Influence of Sodium Humate on the Growth Performance, Diarrhea Incidence, Blood Parameters, and Fecal Microflora of Pre-Weaned Dairy Calves

Simple Summary Diarrhea is a common disease among neonatal calves worldwide and causes serious economic losses in the dairy industry. In most cases, calves receive antibiotics to prevent or treat diarrhea, but the overuse of antibiotics has been linked to the development of antibiotic resistance and negative public health outcomes. Sodium humate (NaH) is a natural product with multiple activities, including antimicrobial, antioxidant, anti-inflammatory, and antidiarrheal properties. This study investigated the effects of different concentrations of NaH on growth performance, diarrhea incidence, serum immunoglobulin and inflammatory cytokines concentration, and fecal microflora in Holstein dairy calves. The results showed that supplementation with 5 g of NaH improved the growth performance, antioxidant and immune status, modulated the fecal microflora, and thereby decreased the diarrhea incidence in dairy calves. This indicated that NaH may be a promising tool for preventing diarrhea in calves. Abstract This study aimed to evaluate the effects of the administration of sodium humate (NaH) on the growth performance, diarrhea incidence, and fecal microflora of pre-weaned Holstein calves. In a 53-day experiment, forty healthy newborn female calves were randomly allocated to the following four treatment groups: (1) control (basal diet); (2) 1-gram NaH (basal diet extra orally supplemented with 1 g of NaH dissolved in 100 mL of milk or milk replacer daily); (3) 3-gram NaH (basal diet extra orally supplemented with 3 g of NaH dissolved in 100 mL of milk or milk replacer daily); and (4) 5-gram NaH (basal diet extra orally supplemented with 5 g of NaH dissolved in 100 mL of milk or milk replacer daily). NaH was mixed with milk (d 2–20) or milk replacer (d 21–53). Calves in the 5-gram NaH group had a higher ADG during d 1 to 21 and d 21 to 53 than the other groups did (p < 0.05). Fecal scores and diarrheal incidence were significantly lower in the 3-gram and 5-gram NaH groups than the 1-gram NaH and control groups during d 1 to 20 (p < 0.05). The serum IgA, IgG and IL-4 concentrations, and T-SOD and T-AOC activities were higher, and the serum IL-6, TNF-α, D-lactic acid, and MDA concentrations were lower in the 5-gram NaH group than the control group (p < 0.05). Furthermore, NaH supplementation increased the abundances of Bifidobacterium and Lactobacillus but decreased the abundance of Escherichia coli in feces (p < 0.05). These encouraging findings indicated that supplementation with 5 g of NaH effectively improved the immune status, antioxidant capacity, and intestinal beneficial bacteria, and further improved the growth performance and reduced the diarrhea incidence of the pre-weaned dairy calves.