Past research (40+ years ago) suggests feeding fat to sows prior to parturition and during lactation improves piglet energy stores, sow colostrum fat percentage, sow milk fat percentage and piglet survival. Therefore, the objective was to evaluate the impact of sow fat feeding on piglet survival and throughput in a modern production system. Data was collected from 1866 sows at a 3600 sow commercial farm in eastern North Carolina between May and August. Sows were randomly assigned to one of four treatments from day 108 of gestation until farrowing (no supplementation (Control), supplemented with 227g or 454g of soybean oil per day, supplemented with 227g of coconut oil per day). Oil sources were top dressed daily with 2.27kg of lactation diet. After farrowing, sows had ad libitum access to the lactation diet. At birth, piglets received a colored ear tag corresponding to prefarrow diet. Traits recorded included; total number of piglets born, stillborns, crossfosters, number weaned, piglet survival (number weaned ÷ total number born), litter weaning weight, lactation length, whether a sow farrowed a subsequent litter, subsequent total number born, subsequent number born alive, subsequent stillborns, Knauer sow body condition caliper score prefarrow and sow caliper score at weaning. Linear models were used in statistical analysis. Fixed effects included sow prefarrow diet, parity, contemporary group and location of the sow within the farrowing room. Covariates were included when applicable. Results are shown in Table 1. Stillborns and stillborn percentage did not differ (P >0.05) between dietary treatments. Yet sows supplemented with soybean oil tended (P=0.10) to have fewer stillborn piglets (0.06 piglets) than Control sows. No differences (P >0.05) in piglet survival across dietary treatments were observed. Sows supplemented with soybean or coconut oil prefarrow had greater (P< 0.05) subsequent total number born (13.71 vs. 13.31 piglets) and tended (P=0.07) to have greater subsequent number born alive (13.07 vs. 12.72 piglets) than Control fed sows. Accordingly, sows supplemented with soybean oil tended (P=0.08) to have more subsequent total number born (13.69 vs. 13.31 piglets) and tended (P=0.09) to have higher subsequent number born alive (13.07 vs. 12.72 piglets) than Control fed sows. No differences (P >0.05) in sow body condition loss during lactation were observed between dietary treatments.