Sources of variation in body temperature in relation to its measurement in the New Zealand Romney sheep

Abstract

Two experiments on the sources of variation in body temperature of the Romney sheep are reported. In the first, rectal temperatures of six sheep under three different feeding treatments and four ambient temperatures were continuously measured. Feed (time and amount) and ambient temperature both affected variability of the diurnal cycle of body temperature. The interactions showed that the sheep were ranked the same for body temperature over 24 hours, but not at the different ambient temperatures. Thus sampling at particular times should give a result for sheep differences similar to the average of continuous measurements.

The second experiment was designed to measure possible errors of techniques of measuring rectal temperatures of large numbers of yarded sheep. It was found that if sheep were measured in a catching pen twice daily for at least 2 days, it should be possible to detect differences of the order of about O.25°F between groups of 16 sheep each. Under the suggested system it should be possible to measure 200 sheep in a day.