Models for Weight-Linear Body Measurement Relationships in West African Dwarf, Yankasa and Their Crossbred Lambs

Abstract

Weight and linear body measurements of forty-seven lambs comprising 10 West African Dwarf, 17 Yankasa and 20 crossbred (West African Dwarf x Yankasa) from birth to 12 weeks of age were studied using simple linear, quadratic and exponential functions. The linear body measurements
include height at withers, body length, heart girth, shoulder width and tail length. The coefficient of determination (R2) ranged from 0.13 to 0.87, being highest for heart girth in Yankasa lambs and lowest for shoulder width in West African Dwarf lambs. Generally, a comparison on the basis of R2 values showed that the lambs weight-linear measurements of the three genotypes were best fitted by quadratic function, followed by linear and exponential respectively. However, exponential function was the best fit for tail length (0.75) in crossbred lambs. Among the body measurements, accuracy of prediction for weight was better with height at withers (R2 : 0.71 - 0.80) and heart girth (R2: 0.73 - 0.87) in quadratic function.

Keywords: Model, West African Dwarf, Yankasa, Crossbred, Weight, Linear body measurements, lambs