Pigment in Angora goats
By Dr Mackie Hobson BSc(Agric),BVSc

1. Reproduction

Certain pigments are selected against by breeders due to the concern that they may appear in the fleece and so effect the economic value to the hair. How effective or true is this?

Types of pigmentation in Angora goat skin.

The two types of melanin pigmentation of the skin can be found in Angora goats. These can sometimes be seen on the face, ears, eyelashes and legs. Differences in skin pigmentation result both from the ratio of eumelanin (brown–black) to pheomelanin (yellow–red).

Dominance relationships at the Agouti locus are such that pheomelanic (red and yellow) areas are consistently expressed while the completely eumelanin (brown/black) phenotype caused by non-agouti is recessive to all.

The Angora goat has long been selected for whiteness, and other colours occur very rarely in the breed. The result of using two dominant genes, each of which can result in white, would assure that few coloured kids were ever produced.

Repeatability, does colour change with the age of the Angora goat?

In a study at Grootfontein by Nel, 72 ewes were separated into colour groups of 24 in each of (Grootfontein inspectors) red eyelashes, black pigment and no pigment. These ewes were then re-classed a year later.

This trial was repeated with kids seperated into colour groups at 2 months and then a year later. This was repeated for 5 years

One can conclude that subjective classification and selection on colour is difficult. Studies have shown repeatability figures of pigmentation to be 0.62, 0.62, 0.43 and 0.49

How inheritable is pigment?

5 years of data was collected where red and black classed rams were mated to white, red and black ewes and their progeny classed at 2 months of age.

These progeny were then re-classed at 1 year of age.

The study suggested:

Although red eyelashes occurred in the progeny of red eyelashes rams there is no major concern that using a ram with red eyelashes will lead to the significant increase in the pigment in the fleece. Of 119 kids over 5 years from a red ram at 1 year of age only 1 progeny was produced with red or back pigment in the fleece. During the 5 years there were 2 kids born with reddish tinge on knees and hocks which disappeared by 6 months old.

This trial showed that red and black pigment on the face and ears was carried over to progeny. The pigment also remained in the ears and face and not the fleece. Historical figures for pigmentation heritability are 0.13, 0.08, 0.14 and 0.1

How does pigmentation on the face and ears correlate to pigmentation occuring the fleece?

• The points above from the trial suggested pigment remained in the face and ears.
• Research by both C. H. S. Dolling and Brooker in Merino sheep found that that hoof and horn black pigment is not related to fibre pigment.
• A trial over a 30 year period of selection at Grootfontein – attempt to select for pigmentation transfer to wool failed.

References:RESULTATE VAN TOETSPARINGS MET GEPIGMENTEERDE ANGORABOKKE J. E. NEL, Landbounavorsingsinstituut van die Karoostreek, Grootfontein.
Inheritance of color in Angora goats. D. Phillip, Sponenberg ,Snejana Alexieva, Stefan Adalsteinsson