[Treatment and gestation results of mares with secondary retention]. / Behandelings- en drachtigheidsresultaten van merries met retentio secundinarum.

Twenty nine mares with retained fetal membranes were treated IV with an oxytocine infusion. Within two hours the placenta released in 24 mares (83%). Twenty six (90%) mares got pregnant during the same season.

[Sperm received in shipment versus fresh sperm in relation to fertilization results]. / Verzend sperma versus vers sperma in relatie tot bevruchtingsresultaten.

The conception rates of semen intended for shipment and those of recently obtained semen are compared in the present paper. Conception rates using recently obtained semen were significantly superior to those obtained with semen intended for shipment. A number of factors to which this difference could be due are briefly discussed.

[Determination of progesterone levels in the milk of mares: a useful aid in the diagnosis of early pregnancy]. / Progesteronbepaling in melk van merries: een goed hulpmiddel bij vroege drachtigheidsbepaling.

The concentration of progesterone in milk was determined in 327 mares to establish pregnancy in an early stage (sixteen days or more). The 5 ng/ml-level of progesterone as a threshold in the EIA-system used resulted in a very useful aid in the diagnosis of early pregnancy in mares. The results of testing were not in accordance with the confirmed reality in fourteen out of 327 mares (4.3 percent). The result of the test was false non-pregnant in five mares (1.5 percent) and false pregnant in nine mares (2.8 percent).

[Progesterone in mare's milk: suitable for early pregnancy detection?]. / Progesteron in melk van merries: geschikt voor een vroege drachtigheidsbepaling.

The concentrations of progesterone in milk were determined in twenty-one mares to establish a diagnosis of pregnancy in an early stage (15-19 days). Progesterone levels varied from 0.0 to 4.2 ng/ml in nine non-pregnant mares and from 6.7 to 30.0 ng/ml in twelve pregnant mares. Progesterone levels were determined by an enzyme-linked immunosorbent assay (ELISA).