B.App.Sci., (App.Biology) R.M.I.T.,
Cert. Animal Technology, F.I.T.
Reprinted by permission of Elizabeth Paul and the Australian Alpaca Association (AAA)
Author’s Note
This study, while dealing specifically with grey alpacas and their occurrence in the Australian alpaca herd, is also a direct continuation of the author’s previous article, ‘Theory of Colour Inheritance in Alpacas, first published in Issue No. 28 of Alpacas Australia. The final table of results in that article was Table No. 3: the first table of results in this article is therefore Table No. 4.
Introduction
The relationship between black and brown colour in alpacas does not seem to be the same as that which exists in dogs or horses. In dogs, black B is the clear dominant allele of the black/brown gene. The recessive allele b produces liver colour when it is homozygous and is also associated with amber or yellow eyes and brown noses. Mating a homozygous BB black dog to a liver bb dog produces all black, Bb offspring. Mating a heterozygous (Bb) black dog to a liver bb dog should produce half Bb black offspring and half bb liver offspring (Little, C.L.).
In the model originally proposed by the author, it was assumed that red and black were the two base colours found in alpacas. However, it would appear from the results assessed so far that the base colour may be red and brown, with black being the recessive allele of brown. Mating black to brown alpacas has produced approximately 50% brown progeny and 40% black progeny, with less than 10% red and white progeny being produced. (It is interesting to note that red x black matings produced 55% brown progeny, 18% each of red and black progeny and 8% white progeny.) (Paul, E. 1999, Table 2.)
There are several genes which produce grey hair in animals, including greying genes and diluting genes. Both may exist in the one species of animal (Searle, A.G.).
Breeds of horses such as the Lippizaner and Percheron are born dark and progressively lighten with age as the greying gene takes increasing effect (Draper, J.).
Diluting genes dilute black pigment to blue-grey, as in blue greyhounds; and liver to a silvery, milk-coffee as in Weimaraners. These types of dogs are born more or less the adult colour (Little, C.L.).
Silvergrey alpacas are born silvergrey and could certainly be described as being shades of blue. However, rosegrey alpacas are not any shade of liver, but are born with a russet coloured or dark baby coat with the grey showing in the fleece or on the tail and legs. They range from a light, warm lavender shade to a much darker shade which has brown tips and shows grey only when the fleece is parted.
Most grey alpacas also have white throats and faces and white or pale lower legs, at least, when young. In some of the darker shades of rosegrey, the white may be restricted to a white face and feet, or a white throat patch, or even just a greyer shade down the throat.
In order to assess the status of grey alpacas in Australia, the Australian Alpaca Association Herd Books Volumes 2-6 were surveyed and all matings involving at least one grey parent were assessed. The results are presented in Table 4.
All matings involving non-grey parents which produced grey progeny were also assessed and the results presented in Table 5. Only matings where both the parents’ and the progeny’s colours were listed have been surveyed. For this reason, the Association’s Herd Book Volume 1 was excluded from the survey. Herd Books Volumes 1-6 were surveyed for imported grey alpacas to form a base level of parents.
There were 209 rosegrey alpacas and 536 silvergrey alpacas, forming approximately 12% of imported alpacas.
If the rosegrey and silvergrey colours are assumed to be dilute brown and dilute black fleece colours respectively, then the progeny colour results from matings involving grey parents would be expected to be similar to the patterns found in solid colour matings.
Summary
Grey progeny accounted for 62% of total progeny produced from grey x grey matings, and for 24% of total progeny from other matings involving at least one grey parent.
Rosegrey x silvergrey matings produced approximately twice as many rosegrey and brown progeny as silvergrey and black progeny. Overall, grey progeny accounted for 33% of total progeny from all matings involving at least one grey parent.
Solid brown progeny accounted for 27%; solid black progeny accounted for 18%; and solid white progeny accounted for 14% of total progeny.
Solid red progeny accounted for 8% of total progeny and were least likely to be produced from grey x grey matings.
Rosegrey progeny accounted for 14% of total progeny and silvergrey progeny for 18% of total progeny from this whole group of matings.
These results generally follow a similar pattern to solid brown x solid black matings. The larger number of silvergrey progeny overall is due to the fact that there were more than three times as many silvergreys as rosegreys in the original importation and there have been more than twice as many matings involving silvergrey parents than involving rosegrey parents.
Summary
White x white matings produced 2.2% grey progeny. Solid colour x solid colour matings produced 1.7% grey progeny. White x solid colour matings produced 8% grey progeny.
Rosegrey accounted for approximately 6% of total progeny from white x solid brown matings.
Silvergrey progeny accounted for approximately 12% of total progeny from white x solid black matings.
Grey progeny were least likely to be produced from solid red x solid red matings, where they accounted for less than 1% of total progeny.
Overall, grey progeny were produced in a proportion of approximately 3% of total progeny from this group of matings.
