The objective of this study was to determine associations of subclinical ketosis (SCK) and blood β-hydroxybutyrate (BHB) with milk yield, supplemental feed consumption, and rumination time of cows in herds using automated milking systems (AMS). We also examined ratios of milk yield relative to supplement intake and rumination time. We monitored 605 cows from 9 AMS herds, testing blood BHB concentrations 1 ×/wk for the first 3 wk of lactation. Milk yield, supplement intake, and rumination data were collected from the AMS computer on each farm for the first 28 DIM for each cow. For analyses, only multiparous cows from 8 herds were included (n = 172 total) and were matched, within farm, to include an equal number of cows in each of 4 health status groups (n = 43 per group): SCK− (BHB ≥ 1.2 mmol/L at ≥1 of 3 tests, with no other disorder in the first 30 DIM), SCK+ (BHB ≥1.2 mmol/L at ≥1 of 3 tests, with another health disorder), HLT− (BHB always <1.2 mmol/L, with no other disorder), or HLT+ (BHB always <1.2 mmol/L, with a health disorder). Multivariable mixed-effect linear regression models were used to make comparisons by health status. Linear and logistic regressions were used to analyze associations of BHB concentrations and risk of SCK, respectively. Milk yield (P < 0.001) and rumination time (P < 0.001) varied by health status (HLT+: 32.8 kg/d, 477 min/d; SCK+: 35.1 kg/d, 431 min/d; SCK−: 39.5 kg/d, 484 min/d; HLT−: 37.2 kg/d, 500 min/d), but there was no difference in supplement intake by health status group (averaging 4.2 kg/d). As a result, milk yield relative to supplement intake (P < 0.001) and rumination time (P < 0.001) differed by health status, and both were associated with BHB and risk of SCK (P < 0.05). Cows in SCK- had the highest milk yield and ratio of milk yield:supplement intake, but SCK+ cows had the lowest rumination time and the highest milk yield:rumination ratio. These results highlight the differences in milk production (per day and relative to supplement consumption or rumination time) associated with blood BHB and health status, and the potential to modify supplementation in AMS to reduce negative energy balance.