Relationship of prepartum plasma concentrations of estrone sulfate and estradiol‐17β with the weight of the calf and placental parameters in Holstein–Friesian cows

Abstract

ABSTRACTThe aim was to evaluate the relationship of prepartum plasma estrone sulfate (E1S) and estradiol‐17β (E2β) concentrations with the weight of the calf and the placental parameters. Holstein–Friesian cows (n = 33) inseminated artificially with Japanese Black beef bull semen at Hiroshima University Farm in Japan were used for the experiment. Blood samples were taken every day from day 270 of gestation until the day after calving. The plasma samples were analyzed for E1S and E2β by enzyme immunoassay. The calf birth weight was taken immediately after calving. Complete fetal membranes were collected from 19 cattle and the weights of the placental components and the number of cotyledons were recorded. All 33 cattle delivered singleton normal calves. The prepartum plasma E1S concentration was found to correlate significantly (P < 0.01) with the calf birth weight (r = 0.83), total fetal membrane weight (r = 0.81), cotyledonary weight (r = 0.79) and inter‐cotyledonary membrane weight (r = 0.64), but it did not correlate significantly with the number of cotyledons, whereas prepartum plasma E2β was not found to correlate significantly with the weight of either the calf or any of the placental components except the number of cotyledons. In conclusion, prepartum plasma E1S, not plasma E2β, was found to correlate significantly with the weight of the calf and the placental components.