whereRU: Aresty Poster 2 - Conception Rates of Estrus-synchronized Dairy Heifers in Three Different Breeding Protocols by Aresty Posters 2009

Full Title: Conception Rates of Estrus-synchronized Dairy Heifers in
Three Different Breeding Protocols

Abstract:
New approaches to estrus detection are aimed at providing automated
detection of standing heat in dairy cattle using electronic
technology, so as to eliminate labor-intensive daily behavioral
observations. Bovine activity and movement increase significantly when
the female comes into estrus. This provides an opportunity for
electronic activity monitoring to replace time-consuming behavioral
observations. We hypothesized that insemination of 36
estrus-synchronized heifers based on measurement of activity or
observation of estrus will yield higher rates of conception than
breeding based on fixed-time insemination. All heifers in the study
were fitted with motion-sensing activity monitor collars which collect
and transmit data into a computer program, Heatime®. The heifers were
randomly assigned to three treatment groups. Group B (n=13) was
inseminated based on three times daily observation for behavioral
estrus; Group H (n=11), based on notification of peak activity by
Heatime®; and Group T (n=12), fixed time. Twenty-two heifers were
confirmed pregnant at 39 days by ultrasound. Our hypothesis was not
supported, as Group B heifers tended to exhibit a higher conception
rate than both Group H and Group T heifers. Results suggest that
observation of behavioral estrus is more reliable than both Heatime®
automated estrus detection and fixed-time insemination.

Linda Marie Pedro, Aresty Presenter, lmpedro@eden.rutgers.edu
Dr. Larry Katz, Advisor, katz@aesop.rutgers.edu