Background
Estrus is a preovulatory period in the ovarian cycle when cows are sexually receptive (in heat). Estrus occurs every 21 days and lasts on average 13.5 hours (Schofield et al. 1991).On the ovary, follicles grow producing increasing amounts of estradiol (E2). This increase in E2 is processed in the hypothalamus and is responsible for behavioural changes during estrus, such as increased activity, mounting, and standing to be mounted. Since the majority of the dairy industry uses artificial insemination to reproduce, producers must detect estrus themselves by observing estrus behavioural changes.
.
Cow in tie-stall with pedometer attached to right leg
It has been determined that pedometers can accurately detect estrus in free-stall facilities (Lehrer et al., 1992, Firk et al., 2002, Roelofs et al., 2005), however research has not been completed using cows housed in tie-stalls. This information is important as 35% of dairy herds across Canada are in tie-stalls (DHI. 2009).
Research objectives
The objective of this study was to (1) determine if pedometers can accurately monitor cow activity using the programmed parameters, steps, lying bouts, and lying times and (2) determine if the pedometers can accurately detect an increase in activity (estrus) during the predicted estrous period (days 2-4) in dairy cattle housed in tie-stalls 24 hours per day.
Expected results
The expected results are 1) that the pedometers will accurately monitor cows’ steps, lying time, and lying bouts in a tie-stall facility and 2) pedometers will accurately predict estrus by monitoring an increase in steps and lying bouts and a decrease in lying time during the predicted period. If the above expectations are accurate, pedometers could improve estrus detection rates in tie-stall dairy herds. By improving estrus detection, conception and pregnancy rates would subsequently improve, which would increase overall reproductive performance in dairy cattle.