Ionomics-metabolome association analysis as a new approach to the impact of dietary copper levels in suckling piglets model

Ionomics-metabolomics association analysis is a novel method to elucidating the potential mechanisms underlying the effects of dietary copper on the overall health parameters of suckling piglets model. Few studies have elucidated the relationship between the changes of ionic and metabolic homeostasis responses to dietary copper level. The growth performance data was obtained from 180 suckling piglets which access to different copper levels: 6 (low copper diet, LC), 20 (control diet, CON), and 300 (high copper diet, HC) mg·kg(−1) copper (based on diet, supplementation from CuSO(4)), and offered ad libitum from d 14 until weaning at 40 d of age. Dietary high level copper (300 mg·kg(−1)) increased the ADG and ADFI during d 14 to 28 of piglets. Six elements (Mg, Na, K, P, Cu, and Mn) concentrations significantly changes in hair among the three treatment diets. The significant increased concentrations of Na and K, and decreased concentration of Mg and Mn in 300 mg·kg(−1) than 20 mg·kg(−1) copper diet was observed. In current study, with the increase in copper level from 20 to 300 mg·kg(−1) in diet, the correlation between hair Na, K and Cu, Mn, Zn vanish. Hair Na and K were positively correlated with serum total antioxidant capacity (T-AOC) and negatively correlated with tumor necrosis factor-α (TNF-α). The hair Cu was negatively correlated with serum malondialdehyde (MDA), total bile acid (TBA). The fecal Cu was positively correlated with serum growth hormone (GH). The results suggested that the average daily gain (ADG) in 6 mg·kg(−1) copper diet and the average daily feed intake (ADFI) in 20 mg·kg(−1) copper diet were decreased than 300 mg·kg(−1) copper diet during d 14 to 28 and the ADG was decreased in 6 and 20 mg·kg(−1) copper diets in d 29 to 40 of piglets. Dietary 20 mg·kg(−1) copper maintain ion homeostasis due to increase the number of positive correlations between macroelements-microelements in hair and serum. Significantly changed Na, K, Mg, Mn and Cu concentrations in hair can reflect the adverse effects of dietary 300 mg·kg(−1) copper of suckling piglets. We believe our results may benefit people to gain a better understanding of the ion interactions and metabolic homeostasis of heavy metal elements that are critical to human and animal health.