Effects of Modified Attapulgite on Daily Weight Gain, Serum Indexes and Serum Metabolites in Fattening Beef Cattle.

In this study, we investigated the effects of dietary supplementation with thermally modified attapulgite on the daily weight gain, serum biochemical indices, and serum metabolites of Simmental fattening cattle. A total of 30 healthy Simmental fattening beef calves of similar age (8 to 9 months old) and body weight (370 ± 10 kg) were randomly divided into two groups, each containing 15 animals. A control group was fed the basal diet, and a treatment group was fed the same basal diet with the addition of 4 g/kg of thermally modified attapulgite. After 75 days of formal experiment, the calves in the two groups were weighed, and blood samples were collected by tail vein blood sampling for determinations of the serum biochemical indices and serum metabolites using liquid chromatography-mass spectrometry (LC-MS) analysis. The results indicated that the addition of thermally modified attapulgite to the diet had no significant effects on the daily weight gain of fattening beef cattle. After feeding with modified attapulgite, the glutathione peroxidase and superoxide dismutase activities in the serum of the experimental group were 55.02% (257.26 U·mL-1 to 165.95 U·mL-1, p < 0.05) and 13.11% (18.98 U·mL-1 to 16.78 U·mL-1, p < 0.05) higher than that in the control group. Compared with the control group, the tumor necrosis factor-alpha content was reduced by 14.50% (31.27 pg·mL-1 to 36.57 pg·mL-1, p < 0.01), and the concentration of interleukin-6 and lipopolysaccharide decreased by 17.00% (34.33 pg·mL-1 to 41.36 pg·mL-1, p < 0.001) and 23.05% (51.34 EU·L-1 to 66.72 EU·L-1, p < 0.001) in the serum of the experimental group. Contrastingly, the thermally modified attapulgite had no significant effects on the levels of serum total protein, albumin, or globulin in Simmental fattening cattle (p > 0.05). Furthermore, the results of serum metabolomic analyses revealed that there were a total of 98 differential metabolites, which were mainly enriched with respect to glycerophospholipid metabolism, Th1 and Th2 cell differentiation, autophagy-other, retrograde endogenous cannabinoid signaling, and the NF-κB signaling pathway. Overall, thermally modified attapulgite was found to effectively increase the activity of antioxidant enzymes, reduce serum inflammatory mediators, may suppress oxidative damage, enhance immunity, and have a positive influence on the health of Simmental fattening beef calves.