Molybdenum Fertilization Improved Antioxidant Capacity of Grazing Nanjiang Brown Goat on Copper-Contaminated Pasture.

Copper (Cu) is an essential trace element, but excessive Cu intake can induce poor performance and Cu poisoning and result in various health problems. Cu and molybdenum (Mo) antagonize each other in vivo. Therefore, Mo can reduce the absorption and utilization of Cu. The aims of this study were to investigate the impacts of Mo fertilization on antioxidant capacity of grazing Nanjiang brown goat on Cu-polluted meadow and explore the control methods of Cu pollution in natural pasture. Fertilization and grazing experiments were carried out in Liangshan Yi Nationality Prefecture of the Western Sichuan Plateau, Sichuan Province, Southwest China. Cu-polluted meadows of 12 hm2 were fenced, and randomly divided into two groups (3 replications/group, 2 hm2/replication), control group and treatment group, fed with basic diets supplemented with 0 and 3 kg Mo/hm2 [ammonium molybdate tetrahydrate, (NH4)6Mo7O24·4H2O], respectively. In the current study, 36 healthy Nanjiang brown goats (1 year old, 32.8 ± 1.1 kg) were randomly divided into two groups (3 replications/group, 6 goats/replication) and assigned to the experimental pastures. The grazing experiment lasted for 60 days. The results showed that the concentration of Mo in soil in treatment group was 96.28 mg/kg, far exceeding the normal levels. At days 30 and 60, the levels of Hb, RBC, and PCV in blood in treatment group and the activities of serum SOD, GSH-Px, T-AOC, CAT, and Cp were higher than those in control group (P < 0.01). The MDA content in treatment group was lower than that in control group (P < 0.01). The contents of Cu in blood and liver in treatment goats were lower than those in control animals (P < 0.01). The contents of Zn and Mo in blood and liver in treatment goats were higher than those in control animals (P < 0.01). The Mn content in liver in treatment group was higher than that in control animals (P < 0.01). These results indicated that fertilization of (NH4)6Mo7O24 not only markedly influenced the mineral contents in blood and liver, but also extremely improved antioxidant capacity of grazing Nanjiang brown goat from fertilized pastures and relieved the damage caused by Cu pollution.