield from the forage (according to the NEL supply) amounted to 7.2 kg ECM in winter and 15.5 kg ECM for the summer rations (i.e. 4001 kg assuming 200 days for winter feeding and 165 days for summer feeding). The main results of these investigations allowed to derive some basic trends for different types of forage rations (effects of maize silage, legumes and root-crops) for the level of forage intake, protein supply and mineral status.
Varying results were observed between the farms. Also the content of the feed stuffs was differing in a wide range. In conclusion, it seems necessary for daily feeding practice and for supplementing required nutrients and minerals to measure feed intake of the dairy cows as well as to analyse the feed stuff.
Key words: dairy cows, feed intake, nutrient supply, rations.