DETERMINATION OF PREDICTION EQUATIONS TO ESTIMATE BODY CONDITION SCORE FROM BODY SIZE AND TESTICULAR TRAITS OF YANKASA RAMS
Abstract: The study was aimed
to develop prediction models using stepwise multiple linear regressionanalysis
for estimating the body condition score (BCS) from the body weight (BW),
testicular length(TL), testicular diameter (TD) and scrotal circumference (SC)
of indigenous Yankasa rams. Data wereobtained from 120 randomly selected rams
with approximately two and half years of age, from differentextensively managed
herds in Nasarawa State, Nigeria. Although pairwise phenotypic
correlationsindicated strong association (P<0.01) among the measured
variables, there was collinearity problembetween BW and SC as revealed by the
variance inflation factors (VIF) and tolerance valves (T). TheVIT was higher
than 10 (VIF = 19.45 and 16.65 for BW and SC, respectively). The Twas smaller
than0.1 (T = 0.05 and 0.06 in BW and SC, respectively). BW was retained among
the collinear variables, andwas singly accounted for 83.7% of the variation in
BCS. However, a slight improvement was obtainedfrom the prediction of BCS from
BW and TL [coefficient of determination (R2), adjusted R2 and rootmean squares
error (RMSE) were 85.3%, 85.1% and 0.305, respectively]. The prediction of the
BCS ofYankasa rams from BW and testicular measurements could therefore be a
potential tool for sustainableproduction and improvement of small ruminants in
Nigeria.
Author: A. Yakubu, O.F.
Fakuade, E.A. Faith, I.S. Musa-Azara, O.A. Agunwole
Journal Code: jppeternakangg130045
