Effects of dietary copper and molybdenum on copper status, cytokine production, and humoral immune response of calves.

Twenty-four male Holstein calves were used to determine the effects of dietary Cu and Mo on performance, Cu status, and immune function of calves. Calves were fed a milk replacer that was deficient in Cu for 8 wk and then were randomly assigned after weaning to one of four treatments: 1) control (no supplemental Cu or Mo), 2) 10 mg of Cu (from CuSO4)/kg of dry matter (DM) (Cu diet), 3) 5 mg of Mo (from Na2MoO4)/kg of DM (Mo diet), or 4) 5 mg of Cu (from CuSO4) and 5 mg of Mo (from Na2MoO4)/kg of DM (Cu + Mo diet). The basal diet was a semipurified diet that contained approximately 1.1 mg of Cu and 1.1 mg of Mo/kg of DM. Calves fed the Cu and Mo diets gained weight more efficiently than those fed the control and Cu + Mo diets during the 112-d study. By d 84 of the study, calves fed the Cu diet had higher plasma Cu concentrations and plasma ceruloplasmin activities than did calves fed the other three diets and had higher liver Cu concentrations on d 136. Plasma and liver Cu concentrations did not differ among calves fed the control, Mo, and Cu + Mo diets. At d 112, activity of Cu-Zn superoxide dismutase was lower in calves fed the Mo diet than in calves fed the Cu diet. Serum total antibodies to porcine erythrocytes (primary response) were lower in calves fed the Mo diet than in calves fed the Cu diet at 7, 14, and 21 d postinoculation. Production of tumor necrosis factor and interleukin-1 by isolated peripheral blood monocytes was not significantly affected by treatment. Although no differences were apparent in plasma or liver Cu concentrations among calves fed the control, Mo, and Cu + Mo diets, calves fed the Mo diet had a more severe Cu deficiency based on depressed humoral immune response and superoxide dismutase activity.

The effects of copper deficiency with or without high dietary iron or molybdenum on immune function of cattle.

Two experiments were conducted to determine the effects of Cu deficiency with or without high dietary Mo or Fe on the specific immunity of calves. In Exp. 1, calves from 38 bred heifers, fed corn silage-based experimental diets from the last third of gestation until the calves were weaned, were used. Dietary treatments were control (no supplemental Fe, Mo, or Cu), 600 mg of supplemental Fe/kg of DM, 5 mg of supplemental Mo/kg of DM, and 10 mg of supplemental Cu/kg of DM. In Exp. 2, 18 Holstein bull calves were fed commercial milk replacer low in Cu for 49 d and then fed semipurified diets containing approximately 1.1 mg of Cu/kg of DM or diets supplemented with 5 mg of Mo or 10 mg of Cu per kilogram of DM for 126 d. Feeding diets not supplemented with Cu resulted in severe Cu deficiency in both experiments. During Exp. 1, control calves had higher (P < .10) secondary antibody response to pig erythrocytes than Cu-, Mo-, and Fe-supplemented calves. During Exp. 2, in vitro Cu supplementation decreased (P < .01) lymphocyte blastogenic response. In vivo cell-mediated response to phytohemagglutinin was decreased (P < .10) by Cu supplementation during Exp. 1 but was increased (P < .10) by Cu and Mo supplementation during Exp. 2. Copper deficiency and Cu deficiency coupled with high dietary Mo or Fe produced inconsistent immune function responses, indicating that Cu deficiency may not affect specific immune function of calves.

Effects of copper deficiency and copper deficiency coupled with high dietary iron or molybdenum on phagocytic cell function and response of calves to a respiratory disease challenge.

