Last update: November 19, 2010 11:44:09 AM E-mail Print

 

Sources of shared variability among body shape characteristics

for wool and hair type Dorper sheep

 

P. G. Marais1, M.A. Snyman,1 W. J. Olivier1, P.J. Griessel1 and T.Buys2

1Grootfontein ADI, P/Bag X529, Middelburg (EC), 5900;

2Carnarvon Experimental Station, P.O. Box 98, Carnarvon, 8995

 


Body measurements have been used to contrast variation in size and shape and to estimate body weight. As body measurements are interrelated both genetically and phenotypically, the analysis of these traits should consider interdependence among the traits. Analysis of multicollinear data with multiple regression may limit the use of such analysis in inference and prediction. Interrelationships among body dimensions (conformation) and body weight of Dorper sheep treated as multivariates (simultaneously analysed) have not been investigated to any extent. The objectives of this study were (a) to disclose the main sources of shared variability among body shape characteristics, (b) deduce the factors that describe these traits and (c) quantify the type differences in size and shape from orthogonal body shape characters. Body measurements (body length, body depth, body height, width of rump, length of hind leg) of 2835 Dorper lambs (wool and hair type) at 6 months of age over a 12 year period were subject to factor analyses. The results indicated that most of the common variability in body dimensions could be accounted for by factors representing general size.