Our objective was to determine DM and CP ruminal degradability and intestinal digestibility of camelina meal (CM) and carinata meal (CR) compared with other oilseed meals, soybean meal (SBM) and reduced-fat distillers dried grains (DG). In situ measurements were done using 3 multiparous, ruminally-cannulated Holstein cows (BW 848.6 ± 94.7 kg). Six feeds were evaluated: CM, CR, canola meal (CN), linseed meal (LN), DG, and SBM. Duplicate 5 g samples were weighed into 10 × 20 cm nylon bags and ruminally incubated for 0, 2, 4, 8, 12, 24 and 48 h. Six additional bags of each feed were incubated at 12 h for use in determination of in vitro intestinal digestibility of CP. Residues were incubated with pepsin and pancreatin solutions for 1 h and 24 h, respectively. Rumen degradation constants for DM and CP were estimated using the NLIN procedures in SAS 9.3. Intestinally digestible protein (IDP), intestinally absorbable dietary protein (IADP = ruminally undegradable protein (RUP) × IDP), and total digestible protein (TDP = ruminally degradable protein (RDP) + IADP) were evaluated using MIXED procedures in SAS. Ruminally degradable DM (RDDM) was greatest in CM, CR, and SBM. The CM and CR had the greatest RDP and least RUP of the feeds. The IDP was less in CM and CR compared with SBM and LN, but greater than CN and DG. The CR and CM had less IADP compared with the other feeds. The TDP was similar for CM and CR compared with SBM and LN, but greater than CN and DG. Overall, results indicate that CM and CR are highly degradable in the rumen and are comparable protein sources to SBM and LN for total digestibility. Table 1.

Item	CM	CR	CN	LN	DG	SBM	SEM
CP, % DM	40.9	43.9	45.3	40.4	35.0	53.9	—
RDDM, % of DM	65.0a	63.0a	50.9c	55.8b	50.8c	65.0a	0.64
RDP, % of CP	76.4a	70.5b	52.0d	61.2c	44.1e	58.4c	0.95
RUP, % of CP	23.6e	29.4d	48.0b	38.8c	55.9a	41.6c	0.95
IDP, % of RUP	80.9b	80.9b	70.9c	81.6b	63.2c	90.5a	2.61
IADP, % of CP	19.1c	23.8c	34.0ab	31.7b	35.4ab	37.6a	1.42
TDP, % of CP	95.5a	94.4a	86.0b	92.9a	79.5c	96.0a	1.22

^a–eValues with unlike superscripts differ by P < 0.05.