Dietary yeast culture supplementation alleviates transportation stress in goats.

The addition of yeast cultures to diets has been demonstrated to maintain the homeostasis of the rumen endo-environment and to enhance the body's immunity. However, the effect of yeast cultures on alleviating transportation stress remains unclear. A total of 16 goats were randomly distributed into 2 dietary treatments (8 replicates/treatment) as follows: Basic diet group (CON); basic diet + 0.3% YC group (YC). The experiment lasted for a total of 46 days, consisting of a 30-day growth trial, followed by a one-day transportation stress treatment, and subsequently a 14-day feeding trial. Samples were taken on days 31, 32, 39 and 46. The results showed that YC improved growth performance, as evidenced by an increase in the average daily gain and a reduction in feed intake and weight gain ratio in goats (P < 0.05). There was a significant interaction between time effect and dietary effect on the rumen histamine (His) and lipopolysaccharide (LPS) content (P < 0.05). There were significant interactions between diet and time on serum interleukin (IL) -1β, IL -6, Tumor Necrosis Factor-α, Glutamic pyruvic transaminase, His, LPS and immunoglobulins (IgA, IgG, and IgM) concentrations (P < 0.05). At the phylum level, Bacteroidota and Firmicutes showed significant interactions between time and diet (P < 0.05). These evidences suggests that the supplementation of YC in the diet has been demonstrated to significantly enhance the immune function of goats, while simultaneously maintaining the homeostasis of the intra-rumen environment. This has the beneficial effect of alleviating the physiological stress associated with transportation.