Supplementing steers up to 43 % canola meal had no negative effects on either ruminal parameters or the degradation characteristics of lucerne hay

Abstract

Interpreting in sacco and in vitro results needs to be undertaken with caution, as many variables, such as diet, can influence the rate of degradation and degradation kinetics. Four ruminal fistulated donor steers were fed rations based on low quality cereal roughages with one of four inclusion levels of canola meal, viz. 0 % (control), 13 %, 27 % or 43 % on a DM basis. Two degradation methods, in sacco and in vitro Ankom Daisy™ incubation, were used to determine the degradation kinetics of ground lucerne hay (lucerne standard) over 72 h Supplementing donor steers up to 43 % canola meal had no negative (P > 0.05) effects on the degradation of the ground lucerne standard, regardless of which incubation method was used. The average ruminal NH₃-N concentration increased (P < 0.001) with increasing levels of canola meal in the ration, while total volatile fatty acid concentrations and molar proportions were within the normal range for microbial synthesis. Average ruminal pH was not affected (P > 0.05) by the ration fed to the steers and did not decrease below 6.3, indicating canola meal was safe to include at 43 % in a basal, low-quality ration for cattle.