Power maize silage (WPMC) – a mixture of whole-plant maize and cobs used in cattle fattening – has different characteristics from whole-plant maize (WPM). A digestibility test was carried out to determine the nutritional value of WPMC, study the influence of the composition of the ration and verify the application of equations predicting digestibility. Four rations comprising 20 %, 50 %, 80 % or 100 % WPMC silage and hay were fed to wethers. Compared to the nutrient content of a maize silage containing 55 % cobs published in the tables, WPMC had a 58 % higher starch content, a 34 % higher fat content, a 31 to 62 % higher fatty-acid contents and an approx. 30 % lower parietal constituent content. The higher the WPMC content of the rations, the less favourable the digestibility of the parietal constituents. Digestibility of the organic matter, crude protein and cell walls (NDF) of power maize silage was not influenced by the composition of the ration (P > 0.1). The equation for whole-plant maize correctly predicted the digestibility of power maize silage from rations containing 50 to 80 % WPMC; with 100 % power maize silage, the equation for non-whole-plant maize was more appropriate. WPMC obtained energy values (NEL, NEV) 10 to 13 % higher than those of a common maize silage.
Pontiggia A., Münger A., Ammer S., Philipona C., Bruckmaier R. M., Keil N.M., Dohme-Meier F.
Even in temperate climate zones, an increase in the ambient temperature and solar radiation can cause heat stress in grazing dairy cows. Agroscope studied the physiological changes in cows caused by increasing heat load.
Lazzari G., Münger A., Heimo D., Seifert S., Camarinha-Silva A., Borda-Molina D., Zähner M., Schrade S., Kreuzer M., Dohme-Meier F.
In dairy cows, herbage-based diets often lead to increased nitrogen excretion. Tanniferous sainfoin and extract of acacia can reduce nitrogen excretion from urine and thus ammonia volatilization from slurry.
Excessive nitrogen inputs from the air lead to over-fertilisation of sensitive ecosystems. Continuous feeding optimisation can make an important contribution to reducing ammonia losses and thus nitrogen inputs.