Production performance, immunity, and heat stress resistance in Jersey cattle fed a concentrate fermented with probiotics in the presence of a Chinese herbal combination

The goals of this study were to investigate the production performance, immunity, and heat stress resistance of Jersey cattle fed a concentrate fermented with compound probiotics in the presence of a Chinese herbal combination (CHC). First, the appropriate concentrations for the six Chinese herbs required to stimulate probiotic proliferation were investigated in vitro. Next, the optimal time and moisture content were determined for fermentation. We then tested the feeding effect of our fermented product on 36 growing cattle and 36 milking cows. The animals were randomly assigned to receive the product or not, resulting in half of each group receiving the treatment or serving as the control group. For 60 days, the experimental group was fed with the fermented product and the control group was fed with a basic concentrate that did not contain the probiotics or the Chinese herbs. The results showed that the cattle that received the fermented concentrate showed improved weight gain and milking cows that received the fermented concentrate showed increased average milk yield, milk fat content, and solid-not-fat content (P < 0.05). In addition, the serum levels of growth hormone, the 70 kDa heat shock protein (HPS70), and immunoglobulin G (IgG) of the cattle in the experimental group were significantly higher than the levels of cattle in the control group. A similar increase in the serum levels of HPS70, IgG, immunoglobulin A, and interferon γ was observed in milking cows that received the treatment (P < 0.05). No significant differences (P > 0.05) were observed in the serum levels of interleukin-2. Moreover, milking cows that received the fermented concentrate showed increased apparent digestibility of crude protein, ether extract, and crude fiber (P < 0.05). For the growing cattle, only crude protein digestibility was significantly increased in the experimental group (P < 0.05). Finally, we found that the ammonia content in the barn was decreased after the animals received the fermented concentrate. These results demonstrated that our fermented concentrate improved production performance, immunity, and heat stress resistance in Jersey cattle. We also demonstrated that this CHC and a mixture of probiotic strains acted as an ideal leavening agent for cattle's concentrate.