Left displacement of abomasum (LDA) is a metabolic disease affecting dairy cows within the first 30 DIM. Dairy farms in central Chile, consisting of Holstein cows maintained under confinement, use advanced technology including computerized record keeping systems. These farms have well-established postpartum health monitoring programs and LDA is regularly diagnosed. However, due to a scarcity of immediate veterinary assistance, many cows with LDA are treated conservatively by administering oral fluids, anti-inflammatory drugs and/or antibiotics. The hypothesis was that cows with LDA treated conservatively would produce less milk than cows with LDA treated surgically. The objective was to compare daily milk production among cows with LDA that received a conservative treatment, had surgery (right omentopexy or toggle suture) or were not affected (negative controls). Data between 2010 and 2012 from 4 high-producing dairies in Central Chile were analyzed. Cases (n = 146) were categorized as treated surgically (DAs, n = 72), treated with toggle suture (DAt, n = 16), or treated conservatively (DAc, n = 58). For each case, 2 healthy contemporary cows (controls) were selected at random and matched by farm, parity and DIM (±15 d; n = 289). A mixed model for repeated measures was developed for the analysis of daily milk yield up to 90 DIM with the corresponding covariance structure based upon the best goodness of fit criteria. The mean and median DIM for LDA diagnosis was 13 and 9 d, respectively. Average daily milk up to 90 DIM was 43.0 kg/d for controls, 30.4 kg/d for DAs, 30 kg/d for DAt, and 14.2 kg/d for DAc. Controls produced more milk than DAs, DAt, and DAc group (P ≤ 0.01). DAs and DAt produced a similar amount of milk (P > 0.05), but more milk than the DAc group (P ≤ 0.01). It is concluded that cows with LDA receiving conservative treatment produced substantially less milk than control cows (30 kg/d) and cows with LDA treated with surgery or toggle suture (16 kg/d). Furthermore, control cows produced more milk than cows with LDA treated with surgery or toggle suture (13 kg/d). In light of these results, it is recommended that all cows developing LDA should be treated surgically or with toggle suture.