Concentrations of oestrone sulphate in milk during pregnancy in
dairy cows
K.M. Henderson, M. Karanikolas, L. Kenealy, K.L. MacMillan
AgResearch, Wallaceville Research Centre, P.O. Box 40063, Upper
Hutt, New Zealand
Proceedings of the New Zealand Society of Animal Production.
1992, 52: 17-20
A monoclonal antibody to oestron sulphate (ES) was generated,
and used in the development of a radioimmunoassay to measure ES
concentrations in whole milk of cows. The mean ± s.e.m. concentration
of ES in milk samples from non-pregnant cows was 58 ± 5 pg/ml (n=20).
In pregnant cows, ES concentrations in milk samples rose progressively
from a mean ± s.e.m. value of 99 ± 10 pg/ml (n=20) at 40 to 60 days of
pregnancy, to a plateau value of approximately 1000 pg/ml at about day
160 of pregnancy. Examination of the ranges of ES concentrations in
milk sampled from non-pregnant and pregnant cows indicated that all non-
pregnant cows and 46% of cows <120 days pregnant had milk ES
concentrations <125 pg/ml. However, only 4% of cows >/= 120 days
pregnant had milk ES concentrations <125 pg/ml. Measurement of ES
concentrations in milk samples taken at least 120 days after
mating/insemination could provide an accurate indication of pregnancy
status in New Zealand dairy cows.
Keywords: NZSAPAB;
Oestrone sulphate; monoclonal antibody; cows; milk; pregnancy;
radioimmunoassay
Download abstract in text format
Last Updated 25-01-1997
