Effect of High Molybdenum Diet on Copper Status, Growth Performance, Blood Metabolites, Select Liver and Kidney Minerals, and Immune Responses of Boer Crosses

Abstract

This study examined the effects of elevated molybdenum (Mo) in goat diets on the growth, blood parameters, and immune responses in goats. Eighteen Boer crosses goats (BW = 25.6 ± 1.03 kg) were randomly assigned to three treatment groups: (1) control (no additional Mo), (2) 5 ppm Mo, and (3) 10 ppm Mo as ammonium molybdate was added to the grain mix. Animals were fed a 50:50 hay:grain diet ad libitum twice daily. Daily feed refusals were monitored, and intake was adjusted weekly. Body weights were recorded every 14 days and blood samples were collected on the second week of every month to determine Cu, Mo, Fe, Zn, and other blood metabolites. After 85 days, animals were humanely euthanized and carcass traits were measured. Liver, longissimus muscle area, and kidney samples were collected postmortem. Liver Cu (p < 0.003), blood triacylglycerides (p < 0.03), and serum total protein (p < 0.03) levels were reduced; the liver (p = 0.07) and kidney (p < 0.001) Mo concentrations were increased; and the immune response was decreased linearly (p < 0.01) with additional Mo. Low levels of Cu with increasing Mo levels in the diet did not negatively impact animal performance or blood metabolites, in the duration of this study (85 days); however, it lowered the liver Cu, Fe, and immune responses in goats.