Influence of pectin on intestinal digestion of chromogens in steers

• Intestinal pectin infusion decreased the βcarotene and chlorophyll-b absorption in the small intestine.
• The high-dose of intestinal infusion of pectin in intestine did not affect the digestion of organic matter.
• Pectin administration offers an alternative to reduce the yellow pigmentation in adipose tissue of grass-fed cattle.

The study was conducted to determine the effect of duodenal infusion of pectin on the intestinal digestion of chromogens in order to project future research to reduce the yellow pigmentation in adipose tissue of grass-fed cattle. Four steers (462.5 ± 48 kg) with cannulas in the rumen and proximal duodenum were used in a 4 × 4 Latin square design to evaluate the effect of duodenally infused pectin on intestinal digestion of β-carotene and chlorophylls-a and -b. The basal diet consisted of 97% alfalfa hay and 3% of a mineral premix. Dry matter intake was restricted to 9.6 kg/d. All steers were infused with 2.97 g d−1 β-carotene via the ruminal cannula. Chromium oxide was administered simultaneously with β-carotene as an inert digesta marker. Experimental treatments consisted of daily infusions of 0 (saline alone), 18.5, 46.25, and 92.5 g d−1 of pectin. Infusion of treatments into the pyloric region of the abomasum was accomplished using a drip line inserted via the duodenal cannula and regulated to dispense respective treatments over a period of approximately 10 min every 3 h. There were no treatment effects on intestinal digestion of OM. Pectin infusion did not affect (P = 0.90) intestinal digestion of chlorophyll-a, but decreased intestinal digestion of β-carotene (P = 0.03) and chlorophyll-b (P = 0.02). β-carotene digestion tended to decrease with increasing level of pectin infusion (linear component, P = 0.09). It was concluded that pectin may affect intestinal digestion of β-carotene and chlorophyll-b.