Effects of forage family (legume vs. grass) on apparent ruminal synthesis and post-ruminal supply of vitamin B₆ and folates were evaluated in 2 experiments. Diets containing either alfalfa (AL) or orchardgrass (OG) silages as the sole forage were offered to ruminally and duodenally cannulated lactating Holstein cows in crossover design experiments. Experiment 1 (E1) compared diets containing AL and OG (~27% total NDF) offered to 8 cows in 2 15-d treatment periods. Experiment 2 (E2) compared diets containing AL and OG (~30% total NDF) offered to 13 cows in 2 18-d treatment periods. Intake, duodenal flow and apparent ruminal synthesis (ARS) for each vitamin were analyzed using SAS mixed procedure. The experiments were analyzed separately. Differences were declared significant at P < 0.05. Vitamin B₆ intakes were greater for AL than OG in E1 (368 vs. 236 ± 18.2 mg/d; P < 0.01) and E2 (180 vs. 77 ± 5.1 mg/d; P < 0.01). In contrast, folates intakes were lower for AL than OG in E1 (7.6 vs. 9.2 ± 0.51 mg/d; P = 0.02) and E2 (8.7 vs. 10.2 ± 0.29 mg/d; P < 0.01). In E1, duodenal flows of vitamins were not affected by treatment (vitamin B₆, 72 ± 6.2 mg/d, P = 0.63; folates, 33 ± 4.2 mg/d, P = 0.15). In E2, duodenal flows of vitamin B₆ were greater for AL than OG (59 vs. 31 ± 5.2 mg/d; P < 0.01) but the duodenal flows of folates were not affected by treatment (39 ± 2.7 mg/d; P = 0.78). Alfalfa increased the apparent ruminal degradation of vitamin B₆ compared with OG in E1 (−294 vs. −167 ± 14.5 mg/d; P < 0.01) and E2 (−121 vs. −46 ± 4.9 mg/d; P < 0.01). The ARS of folates were not affected by treatment in either experiment (E1: 25 ± 3.9 mg/d, P = 0.19; E2: 30 ± 2.5 mg/d, P = 0.81). Combining data from both experiments, vitamin B₆ intake was correlated positively with its duodenal flow (r = 0.68, P < 0.01) but negatively with ARS synthesis of the vitamin (r = −0.98, P < 0.01). Folates intake was correlated positively with its duodenal flow (r = 0.68, P < 0.01) and its ARS (r = 0.59, P < 0.01). Forage family affected the ruminal balance of vitamin B₆ but had little or no effect on the post-ruminal supply of vitamin B₆ and folates.