• Use mainly renewable resources that have a minimal dairy carbon footprint
• Create happy and healthy dairy cows that use minimal amounts of antimicrobials
• Ensure profitability because healthy dairy cows produce healthy and nutritious animal proteins, both now and in the future.

Sustainable dairy farming has many different elements that are all interrelated. An integrated programme with sustainable dairy farm practices is therefore required.

The carbon footprint of a dairy farm is mainly related to the production of greenhouse gasses. Greenhouse emissions can come directly from the cow or can be related to the farm operations. A clear example of the latter is the CO2 which is produced because the farm uses fossil fuels to produce energy. Another less well-known example is the use of fertilizer. About 2% of the global fossil energy sources are being used for the production of fertilizer every year, resulting in a significant dairy carbon footprint.

How to make dairy farming more sustainable? Healthy dairy cows on a farm produce 3 different greenhouse gasses that potentially increase the dairy carbon footprint: carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4):

• Dairy cows produce a lot of carbon dioxide, but this is a circular process: plants use CO2 and water to produce sugars and oxygen, the cow uses these plants and oxygen to produce energy and CO2 (see Figure 1). Most of the CO2 emission of a dairy farm comes from the farming operations.
• Nitrous oxide is mainly released when manure is injected into the soil.
• When the feed the cow eats is fermented in the rumen, there is enteric production of methane (CH4). Most of this enteric CH4 is expelled through belching. A small percentage of enteric CH4 is produced in the cow’s large intestine and then expelled. Next to enteric production of CH4, there is also production of CH4 via manure after this manure has been produced by the cow. Methane has a big impact on the dairy carbon footprint because the greenhouse gas effect is 34 times bigger than the greenhouse gas effect of CO2.

Several strategies to reduce greenhouse gas emissions of a dairy farm exist. Most of these sustainable dairy farm practices are based on increasing the efficiency of production, resulting in an increase of lifetime production, an increase of income over feed costs of the dairy farm and a reduction of the dairy carbon footprint. It is also possible to influence the rumen fermentation of healthy dairy cows with feed additives in such a way that carbon emission shifts away from methane. Selko IntelliBond is an example of a feed additive that reduces the carbon footprint of a daiy farm because it improves feed efficiency. Selko Fytera Balance is an exmaple of a feed additive that has a direct effect on the carbon footprint because it reduces CH4 production as result of rumen fermnation, next to improving feed efficiency.

Storage and injection of cattle manure into the soil can increase the dairy carbon footprint because it results in production of methane (CH4), ammonia (NH4), nitrous oxide (N2O) and sulphur dioxide (SH2). Next to that, injection of cattle manure into the soil creates environmental issues because of the odour and the deposition of phosphorus. There are sustainable dairy farming methods to reduce methane emission from manure.

Most of the health problems on a dairy farm are directly or indirectly related to poor transition to lactation. Poor transition management of dairy cows increases the incidence of metritis, mastitis and lameness. These problems are responsible for a large proportion of the use of antibiotics on a dairy farm. Thus, reducing transition problems in dairy cows improves efficiency of production, leading to a reduction of greenhouse gas emission per kg of milk produced. Sustainable dairy farming practices that improve the transition to lactation also result in a significant reduction of antimicrobial use.

• Significant reductions of greenhouse gas emission per litre of milk produced can be achieved by using feed additives that reduce the carbon footprint of dairy farming. Additional opportunities to make dairy farming more sustainable are programmes to reduce the age at first calving, increase the production per lactation as well as the number of lactations per cow. Each of these sustainable dairy farming practices will result in an increase of profitability of the farm next to a reduction of the dairy environmental footprint.
• Many of the disease problems on a dairy farm are related to problems with the transition to lactation. Sustainable dairy farm practices that optimise transition management of dairy cows will result in a reduction of the incidence of disease and a reduction of veterinary costs. Healthy dairy cows are also more efficient and thus more profitable.
• Reducing the greenhouse gas emissions from manure means that the manure will be more suitable for biogas production with a higher yield of biogas from the same amount of manure while reducing the carbon footprint of dairy manure. Secondly, the manure will maintain more of its value to fertilise land, opening the possibility to reduce the purchases of artificial fertilizer, leading to a further reduction of the dairy carbon footprint.