Mohair production and reproduction of Angora and Angora×Boer goat genotypes in a sub-optimum environment

Abstract

Production and reproduction performance of two mohair producing genotypes (G1—75% Angora goat:25% Boer goat and G2—87.5% Angora goat:12.5% Boer goat) were evaluated against that of a pure bred Angora goat genotype at the Jansenville Experimental Station in South Africa. Data on body weights, mohair production, subjectively assessed fleece and conformation traits from kids born from 1992 to 2000 in the G1 ( n=921), G2 ( n=827) and Angora ( n=361) herds were available. Data collected on the does from 1991 to 2001, included records on body weight, fleece traits and reproduction. Significant differences in body weight at all ages, where G1 kids were the heaviest, followed by the G2 kids and then the Angora kids, were recorded. Angora kids produced the heaviest fleeces ( P<0.05) at 10 months of age, followed by the G2 kids and then the G1 kids, while G2 kids produced the heaviest fleeces at 18 months of age. Angora kids produced fleeces with lower fibre diameter than those produced by G1 and G2 kids ( P<0.05). Medullation in G1 kids decreased from 1.47±0.15 and 1.34±0.14% at 10 and 18 months of age in first generation kids, to 0.74±0.11 and 0.69±0.10% in third generation kids. Similarly, medullation in the G2 herd decreased from 1.01±0.14 and 0.75±0.12% in first generation kids to 0.40±0.15 and 0.38±0.14% in third generation kids, respectively. Thus, by basing selection on objective measurements, medullation was nearly halved from the first to the third generation in both herds. G1 does had the highest body weight and produced the lightest fleeces, with the highest clean yield, lowest fibre diameter and shortest staples. Angora does on the other hand, had the lowest body weights, but they produced the heaviest fleeces with the lowest clean yield and longest staples. With the exception of kid survival rate, significant differences were observed in all reproductive traits and mating weight among does in the three herds, where G1 does performed the best, followed by the G2 does and then the Angora does. This study showed that by utilizing Boer and Angora goat genetics, it was possible to breed a robust mohair producing genotype, which is able to produce and reproduce under extensive conditions without any form of supplementary feed. For all traits analyzed, with the exception of amount of medullation, G1 animals performed better than G2 animals. It is suggested, that further selection for improved mohair quality be done in the G1 herd.