A study was conducted to determine the effects of supplementing a diet marginally deficient in copper (Cu) with iron (Fe), molybdenum (Mo), or Cu on phagocytic cell function and disease resistance of calves. Thirty-one calves were born to heifers fed a corn silage-based diet containing 4.5 mg of Cu/kg. Treatments consisted of 1) control (CON; no supplemental Cu, Fe, or Mo), 2) 600 mg of Fe added/kg (FE), 3) 5 mg of Mo added/kg (MO), or 4) 10 mg of Cu added/kg of DM (CU). Activity of superoxide dismutase was lower (P < .06) in neutrophils from MO vs CON or CU calves at 170 d of age. bactericidal activity of neutrophils from MO calves tended (P = .15) to be lower compared with those from CU calves at 70 d of age. Calves were inoculated intranasally with live infectious bovine rhinotracheitis virus (IBRV) 2 d after weaning, followed by intratracheal administration of Pasteurella hemolytica 5 d later. Iron- and Cu-supplemented calves exhibited higher (P < .01) body temperatures and lower (P < .06) feed intakes following IBRV inoculation compared with CON and MO calves. Copper-supplemented calves had higher levels of plasma tumor necrosis factor (TNF) than MO calves at weaning (P < .05) and tended to have higher plasma TNF (P = .11) than FE and MO calves 5 d after IBRV inoculation. These data indicate that dietary levels of Mo and Cu can affect body temperature and feed intake responses to disease by affecting TNF and perhaps other cytokines.

Differences in copper status and copper metabolism among Angus, Simmental, and Charolais cattle.

Thirty-eight pregnant Angus, Charolais, and Simmental heifers and their offspring were used to determine whether differences in Cu metabolism existed among breeds. The heifers were fed either 0 or 10 mg of supplemental Cu per kilogram of DM. Calves were born between d 70 and 125 of the 280 d experiment. There were few differences among breeds in plasma Cu concentration and ceruloplasmin activity when heifers were fed supplemental Cu. When heifers were not fed supplemental Cu, Angus heifers had greater (P < .10) plasma Cu concentrations than Simmental heifers from d 0 until 140 and Charolais heifers from d 28 until 140. Angus heifers had greater (P < .10) ceruloplasmin activity than Charolais and Simmental heifers between d 28 and 196. When dams were fed supplemental Cu, Angus calves had greater (P < .10) plasma Cu concentrations than Simmental calves on all days tested and Charolais calves on d 252 and 280. Ceruloplasmin activity of Angus calves in the Cu-supplemented group was greater (P < .10) than that of Charolais calves on d 224 and 280 and Simmental calves from d 224 until 280. Angus calves born to dams not receiving supplemental Cu had greater (P < .10) plasma Cu concentrations and ceruloplasmin activities than Simmental calves on all days tested. Angus calves also had greater (P < .10) plasma Cu concentrations than Charolais calves on d 196 and greater ceruloplasmin activities than Charolais calves from d 168 until 224. Eight Angus and eight Simmental steers were used to evaluate apparent Cu absorption and retention.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of dietary copper, iron, and molybdenum on growth and copper status of beef cows and calves.

A study was conducted to determine the effects of copper (Cu) depletion by feeding diets high in either iron (Fe) or molybdenum (Mo) on performance and Cu status of beef cows and calves. Thirty-eight 2-yr-old beef heifers, entering the last one-third of gestation, were randomly assigned by expected calving date to one of four diets: 1) control (CON; corn silage-soybean meal-based diet, 4 mg of Cu/kg), 2) control + 600 mg of Fe (as FeCO3)/kg, 3) control + 5 mg of Mo (as Na2MoO4)/kg, and 4) control + 10 mg of Cu (as CuSO4)/kg. From d 28 until after the end of the calving season (d 125), heifers receiving supplemental Cu had higher (P < .05) plasma Cu levels and ceruloplasmin activities than heifers fed the other diets. By d 224, plasma Cu concentrations of heifers fed the CON and Fe diets had increased to levels similar to those observed in the Cu-supplemented heifers, whereas the Mo heifers exhibited the lowest (P < .05) plasma Cu of the four treatments from d 168 through the remainder of the 280-d trial. Plasma Cu concentrations and ceruloplasmin activities were greater (P < .05) in Cu-supplemented than in non-Cu-supplemented calves (diets 1, 2, and 3) from d 168 onward, and the Fe- and Mo-supplemented calves did not differ in either measurement at any time during the trial. Rate of gain did not differ among calves fed the CON, Fe- or Cu-supplemented diets, whereas the Mo-supplemented calves gained at a much slower (P < .05) rate.(ABSTRACT TRUNCATED AT 250 WORDS)