Clinical observation on differential effects of the trace elements selenium and copper during bovine embryo transfer
Keywords:bovine, embryo transfer, copper, selenium, beef cattle, beef cows, blood chemistry, cows, embryos, nutrition physiology, pregnancy rate, reproductive performance, trace element deficiencies, trace elements
This field study was undertaken because previous studies indicated that deficiencies in selenium (Se) and/or copper (Cu) could negatively affect reproductive performance in cattle. Blood (EDTA) and serum were collected from 43 cows four weeks after embryo transfer at the time of pregnancy examination, and Se and Cu levels were measured. Mean blood Se and serum Cu levels were 0.1±0.07 ppm and 0.66±0.12 æg/ml, respectively. Observed rate of successful pregnancy in recipient cows (termed pregnancy rate in this paper) was decreased with low or marginal blood Se concentrations (P=0.02), but serum Cu concentrations had no influence on pregnancy rate. While embryos of quality 1 or 2 had an equivalent pregnancy rate and the two sires used had no effect on pregnancy rate, a significant effect of donor cow on the pregnancy rate in recipients was observed (P=0.03). If the donor effect was included in the analysis, recipient cows with low or marginal blood Se concentration tended to have reduced embryo transfer efficacy (P=0.08).