Effects of unprotected choline chloride on microbial fermentation in a dual-flow continuous culture depend on dietary neutral detergent fiber concentration

Choline is usually supplemented as ruminally protected choline chloride to prevent its degradation in the rumen, but effects of unprotected on ruminal fermentation are unclear. Some research indicates a possible role dietary fiber microbial choline; therefore we aimed evaluate and investigate whether those depend neutral detergent (NDF) concentration. Our hypothesis was that NDF concentration would influence fermentation. We used 8 fermentors duplicated 4 × Latin square with 2 factorial arrangement, combining factors: (1) (2) supplementation. Resulting treatments 30%NDF/Ctrl [30% control diet without supplemental (Cho)]; 30%NDF/Cho plus 1.9 g ion per kg dry matter (DM)]; (3) 40%NDF/Ctrl (40% choline); (4) 40%NDF/Cho DM). Four 10-d periods were completed, each consisting 7 d for adaptation 3 collection samples estimation nutrient disappearance daily average concentrations volatile fatty acids NH3-N. In addition, kinetics pH, acetate, propionate evaluated at 0, 1, 2, 4, 6, h after morning feeding. On last day period, bacteria pellets harvested 15N analysis N metabolism. Fixed concentration, supplementation, their interaction (NDF Cho) tested using MIXED procedure SAS version 9.4 (SAS Institute Inc., Cary, NC). tended increase total acid decreased acetate molar proportion regardless it increased ratio only 30% diet. Supplementing NDF; however, organic be reduced when added 40% NDF. data indicate allowing greater synthesis decreasing fed