Ruminal degradation and intestinal digestibility of camelina meal and carinata meal compared with other protein sources

Production of reneweable feedstocks for biodiesel have drawn attention to alternative oilseed crops. Our objective was to determine DM and CP ruminal degradability and intestinal digestibility of camelina meal (CAM) and carinata meal (CAR), compared with canola meal (CAN), linseed meal (LIN), soybean meal (SBM), and distillers dried grains with solubles (DDGS) as controls. In situ degradability measurements were done using 3 multiparous, mid-late lactation ruminally cannulated Holstein cows. Sample bags were ruminally incubated in duplicate for each cow and feedstuff for 0, 2, 4, 8, and 12 h and in triplicate for 24 and 48 h. Eight bags of each feed were incubated at 12 h for use of the residues in determination of in vitro intestinal digestibility. Ruminal particulate passage rate averaged 6.0%/h. Rate of DM degradation was greatest (P < 0.05) for CAM and LIN and least for DDGS, whereas CAR and SBM were similar. Ruminally degradable DM was greatest (P < 0.01) in CAM, CAR, and SBM. The CAM and CAR had the greatest (P < 0.05) RDP and least RUP. Intestinal digestible protein was similar (P > 0.05) for LIN, CAM, and CAR, which was greater (P < 0.05) than CAN and DDGS. Intestinally absorbable digestible protein was least for CAM and CAR (P < 0.01) compared with the other feeds. Total digestible protein was similar (P > 0.05) for CAM and CAR compared with SBM and LIN. Results indicate that CAM and CAR are highly degradable and comparable to SBM and LIN for protein utilization.