Net Energy Content 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 content 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 × Landrace) × Duroc] with an average body weight (BW) of 16.8 ± 1.4 kg (mean ± SD) 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 Mixed1 diet contained 67.52% corn, 20.0% SBM, and 10.0% CC, and the Mixed2 diet 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 BW^0.60 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 and SBM were 3,348, 3,254, and 2,579 kcal/kg and 3,626, 3,405, and 2,129 kcal/kg, respectively, whereas, respective values for CC were 3,755, 3,465, and 2,383 kcal/kg. No differences between the predicted and determined DE, ME, and NE were observed in the two mixed diets. Differences between predicted and determined DE, ME, and NE values for the Mixed1 diet were 29, 13, and 20 kcal/kg, respectively. Respective values for the Mixed2 diet were 47, 38, and 38 kcal/kg (as-fed basis), respectively. In conclusion, the DE, ME, and NE of CC were 3,755, 3,465, and 2,383 kcal/kg, respectively. In addition, the observed additivity of energy values in the mixed diets indicates that the CC can be used to accurately formulate swine diets.