Coupled dairy-beef systems are of major significance in Switzerland’s cattle sector. Using Swiss reference data, the present study modelled greenhouse gas emissions per cow and year for a range of different milk and meat yield levels. The study also determined the impact on greenhouse gas emissions of using a combination of sexed semen and beef bull semen respectively on dairy cows. The results have shown that the ratio of milk to meat production of a dual-purpose cow (around 24) corresponds almost exactly to the ratio in Swiss production overall in 2017 and in the years prior. Taking only milk yield into account, the greenhouse gas emissions per reference cow and year fall from 9,226 kg CO2eq. (dual-purpose cow) to 5,842 kg CO2eq. (high-yielding cow). Taking both milk and meat yields into account, the CO2 emissions of dual-purpose cows are lower than those of dairy cows. However, if for the insemination of dairy cows sexed semen is consistently used to produce replacements and beef bull genetics are used for all other inseminations, CO2 emissions at an annual milk yield of 10,000 kg (8,787 kg CO2eq.) are even lower than the emissions caused by a dual-purpose cow. For reasons of climate change mitigation, inseminations should consistently be carried out using sexed semen for replacements and beef bull genetics in other cases. For producers in mountain areas and for organic holdings the utilisation of dual-purpose breeds is expedient.
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.