2019-08-022019-08-022019-052019-05May 2019https://hdl.handle.net/2346/84994The objectives of this doctoral dissertation were to 1) evaluate how coprophagy benefits piglets, 2) the identification of maternal semiochemicals that might be acting as a fecal maternal pheromone, and 3) to evaluate if putative maternal semiochemicals (FMS) could be used to improve wean pig welfare and performance. The effect of coprophagy on nursing piglet hematology, behavior, and performance were assessed by depriving piglets of maternal feces the first seven days of age. Deprivation of maternal feces had no statistically significant effect on piglet behavior, RBC, HCT, and Hb (P > 0.05). Piglets with access to maternal feces (control) had better pre- and post-weaning performance than piglets deprived of maternal feces for the first seven days of age. Deprivation of maternal feces reduced piglets average daily gain and feed intake by 10 %. Piglets with access to maternal feces the first seven days of age weighed 9.6 kg more at 123 d post-weaning compare to the ones deprived of maternal feces the first seven days of age (P < 0.05). To identify fecal maternal semiochemicals that might be acting as a maternal fecal pheromone and inducing coprophagy, fecal samples were collected from eight sows during gestation and lactation. Fecal semiochemicals were extracted with a SPE procedure and analyzed by GC/MS. Results showed that lactation increased the fecal concentrations of skatole and myristic acid (P < 0.05). During gestation the concentration of skatole and myristic acid were 11. 69 µg/g and 66.24 µg/g respectively. However, during lactation the concentration of these analytes significantly increased by 62 % and 11 % respectively (P < 0.05). A free-choice preference assessment showed that piglets had a preference for feeders sprayed with 5 mL of a mineral oil solution containing skatole (4.5 mg) and myristic acid (9.0 mg) (P < 0.05), but not either molecule alone. The application of skatole and myristic acid to the feeders of weaned pigs statistically reduced piglet aggression by 30 % and increased feeding behavior by 35 % the first 24 h post weaning (P < 0.05). No difference in performance was observed over a 28-d period. Overall, because having access to maternal feces improved piglet performance by 10 %, coprophagy presents as a beneficial behavior to piglets. In addition, skatole and myristic acid might be acting as a multicomponent maternal semiochemical that attracts piglets and has a calming effect at weaning.application/pdfengCoprophagyMaternal semiochemicalsPigletsWeaning stressThesis2019-08-02Unrestricted.