In regions with high density of animal production, Import/Export-balances (IMPEX) are used to monitor the use of diets with reduced P- and N- concentrations. Based on the IMPEX data, the farms can claim a reduction in waste nutrients. The aim of the presentment study was to analyze 1665 IMPEX-balances from pig farms in the state of Lucerne (Switzerland). All data were from 2008. The data from 899 grower/finisher farms were analyzed in more detail and N-efficiencies (N-Export/N-import) estimated. The average N-efficiency for grower/finisher farms was 32 % with an average dietary crude protein (CP) concentration of 159 g/kg (13,74 MJ DE). The between farm comparison showed a large farm effect on both, N-efficiency and N-output as manure. Only a minor portion of this variation could be explained by feeding strategy. The data suggest that a large optimization potential for N-efficiency exists with respect to production technique, animal health and overall farm management. The N-efficiency in grower/finisher farm is a good indicator for the evaluation of good farm practices. However, in farrowto finish operations, it is very difficult to evaluate the N-efficiency for different production phases.
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.