Brassica carinata (Yellow: AAC A110; Brown: 110915EM) are newly developed oil crop lines for bio-fuel industry. However, there is little research on chemical profile, nutritive value and biodegradation characteristics of seeds as a feed source for animal diets. The objectives of this study were to systematically determine (1) chemical composition, (2) energy values, (3) protein fractions, (4) rumen protein degradation kinetics of the new yellow and brown carinata lines in comparison with brown commercial canola seeds, and to provide detailed information for feed registration in Canada. The 2 carinata lines were bred by Agriculture and Agri-Food Canada, and 2 sources of seeds were combined for each line. Four cannulated lactating dairy cows were used for rumen degradation trial. Protein fractions were partitioned based on Cornell Net Carbohydrate and Protein System (CNCPS). Statistical analyses were performed using PROC MIXED procedure of SAS 9.3 with significance declared at P ≤ 0.05. The results showed that yellow carinata seeds were higher than canola seeds in crude protein, non-protein nitrogen but lower in neutral detergent insoluble crude protein and acid detergent insoluble crude protein (P ≤ 0.05). Yellow carinata seeds were not significantly different from canola seeds in total digestible nutrient (TDN) and energy values, while brown carinata seeds had the lowest TDN and energy values. Results from CNCPS indicated that yellow carinata seeds were lower in unavailable protein C fraction and higher in true protein (P ≤ 0.05), while brown carinata seeds had no significant difference with canola seeds in protein subfractions. Yellow carinata seeds had more rumen undegraded feed crude protein (RUP) and effective degradability of feed crude protein (EDCP) than canola seeds. In conclusion, Brassica carinata have potential to be utilized as a good feed protein source compared with commercial canola seeds, and the yellow carinata line had a higher protein supply than the brown line.