Abstract

Bio-ijmpedance (BI) is the opposition of biological tissues to the flow of an alternating low electrical current. Tissue BI is quantitatively inversely related with tissue hydrational status. Several reproductive events of importance in the management of the cow are characterised by changes in fluid content and electrolyte concentration of the genital tissues; these changes can be detected and quantified by genital tissue BI monitoring. The objective of this presentation is to review existing and potential applications of monitoring genital tissue BI in cows as aids to cattle reproductive management. The main application is genital BI monitoring to determine the optimal insemination time. It is based on the fact that intravaginal and vulvar tissue BI decline ca 10-30% during the peri-ovulatory stage of the ovarian cycle. Genital BI measurements can also be used to detect pending calving as well as post partum reproductive disorders: vulvar BI, measured with chronically implanted electrodes, declines ca 15 d before, and remains low until calving. During ca 40d post-calving, vulvar BI increases gradually and stabilises at about the time of resumption of ovarian luteal cyclicity. Intravaginal BI during the first 4-6 weeks post-calving is significantly lower in cows with reproductive disorders than in

J, Lee, JR Rounce, JE Hocking-Edwards, and PM Harris

Proceedings of the New Zealand Society of Animal Production, Volume 55, , 179-182, 1995