Use of progesterone 11-glucuronide--alkaline phosphatase conjugate in a sensitive microtitre-plate enzymeimmunoassay of progesterone in milk and its application to pregnancy testing in dairy cattle

Abstract

A simple direct-addition microtitre plate enzymeimmunoassay (EIA) for progesterone in whole milk is described. The assay used antiserum raised against 11 alpha-hydroxyprogesterone 11-hemisuccinate (progesterone 11-hemisuccinate) and a heterologous label prepared by conjugation of 11 alpha-hydroxyprogesterone 11-glucuronide (progesterone 11-glucuronide) with alkaline phosphatase using an active ester procedure. The sensitivity, analytical recovery, linearity of response and precision of the assay compared favourably with radioimmunoassay (RIA). Results from EIA of milk samples were compared with determinations made after isolation of progesterone by HPLC (r = 0.910). Milk samples (200) were assayed by RIA at both the Milk Marketing Board and the Cattle Breeding Centre and the results were correlated with EIA performed at the Cattle Breeding Centre (r = 0.890 and r = 0.833 respectively). Calving data were obtained from a further 110 cows for which the milk progesterone EIA had provided a pregnancy test 24 days after AI; 46 cows were correctly identified as non-pregnant and 58 as pregnant and there were 4 false positive and 2 inconclusive results.

Effect of offering dairy cows diets differing in phosphorus concentration over four successive lactations: 2. Health, fertility, bone phosphorus reserves and nutrient utilisation

“…Milk progesterone concentrations were determined using an enzyme-linked immuno-sorbent assay kit (Ridgeway Science Ltd, Gloucestershire, UK), based on the method of Sauer et al (1986), as described in detail by McCoy et al (2006). Interval to the commencement of luteal activity was defined as the interval from calving to the first of at least two consecutive increases in milk progesterone concentration of .3.0 ng/ml (Darwash et al, 1997).…”

Bone morphogenetic protein (BMP) ligands and receptors in bovine ovarian follicle cells: actions of BMP-4, -6 and -7 on granulosa cells and differential modulation of Smad-1 phosphorylation by follistatin

“…E2 levels were determined by RIA as described previously ) with a detection limit of 1.5 pg/ml and within-and between-assay CV values of 5.6 and 6.0% respectively. Progesterone (P4) concentrations were measured by ELISA (Sauer et al 1986) with a detection limit of 20 pg/ml and within-and between-assay CV values of 7.4 and 11.6% respectively.…”

Diagnostic précoce de gravidité chez la vache grâce à l'observation de l'éjection du lait induite par l'ocytocine lutéale

“…The tests were performed in 410 lactating cows, 18-22 days after insemination (mean 19.95 (Tainturier et al, 1983;Chaffaux et al, 1988) et ce n'est qu'à partir du 30 e j que le test PSPB offre suffisamment de garantie (Humblot et al, 1988) dans la mesure où chez les multipares, il ne subsiste pas de reliquats de PSPB de la gestation précédente qui interdisent son emploi avant le 100 e j post P artum (Humblot, 1991 Les diagnostics plus précoces ne sont donc pas basés sur la recherche directe de l'embryon, mais sur celle du maintien du corps jaune au stade où, a contrario, il y a déjà lutéolyse chez les femelles cycliques ou non gravides. C'est la progestérone qui, jusqu'à maintenant, a été l'unique «révélateur» de l'activité lutéale par les variations de sa concentration dans le plasma sanguin (Terqui et André, 1982;Humblot et Thibier, 1984;Kishimoto et al, 1987) et dans le lait (Laing et Heap, 1973;Heap et al, 1976;Hoffman et al, 1976;Cox et al, 1978;Booth et al, 1979;Thibier, 1980;Laitinen et al, 1985;Sauer et al, 1986;Stanley et al, 1986; Van de Wiel et Koops, 1986 (Humblot et al, 1987). Par ailleurs, malgré leur apparente simplicité, les kits EIA peuvent parfois exiger des temps de réaction de 20!0 min pour que la lecture soit interprétable (Tainturier et al, 1988 (Mialot, 1988) (Wathes et al, 1984;Ivell et al, 1985).…”

“…man et al, 1976;Cox et al, 1978;Ball, 1978;Kummerfeld et al, 1982;Sauer et al, 1986;Stanley et al, 1986; Van de Wiel et Koops, 1986;Humblot et al, 1987;Thibier, 1988 …”