Using UHF proximity loggers to quantify male–female interactions: A scoping study of estrous activity in cattle

Reproductive efficiency is an important determinant of profitable cattle breeding systems and the success of assisted reproductive techniques (ART) in wildlife conservation programs. Methods of estrous detection used in intensive beef and dairy cattle systems lack accuracy and remain the single biggest issue for improvement of reproductive rates and such methods are not practical for either large-scale extensive beef cattle enterprises or free-living mammalian species. Recent developments in UHF (ultra high frequency) proximity logger telemetry devices have been used to provide a continuous pair-wise measure of associations between individual animals for both livestock and wildlife. The objective of this study was to explore the potential of using UHF telemetry to identify the reproductive cycle phenotype in terms of intensity and duration of estrus. The study was conducted using Belmont Red (interbred Africander Brahman Hereford–Shorthorn) cattle grazing irrigated pasture on Belmont Research Station, northeastern Australia. The cow-bull associations from three groups of cows each with one bull were recorded over a 7-week breeding season and the stage of estrus was identified using ultrasonography. Telemetry data from bull and cows, collected over 4 8-day logger deployments, were log transformed and analyzed by ANOVA. Both the number and duration of bull-cow affiliations were significantly (P < 0.001) greater in estrous cows compared to anestrus cows. These results support the development of the UHF technology as a hands-off and noninvasive means of gathering socio-sexual information on both wildlife and livestock for reproductive management.

Electrophysiological activity of the Sirex noctilio ovipositor: You know the drill?

Sirex woodwasp (Sirex noctilio F: Hymenoptera: Siricidae) is a major worldwide pest of pine (Pinus) species. The female woodwasp undertakes exploratory drills with the ovipositor prior to egg-laying to assess tree suitability. Previous work has shown that this behaviour is associated with assessing the osmotic pressure of the tree. Here we show that, in addition, the ovipositor is electrophysiologically active and capable of detecting ethanol and chemical components of solvent extracts of pine needles and bark. Scanning electron micrographs of the ovipositor show the presence of structures which may have a chemoreceptive function. Our research expands our knowledge of the role that the Sirex ovipositor plays in egg-laying site selection.