In vitro biohydrogenation and total tract digestibility of oleamide by sheep

Disappearance of cis‐18:1(n‐9) from ruminal in vitro cultures supplemented with either oleic acid or oleamide was measured over 48 h to determine if the amide resisted biohydrogenation. Oleamide added to the substrate maintained higher concentrations of cis‐18: 1(n‐9) in the microbial cultures at 24 and 48 h of incubation compared to substrates with added oleic acid. Disappearance rates of cis‐18: 1(n‐9) from the cultures, which were calculated as a measure of biohydrogenation, were 0·064 and 0·025 h−1 for the oleic acid and oleamide supplements, respectively. Four sheep were fed four diets (control, 42 g kg−1 oleic acid, 23 g kg−1 oleamide, and 45 g kg−1 oleamide) in a 4×4 Latin square to determine how the amide affected fatty acid digestibility. Total tract digestibilities of protein and fibre were not affected (P>0·05) by either oleic acid or oleamide compared to the control diet. Fatty acid and energy digestibilities were not changed (P>0·05) by oleic acid, but were increased (P