Jens Gudike Fly Christensen runs the Enghave farm north of Skive in Jutland, producing some 20,000 slaughter pigs annually. The farm’s climate accounting shows that the combined CO2-emissions are already substantially below the average of the climate-controlled farms on the Climate Track.

In September 2019, the average was 223 kg CO2-eq per pig for the climate-controlled farms, while emissions from Jens’ pigs in 2019 were only 209.7 kg CO2-eq per pig.

This also marks a 12 per cent reduction relative to the average CO2 emissions from Danish pig production in 2016 and is already notably lower than the average 2022 target for certified farms of 212.5 kg CO2-eq per pig.

As a result, Jens has defined an even more ambitious target for 2022 – reducing emissions to 199.9 kg CO2-eq per pig.

Frequent discharge of slurry

Frequent discharge of slurry from the buildings accounts for a full 46 per cent of the CO₂ reduction that Jens has achieved per pig since 2016. The slurry is collected in slurry containers below the pigsties and discharged once a week directly from the buildings into tankers, which transport the slurry to a biogas production facility while it is fresh. This helps ensure a high gas yield and reduces the evaporation of ammonia and the harmful greenhouse gas methane.

In one third of the buildings, the pigsties also have a partially solid floor – in other words an area with straw bedding where the pigs can rest and an area with slatted floors where the pigs relieve themselves. This means the slurry containers under the slatted floor areas have a smaller surface area, resulting in less ammonia evaporation, which is not only good for the climate, but also for the indoor climate in the buildings. The solid floor and straw bedding also means better welfare.

Slurry used for biogas and fertiliser

Jens delivers some 11,000 tonnes of slurry each year for biogas production, thus providing many homes with gas. The degasification of slurry accounts for 31 per cent of the CO₂ reduction achieved since 2016.

Tankers collecting fresh slurry deliver degassed slurry at the same time, which Jens uses as fertiliser on his fields.

Degassed slurry seeps more quickly into the soil than slurry that has been spread directly onto the fields, thereby reducing both CO2 emissions and odour nuisance in connection with slurry spreading. Furthermore, plants can more easily absorb nitrogen from degassed slurry, and by using a GPS on the slurry spreader Jens is able to fertilise his fields very precisely and achieve minimal leaching of nitrogen from the fields.

Optimised feed consumption

In recent years, Jens has made a dedicated effort to optimise the feeding of this pigs, and these efforts account for the remaining 23 per cent of the CO2 reduction he has achieved since 2016. Feeding routines have been changed so that the pigs are fed every six hours and thus get hungry before they are fed. This has resulted in a 6 per cent increase in daily weight gain for the pigs with the same volume of feed, which is good both for the climate accounting and the farm’s profitability.

Coupled with frequent supervision of the pigs and thorough cleaning in the buildings, the changed feeding routines have also reduced pig mortality to around 1.8 per cent. A low mortality rate means more pigs relative to the farm’s feed consumption and, by extension, a lower climate impact.

The feed mixtures Jens uses consist of around 80 per cent locally produced grain and about 2 per cent minerals. However, the mixtures also contain up to 18 per cent imported ground soy, which is an important protein source. Going forward, Jens will team up with his feed supplier to ensure the soy derives from producers who can document sustainable production processes.

Jens plans to further optimise feed consumption in the coming years. Together with his regular supplier of weaners he intends to breed pigs that digest feed optimally and so ensure the lowest possible consumption of feed. He also plans to ensure the composition of the feed is carefully adjusted to the age of the pigs. Moreover, he aims to limit feed waste in his feed system and loss of nutrient value in connection with storage. These initiatives will place Jens well on the way to meeting his ambitious 2022 targets.