DESIGN AND FABRICATION OF A DISCOMFORT INDEX METER FOR DETERMINATION OF STRESS IN LIVESTOCK

This research was aimed at designing and developing a discomfort index meter for evaluating transportation stress on broilers. The newly developed discomfort index meter is capable of recording and logging data every 5 seconds. The device was designed using LM35 electronic sensor to measure the dry bulb and wet bulb temperatures in degree Celsius ( o C) and then use it to compute the discomfort level using the Thom model with the help of microcontroller. The newly developed equipment was successfully used to evaluate the effect of transport on the level of stress of four weeks old broilers over various distances and stocking densities using different means of transportation. The equipment was calibrated and compared with other available measuring instruments which showed that a high correlation exist between the values (r 2 = 0.89).Also, a single factor (one-way) analysis of variance (ANOVA) was carried out and the results showed no significant difference between the two sets of values at 0.05 level of confidence which implies that the two readings are identical. The relative humidity readings of the device were compared with that of standard digital hygrometer reading using a regression analysis which also showed a high correlation coefficient (r 2 =0.98). A straight line regression equation y = 0.9497x + 5.1542 describes the relationship. The equipment is affordable and therefore recommended for determining stress on broilers and other livestock animals in transit http://dx.doi.org/10.4314/njt.v36i3.40