Genetic parameters for physical and quality traits of mohair in South African Angora goats

Abstract

The continuous evaluation and genetic improvement of fleece traits in Angora goats are of major importance to the Angora goat industry. The objective of this study was to estimate variance components and genetic parameters for both physical and quality traits of mohair in South African Angora goats. The data used for this study were collected on between 898 and 6211 kids (depending on the trait measured) born between 2000 and 2006 in 11 different Angora goat studs. Variance components and genetic parameters were estimated with the ASREML programme for fleece weight, fibre diameter, coefficient of variation of fibre diameter, standard deviation of fibre diameter, comfort factor, spinning/effective fineness and standard deviation of fibre diameter along the length of the staple. Most of these traits (excluding fleece weight) are measured using OFDA technology exclusively, and this study was the first attempt to calculate genetic parameters for these traits in South Africa. A model including the direct additive genetic effects only, were the most appropriate for estimation of all parameters. Heritability estimates were 0.24 ± 0.03 for fleece weight, 0.45 ± 0.03 for fibre diameter, 0.37 ± 0.10 for coefficient of variation of fibre diameter, 0.32 ± 0.11 for standard deviation of fibre diameter, 0.63 ± 0.10 for comfort factor, 0.61 ± 0.10 for spinning/effective fineness and 0.14 ± 0.08 for standard deviation of fibre diameter along the length of the staple. Results from this study can now be applied for the estimation of breeding values for fleece production of South African Angora goats and in incorporation into selection programs.