THE EFFECT OF WHOLE SUNFLOWER SEEDS ON THE FLOW OF FAT AND FATTY ACIDS THROUGH THE GASTROINTESTINAL TRACT OF CANNULATED HOLSTEIN STEERS

Abstract

Four cannulated (rumen, abomasum and ileum) Holstein steers were randomly allotted to four experimental diets in a 4 × 4 Latin square design. Diets contained (1) 4% sunflower oil (SFO); (2) 10% whole sunflower seeds (WSS); (3) 20% WSS and (4) 10% canola meal (LFCM). Dysprosium was used to calculate the flow of the particulate digesta through the gastrointestinal (GI) tract. The ratio of rumen acetate to propionate was increased (P < 0.05) when the LFCM diet was fed compared to when the three oil- or seed-containing diets were fed; there were no differences (P < 0.05) among the oil- or seed-containing diets. Apparent output of fat from the rumen compared to dietary intake was increased (P < 0.05) for all diets except SFO. Differences in fatty acid flow among the four diets diminished (P < 0.05) as the fat flowed through the GI tract. There was a decreased (P < 0.05) output of linoleic acid and an increased (P < 0.05) output of stearic and palmitic acids in the rumen compared to the dietary intake. The three oil diets had a higher (P < 0.05) flow of octadecanoic acids through the GI tract than the LFCM diet, and only the flow of stearic acid through the rumen differed (P < 0.05) among the three oil diets. Apparent digestibilities of dry matter (DM), crude protein (CP), and energy were not different (P < 0.05) among the four diets. Fiber digestibility was unaffected by the increasing fat levels. Fat digestion coefficients increased with increasing dietary intake of fat, and calculated true digestibility of sunflower oil was 83.4%. Key words: Sunflower seeds (whole), fatty acid flow, gastrointestinal tract (lower)