IN-VITRO BIOHYDROGENATION AND TOTAL TRACT DIGESTIBILITY OF OLEAMIDE BY SHEEP

Disappearance of cis-18 :l(n-9) from ruminal in vitro cultures supplem ented with either oleic acid or oleamide was measured over 48 h to det ermine if the amide resisted biohydrogenation. Oleamide added to the s ubstrate maintained higher concentrations of cis-18 : l(n-9) in the mi crobial cultures at 24 and 48 h of incubation compared to substrates w ith added oleic acid. Disappearance rates of cis-18 : l(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, re spectively. 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 x 4 Lati n 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 < 0.05) when oleamide was added to the sheep diets at 45 g kg(-1). These results show that oleamide resis ts ruminal biohydrogenation without impairing fatty acid digestibility . (C) 1998 SCI.