L-Arg_sow_fecal_micro

Arginine plays an important role during reproduction, however, the amount of supplementation in sow diet is still uncertain and literature is focused on high supplementation doses. The aim of the study was to verify the efficacy of a gestating diet enriched or not with a low doseof L-arginine (Arg) on sow productive performance in terms of numbers a weight of piglets at birth and at weaning, presence of intrauterine growth retardation (IUGR) and piglets' mortality, sow placenta weight and intestinal microbial balance of the sows and their response in humoral immunity. 205 sows (Landrace x Large White) were divided into two experimental groups: a control group (CON) (102 sows) and a group supplemented with 0.25% of total Arg (ARG) for the whole pregnancy period. Saliva and fecal samples were collected two days before farrowing and used for immunoglobulins and microbial analysis, respectively. Arg improved the number of total born pigles (p = .04) and tended to improve the number of total born alive (p = .086) and to reduce IUGR % (p = .09) and dead piglets at d0-d3 (p = .088). Placenta weight and humoral immunity were not influenced by Arg. Arg did not modify the fecal microbial structures in terms of alpha and beta indices and increase the relative abundance of Bacteroidaceae family and Bacteroides genera (p xxx). The obtained results support the knowledge that Arg plays a key role in nutrition and physiology of pregnant sows without compromising gut eubiosis and suggest a practical and beneficial effect on sow productive performance at a low supplementation dose.