Blood parameters and turnover data in calves infested with lice.

Erythrokinetic and plasma protein turnover studies using 51Cr-red cells, 59Fe-transferrin and 125I-albumin, were carried out on young Ayrshire calves naturally infested with the long-nosed sucking louse Linognathus vituli. Throughout the trial none of the animals lost their appetite. Liveweight gain was greater in the uninfested animals but not significantly so. The infestation did not cause the animals to become anaemic, but plasma iron turnover rates were decreased and there was a significant increase in the red cell survival time. The circulating volumes of red cells and plasma were not significantly affected and the fractional catabolic rate of albumin was not markedly altered. At the end of the trial the mean red blood cell and mean total blood content of one louse was evaluated at 0.157 microliters and 0.443 microliters respectively, using 51Cr, and 0.120 microliters and 0.350 microliters respectively, using 59Fe. Using 125I the mean albumin content of one louse was 98.4 micrograms.