Effects of Multistrain Probiotic Supplementation on Sows' Emotional and Cognitive States and Progeny Welfare

Simple Summary Feeding technologies, such as probiotics, are widely used in the animal industry for purposes beyond nutritional needs. Probiotic bacteria have been shown to have multiple effects on sow physiology during gestation and lactation, making them a subject of great interest when it comes to animal behavior and welfare. In this study, the use of probiotics mitigated the apathetic state of gestating sows housed in individual cages, in addition to reducing fear and aversion towards humans during interaction tests. The influence was also observed in the progeny, as piglets from sows supplemented with probiotics were less resistant in fear assessments, which may indicate lower stress levels. The findings indicate that the use of probiotics during gestation and lactation can be used as a tool in enhancing animal welfare.Abstract The intensification of production systems has resulted in detrimental effects on sow welfare, which can have an adverse influence on their offspring. Considering the relevance of the microbiota-gut-brain axis, probiotics can mitigate such impacts. To investigate the effects of the dietary inclusion of probiotics on the welfare of sows and piglets, 147 multiparous sows were randomly assigned to two groups: a control group or a group supplemented with a multistrain probiotic from the beginning of pregnancy to the end of lactation. The human-animal relationship (HAR), stereotypic behavior, position changes, salivary cortisol, and plasma serotonin levels were assessed in the sows. The piglets' back test behavior and organ weight were analyzed. The probiotic-supplemented sows exhibited a better HAR index (p = 0.017), which indicated reduced aversion towards humans. The frequency of stereotypies was not influenced by the treatments. However, the supplemented sows spent more time standing (p = 0.054) and less time lying down (p = 0.008). The cortisol level of the supplemented sows was 50% lower (p = 0.047) and the serotonin levels were 11% higher (p = 0.034) than control animals. The multistrain piglets were more passive and less resistant (p = 0.076) in the back test. The organ weights were not influenced by treatments. In conclusion, the sows supplemented with probiotics showed less fear and more motivation indicators, while their piglets showed less aggression behaviors.