From the limited amount of literature available (Cape, D. and M.) and from personal observations, the white fleece on white/coloured and grey alpacas appears to extend in a regular pattern from the feet upwards to the belly, throat and face and, occasionally, across the withers or higher. This is similar to the effects of regular white-spotting genes in dogs such as Welsh Corgis and Beagles (Little, C.L.). The incidence of white/coloured (non-grey) alpacas in the Australian alpaca herd was surveyed to determine what, if any, links there were between this group and the greys.
For the purpose of the survey, alpacas listed as white/coloured in the Herd Books were assumed to follow the above pattern.
Matings involving two solid coloured (non-grey) parents which produced white/coloured (non-grey) progeny were assessed and the results presented in Table 6. Matings involving at least one white/coloured (non-grey) parent were also assessed and their results were included in this Table.
* Grey x grey matings produced 4 white/coloured (non-grey) progeny.
White x white/coloured (non-grey) matings produced 4 grey progeny.
Solid colour x white/coloured (non-grey) matings produced 10 grey progeny.
Discussion of Results of Table 6
White/coloured (non-grey) progeny accounted for 26% of all matings involving at least one white/coloured (non-grey) parent. They accounted for 14% of total progeny from white x white matings; and for approximately 10% of total progeny from white x solid colour (non-grey) matings.
White/coloured (non-grey) progeny were produced at less than 3% of total progeny for solid colour x solid colour matings.
Comparing these results with those of Table 5, it would seem reasonable to conclude that there is an overlap in the production of grey progeny and white/coloured (non-grey) progeny from white x solid colour matings.
An interesting aspect of breeding grey alpacas is the effect of mating greys to white/coloured partners. Matings involving one clear grey parent and one white/coloured (non-grey) parent were surveyed and the results presented in Table 7.
Discussion of Results of Table 7
These results are very small, as both grey and white/coloured alpacas occur in low numbers in the Australian herd. However, they show similar patterns of progeny colour production as larger groups and may, therefore, be considered as valid.
Matings between grey and white/coloured partners resulted in approximately 43% solid colour progeny; 32% white progeny; 14% white/coloured progeny and 12% grey progeny.
Thus grey alpacas have the capacity to reduce the white/colour factor and produce more solid colour and white progeny than either grey or white/coloured progeny.
This capacity has been previously noted by George Davis of New Zealand in his 1996 paper and is well known to breeders of grey alpacas.
Conclusions
The patterns of progeny colour production were similar across all types of matings.
The results of the survey support the assumption that rosegrey alpacas are a form of brown and that silvergrey alpacas are a form of black fleece colours.
Crossing two grey alpacas had at least a 60% chance of producing grey progeny. Crossing a grey with a non-grey alpaca had approximately a 25% chance of producing grey progeny. Crossing two non-grey alpacas produced less than 5% grey progeny.
(This study has not examined particular pedigrees. Non-grey alpacas with grey ancestors would be more likely to produce grey progeny themselves in the right mating.)
Grey progeny were least likely to be produced from red x red matings. Grey x grey matings produced less than 1% red progeny.
Both grey and white/coloured (non-grey) progeny were produced in a proportion of 8-10% of total progeny from white x solid colour matings.
Crossing grey alpacas with white/coloured (non-grey) alpacas was more likely to produce solid colour or white progeny, than either grey or white/coloured progeny.
In summary, it seems probable that the grey fleece colours in alpacas are the results of a combination of recessive diluting genes operating on brown and black pigment; and minor white-spotting genes producing the characteristic white face and feet of greys. Such a combination may account for the extreme rarity of grey alpacas.
Once this combination has been achieved however, the further production of grey progeny from grey x grey matings should not be difficult.
References
Paul, Elizabeth. ‘Theory of Colour Inheritance in Alpacas.’ pp10-17, Alpacas Australia, Issue No.28, ’99
Little, C.L., ‘The Inheritance of Coat Colour in Dogs.’ Fifth Edition, Howell Book House, New York, 1973.
Searle, A.G., ‘Comparative Genetics of Coat Colour in Mammals.’ Logo Press Limited, London, 1997.
Draper, Judith. ‘Horse Breeds of the World.’ Sebastian Kelly, Oxford. Anness Publishing Limited,London, 1997Australian Alpaca Association Herd Books, Volumes 2-6 incl.
Davis, George. MS. ‘Observations on Fleece Colour Inheritance Patterns.’ The Alpaca Registry Journal, Volume 1, No. 2. Summer-Fall 1996. pp 71-73.
Cape, D and M, ‘Alpacas on the Move’, Volumes 1-6 inclusive. Tangilly Rural Enterprises, Vic. 1998-1999.
Disclaimer
The author’s opinions are based solely on personal research and interpretation of the mating results presented in the Australian Alpaca Association Herd Books Vols. 1-6 inclusive. The author is not responsible for any breeding or other decision taken by any other person in relation to these opinions or interpretations.