Frank J.C.M. Van Eerdenburg

Learn More
Fertility indices, such as non-return rate and number of services per conception, have worsened significantly over the past few years. Because oestrus detection is one of the major factors influencing these indices, this study was performed to determine whether, how long, and at what time dairy cows show signs of oestrus in their behaviour. Two high(More)
Economic profitability of a dairy farm is based, in part, on the calving interval of the cows. The optimal interval is 365 d. To achieve this, the cow needs to be pregnant within 85 d post partum. The first and most problematic step in this process is the determination of the optimal time for insemination, which is based on estrous behavior. The expression(More)
OBJECTIVE To design a treatment that increases plasma corticosteroid concentrations to mimic prenatal stress in pregnant sows. ANIMALS 24 pregnant sows. PROCEDURE Sows were assigned to 1 of 4 treatment groups; treatment consisted of twice-daily oral administration of a placebo or 20, 60, or 180 mg of hydrocortisone acetate (HCA)/sow from 7 to 11 weeks(More)
Two herds of approximately 50 dairy cows were observed for oestrous behaviour for 6 weeks, 12 time a day for 30 minutes. It appeared that 3.08% of the pregnant cows showed oestrous behaviour during pregnancy (EBP) in such an intensity that they would have been considered in oestrus. With a less rigid oestrus detection threshold, 10.8% of the pregnant cows(More)
To compare an injectable progesterone (MAD-4) with an intravaginal device (IPD), and natural O17 with synthetic oestradiol (OB) in a synchronisation protocol, 51 cows were divided into four groups. Each group was treated with one of the two sources of progesterone and one of the two oestradiol formulations. Oestrus behaviour, follicle diameter, and(More)
  • 1