The effect of tail paint formulation and heifer behavior on estrus detection.

Although heifers can have better conception rates than cows, they are still subject to poor estrus detection and economic losses from reduced reproductive efficiency. Tail paint has been successful in identifying estrus, but behaviors such a licking or rubbing have been believed to remove the paint and lead to false-positives. To investigate tail paint utilization and potential relationships among behaviors, eighteen Holstein heifers were randomly assigned to one of three treatments: a control tail chalk (), tail chalk with proprietary ingredient (); and a spray formulation (). Experimental design was a replicated 3 × 3 Latin square. Visual observations were performed in 30 min segments every 2 h from 6 AM to 6 PM. Ovaries were examined via ultrasound imaging on d 0, 7, and 9 of each period. The presence of follicles or a corpus luteum (CL) was recorded with their respective sizes. Heifers receiving SPRAY had a lower number of licks received per day and less tail paint removed regardless of day or follicle size when compared with CON or CHALK+. Rump lick received, chin rest received, anogenital sniff received, mount received, and both initiated and received behaviors for attempt to mount occurred more in heifers with large follicles regardless of day. Producers looking for heifers to breed should focus on those receiving rump lick, chin resting, anogenital sniff, mount, and attempt to mount. The use and combination of these estrus detection tools can improve reproductive efficiency in dairy operations.