The study was conducted to determine the accuracy of the liveweight estimation formula commonly used by swine growers and to propose a modification to make it suitable for use on various classes of swine.

A total of 1197 heads of hogs comprising of 101 sows, 480 finishers, 486 growers, and 130 weanlings were used in the study. The heartgirth and body length measurements of the animals were taken then weighed individually. The measurements were used in estimating the liveweight of the animals using the original formula and the modified formula proposed in the study. The correlation and accuracy of the estimated weights as compared to the actual weights was determined through simple linear regression.

Results showed that the original liveweight estimation formula underestimated the actual weights of the animals. The degree of underestimation was computed to be 0.3822% for sows, 3.3402% for finishers, 4.4656% for growers, and 16.0916% for weanlings.

A constant c was introduced in the modified liveweight estimation formula using the percentage of underestimation. The constants c were computed as 1.00384 for sows, 1.03456 for finishers, 1.04774 for growers and 1.19178 for weanlings. The constants were multiplied to the original weight estimation formula to arrive at the modified weight estimation formula for various classes of swine. With the use of the modified formula, a slight weight overestimation could be obtained favoring the seller.

For a simpler weight determination with greater accuracy, a weight estimation table (WET) and a weight estimation chart (WEC) were prepared for each class of swine.

Thesis (Master of Science - Animal Science)

Thesis (Master of Science - Animal Science)