Night feeding in lactating sows is an essential management approach to decrease the detrimental impacts of heat stress.

The present study investigated the litter performance of multiparous sows had different feeding frequencies during summer season. A total of 60 crossbred multiparous sows was allotted to one of two treatments based on body weight (BW) according to a completely randomized design. Two different feeding frequencies based on NRC (National Research Council) were applied as conventional feeding (T1; 2 kg per meal at 06:00, 11:00, and 17:00) and night feeding (T2; 1.5 kg per meal at 06:00, 11:00, 17:00, and 2 kg at 22:00). Sows in T2 treatment had lower (p < 0.05) BW changes during lactation. The backfat thickness change of sows was decreased in T2 treatment during lactation (p < 0.05). The daily feed intake differed significantly between T1 and T2 with increased feed intake of the T2 group at 5.47 kg/d to 5.14 kg/d in the T1 group (p < 0.05). There was a significant difference in total weight of weaned piglets between T1 (70.50 kg) and T2 (74.34 kg). A greater total litter weight gain was observed in sows in T2 treatment. Night feeding is suggested for lactating sows with significant beneficial effects on litter growth during summer season.