VARIABILITY IN INDIVIDUAL ANIMALS INTAKE OF MINERALS OFFERED FREE-CHOICE TO GRAZING RUMINANTS

A review of the literature indicates that there is very little publish ed information on the variation in intake of minerals and other supple ments offered free-choice to grazing animals. Most of the studies have been conducted with molasses feedblocks and liquid licks and the data indicate large day to day and among animal variation. A computer reco rding system has been developed and tested which allows for more infor mation to be collected with regard to frequency of consumption of free -choice supplements by grazing animals. Studies have been conducted wi th molasses blocks and loose mineral supplements provided to grazing c attle. Results indicate that the supplements were consumed by almost a ll animals on a regular basis. However, there was considerable variati on among animals in the quantity of supplement consumed. For the molas ses blocks daily intake averaged 1.2 +/- 0.6 kg per head within a rang e of 0.72-1.65 kg. For the mineral supplement the average daily consum ption was 135 +/- 55 g per head within a range of 50-300 g. The supple ment feeders were visited every hour of the day but approximately 40% of the visits occurred in the late evening. Information on the behavio ural pattern of consumption may enable strategies to be developed whic h could reduce the variation in consumption.