Estimation of Liveweight from Chest Girth and Wither Height Measurements in West African Dwarf Goats

Abstract

Linear and geometric regression equations were used to estimate liveweight of two hundred and eighty six semi-intensively managed West African Dwarf (WAD) goats from Chest girth (CG) and Wither height (WH) measurements. CG accounted for 52 and 58% variation in the liveweight of goats using linear and geometric equations respectively, thus showing a curvilinear relationship. WH accounted for 31% variation in liveweight of goats using both equations. CG measurement was found to be more reliable for estimating liveweight of WAD goats than WH measurement. Using linear regression equation, CG and WH estimated the liveweight of females better than males with average increases of 57% and 25% R' values respectively. Using geometric regression equation, CG and WH also estimated the liveweight of females better than males with average increases of 55% and 22% R' values respectively. In essence, CG and WH measurements estimated the liveweighi of does better than bucks using both regression equations. Generally, CG and WH better estimated the liveweight of goats that are greater or equal to 3 years old than goats that are greater than / year but less than 3 years old and goats that are less or equal to 1 year old using both regression equations. Even though, each of the geometric or linear regression equations may be used to estimate liveweight of WAD goats with a high degree of reliability in a specific class of animals, it would be simpler and less cumbersome to use the regression equation obtained from pooled data to estimate liveweight in all animals