In a feeding trial set up as a 2 x 2 factorial design, the effect of 30 g and 40 g of potassium per kg of DM in a diet containing 100 % or 200 % of Swiss sodium recommendations on mineral metabolism and on selected parameters of 12 dairy cows was investigated. The desired K and Na contents were adjusted by feeding hay differing in its natural K content and by varying NaCl supplementations. The experimental rations contained comparable energy, protein and mineral concentrations, except for K, Na and chloride. Hay was offered close to ad libitum, though within a same block cows were fed the same amount. Concentrate allowances were constant. After an adaptation period of 47 days followed a balance period of 2 x 4 days with quantitative faeces and urine collection.Increasing K supply from 30 g to 40 g per kg of diet DM resulted in a significant higher water consumption (103 l/cow, day; 119 l/cow, day) and urine production (30 kg/cow, day; 52 kg /cow, day). Mg digestibility tended to be reduced (10 %; 5 %). Ca, P, Mg, Na, and Cl retention did not differ significantly between the two K levels. Likewise, milk mineral content – except for Iodine – remained unaffected. The diet containing 40 g of K compared to 30 g of K significantly decreased iodine milk content from 1.04 mg/kg DM to 0.74 mg/kg DM. With respect to K, Na and Cl serum concentrations, the two dietary K levels had no biologically relevant effect. The high K supply, however, caused an intensified alkalization of the metabolism.
Although milk-production oriented (MPO) cow breeds have also become established in the mountain region, farms with the dual-purpose ‘Original Simmental’ breed are proving to be economically viable, with lower costs and higher direct payments making up for lower revenues from milk.
High milk yields before drying-off increase the risk of udder infections during the dry period. An online survey highlights what drying-off methods are currently used and how farmers rate the ‘incomplete milking’ approach for reducing milk yield.
Herholz C., Siegwart J., Bruckmaier R.M., Rytz E., Lamon I., Muhr M. und Stirnimann R.
In both sport and alternative agriculture, horses are once again being used as draught animals. Efficient power transmission plays an important role in the wellbeing of draught horses.