Nutritional value of Spanish Camelina sativa co-products for pigs

This study evaluated and compared the digestible energy (DE) and metabolizable energy (ME) and the coefficient of ileal standardized digestibility (CISD) of crude protein (CP) and amino acids (AA) in camelina expellers (CAE) and camelina meal (CAM) for growing pigs. In Exp. 1, thirty-six barrows Pietrain × (Landrace × Large White) of 61.8 ± 2.83 kg body weight were allotted to 6 diets, a basal corn-soybean meal diet and 5 diets in which a proportion of the corn and soybean meal in the basal diet was replaced by CAE (100, 200 or 300 g/kg) or CAM (100 or 200 g/kg). The experiment lasted 15 days and during the last 5 days the total amount of feces and urine were collected to calculate the energy metabolizability of diets. The CTTAD of energy and DE and ME concentration in CAE and CAM were calculated by the difference procedure as well as by the regression method. In Exp. 2, thirty-three barrows Pietrain × (Landrace × Large White) of 82.0 ± 2.57 kg body weight were allotted to three treatments, two cornstarch-based diets containing 350 g/kg CAE or 300 g/kg CAM as the sole source of CP and AA and a N-free diet. After 7 days of feeding, animals were euthanized and ileal digesta were sampled. The CISD of AA on CAE and CAM was determined using the direct method. Camelina meal had a greater concentration of CP and AA and a lower ether extract than CAE. The most abundant indispensable AA were arginine, leucine, valine, and lysine in both ingredients (26.3, 21.9, 19.1 and 16.2 g/kg dry matter (DM) in average, respectively). Camelina expellers contained 8.0 g/kg DM more soluble and 4.6 g/kg DM less insoluble fiber than CAM. The CTTAD of energy was 0.682 and 0.665 in CAE and CAM, respectively, when calculated using the difference method, and 0.665 and 0.655 in CAE and CAM, respectively, when estimated via the regression method. The DE and ME were on average greater (P < 0.05) for CAE compared with CAM both, using the difference or the regression method (DE, in average:14.3 MJ/kg DM and 13.1 MJ/kg DM, respectively and ME, in average: 14.1 MJ/kg DM and 12.9 MJ/kg DM, respectively). Between methods, no statistical differences were detected. The CISD of CP was greater (P < 0.05) in CAM compared with CAE (0.579 in CAE and 0.670 in CAM). The most digestible essential AA in both ingredients were methionine, arginine and histidine, with average digestibilities of 0.77, 0.75 and 0.83, respectively. The CISD of leucine and cysteine was greater in CAM compared with CAE (P < 0.05). In conclusion, CAE had greater energy value than CAM, whereas the digestibility of leucine and cysteine was less in CAE than in CAM, probably due to the greater concentration of soluble dietary fiber in CAE.