Effect of an innovative precision biotic on laying hens’ welfare

The object of the research was to determine the effects of SymphiomeTM in laying hens on the welfare of animals improving intestinal well-being allowing a general improvement of behavioral reactivity. The study was conducted on a commercial farm. 16,000 beak trimmed Lohmann Brown kept in an aviary system were monitored from 48 weeks to 79 weeks of age. The hens were divided into two sheds: A, treated (T) supplemented with SymphiomeTM in the diet (900 g/T); B control (C). Productive data were recorded weekly. Moreover, at weeks 48, 55, 60, 66, 72 and 79 both egg quality and behavioral data were evaluated. At each sampling point, 60 eggs per shed were collected and analyzed to assess egg quality. The whole and different component of eggs were weighed. The thickness of the shell was measured with a digital caliber; the yolk color was measured using the Digital YolkFan Pro (Nix/DSM); finally, the egg breaking strength was measured using the Egg Force ReaderTM (Orka). The avoidance distance test (ADT) and the novel object test (NOT) were performed to study the human-animal relationship and animal reactivity, (Welfare Quality®, 2019). Moreover, 100 hens per shed were weighed and the feathers in different regions of the body and foot pad were scored (Welfare Quality®,2019). The T group had a significantly higher persistence of egg deposition than the C group, starting from week 71 (p < 0,01). Mortality in the T group was lower than in the C group (2.93% versus 4.31%). SymphiomeTM shifts the microbial metabolic functions to produce desired metabolites and reduce undesirable metabolites, consequently, this favours beneficial bacteria and reduces pathogens enhancing gut health through precision microbiome and improving resilience to enteric stress. The condition of the feathers was better in the T group than in the C group at weeks 48, 55, 66 and 79 (p < 0, 001). In this study, the FPD score was higher in the C group than in the T group (mean score 0,34+/-0,07 vs 0,27+/-0,04). A positive effect was found on the reactivity of the animals: the response to the tests was better in T hens that were more curious about the NOT and kept smaller distances from the operator in ADT than the C group. These findings seem to confirm the initial hypothesis of the study that an improvement in intestinal health may have a positive impact on the reactivity of the animals and on feather pecking, with a positive impact on the welfare.