Digestible, metabolizable, and net energy of camelina cake fed to growing pigs and additivity of energy in mixed diets

This experiment was conducted to determine the DE, ME, and NE contents of camelina cake (CC) and to test the hypothesis that dietary glucosinolates originating from CC will affect the additivity of energy in mixed diets containing different inclusion levels of corn, soybean meal (SBM), and CC. A total of 30 growing barrows ([Yorkshire x Landrace] x Duroc) with a mean BW of 16.8 kg (SD 1.4) were randomly allotted to 1 of 5 treatments with 6 replicates per treatment. Pigs were fed experimental diets for 16 d, including 10 d for adaptation and 6 d for total collection of feces and urine. The 5 experimental diets consisted of 3 corn-based diets to determine the DE, ME, and NE of the 3 ingredients (corn, SBM, and CC) and 2 mixed diets to test the additivity of DE, ME, and NE. The corn diet contained 97.52% corn; the SBM diet contained 67.52% corn and 30.0% SBM; the CC diet contained 67.52% corn and 30.0% CC; the Mixed diet 1 contained 67.52% corn, 20.0% SBM, and 10.0% CC; and the Mixed diet 2 contained 67.25% corn, 10.0% SBM, and 20.0% CC. Vitamins and minerals were included in the diets to meet or exceed the requirements for growing pigs (NRC, 2012). Pigs were fed their assigned diets at 550 kcal ME/kg BW0.60 per day on the basis of BW on d 1, 5, and 10, which was close to ad libitum intake. Pigs had free access to water. Determined DE, ME, and NE contents of corn were 3,348, 3,254, and 2,579 kcal/kg, respectively; those of SBM were 3,626, 3,405, and 2,129 kcal/kg, respectively; and those of CC were 3,755, 3,465, and 2,383 kcal/kg, respectively. No differences between the predicted and determined DE, ME, and NE were observed in the 2 mixed diets. In conclusion, DE, ME, and calculated NE content of CC fed to growing pigs were 3,755, 3,465, and 2,383 kcal/kg (as-fed basis), respectively. In addition, additivity of DE, ME, and calculated NE was observed in the mixed diets containing corn, SBM, and CC, which indicates that dietary glucosinolates originating from up to 30% of CC inclusion do not affect DE, ME, and calculated NE of diets.