Gruel creep feed provided from 3 days of age did not affect the market weight and the sow's catabolic state

•Gruel creep feed provided to piglets did not reduce the heterogeneity within-litter.•Gruel creep feed from suckling piglets did not improve market weight.•Gut structure of weaned piglets was not affected by gruel creep feed.•Gruel creep feed from 3 days of age did not reduce the sow's catabolic state.•There is limited evidence on effect of gruel creep feed provided to suckling piglet. The provision of a suitable, high-quality starter diet to piglets has been described as a potential tool to minimize effects on the sow's catabolism during lactation and decrease the lag time between weaning and first feed intake at the nursery stage. This study aimed to determine the effects of gruel creep feed on (1) the piglets' performance from pre-weaning to finishing and (2) the sows' catabolism during lactation and its subsequent reproductive performance. Sixteen hybrid sows were selected according to parity, and were allotted in three treatments: control (CON, n = 5) only maternal milk without creep feed; dry creep feed (DCF, n = 5) maternal milk + dry creep feed; gruel creep feed (GCF, n = 6) maternal milk + gruel creep feed. The treatment was randomly assigned to a litter from day 3 post-farrowing until weaning. The experimental unit pre-weaning was considered the litter. After weaning, the cages with four piglets were considered the experimental units. The sows' catabolism was measured weekly through body weight and backfat losses during the lactation, associated with plasma metabolites parameters. Weaning-to-estrus interval (WEI) and estrus duration were used to measure reproductive performance after weaning. A total of 136 piglets had the body weight (BW) and feed intake measured at birth and on days 7, 14 and 21 (maternity period); 35, 49 and 63 (nursery period) and 104 and 133 (growing and finishing period) to calculate the average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR). On day 14 and 28, six piglets by treatment were randomly euthanized to analyze of intestinal morphometry. Sows had similar (P > 0.05) body weight and backfat loss during the lactation among the treatments. Also, the plasma metabolites were similar, except BHB was higher in GCF sows than in the other groups (P