Effects of parenteral supplementation of Cu in female cattle with different levels of cupremia

Abstract

The experiment was carried out in two stages with the objective of determining the effect of parenteral supplementation of 50 mg Cu on the reproductive behaviour of both hypo-and normocupremic cyclic female cattle. In the first stage, 62 hypocupremic, cyclic animals were selected, 32 heifers (16 in the control group and 16 in the treatment group) and 30 cows (12 in the control group and 18 in the treatment group). In the second stage, 98 normocupremic, cyclic heifers were selected (49 in the control group and 49 in the treatment group). 50 mg of Cu were administered to the animals in the treatment groups parenterally (subcutaneously) every two months until three successive applications were completed, while the control animals were not given copper supplementation. The effects of the copper therapy on cupremia and the percentage of heat and gestations presented were determined. The relative risk of treated animals of presentating anoestrus and service repetition was evaluated by the formation of a 2 × 2 contingency table and the application of a χ² test. The levels of serum copper were compared using a t-test, while heat and gestations were compared using a proportion comparism test. The parenteral administration of 50 mg Cu in hypocupremic, cyclic heifers and cows led to significant increases of cupremia (P<0.001) and the percentages of heat presentations and gestations (P<0.01); in the normocupremic animals, there were significant increases in the values of serum copper (P<0.0001), heat presentations (P<0.01) and gestations (P<0.001), especially in animals with cupremia values below 14 mmol/L. The treatment reduced the relative risk of reproductive disorders. It is concluded that the parenteral administration of 50 mg Cu in female cattle with Cu blood serum level <14 mmol/L increased cupremia and the percentages of heat presentations and gestations, and reduced the relative risk of reproductive disorders.

Efecto de la suplementación parenteral del cobre sobre la ganancia de peso de toros en ceba

“…In the case of Fe, results are in contrast with studies conducted in Cuba on grazing adult bovine females, where parenteral Cu supplementation increased serum Fe concentrations (2,21,22). Although there is a close relationship between blood copper and Fe blood levels (1), the lack of coherence in these results may be explained because Cu was administered in this study, animals were kept in stables for 18 h, with very little contact with the soil, where bovines can consume Fe while grazing, and because this mineral, which is present in the plant, is oxidized when the plant is milled (1,23).…”

“…The supplement had a protective effect on anestrous presentation and the repetition of Artificial Insemination services (3,21,22).…”

“…La suplementación tuvo un efecto protector para la presentación del anestro y la repetición de los servicios de Inseminación Artificial (3,21,22).…”

“…En el caso del Fe, los resultados contrastan con estudios desarrollados en Cuba en hembras bovinas adultas en pastoreo, donde la suplementación parenteral de Cu incrementó las concentraciones de Fe sérico (2,21,22). Aunque existe estrecha relación entre la cupremia y los niveles de Fe en sangre (1), la falta de concordancia en estos resultados…”

Parenteral Copper Administration at the Beginning of a Fixed-Time Artificial Insemination Protocol in Beef Cattle: Effect on Ovarian Function and Pregnancy Rates

“…We suggest at least two possible explanations for that result: (a) on the one hand, the plasma Cu concentration necessary for normal reproductive function could be higher than that defined as adequate by Kincaid [5]. Recently, García-Díaz and colleagues [17] reported a positive effect of Cu administration on the percentage of heat detection and gestation in cattle with plasma Cu concentration ≤ 88.9 µg/dL Cu, suggesting 89 µg/dL Cu as the lower limit of adequate Cu level for reproductive efficiency in cattle. In the present study, the plasma Cu concentration of the animals used to evaluate pregnancy rate was below 89 µg/dL Cu (Experiment 4).…”