Evaluation of corn cob mix in organic finishing pig nutrition

Two consecutive experiments were performed to evaluate corn cob mix (CCM) inclusion in an organic diet. The experiments were performed in an organic barn on nine pens of four pigs (two barrows and two sows) of commercial breeds from 45 kg to slaughter. In the first experiment, an organic concentrate was mixed with organic CCM-silage to obtain three concentrate:CCM ratios of 1:0, 4:1 and 3:2 (w:w). In the second experiment, three concentrates were produced to obtain diets with equal nutrient levels on a dry matter basis after 0, 200 and 400 g kg(-1) CCM inclusion respectively. In all groups of both experiments, meat and carcass traits were comparable with common practice and differences between treatment groups were not seen. Feed conversion ratio on an as-fed basis was worse with higher CCM levels in the diet, most likely due to the dilution effect by the lower dry matter content of CCM. In the first experiment, pigs on a higher concentrate:CCM ratio showed a higher feed intake, indicating a compensation for the lower energy density of these diets. In the second experiment, the 400 g kg(-1) CCM group showed a lower daily dry matter intake (p = 0.048) leading to slower growth (p = 0.015). This indicated a bulk effect of the CCM in this case. In conclusion, lean carcasses with good meat quality can be obtained even in situations where up to 400 g kg(-1) organic CCM-silage is included in a balanced organic pig fattening diet. Moreover, a bulk effect of CCM-silage can be used in some cases to limit the typically high dry matter intake in outdoor pig fattening, thereby preventing excessive fat accretion. (c) 2005 Society of Chemical Industry.