Relationship between carbon dioxide production and performance in cattle and pigs

Abstract. An extensive number of metabolic experiments have been carried out at the former Oskar-Kellner-Institute, now the ›Oskar Kellner‹ Research Unit of Nutritional Physiology at the Research Institute for the Biology of Farm Animals (FBN), Dummerstorf, on cattle, pigs and humans. Their expired amounts of CO₂ having been compiled and stratified with regard to various performance and nutrition levels. The annual CO₂ emission of a 700 kg cow with an annual milk yield of 10 000 kg has been estimated to be 4.7 t. With increasing food intake and performance, a concomitant increase of CO₂ production per time unit has been observed. However, with increasing performance, we have determined a strong decrease of CO₂ output per mass unit of animal-derived food (i.e. meat and milk). This decrease amounts to 40 % when comparing cows with 4 000 kg and 8 000 kg annual milk yields. The CO₂ emission per kg dry matter (DM) intake amounts to 0.55 kg and is relatively constant, irrespective of live weight and performance. According to this, the world cattle livestock of 1.3 thousand million (UK)/billion (US) individuals produce 6 % of the total yearly CO₂ emission of 30 thousand million (UK)/ billion (US) t. Similarly, in pigs, increasing daily weight gains of an additional 200 g result in a reduction of 10–15 % of CO₂ emissions. Sows produce 1.5–1.7 kg CO₂ daily; fattening pigs and humans each produce 1 kg CO₂.