Application of path coefficient analysis in assessing the relationship between growth-related traits in indigenous Nigerian sheep (Ovis aries) of Niger State, Nigeria

Abstract

Indigenous Nigerian sheep raised under extensive management were evaluated with the aim of assessing variability among body weight and body measurement traits thereby deducing components that best describe the relationship using path coefficient analysis. The parameters measured were body weight (BW), body length (BL), head length (HL), head width (HW), height at withers (HAW), chest depth (CD), chest girth (CG) and shin circumference (SC). Pair wise correlation between body weight and body measurements were positive and significant (r = 0.475 – 0.655 in males, 0.262 – 0.449 in females, and 0.336 – 0.509 in the combined population, P<0.01). Path analysis showed that shin circumference and chest depth had the greatest direct effect on body weight in male, female and the combined population (path coefficient = 0.250, 0.252 and 0.250, respectively) while the least direct effect was observed for head width (in male and female with path coefficient = 0.007 and -0.017, respectively), and height at withers in the combined population (path coefficient = -0.020). Percentage direct contribution to body weight was 6.25, 6.35 and 6.25% from shin circumference (male), chest depth (in female and the combined population 2 respectively). The optimum linear regression models with coefficient of determination (R ) value of 0.45, 0.31 and 0.37 included forecast indices such as chest depth and shin circumference in males, body length, head length and chest depth in females and the combined population, respectively.