Mahdi Mokhber; Hosein Moradi Shahr Babak; Amirhosein Khelt Abadi Farahani
Abstract
The objective followed in the present study was to survey the relationship between 18 body trait measurements (live weight, height at wither, paunch girth, neck diameter, body length, girth around the body, width of fat tail at above, below and midpoint of fat tail, fat tail length lowers right and left ...
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The objective followed in the present study was to survey the relationship between 18 body trait measurements (live weight, height at wither, paunch girth, neck diameter, body length, girth around the body, width of fat tail at above, below and midpoint of fat tail, fat tail length lowers right and left sides, fat tail gap length, fat tail depth at the above, below, and midpoint, and girth around fat tail at the above, mid and down point ) and the traits of fat tail weight and carcass (weight with and without fat tail) in Makooei Sheep and to Predict these traits, performance though multivariate Linear Regression Method Based on Principal Component Analysis. Sex showed significant effects on all the measured traits expect fat tail, depth at above, midpoint and down point, fat tail length towards right side plus gap length, width of fat tail at the above and below point of tail. Means and standard error for each trait were evaluated by sex. Multicollinearity was detected through a survey of the relationship among these traits, variance inflation factor and tolerance value. Principal component analysis was employed to resolve multicollinearity problem among independent variables and for a clearer explanation of the results. R2 range for different regression models varied between 0.973 for carcass weight without tail in male sex and 0.561 for carcass weight with fat tail in female sex of Makooei lambs.
mohammadreza bakhtiarizade; mohammad moradi shahre babak; hossein moradi; mahmood vatankhah
Abstract
The relationship between live body weight, body length, girth circumference, animal hight, upper, middle as well as lower width of fat-tail, fat-tail length, fat-tail gap length, fat-tail depth and fat-tail circumference along with fat-tail weight were determined using records of 731 Loribakhtiari sheep. ...
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The relationship between live body weight, body length, girth circumference, animal hight, upper, middle as well as lower width of fat-tail, fat-tail length, fat-tail gap length, fat-tail depth and fat-tail circumference along with fat-tail weight were determined using records of 731 Loribakhtiari sheep. Principal Component and Least Square Analyses were applied to solve the collinearity instability. Collinearity problems as portrayed by variance inflation factors above 5 or 10 were evident in some of independent variables. Results showed that the problem of collinearity in relation with fat-tail weight of 11 independent variables could be solved by using Principal Component Analysis method. Fat-tail gap length, fat-tail depth, and fat-tail circumference vs. girth circumference, and fat-tail length respectively represented the highest and the lowest coefficients regarding the estimation of fat-tail weight.
