Local protein sources for growing-finishing pigs and their effects on pig performance, sensory quality and climate impact of the produced pork

The public demand for increased sustainability and reduced climate impact of the pork production incites using high yielding local protein sources as substitutes for the imported protein used presently. Substitution must be done without compromising the productivity, which could counteract the positive effect on climate impact.The aim of the study was to document the effects of replacing imported protein with local protein sources on animal productivity, meat quality and climate impact of pork production. Soybean and sunflower meal represented imported protein (group 1), and biorefined Green protein in combination with fava beans (group 2) and a price-competitive feed with fava beans and rapeseed cake (group 3) presented the local protein. Groups of 120 pigs were fed one of the three diets from 30 kg and until slaughter.Daily growth was not affected by diet, however daily feed intake was higher in group 2 (2.82 kg/pig/day) compared to group 1 and 3 (2.74 kg/pig/day and 2.70 kg/pig/day, respectively) (P=0.0039). Feed conversion ratio (FCR) was lower in group 3 (2.47 kg feed/kg gain) compared to group 1 and 2 (2.52 kg feed/kg growth for both) (P=0.033). Sensory evaluation reported that meat from group 3 was more tender (P=0.003) and with lower chewing time (P<0.0001). The diet did not affect taste or odour of the meat. The carbon footprint (CF) per kg live weight (LW) of pig at farm gate was 10% lower for group 3 compared to group 1, and when the contributions from soil carbon changes and direct land use change (dLUC) were included, CF for group 3 pigs on the price-competitive local protein was 25 % lower than CF for group 1 pigs on imported protein. In this scenario, the CF of diet 2 was assumed to equal that of diet 3, and thereby CF of Green protein was quantified to 290 g CO2/kg DM.In conclusion, imported protein sources can be substituted with local protein without adverse effects on animal productivity. Biorefined Green protein can be included without compromising feed efficiency and meat sensory profile. The study demonstrated potential to reduce CF of pork by using feed with only locally produced protein sources like fava beans and rapeseed cake, and probably also Green protein, as the feeding trial indicated that local protein sources can successfully be sustainable alternatives to imported protein. However, further studies are needed to quantify the climate and environmental impact of Green protein.

Automated summary

Replacing imported protein with local protein sources in pork production can improve animal productivity and reduce climate impact without adverse effects on meat quality. Using locally produced protein sources can lower the carbon footprint of pork and potentially provide sustainable alternatives to imported protein. Further studies are needed to quantify the climate and environmental impact of Green protein.